2.17.1 — re-cut 2.17.0 after the release pipeline dropped it (#109)

Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/109

.forgejo/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,30 @@
+---
+name: Bug report
+about: Something doesn't work the way it should
+title: ""
+labels:
+  - bug
+---
+
+### What happened
+
+
+### What you expected
+
+
+### Steps to reproduce
+1.
+2.
+3.
+
+### Environment
+- Calendula version: <!-- Settings → bottom of the screen -->
+- Android version:
+- Device:
+- Installed from: <!-- official F-Droid / the self-hosted repo / built from source -->
+- Affected calendar: <!-- Google, CalDAV (DAVx5, Nextcloud, …), on-device/local,
+                         subscribed/WebCal, birthdays — provider behaviour differs
+                         a lot per account type, so this often points straight at
+                         the cause -->
+- Time zone: <!-- only if the problem involves dates or all-day events -->
+

.forgejo/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,18 @@
+# Kept enabled so anything that doesn't fit the four templates still has a way
+# in (the `ToDo` label exists for exactly those).
+blank_issues_enabled: true
+
+contact_links:
+  - name: Translate Calendula
+    url: https://weblate.dev.jeanlucmakiola.de/engage/calendula/
+    about: >-
+      Translations are managed on Weblate, not here — it owns every values-*
+      file, so a hand-edited translation gets overwritten on the next sync.
+      No coding needed: pick or request a language and translate in the browser.
+
+  - name: Contributing guide
+    url: https://codeberg.org/jlmakiola/calendula/src/branch/main/CONTRIBUTING.md
+    about: >-
+      Before opening a pull request: the issue-first workflow, which release
+      branch to target, how to build (there's a submodule), and the
+      architectural rules a change is reviewed against.

.forgejo/ISSUE_TEMPLATE/crash_report.md

@@ -5,7 +5,7 @@ title: "Crash: "
 labels:
   - bug
   - crash
-  - priority:high
+  - priority/high
 ---
 
 <!--

.forgejo/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,41 @@
+<!--
+Thanks for contributing to Calendula!
+
+Please skim CONTRIBUTING.md if you haven't:
+https://codeberg.org/jlmakiola/calendula/src/branch/main/CONTRIBUTING.md
+
+Two things it's easy to get wrong:
+  • Features need a discussed issue first — an undiscussed feature PR may be
+    closed unmerged even when the code is good.
+  • Target the release branch for your issue's milestone (milestone 2.18.0 →
+    release/v2.18.0), not main. If you targeted main, just say so below and it
+    will be retargeted.
+-->
+
+### What this changes
+
+
+### Why
+
+<!-- Closes #123 — link the issue this implements or fixes. -->
+
+
+### How it was tested
+
+<!--
+Which of these ran green, and anything you exercised by hand. On-device notes
+are especially useful for UI changes.
+
+  ./gradlew lint test assembleDebug
+  python3 scripts/check_translations.py
+-->
+
+
+### Checklist
+
+- [ ] There's an issue for this, and (for a feature) it got a go-ahead
+- [ ] Targeting the release branch for that issue's milestone — or `main`, noted above
+- [ ] `./gradlew lint test assembleDebug` passes locally
+- [ ] No `values-*/strings.xml` touched (Weblate owns those; new English strings in `values/` are fine)
+- [ ] `CHANGELOG.md` updated under `## [Unreleased]`, if the change is user-visible
+- [ ] No planning or design documents committed

.forgejo/workflows/ci.yaml

@@ -29,6 +29,7 @@ jobs:
         with:
           # Full history so the base..HEAD diff below has a merge-base.
           fetch-depth: 0
+          submodules: recursive
 
       # Cheap, always-on guard: the release build must stay reproducible for the
       # official F-Droid repo (no AGP VCS-info embedding). Runs regardless of
@@ -36,14 +37,29 @@ jobs:
       - name: Reproducible-release invariant
         run: bash scripts/check_reproducible_release.sh
 
-      # Decide whether anything that affects the app build changed. Docs,
-      # F-Droid metadata and the licence don't, so those PRs skip the SDK +
-      # Gradle work below but still report a green `ci`.
+      # Decide whether anything that affects the app build changed. Docs, store
+      # metadata, licence texts and forge housekeeping don't, so those PRs skip
+      # the SDK + Gradle work below but still report a green `ci`.
       - name: Classify change scope
         id: scope
+        env:
+          # Deliberately a skip-list, not a build-list: a path nobody thought
+          # about defaults to building. Only paths the Gradle build provably
+          # never reads belong here — note that the workflows themselves, the
+          # `.gitmodules` submodule pointer and `scripts/` are *not* in it.
+          SKIP_RE: '(\.md$|^docs/|^fastlane/|^fdroid-metadata/|^licenses/|^\.planning/|^\.(forgejo|gitea)/ISSUE_TEMPLATE/|^\.editorconfig$|^\.gitattributes$|^\.gitignore$|^renovate\.json5$|^LICENSE$)'
         run: |
           set -e
           BASE="${{ github.base_ref }}"
+          # Normally the bare branch name; tolerate a full ref, which would
+          # otherwise make the merge-base lookup fail and quietly degrade this
+          # guard into "always build".
+          BASE="${BASE#refs/heads/}"
+          if [ -z "$BASE" ]; then
+            echo "No base branch on this event — running the full build to be safe."
+            echo "code=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
           # Full (not --depth=1) base fetch so the merge-base is present even when
           # the PR branch forked several commits back; a shallow tip has no merge
           # base with a divergent branch and `git diff base...HEAD` aborts.
@@ -57,11 +73,15 @@ jobs:
           fi
           CHANGED=$(git diff --name-only "$MB" HEAD)
           echo "Changed files:"; echo "$CHANGED"
-          if echo "$CHANGED" | grep -vE '(\.md$|^docs/|^fdroid-metadata/|^fastlane/|^LICENSE$)' | grep -q .; then
+          RELEVANT=$(echo "$CHANGED" | grep -vE "$SKIP_RE" || true)
+          if [ -n "$RELEVANT" ]; then
+            # Naming them makes "why did my docs PR build for four minutes?"
+            # answerable from the log alone.
+            echo "Build-relevant changes:"; echo "$RELEVANT"
             echo "code=true" >> "$GITHUB_OUTPUT"
           else
-            echo "code=false" >> "$GITHUB_OUTPUT"
             echo "Docs/metadata-only change — skipping the Android build."
+            echo "code=false" >> "$GITHUB_OUTPUT"
           fi
 
       - name: Setup Java
@@ -71,9 +91,14 @@ jobs:
           distribution: 'zulu'
           java-version: '17'
 
+      # Fully qualified on purpose. Codeberg resolves bare `uses:` refs against
+      # data.forgejo.org, Forgejo's own action mirror — actions/checkout,
+      # setup-java and cache all exist there, but android-actions/setup-android
+      # does not, and the job dies with "repository not found". Gitea's instance
+      # defaults to GitHub, which is why this never surfaced before the split.
       - name: Setup Android SDK
         if: steps.scope.outputs.code == 'true'
-        uses: android-actions/setup-android@v3
+        uses: https://github.com/android-actions/setup-android@v3
         with:
           # Default ("tools platform-tools") drags in the Android Emulator
           # (~300 MB) which the build never uses.

.forgejo/workflows/translations.yaml

@@ -3,13 +3,15 @@ name: Translations
 # Fast, SDK-free parity check for translation resources, so Weblate PRs (which
 # only touch values-*/strings.xml) get quick feedback without the full Android
 # build. The deeper checks still run in CI via lintDebug (ExtraTranslation).
+#
+# Runs on every PR (no path filter) so the required "Translations / check"
+# status is always reported — like the `ci` job. A path-filtered workflow is
+# skipped on unrelated PRs and never posts its status, which leaves that
+# required check pending forever and blocks the merge of any code-only PR into a
+# release/* branch. The check itself is cheap and simply passes when the
+# committed translations are consistent, so always running it costs nothing.
 on:
   pull_request:
-    paths:
-      - 'app/src/main/res/values*/strings.xml'
-      - 'app/src/main/res/xml/locales_config.xml'
-      - 'scripts/check_translations.py'
-      - '.gitea/workflows/translations.yaml'
 
 concurrency:
   group: translations-${{ github.ref }}

.gitea/ISSUE_TEMPLATE/bug_report.md

@@ -1,23 +0,0 @@
----
-name: Bug report
-about: Something doesn't work the way it should
-title: ""
-labels:
-  - bug
----
-
-### What happened
-
-
-### What you expected
-
-
-### Steps to reproduce
-1.
-2.
-3.
-
-### Environment
-- Calendula version: <!-- Settings → bottom of the screen -->
-- Android version:
-- Device:

.gitea/workflows/release.yaml

@@ -1,11 +1,19 @@
-name: Release — F-Droid repo + Gitea release
+name: Release — F-Droid repo + Gitea/Codeberg release + Play
 
 # A release is cut by merging a release branch into main with a bumped
 # versionName (see docs/RELEASING.md). This workflow reads that versionName and,
 # if no matching tag exists yet, runs tests, builds + signs the APK, publishes
-# it to the F-Droid repo, and only then creates the vX.Y.Z tag + Gitea release
-# itself — the tag is an output of the pipeline, not its trigger. Ordinary
-# merges (no version bump) fall through `detect` and do nothing.
+# it to the F-Droid repo, creates the vX.Y.Z tag + Gitea release, and mirrors
+# that release to Codeberg with the signed APK + a SHA-256 checksum as a
+# direct-download channel — the tag is an output of the pipeline, not its
+# trigger. Ordinary merges (no version bump) fall through `detect` and do
+# nothing.
+#
+# A trailing `play` job then uploads the App Bundle to Google Play. It is last
+# and separate because Play is the only channel that can reject a good build for
+# reasons the pipeline can't see, and that must not endanger a release which has
+# already shipped to F-Droid and Codeberg. It skips cleanly until the
+# PLAY_SERVICE_ACCOUNT_JSON secret exists.
 #
 # A manual workflow_dispatch (from a branch) runs the re-sign-only recovery
 # path: it re-signs the existing F-Droid index with the repo key and re-uploads,
@@ -25,6 +33,14 @@ jobs:
   # whether this push actually cuts a new release (no tag for it yet). Keeps the
   # heavy job from running on every merge to main.
   detect:
+    # Gitea only. The workflow directory split already keeps this file invisible
+    # to Codeberg — Forgejo's lookup is first-match-wins, and .forgejo/workflows
+    # exists — but that only holds while .forgejo/ is non-empty. Move the last
+    # file out of it and Codeberg would fall back to .gitea/workflows and start
+    # running the release pipeline on the contributor-facing runner, with no
+    # secrets. repository_owner differs between the two forges regardless of
+    # URL, proxy or instance rename, so this closes it permanently.
+    if: github.repository_owner == 'makiolaj'
     runs-on: docker
     outputs:
       is_release: ${{ steps.v.outputs.is_release }}
@@ -33,12 +49,22 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          submodules: recursive
 
       - name: Resolve version and whether it is a new release
         id: v
         env:
-          TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
+          # Tags are read from Codeberg, which is canonical — deliberately NOT
+          # from the Gitea API this workflow runs on. The Codeberg -> Gitea sync
+          # is a push mirror, i.e. `git push --mirror`, which deletes refs the
+          # source does not have. A tag minted here on Gitea is therefore wiped
+          # by the next sync (Codeberg does not have it yet) and only reappears
+          # once the tag push at the end of this workflow propagates back.
+          # Asking Gitea inside that window would report "no tag" for a release
+          # that already shipped, and cut it a second time.
+          # Public repo, so this read needs no token.
+          TAG_API: https://codeberg.org/api/v1/repos/jlmakiola/calendula
         run: |
           set -e
           VERSION=$(grep -oP 'versionName\s*=\s*"\K[^"]+' app/build.gradle.kts)
@@ -56,15 +82,28 @@ jobs:
           fi
           # A tag for this version already existing means the release shipped on
           # an earlier push; do nothing. Absent => this merge cuts the release.
-          STATUS=$(curl -s -o /dev/null -w '%{http_code}' \
-            -H "Authorization: token $TOKEN" "$API/git/refs/tags/v$VERSION")
-          if [ "$STATUS" = "200" ]; then
-            echo "Tag v$VERSION already exists — nothing to release."
-            echo "is_release=false" >> "$GITHUB_OUTPUT"
-          else
-            echo "No tag for v$VERSION yet — cutting the release."
-            echo "is_release=true" >> "$GITHUB_OUTPUT"
-          fi
+          #
+          # Anything other than a clean 200/404 is treated as fatal rather than
+          # as "no tag". A Codeberg outage or a network blip would otherwise
+          # read as absent and re-cut a release that has already shipped —
+          # republishing to F-Droid and Play. Failing here is recoverable; a
+          # duplicate release is not.
+          STATUS=$(curl -s -o /dev/null -w '%{http_code}' "$TAG_API/git/refs/tags/v$VERSION" || echo 000)
+          case "$STATUS" in
+            200)
+              echo "Tag v$VERSION already exists on Codeberg — nothing to release."
+              echo "is_release=false" >> "$GITHUB_OUTPUT"
+              ;;
+            404)
+              echo "No tag for v$VERSION on Codeberg yet — cutting the release."
+              echo "is_release=true" >> "$GITHUB_OUTPUT"
+              ;;
+            *)
+              echo "Codeberg tag lookup for v$VERSION returned HTTP $STATUS." >&2
+              echo "Refusing to guess: treating this as 'no tag' could re-cut a shipped release." >&2
+              exit 1
+              ;;
+          esac
 
   # Releases: build + sign + publish, then mint the tag and Gitea release.
   # Also runs on manual dispatch, where it skips the build and just re-signs and
@@ -82,6 +121,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          submodules: recursive
 
       - name: Setup Java
         uses: actions/setup-java@v4
@@ -346,3 +387,264 @@ jobs:
           curl -s -X POST -H "Authorization: token $TOKEN" \
             -F "attachment=@/tmp/$ASSET" \
             "$API/releases/$ID/assets?name=$ASSET" -o /dev/null -w "asset upload HTTP %{http_code}\n"
+
+      # Mirror the release to the Codeberg mirror as a direct-download channel
+      # for users who don't want F-Droid. Gitea already push-mirrors branches +
+      # tags to Codeberg, but releases aren't git objects so they don't sync —
+      # we create the release there over the API and attach the signed APK plus
+      # a SHA-256 checksum. The APK is identical to the F-Droid one (same app
+      # key), so this adds no trust surface. Best-effort: a Codeberg outage
+      # (it 504s under load) must never fail an already-published F-Droid
+      # release. Needs the CODEBERG_RELEASE_TOKEN secret; skips cleanly if unset.
+      - name: Publish release to Codeberg
+        if: env.IS_RELEASE == 'true'
+        continue-on-error: true
+        env:
+          TOKEN: ${{ secrets.CODEBERG_RELEASE_TOKEN }}
+          API: https://codeberg.org/api/v1/repos/jlmakiola/calendula
+          SHA: ${{ github.sha }}
+        run: |
+          set -e
+          if [ -z "${TOKEN:-}" ]; then
+            echo "CODEBERG_RELEASE_TOKEN not set — skipping Codeberg publish."
+            exit 0
+          fi
+          TAG="v$VERSION"
+          APK="app/build/outputs/apk/release/app-release.apk"
+          if [ ! -f "$APK" ]; then echo "No release APK found — skipping." >&2; exit 1; fi
+          ASSET_APK="calendula_v${VERSION}.apk"
+          ASSET_SUM="${ASSET_APK}.sha256"
+          cp "$APK" "/tmp/$ASSET_APK"
+          ( cd /tmp && sha256sum "$ASSET_APK" > "$ASSET_SUM" )
+
+          # Release notes: reuse the section extracted for the Gitea release,
+          # fall back to the CHANGELOG entry if that step's file is gone.
+          if [ ! -s release-notes.md ]; then
+            awk -v ver="$VERSION" '
+              $0 ~ "^## \\[" ver "\\]" { flag = 1; next }
+              /^## \[/ { flag = 0 }
+              flag' CHANGELOG.md > release-notes.md
+            sed -i -e '/./,$!d' release-notes.md
+          fi
+          [ -s release-notes.md ] || echo "_See CHANGELOG.md for ${VERSION}._" > release-notes.md
+          # The pipeline creates the tag via the Gitea API, which the push mirror
+          # (sync_on_commit only fires on real git pushes) doesn't propagate
+          # promptly — so a release POST that carries a target_commitish can
+          # outrun the mirror and 500 on a commit/tag Codeberg hasn't received.
+          # Push the tag straight to Codeberg so it's guaranteed present, then
+          # attach the release to that existing tag with NO target_commitish
+          # (which is what triggered the 500).
+          git tag -f "$TAG" "$SHA"
+          git push -f "https://jlmakiola:${TOKEN}@codeberg.org/jlmakiola/calendula.git" \
+            "refs/tags/$TAG"
+          python3 - "$TAG" <<'PY' > cb-payload.json
+          import json, sys
+          print(json.dumps({
+              "tag_name": sys.argv[1],
+              "name": sys.argv[1],
+              "body": open("release-notes.md").read(),
+              "draft": False,
+              "prerelease": False,
+          }))
+          PY
+          # Create (or update) the release. Codeberg 500s on a POST/GET against a
+          # tag it has only just received — the release request outruns the
+          # indexing of the ref we pushed a moment ago — so a single attempt kept
+          # failing and skipping the mirror even though the very same call
+          # succeeds seconds later. Retry with backoff, and PATCH in place if a
+          # release already exists (re-run safe). A 5xx body still exits curl 0,
+          # so the loop, not `set -e`, controls the flow.
+          ID=""
+          for attempt in 1 2 3 4 5 6; do
+            EXIST=$(curl -s -H "Authorization: token $TOKEN" "$API/releases/tags/$TAG" | jq -r '.id // empty' 2>/dev/null || true)
+            if [ -n "$EXIST" ]; then
+              curl -s -o /dev/null -w "release PATCH HTTP %{http_code}\n" -X PATCH \
+                -H "Authorization: token $TOKEN" -H "Content-Type: application/json" \
+                -d @cb-payload.json "$API/releases/$EXIST"
+              ID="$EXIST"; break
+            fi
+            CODE=$(curl -s -o cb-response.json -w "%{http_code}" -X POST \
+              -H "Authorization: token $TOKEN" -H "Content-Type: application/json" \
+              -d @cb-payload.json "$API/releases")
+            echo "release POST attempt $attempt HTTP $CODE"
+            ID=$(jq -r '.id // empty' cb-response.json 2>/dev/null || true)
+            [ -n "$ID" ] && break
+            sleep $((attempt * 10))
+          done
+          if [ -z "$ID" ]; then echo "Could not resolve Codeberg release id after retries." >&2; exit 1; fi
+
+          # Attach APK + checksum, replacing any prior asset of the same name.
+          for A in "$ASSET_APK" "$ASSET_SUM"; do
+            OLD=$(curl -s -H "Authorization: token $TOKEN" "$API/releases/$ID/assets" \
+              | jq -r --arg n "$A" '.[] | select(.name==$n) | .id')
+            [ -n "$OLD" ] && curl -s -X DELETE -H "Authorization: token $TOKEN" "$API/releases/$ID/assets/$OLD" >/dev/null || true
+            curl -s -X POST -H "Authorization: token $TOKEN" \
+              -F "attachment=@/tmp/$A" \
+              "$API/releases/$ID/assets?name=$A" -o /dev/null -w "asset $A HTTP %{http_code}\n"
+          done
+          echo "Published $TAG to Codeberg."
+
+      # Play takes an App Bundle, not the APK, so it is a second artifact from
+      # the same source and the same signing config — not a repackage of the
+      # APK. The release key signs it, but Play only ever treats that key as the
+      # *upload* key: Play App Signing re-signs with Google's own key before
+      # delivery. A Play install and an F-Droid install therefore carry
+      # different signatures and cannot update each other. That divergence is a
+      # deliberate, documented choice (docs/RELEASING.md), not an accident.
+      #
+      # Built LAST and `continue-on-error`, both deliberately: everything above
+      # has already shipped by this point, and nothing Play-related may put that
+      # at risk. Sitting mid-job without continue-on-error, this block took the
+      # whole 2.17.0 release down with it — no F-Droid publish, no tag, no
+      # Codeberg mirror — over an artifact upload. A failure here now costs the
+      # Play upload and nothing else.
+      #
+      # Nothing here touches the F-Droid path: the AAB is never copied into the
+      # repo, never attached to a release, and its build cannot change the APK
+      # published above.
+      #
+      # AGP embeds the R8 mapping in the bundle's BUNDLE-METADATA, so Play gets
+      # deobfuscated stacktraces without a separate mapping upload.
+      - name: Build release AAB
+        if: env.IS_RELEASE == 'true'
+        continue-on-error: true
+        run: ./gradlew bundleRelease
+
+      # NOT actions/upload-artifact@v4: it runs @actions/artifact v2, which
+      # refuses to start whenever GITHUB_SERVER_URL is not github.com — it reads
+      # any other forge as an unsupported GHES instance and fails before it ever
+      # talks to the server (go-gitea/gitea#36024). Gitea 1.25 serves the v4
+      # artifact API fine; only the client-side check is wrong. This fork is that
+      # client with the check removed. Pinned to a commit, not the v4 branch: a
+      # third-party action in the signing pipeline must not change under us.
+      - name: Hand the AAB to the Play job
+        if: env.IS_RELEASE == 'true'
+        continue-on-error: true
+        uses: https://github.com/ChristopherHX/gitea-upload-artifact@81f940d004763f986ba3582c007fd842dd5cb0d7 # v4
+        with:
+          name: release-aab-${{ needs.detect.outputs.version }}
+          path: app/build/outputs/bundle/release/app-release.aab
+          if-no-files-found: error
+          retention-days: 14
+
+  # Google Play channel.
+  #
+  # A separate job, on purpose, running only AFTER the F-Droid publish and both
+  # forge releases have completed. Play is the one channel that can reject a
+  # perfectly good build for reasons outside the pipeline (listing rules, policy
+  # review, API outage, a track that needs manual promotion). Isolating it means
+  # such a rejection surfaces as one red job next to a release that already
+  # shipped everywhere else, instead of failing the workflow that publishes it.
+  #
+  # Not a `container:` job even though a fastlane image exists: act_runner does
+  # not provide node inside custom job containers, so JavaScript actions
+  # (checkout, download-artifact) can't run there. The Renovate job gets away
+  # with a container because its only step is a shell command. Ruby is installed
+  # the same way sshpass, jq and fdroidserver are in the job above.
+  play:
+    needs: [detect, release]
+    # workflow_dispatch is the F-Droid re-sign recovery path — it must never
+    # touch Play, so gate on a real release only.
+    if: needs.detect.outputs.is_release == 'true'
+    runs-on: docker
+    env:
+      VERSION: ${{ needs.detect.outputs.version }}
+      VERSION_CODE: ${{ needs.detect.outputs.version_code }}
+      # Where the bundle lands. `internal` by default so a release reaches
+      # testers rather than the public, and promotion to production stays a
+      # deliberate human action in the Play Console — the same posture as
+      # holding UI releases for on-device review. Override with the PLAY_TRACK
+      # repo variable once the flow is trusted.
+      PLAY_TRACK: ${{ vars.PLAY_TRACK || 'internal' }}
+      PLAY_RELEASE_STATUS: ${{ vars.PLAY_RELEASE_STATUS || 'completed' }}
+      # Set PLAY_DRY_RUN=true to validate the edit against the API and discard
+      # it instead of committing — used to rehearse the first upload.
+      PLAY_DRY_RUN: ${{ vars.PLAY_DRY_RUN || 'false' }}
+      BUNDLE_PATH: vendor/bundle
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # Skip cleanly (not fatally) when Play isn't configured yet, so the rest
+      # of the release pipeline keeps working during setup — same contract as
+      # the Codeberg mirror step.
+      - name: Write the Play service-account key
+        id: key
+        env:
+          PLAY_SERVICE_ACCOUNT_JSON: ${{ secrets.PLAY_SERVICE_ACCOUNT_JSON }}
+        run: |
+          set -euo pipefail
+          if [ -z "${PLAY_SERVICE_ACCOUNT_JSON:-}" ]; then
+            echo "PLAY_SERVICE_ACCOUNT_JSON not set — skipping the Play upload."
+            echo "configured=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          printf '%s' "$PLAY_SERVICE_ACCOUNT_JSON" > play-service-account.json
+          # Fail here, with a clear message, rather than inside fastlane: a
+          # mangled multi-line secret is the likeliest setup mistake.
+          python3 -c "import json,sys; d=json.load(open('play-service-account.json')); sys.exit(0 if d.get('type')=='service_account' else 1)" \
+            || { echo "PLAY_SERVICE_ACCOUNT_JSON is not a valid service-account JSON." >&2; exit 1; }
+          echo "configured=true" >> "$GITHUB_OUTPUT"
+
+      # Same GHES-detection problem as the upload side, same fix — see the
+      # handoff step in the release job.
+      - name: Download the AAB
+        if: steps.key.outputs.configured == 'true'
+        uses: https://github.com/ChristopherHX/gitea-download-artifact@75635f32b4c1c41c4b3d64e8f85210112ed4c9c7 # v4
+        with:
+          name: release-aab-${{ needs.detect.outputs.version }}
+          path: dist
+
+      - name: Install Ruby
+        if: steps.key.outputs.configured == 'true'
+        run: |
+          set -euo pipefail
+          SUDO=""
+          if command -v sudo >/dev/null 2>&1; then SUDO="sudo"; fi
+          $SUDO apt-get update
+          # ruby-dev + build-essential: several of fastlane's dependencies build
+          # native extensions.
+          $SUDO apt-get install -y ruby-full ruby-dev build-essential
+          ruby -v
+
+      # Only the first release pays the full gem build; afterwards this restores.
+      - name: Cache bundled gems
+        if: steps.key.outputs.configured == 'true'
+        uses: actions/cache@v4
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
+          restore-keys: |
+            ${{ runner.os }}-gems-
+
+      - name: Install fastlane
+        if: steps.key.outputs.configured == 'true'
+        run: |
+          set -euo pipefail
+          gem install bundler --no-document
+          bundle config set --local path vendor/bundle
+          bundle install --jobs 4
+          bundle exec fastlane --version
+
+      - name: Upload to Play
+        if: steps.key.outputs.configured == 'true'
+        env:
+          SUPPLY_JSON_KEY: play-service-account.json
+          # supply is chatty on a TTY-less runner otherwise.
+          FASTLANE_SKIP_UPDATE_CHECK: '1'
+          FASTLANE_HIDE_CHANGELOG: '1'
+        run: |
+          set -euo pipefail
+          test -f "dist/app-release.aab"
+          bundle exec fastlane deploy \
+            aab:"dist/app-release.aab" \
+            track:"$PLAY_TRACK" \
+            release_status:"$PLAY_RELEASE_STATUS" \
+            dry_run:"$PLAY_DRY_RUN"
+          echo "Uploaded $VERSION (code $VERSION_CODE) to the '$PLAY_TRACK' track."
+
+      # The workspace is reused between runs on a self-hosted runner, so the
+      # credential must not outlive the job.
+      - name: Shred the service-account key
+        if: always()
+        run: shred -u play-service-account.json 2>/dev/null || rm -f play-service-account.json

.gitea/workflows/renovate.yml

@@ -29,14 +29,30 @@ jobs:
       - name: Run Renovate
         run: renovate
         env:
-          # Self-hosted Gitea, not github.com.
-          RENOVATE_PLATFORM: gitea
-          RENOVATE_ENDPOINT: https://gitea.jeanlucmakiola.de/api/v1
-          # Bot-account token (Gitea secret). Needs repo read/write + PR scope.
+          # Renovate targets Codeberg (canonical) while still RUNNING on the
+          # Gitea runner. Moving the job to Codeberg would put a repo-write
+          # token on the contributor-facing runner, which is exactly what the
+          # .forgejo/ vs .gitea/ split exists to prevent — so the token stays
+          # where the other secrets live and only the API calls cross over.
+          #
+          # Platform is `forgejo`, not `gitea`: Codeberg runs Forgejo, and the
+          # pinned image ships a distinct forgejo platform module.
+          RENOVATE_PLATFORM: forgejo
+          RENOVATE_ENDPOINT: https://codeberg.org/api/v1
+          # Codeberg bot-account token (Gitea secret). Needs repo read/write +
+          # PR scope on jlmakiola/calendula.
           RENOVATE_TOKEN: ${{ secrets.RENOVATE_TOKEN }}
           # Scope to this repo only — no org-wide autodiscovery.
           RENOVATE_AUTODISCOVER: 'false'
-          RENOVATE_REPOSITORIES: '["makiolaj/calendula"]'
-          # Commits/PRs authored as the bot, not a real maintainer.
+          RENOVATE_REPOSITORIES: '["jlmakiola/calendula"]'
+          # Commits/PRs authored as the bot, not a real maintainer. This address
+          # must be a verified email on the Codeberg bot account, otherwise the
+          # commits show up unattributed there.
           RENOVATE_GIT_AUTHOR: 'Renovate Bot <renovate@jeanlucmakiola.de>'
+          # Read-only github.com PAT (no scopes needed). Unaffected by the forge
+          # move — nearly every dependency is *released* on GitHub, and without
+          # this,
+          # changelog/release-note lookups hit the 60/h anonymous rate limit
+          # and PRs arrive with an empty "Release Notes" section.
+          RENOVATE_GITHUB_COM_TOKEN: ${{ secrets.GITHUB_COM_TOKEN }}
           LOG_LEVEL: info

.gitignore

@@ -50,8 +50,27 @@ google-services.json
 .DS_Store
 Thumbs.db
 
+# Editor swap/backup files
+*.swp
+*.swo
+*~
+
 # F-Droid local artifacts (the pipeline generates them in CI)
 /fdroid/
 
 # KSP
 .ksp/
+
+# Google Play Developer API service-account key. Reconstructed in CI from the
+# PLAY_SERVICE_ACCOUNT_JSON secret and shredded afterwards — never committed.
+/play-service-account.json
+
+# fastlane (Play uploader only — see fastlane/Fastfile)
+/fastlane/report.xml
+/fastlane/README.md
+/vendor/bundle/
+/.bundle/
+Gemfile.lock
+
+# Claude Code
+/CLAUDE.md

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "floret-kit"]
+	path = floret-kit
+	url = https://codeberg.org/jlmakiola/floret-kit.git

.planning/PROJECT.md

@@ -17,9 +17,10 @@ re-inventing the calendar sync stack — leave that to DAVx5 and the system.
 ## Current Milestone
 
 Milestones 1 (read, v1.0) and 2 (write support, v1.1–v2.0.0 incl. reminder
-delivery) are **complete** — v2.0.0 shipped 2026-06-11. Next is v3.0
-(power-user features) plus an undecided "Locations & People" idea backlog;
-see `ROADMAP.md`.
+delivery) are **complete** — v2.0.0 shipped 2026-06-11. Everything since is
+tracked as issues and milestones on Codeberg:
+<https://codeberg.org/jlmakiola/calendula/milestones>. A milestone maps to its
+`release/vX.Y.Z` branch.
 
 ## Stack
 
@@ -27,10 +28,26 @@ Kotlin 2.3.21 (paired with KSP 2.3.9 — Kotlin 2.4.0 has no KSP release
 yet, do not upgrade until one ships). Jetpack Compose + Material 3
 Expressive 1.5.0-alpha21 (alpha is intentional — Expressive APIs only
 live in the 1.5 alpha line). Hilt 2.59.2, DataStore. Gradle Kotlin DSL
-with Version Catalog. AGP 9.1.1, Gradle 9.5.1. JVM target 17.
+with Version Catalog. AGP 9.2.1, Gradle 9.5.1. JVM target 17 (exactly — AGP
+requires it).
 
-Android-only (minSdk 29, targetSdk 36). No iOS. No `INTERNET` permission —
-any feature that would need one is an explicit product decision first.
+The shared Material 3 Expressive kit, **floret-kit**, is a git submodule wired
+in as a Gradle composite build, so it compiles from source rather than resolving
+as a dependency.
+
+## Constraints
+
+- **Platform:** Android-only, Android 10+ (minSdk 29), targetSdk 36. No iOS.
+- **Offline-first:** all data lives in `CalendarContract` — no app database, no
+  sync stack. No `INTERNET` permission; any feature needing one is an explicit
+  product decision first.
+- **Privacy:** zero telemetry, zero analytics.
+- **i18n:** German + English from day one; further languages come from community
+  translators via the self-hosted Weblate, which owns every `values-*` file.
+- **Tests + CI from day one**, JVM-first.
+- **Reproducible release builds**, so the official F-Droid repo can verify the
+  published binary against a from-source rebuild.
+- **Licence:** MIT.
 
 ## Naming
 
@@ -40,5 +57,9 @@ shows a stylized "1" on a slate squircle.
 
 ## Source
 
-Hosted on self-hosted Gitea, released through self-hosted F-Droid repo on
-Hetzner. Same infrastructure as `HouseHoldKeaper`.
+**Codeberg (`jlmakiola/calendula`) is canonical** — git, issues, PRs, tags and
+releases, plus contributor CI. The self-hosted Gitea instance is build
+infrastructure only: it holds the signing key, runs the release pipeline, and
+publishes the self-hosted F-Droid repo on Hetzner. Codeberg push-mirrors `main`
+and tags to Gitea, where a bumped `versionName` triggers the release. Also
+published to the official F-Droid repo. See `docs/RELEASING.md`.

.planning/REQUIREMENTS.md

@@ -1,53 +0,0 @@
-# Calendula — Requirements
-
-See full design spec: `docs/superpowers/specs/2026-06-08-calendar-app-design.md`
-
-## V1 Scope (Variant "B") — shipped in full (v1.0.0, 2026-06-11)
-
-- [x] Foundation & CI infrastructure — v0.1.0 (2026-06-08)
-- [x] Data Layer over `CalendarContract`
-- [x] Permission flow (`READ_CALENDAR`)
-- [x] Month view (S1)
-- [x] Week view (S2)
-- [x] Day view (S3)
-- [x] Event Detail Sheet (S4) — became a full screen, plus full event read (v0.6)
-- [x] Multi-Calendar Filter (M3)
-- [x] Today button (M2) — shipped v0.5; Jump-to-Date **cut from scope**
-- [x] View-Switcher (M1)
-- [x] Settings screen (M4)
-- [x] Empty / no-permission / no-calendars states
-- [x] German + English localization
-- [x] Loading/Failure/Success states per screen (architectural pattern)
-
-## V2 Scope — write support, shipped in full (v2.0.0, 2026-06-11)
-
-- [x] Write foundation: `WRITE_CALENDAR`, read-only-calendar detection, delete (v1.1)
-- [x] Create event: form, FAB, last-used calendar (v1.2; polish v1.2.1)
-- [x] Edit event: shared form, scoped recurring writes, recurrence picker (v1.3)
-- [x] Reminder notifications (v1.4) — **reversal of the original
-  "system handles reminders" assumption:** Calendula targets
-  sole-calendar-app users, so it posts reminder notifications itself
-  (Etar model), incl. `POST_NOTIFICATIONS` onboarding
-- [x] Conflict dialog on save + store polish (v2.0)
-- Quick-add — **cut from scope** (the prefilled form covers it)
-- Calendar switching while editing — moved to v3 backlog
-
-### Out of Scope (V3+)
-
-- Home-screen widget
-- Full-text search
-- Tablet/foldable-specific layouts
-- Locations & People ideas (contact picker, OSM autocomplete) — see
-  `ROADMAP.md` idea backlog, undecided
-- iOS support (Android-only by design)
-
-## Constraints
-
-- **Tech stack:** Kotlin + Jetpack Compose + Material 3 Expressive, Hilt, DataStore
-- **Tech stack pin:** Hilt 2.59.2 + KSP 2.3.9; Kotlin 2.3.21 (KSP for Kotlin 2.4.0 not released yet). Material 3 pinned to `1.5.0-alpha21` (Expressive APIs only exist in alpha). Re-evaluate when KSP/Material3 stable land.
-- **Platform:** Android 10+ (API 29 minimum), Android 16 (API 36) target
-- **Offline-first:** all data lives in `CalendarContract`; no app-side network
-- **Privacy:** zero telemetry, no analytics
-- **i18n:** German + English from day one
-- **Tests + CI from day one**
-- **License:** MIT

.planning/ROADMAP.md

@@ -1,587 +0,0 @@
-# Calendula — Roadmap
-
-## v0.x — Pre-Release
-
-| Version | Milestone | Status |
-|---|---|---|
-| v0.1 | Foundation & CI | complete |
-| v0.2 | Data Layer & Permission Flow | complete |
-| v0.3 | Month + Week + Day views, view switcher | complete |
-| v0.4 | Event Detail (S4) + humanized recurrence | complete |
-| v0.5 | Calendar filter (M3) + Settings (M4) | complete |
-| v0.6 | Full event read — surface every readable field | complete |
-| v1.0 | First public release — polish pass, F-Droid | complete |
-
-Delivery ran ahead of the original table: Day view (S3) shipped in v0.3 and
-Event Detail (S4) in v0.4, so the Filter/Settings milestone became v0.5.
-
-Jump-to-date (the date-picker half of M2) was **cut from scope** and will not
-ship. The "Today" half of M2 already shipped in v0.5 (drawer entry).
-
-## v0.6 — Full event read
-
-Round out the read-only model so a detail view shows everything the system
-actually stores, before write support starts. Scope = `CalendarContract`
-columns we don't yet read/display:
-
-- **Reminders** (`VALARM`) — read `CalendarContract.Reminders`, list lead times
-- **Status** — Confirmed / Tentative / Cancelled (cancelled shown struck-through)
-- **Availability** (`TRANSP`) — Free / Busy chip
-- **Attendee extras** — role (required / optional / organizer) + the user's own
-  `SELF_ATTENDEE_STATUS`
-- **Timezone** (`EVENT_TIMEZONE`) — shown only when it differs from the device zone
-- **URL** — ~~tappable link card~~ **cut**: `CalendarContract` exposes no
-  `Events.URL` column (only `CUSTOM_APP_URI`, an originating-app deep-link).
-  URLs are instead surfaced by linkifying the description text
-- **Access level / class** (private / confidential) — small chip (optional, trivial)
-
-All of the above shipped in v0.6.0 (2026-06-11).
-
-Deliberately out of v0.6:
-- Recurrence exception / modified-occurrence badges — `Instances` already
-  resolves correct per-occurrence times for display; this only matters for
-  editing, so it folds into v2
-- `CATEGORIES`, `ATTACH` — not reliably exposed by `CalendarContract`
-  (provider limitation, not our choice)
-
-## v1.0 — First Public Release — shipped 2026-06-11
-
-All V1 features shipped, polished, on F-Droid. Read-only calendar. Cut directly
-after v0.6 (full event read) plus the onboarding-screen polish pass.
-
-### Polish backlog (pre-1.0)
-- ~~Redesign the initial grant-access (permission) screen~~ — **done**
-  (Material 3 Expressive onboarding, shipped in v0.6.0 / v1.0.0)
-
-## v2.0 — Write Support (complete, shipped 2026-06-11)
-
-Delivered in four releasable slices (plan:
-`docs/superpowers/plans/2026-06-11-03-write-support.md`). The V1 spec is a
-guide here, not a contract — scope per slice is decided as we go.
-
-| Version | Milestone | Status |
-|---|---|---|
-| v1.1 | Write foundation — `WRITE_CALENDAR`, read-only-calendar detection, delete (series + single occurrence) | complete (shipped 2026-06-11) |
-| v1.2 | Create event — form, FAB, last-used-calendar preselect | complete (shipped 2026-06-11) |
-| v1.2.1 | Form polish after on-device review — card design system, optional fields + settings defaults, OptionCard dialogs, expressive motion | complete (shipped 2026-06-11) |
-| v1.3 | Edit event — shared form, scoped recurring writes (this / following / all), recurrence picker | complete (shipped 2026-06-11) |
-| v1.4 | Reminder notifications — see below | complete (shipped 2026-06-11) |
-| v2.0 | Conflict dialog, polish pass (store copy refresh, F-Droid screenshots), release | complete (shipped 2026-06-11) |
-
-v2.0 scope was re-cut on 2026-06-11, after v1.4:
-- **Occurrence edit** already shipped early, in v1.3.
-- **Quick-add** is **cut from scope**: the full form already opens prefilled
-  (visible day, last-used calendar, optional fields hidden), so the sheet
-  would only save one screen transition while adding a second create-surface
-  to maintain. Revisit only if real-world feedback says creation feels heavy.
-- **Calendar switching while editing** moves to the v3 backlog (sync-adapter
-  minefield: `CALENDAR_ID` is sync-adapter-owned, AOSP locks the field; an
-  honest implementation is copy+delete like Google Calendar, with sync-identity
-  and attendee side effects).
-- **Conflict dialog** stays (plan 03, decision 5): on save, compare against
-  the row as it was when the form loaded; on external change, ask
-  overwrite / discard. Closes the silent-clobber gap on synced calendars.
-
-## v1.4 — Reminder Notifications
-
-**Essential**, not nice-to-have: Calendula targets users for whom it is their
-*only* calendar app, so reminder delivery can't be delegated to Google/OEM
-Calendar. The calendar provider schedules reminders and broadcasts
-`android.intent.action.EVENT_REMINDER`, but it does **not** post the visible
-notification — a calendar app must. We become that app (the Etar model).
-
-Scope:
-- Manifest-registered `BroadcastReceiver` for `EVENT_REMINDER`
-  (data scheme `content://com.android.calendar`) — wakes us at reminder time,
-  no foreground service.
-- Read `CalendarContract.CalendarAlerts` / `Reminders`, filter to
-  `METHOD_ALERT` / `METHOD_DEFAULT` (skip `METHOD_EMAIL`); post on a dedicated
-  notification channel; tap opens event detail.
-- `POST_NOTIFICATIONS` runtime permission (API 33+) — requested in onboarding.
-- Onboarding step: (a) request `POST_NOTIFICATIONS`, (b) in-app reminders
-  toggle, **default ON**, with copy warning that a second calendar app with
-  notifications on will cause duplicate reminders. Mirrored into Settings
-  (reversible).
-
-Deliberately deferred (add only if needed):
-- Snooze / dismiss notification actions (Etar has them)
-- Battery-optimization exemption prompt for delivery reliability
-
-## v2.1 — Month event grid + drawer view tabs (shipped 2026-06-15)
-
-- Month grid shows real events as continuous multi-day bars (not just dots)
-- View section in the navigation drawer to switch Month / Week / Day
-- Fix: text cursor no longer jumps in event text fields
-
-## v2.2 — Tap-to-create + local calendar management (shipped 2026-06-16)
-
-- Tap an empty slot in day/week → create form prefilled with that day + the
-  tapped hour (snapped to the hour, 1 h long)
-- Local (device-only) calendar management in a full-screen editor from
-  Settings → Calendars: create / rename / recolor / delete, with name,
-  pastel-previewed colour, and description (stored in `CAL_SYNC1`)
-- Synced calendars listed read-only, grouped by account, each with a
-  per-account "manage in source app" deep-link (resolved from the account's
-  authenticator — DAVx5/ICSx5/…) + an add-account shortcut
-- Shared `InlineTextField` extracted to `ui.common` (event form + calendar
-  editor share one input style)
-
-## v2.3 — Material 3 grouped-list redesign (shipped 2026-06-16)
-
-A structural + visual pass adopting one shared blueprint (modelled on the ReFra
-gallery app) across Settings, the calendar manager and the navigation drawer.
-
-- Shared `ui/common/GroupedList.kt`: `CollapsingScaffold` (a `LargeTopAppBar`
-  whose title collapses on scroll) + `GroupedRow` (Position-based corner
-  grouping, press-animated corners, `selected` + `minHeight` knobs).
-- Settings: category hub with About card on top and sliding sub-pages
-  (Appearance / New event form / Notifications); theme/week-start/language
-  pickers moved from `DropdownMenu` to OptionCard dialogs; token-based icon
-  chips; `ic_gitea.xml` for the About "Source" button.
-- Calendar manager + drawer restyled to match; shared `CalendarColorChip`;
-  drawer scrolls as one with the active view highlighted.
-- Cards use `surfaceContainerHigh` for readable contrast.
-- Donate button on the About card deferred (target TBD).
-
----
-
-# Backlog (theme-based, post-v2.1)
-
-The old v3.0 / "daily-driver polish" / "Locations & People" lists are
-consolidated here by theme. Within a group, **(in progress)** /
-**(next)** mark what is being or about to be worked; everything else is an
-approved-but-unscheduled idea unless tagged **(idea)** /
-**(go/no-go)** / **(rejected)**. Order across groups is not a commitment.
-
-## Near-term sequence (ranked, 2026-06-16)
-
-The theme groups below are the full menu; this is the committed *order* for
-the next stretch. Ranking favours finishing the current create/edit + calendar
-arc before opening new fronts, then cheap-relative-to-value items and ones that
-unblock a later item. Order is a plan, not a contract — revisit after each lands.
-
-**Tier 1 — finish the current arc (create/edit + calendars)**
-1. Tap-to-create in day/week *(shipped v2.2.0)* — prefilled create from an empty slot
-2. Local calendar management + "manage in source app" deep-links *(shipped v2.2.0)*
-3. ~~Settings redesign & restructure~~ *(shipped v2.3.0 — grew into the full
-   grouped-list blueprint across Settings + calendars + drawer; see "v2.3"
-   above)*
-4. ~~Per-event color~~ *(shipped v2.4.0)* — palette calendars write
-   `EVENT_COLOR_KEY` (sync-safe); local/opted-in calendars write a raw
-   `EVENT_COLOR`; off-by-default setting for no-palette synced calendars
-Tier 1's create/edit + calendars arc is effectively closed. **Duplicate event**
-was deprioritised (2026-06-17) as low-importance and dropped to the bottom of
-the sequence; the next item is now **Jump-to-date** (formerly Tier 2).
-
-(Tier 2+ numbering below shifts accordingly; ranking unchanged.)
-
-### Settings redesign & restructure *(shipped v2.3.0)*
-
-The original scope below is kept as a record; the implementation expanded from a
-sub-screen restructure into the shared grouped-list blueprint (see "v2.3" above).
-
-The settings screen has grown into a flat vertical scroll of divider-separated
-sections (Appearance, Event form, Notifications, Calendars, Language, About) and
-will keep accreting rows (per-event-color defaults, default reminder, more
-calendar entries are all queued). It needs structure before it gets unwieldy.
-
-**Decided (2026-06-16): sub-screens**, not flat-but-carded. The top level
-becomes a category list; each category opens its own destination. More
-M3-idiomatic for a settings surface that will keep growing, and it mirrors the
-existing Calendars row, which already navigates out to its own screen.
-
-Structure — top-level settings list → category destinations:
-- **Appearance** → theme, dynamic colour, week start
-- **Event form** → the 6 default-field toggles + the hint text
-- **Notifications** → reminders toggle (POST_NOTIFICATIONS flow stays)
-- **Calendars** → already its own screen (`CalendarsScreen`); just becomes a
-  peer category row, no change to that screen
-- **Language** → single control; keep as a top-level row that opens an
-  OptionCard directly (a whole sub-screen for one choice is overkill)
-- **About** → kept inline on the top-level list as a card (read-only info,
-  not worth a navigation hop). Card layout, top → bottom:
-  - **Identity** — app logo + name "Calendula", with "by Jean-Luc Makiola"
-    as a subtitle beneath the name
-  - **Action buttons** (small, button-styled, sit in a row):
-    - **Source** — Gitea logo, opens the repo (`about_source_url`)
-    - **License** — opens the LICENSE file on Gitea
-    - **Donate** *(tentative)* — sits next to Source; target TBD (decide
-      before building: Liberapay / Ko-fi / Gitea sponsor / etc.)
-  - **Version** — small version number at the bottom of the card
-
-Scope:
-- **Navigation** — add the settings sub-screen destinations alongside the
-  existing settings/calendars routes in `CalendarHost`; back pops to the
-  settings list (mind the existing `BackHandler` that guards against falling
-  through to the activity).
-- **Fix the dialog-pattern violation** — theme, week-start and language use
-  `DropdownMenu`; the project default is the full-width tonal OptionCard modal
-  (radio/dropdown/text-list dialogs are banned, see
-  `option-card-modal-style-default`). Migrate these selectors to OptionCard.
-- **Visual pass** — top-level category rows with leading icons; consistent
-  spacing and row affordances aligned with the event-form card design system.
-
-Out of scope (no new settings *features* here) — this is a structure + style
-pass on the existing controls; new toggles ride in with their own features.
-
-**Tier 2 — navigation & daily-driver completeness**
-5. ~~Jump-to-date — drawer date picker (un-cut from V1); cheap, fills the nav gap~~ *(done, v2.5.0)*
-6. ~~Agenda view — the missing 4th view; serves daily-driver users *and* becomes the data source for the widget~~ *(done, v2.5.0)*
-
-**Tier 3 — platform reach (depends on Tier 2)**
-7. ~~Home-screen widget — built on the agenda data source from #6~~ *(done, v2.5.0 — agenda + month widgets)*
-8. App shortcuts: ~~launcher long-press → New event~~ *(done, v2.5.0)*; ~~quick-settings tile~~ *(done, v2.8.0 — "New event" QS tile)*
-
-**Tier 4 — reliability, data-safety & interop** *(re-ranked 2026-06-17)*
-9. **Reminders — defaults + delivery reliability** *(shipped v2.6.0)* — global
-   default reminder **+ per-calendar override**, bundled with battery-exemption
-   hardening. Full sketch in "Reminders — defaults & delivery reliability" below.
-10. **The `.ics` engine — export + import** *(shipped v2.7.0, 2026-06-18)* — one
-    hand-rolled serializer/parser (zero deps, stays on `kotlinx-datetime`),
-    four surfaces all shipped: single-event share + whole-calendar backup
-    (export), open-`.ics`→form + whole-calendar bulk import (import). Closed the
-    device-local-calendar data-loss gap (#10/#11 merged here). Built as two
-    sequential branches: `feat/ics-export` (write side + UID-on-create precursor)
-    then `feat/ics-import` (parser, restore, dedup by UID). Import is
-    liberal-in/strict-out: skip-and-report foreign `VTIMEZONE` / `RECURRENCE-ID`
-    / guest lists it can't model. Plans:
-    `docs/superpowers/plans/2026-06-18-05-ics-export.md` + `…-06-ics-import.md`.
-11. **Snooze / dismiss notification actions** *(merged into release/v2.8.0)* —
-    followed the `.ics` work; inherits v2.6's deferred exact-alarm/WorkManager
-    decision (snooze must re-fire an alarm).
-
-**Tier 5 — close the read/write gap on the event model** *(opened 2026-06-22)*
-12. **Attendee editing** *(shipped — merged into release/v2.8.0, `feat/attendee-editing`
-    MR !29 / commit `b0f34ff`, 2026-06-22)* — closed the last big read-only gap in
-    the event model: attendees were already *read* (queried, mapped, shown on the
-    detail screen since v0.6) and are now *writable* from the form. An attendees
-    section on `EventEditScreen` / `EventForm` adds by typed email **or** the
-    no-permission contact picker, edits/removes rows, and sets role (required /
-    optional) — writing `CalendarContract.Attendees` rows on insert + dirty-checked
-    update, mirroring the reminders-diff pattern. The sync-adapter *invitation*
-    caveat was **settled record-only** (Calendula never sends invites; the backend
-    decides delivery) — full sketch + decision in "Attendee editing" under Locations
-    & People below.
-
-**Gated — explicit go/no-go before any work (mostly INTERNET-permission calls)**
-- Remote calendar create/edit (re-implements DAVx5; INTERNET + credential storage)
-- Locations & People — the no-permission contact pickers already shipped (location v2.8.0, attendee email v2.8.0); what remains gated is OSM autocomplete (needs INTERNET)
-- Move event to another calendar — sync-adapter minefield (copy+delete model)
-
-**Bottom — deprioritised, not important**
-- Duplicate event (detail action → prefilled create form) — moved here
-  2026-06-17; cheap but low value, pick up only if asked
-
-**Unranked / fill-in** — pinch-to-zoom time scale, tablet/foldable layouts.
-Pulled in opportunistically, not sequenced.
-
-Tier 4 is now fully shipped (#9 reminders defaults v2.6.0, #10 `.ics`
-export/import v2.7.0, #11 snooze/dismiss in release/v2.8.0; drag-drop rejected),
-and Tier 5 #12 — attendee editing — shipped in release/v2.8.0, closing the last
-read-only gap in the event model. v2.8.0 also cleared most Tier 2/3 leftovers —
-full-text search, the "New event" Quick Settings tile, and the now-line all
-shipped there. **No tier work is currently committed as next;** the remaining
-candidates are unscheduled theme-group ideas (pinch-to-zoom, tablet/foldable,
-accessibility pass) plus the gated go/no-go items.
-
-## Navigation & views
-
-- ~~Tap an empty slot in day/week → create form prefilled with that
-  date+time, snapped to the hour~~ **shipped v2.2.0** (long-press variant
-  not added — single tap covers it)
-- Agenda view (fourth view: upcoming events grouped by day; also the
-  natural data source for a future widget)
-- Jump to date — drawer date picker (un-cut from V1)
-- ~~Current-time "now" line in day/week~~ **shipped v2.8.0**
-- Week numbers in the **month** grid — **rejected** (owner decision): clutters
-  the view and shrinks the day cells; the badge stays week-view-only.
-- Pinch-to-zoom time scale in day/week
-- Tablet / foldable layouts *(was v3.0)*
-- ~~Full-text search~~ **shipped v2.8.0** — for a daily driver with real event
-  history, finding an event is core completeness, not optional.
-
-## Event editing & creation
-
-- Duplicate event (detail action → prefilled create form)
-- ~~**Per-event color**~~ *(shipped v2.4.0)* — `EVENT_COLOR` / `EVENT_COLOR_KEY`
-  from the calendar's color list (`Colors` table, `TYPE_EVENT`), OptionCard
-  picker in the form, falling back to the calendar color when unset. Reused the
-  color-picker component and palette plumbing from local calendar management and
-  finished the create/edit theme.
-
-## Calendars & accounts
-
-- ~~Create / manage local (device-only) calendars~~ **shipped v2.2.0** —
-  name + color + description; rename / recolor / delete the calendars the app
-  owns. Inserted under `ACCOUNT_TYPE_LOCAL` as a sync adapter; description in
-  `CAL_SYNC1`. Full-screen "Calendars" editor reached from Settings.
-- ~~Per-calendar "manage in source app" deep-link~~ **shipped v2.2.0** — for
-  synced calendars, open the app the calendar actually came from based on
-  its `ACCOUNT_TYPE` (DAVx5 `bitfire.at.davdroid`, Google `com.google`,
-  …); fall back to system account/sync settings. Plus an "add account"
-  entry into system Accounts. Honest boundary for remote calendars.
-- **Remote calendar create/edit** *(go/no-go)* — creating a CalDAV
-  collection (`MKCALENDAR`) or a Google calendar means an in-app sync
-  client: **INTERNET permission, credential storage, the full server
-  round-trip** — i.e. re-implementing DAVx5. DAVx5 exposes no public
-  intent to delegate the create to it. Cosmetic local edits (color/name)
-  to an existing synced row are possible but don't propagate to the server
-  and may be overwritten on next sync — not promised. Same explicit
-  go/no-go gate as the OSM/INTERNET item below.
-- Move event to another calendar (copy+delete model with a consequences
-  warning — deferred from v2.0; `CALENDAR_ID` is sync-adapter-owned) *(was v3.0)*
-- ~~**Local-calendar backup / export** *(Tier 4 #10)*~~ **shipped v2.7.0** —
-  device-only (`ACCOUNT_TYPE_LOCAL`) calendars had no sync and therefore no
-  backup. Settings → Calendars → Export writes every event to a user-chosen
-  `.ics` file (SAF); restore is the bulk-import path (pick a calendar, dedup by
-  UID). Closed the silent data-loss gap.
-
-### Disable a calendar in-app *(captured 2026-06-25)*
-
-A second, heavier visibility level **above** the existing per-view filter. Today
-the drawer's calendar filter (`hiddenCalendarIds` in `CalendarPrefs`) only hides
-a calendar's *events* from the month/week/day/agenda views — the calendar itself
-still clutters the drawer filter list, the event-form calendar picker, and the
-import target picker. "Disable" removes a calendar from the app's surfaces
-entirely; "hide" stays the lightweight, frequently-toggled control.
-
-**Two-level model (both kept):**
-- **Hidden** (existing) — `hiddenCalendarIds`; a quick per-view checkbox in the
-  drawer. Toggles events on/off in the views; the calendar stays listed
-  everywhere. Operates only over the *enabled* calendars.
-- **Disabled** (new) — the calendar is gone from the app: not in the drawer
-  filter list, not in the event-form picker, not in the import picker, and its
-  events never appear (it's gated out of `instances()` like a hidden one). It
-  remains visible **only** in Settings → Calendars, where the enable/disable
-  toggle lives, so it can be brought back.
-
-**Storage — app-side (DataStore), mirrors the hidden set.** Add
-`disabledCalendarIds: Set<Long>` + `setDisabledCalendarIds(...)` to
-`CalendarPrefs` (comma-separated string key, same shape as `hiddenCalendarIds`).
-**Does not touch** `CalendarContract.Calendars.VISIBLE` / `SYNC_EVENTS` — purely
-a Calendula-local preference, so other calendar apps are unaffected and the sync
-adapters stay out of it (privacy-clean, reversible).
-
-**Where the disabled set is applied:**
-- `CalendarRepositoryImpl.instances()` + `searchEvents()` — exclude
-  `calendarId ∈ (hidden ∪ disabled)` so a disabled calendar's events never show
-  and aren't searchable. (`repository.calendars()` itself stays unfiltered/raw —
-  the screens that need everything still get everything.)
-- `FilterViewModel.state` — drop disabled calendars from the drawer filter list
-  (you can't hide/show what's disabled).
-- `EventEditViewModel.writableCalendars` — exclude disabled, so you can't create
-  into a calendar you've removed from the app. Handle the last-used-calendar
-  preselect falling on a now-disabled calendar (fall back to first enabled
-  writable).
-- `ImportViewModel` — exclude disabled from the import target list.
-- `CalendarsScreen` / `CalendarsViewModel` — the **only** surface that lists
-  disabled calendars; add `setDisabled(id, Boolean)` and a per-calendar toggle.
-
-**UI — Settings → Calendars (no new tab).** Add an enable/disable control to each
-row on the existing `CalendarsScreen` (both the local and the synced/read-only
-groups — disabling is an app-side view choice, independent of write access).
-Disabled rows render visibly de-emphasised (dimmed) but keep the toggle so
-they're re-enableable. Follow the project dialog/list conventions (M3 grouped
-list, `option-card-modal-style-default` if a confirm/selection surface is needed).
-
-**Decided behaviour:**
-- All calendars disabled → views show the existing empty state.
-- A disabled calendar that still holds events: events simply vanish from
-  views/search until re-enabled (no data touched — it's a filter, not a delete).
-- Deep links / notifications pointing at an event in a disabled calendar still
-  open its detail screen — detail is a direct id lookup, not an `instances()`
-  query, so disabling never strands an existing link.
-
-## Reminders — defaults & delivery reliability *(shipped v2.6.0; built on `feat/default-reminders`)*
-
-Two themes bundled because both are "make reminders trustworthy" — the core of
-the "Calendula is your only calendar app" promise.
-
-**Built in this slice (A + the safe half of B):** global timed default reminder
-+ a **separate all-day default** (day-scale lead times) + per-calendar override
-(timed events), applied on create with manual-edit / calendar-switch / all-day-
-toggle handling; three pickers + per-calendar override list in Settings →
-Notifications; battery-optimisation exemption row (status + system deep-link, no
-extra permission). `resolveDefaultReminder` + prefs round-trips unit-tested.
-Resolution model: all-day events use the all-day global default outright;
-per-calendar overrides govern timed events only. Reviewed (8-angle), fixes
-applied: form-reset state race, label-fn consolidation with the detail screen,
-inline wrapper + single combined flow read.
-
-**Deliberately deferred (documented decisions, not oversights):**
-- *Absolute time-of-day for all-day reminders* — the all-day default is still
-  minutes-before-midnight (day-scale presets), not "9am the day before" (open
-  decision #2's richer half). Per-calendar all-day overrides also deferred.
-- *Self-scheduled alarms* — kept the existing provider-broadcast architecture
-  (open decision #1). The battery exemption is the reliability lever; no
-  `AlarmManager`/`USE_EXACT_ALARM` subsystem was added.
-- *Test-reminder diagnostic* and *battery prompt inside onboarding* — the
-  exemption lives only in Settings for now (onboarding flow untouched to keep
-  the change reviewable).
-
-### A. Default reminders (global + per-calendar override)
-
-**No provider backing.** `CalendarContract` has no column that auto-applies a
-default reminder per calendar — Google's per-calendar defaults live server-side.
-So both the global default *and* the per-calendar override are **app-side
-preferences**, applied by us at event-insert time. We inherit nothing from the
-synced calendar.
-
-- **Storage (DataStore):**
-  - `defaultReminderMinutes: Int?` — global default; `null` = "no reminder".
-  - `defaultAllDayReminderMinutes: Int?` — separate all-day default (all-day
-    reminders are expressed as minutes before midnight / day-before-at-time, not
-    minutes before a start instant — they need their own value).
-  - `perCalendarReminderOverride: Map<Long, Int?>` — keyed by calendar id;
-    **absent key = inherit global**, explicit `null` = "no reminder for this
-    calendar". (Same for an all-day override map if we want per-calendar all-day.)
-- **Apply on create:** a fresh event prefills its reminders list from
-  override-or-global for the preselected calendar. Changing the calendar in the
-  form re-applies the *new* calendar's default **only if the user hasn't manually
-  edited the reminders** — track a dirty flag, mirroring the per-event-color
-  reset pattern (v2.4).
-- **Edit semantics:** defaults apply to **new events only**; never rewrite
-  reminders on existing events on open or on calendar-switch-during-edit.
-- **Settings UI (Notifications sub-page):**
-  - Global default via OptionCard (None / at time of event / 5 / 10 / 15 / 30 min
-    / 1 h / 1 day / custom), plus the separate all-day default.
-  - Per-calendar overrides: a row per writable calendar (in the Calendars screen
-    or a Notifications subsection), each opening the same OptionCard with a
-    leading **"Use global default"** option.
-
-### B. Delivery reliability (exact alarms + battery)
-
-The provider broadcasts `EVENT_REMINDER`, but on modern Android (Doze / OEM
-battery managers) delivery can be silently delayed or dropped. v1.4 deferred this;
-it directly undermines the feature's premise, so it rides in here.
-
-- **Exact alarm — decision first:** trust the provider broadcast, or
-  self-schedule via `AlarmManager.setExactAndAllowWhileIdle` for reliability?
-  If we self-schedule, declare `USE_EXACT_ALARM` (API 33+, auto-granted for
-  calendar/alarm-category apps, F-Droid-clean) with a `SCHEDULE_EXACT_ALARM`
-  fallback for API 31–32 (user-revocable → settings deep-link prompt).
-- **Battery-optimization exemption:** a *soft, optional* prompt via
-  `ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS` (settings deep-link — never the
-  auto-grant intent), honest copy: "Android may delay reminders to save battery;
-  exempt Calendula for on-time delivery." Shown once after the existing
-  `POST_NOTIFICATIONS` onboarding step, reversible in Settings → Notifications.
-- **Diagnostics:** a "send a test reminder in 1 minute" button in Notifications
-  settings so users can verify delivery on their specific OEM (Samsung / Xiaomi
-  are notorious for suppressing it).
-
-### Decisions made (as shipped in v2.6.0)
-
-1. **Provider broadcast kept** — did not self-schedule via `AlarmManager`; the
-   battery-optimisation exemption is the reliability lever (simplicity + battery
-   cost won over the exact-alarm subsystem).
-2. **All-day reminders = minutes-before-midnight** (day-scale presets); absolute
-   time-of-day ("9am the day before") deferred — see the deferred list above.
-3. **Per-calendar overrides live in the Notifications sub-page** (override list),
-   governing timed events only.
-
-### Round two
-
-- ~~Snooze + dismiss actions on the notification~~ *(shipped in release/v2.8.0,
-  Tier 4 #11)* — snooze re-fires a snooze-only exact alarm.
-
-## Sharing & interop
-
-- ~~Share event as .ics + open/receive .ics into a prefilled create form~~
-  **shipped v2.7.0** — single-event share from detail; opening an `.ics` with one
-  event prefills the create form, many events opens a bulk import (dedup by UID)
-- ~~ICS file import~~ **shipped v2.7.0** — covered by the open/receive `.ics`
-  flow above (single → form, many → bulk import)
-
-## Platform & launchers
-
-- ~~Home-screen widget~~ **shipped v2.5.0** — agenda + month widgets
-- ~~App shortcuts (launcher long-press → New event)~~ **shipped v2.5.0**
-- ~~"New event" Quick Settings tile~~ **shipped v2.8.0**
-
-## Quality & reliability
-
-- **Accessibility pass** — TalkBack content descriptions across all screens,
-  dynamic-type / large-font reflow, touch-target audit. Quality bar for an
-  F-Droid app; nothing tracks it yet.
-- **Reminder delivery reliability** — exact alarms + battery-optimization
-  exemption; specced in the "Reminders — defaults & delivery reliability" slice
-  above (Tier 4 #9).
-
-## Locations & People *(go/no-go, captured 2026-06-11)*
-
-Beyond classic calendar-client scope; discussed, deliberately not planned
-in detail yet:
-
-- ~~**Contact address picker** for the location field via the system picker
-  (`ACTION_PICK`)~~ **shipped v2.8.0** — one-shot, needs no READ_CONTACTS, fits
-  the privacy story. The same no-permission mechanism was then reused for the
-  attendee email picker (v2.8.0).
-- **OSM address autocomplete** in the location field (type "Brandenburger
-  Tor" → tap suggestion → resolved address inserted). Backend would be
-  Photon (Nominatim's public policy forbids autocomplete). **Requires the
-  INTERNET permission** — first dent in the "no network access" promise;
-  if built: opt-in (off by default), honest copy, configurable endpoint
-  for self-hosters, onboarding footnote + F-Droid copy reworded. This
-  trade-off is an explicit go/no-go decision before any work starts.
-- **Inline contact suggestions** while typing (needs READ_CONTACTS) — only
-  if the picker proves clunky.
-- **Attendee editing** *(promoted out of this gated bucket 2026-06-22 — now
-  Tier 5 #12, high-importance; the no-permission typed-email path is not an
-  INTERNET/contacts call)*. See the "Attendee editing" sketch below.
-
-### Attendee editing *(Tier 5 #12, opened 2026-06-22)*
-
-The last read-only gap in the event model: attendees are read & shown on the
-detail screen (since v0.6) but the form can't write them. Make guests editable.
-
-- **Read side already done:** `Attendee` domain model + status/relationship/type
-  enums, `queryAttendees` + `EventDetailMapper.toAttendee` (with tests), and the
-  attendees `DetailCard` + `AttendeeRow` in `EventDetailScreen`. Nothing to add
-  there.
-- **Write side — SHIPPED (`feat/attendee-editing`, commit b0f34ff, 2026-06-22):**
-  `attendees` on `EventForm`; a Guests section in `EventEditScreen` rendered as an
-  inline grouped list — each guest a tonal card (avatar, name/email, tappable
-  Required/Optional role chip, remove), the trailing card an inline email field
-  (type → Done commits). Persisted by `reconcileAttendees` diffing the provider's
-  `CalendarContract.Attendees` rows on insert + dirty-checked update (new guests =
-  `RELATIONSHIP_ATTENDEE` / `STATUS_INVITED`; kept rows keep their status, only the
-  required/optional type updates; organizer/resource/no-email rows untouched).
-  Reminders restyled to the same grouped-list pattern in passing. Needs only the
-  existing `WRITE_CALENDAR` — no new permission.
-- **Name on manual add — SHIPPED via a contact picker** (2026-06-22). The inline
-  field is email-only (the quick path); the add row also has a **"from contacts"
-  button**: `ACTION_PICK` on `ContactsContract.CommonDataKinds.Email.CONTENT_URI` →
-  the system Contacts app returns a URI to the picked email row, queried for
-  `Email.ADDRESS` **and** the contact `DISPLAY_NAME`, so a picked guest gets both
-  email and name in one tap. The result Intent grants temporary read access, so
-  **no `READ_CONTACTS` permission** — one-shot and user-driven, same no-permission
-  mechanism as the location address picker above. Self/organizer rows stay
-  non-editable.
-- **Invitation behavior — DECIDED 2026-06-22: record-only, all writable
-  calendars.** Calendula has no INTERNET and never sends an invitation itself; it
-  only writes `Attendees` rows. Whether a guest is notified is decided downstream:
-  local calendars notify no one (no sync); CalDAV/DAVx5 PUTs the `ATTENDEE` lines
-  and the *server* decides iMIP delivery; Google's sync adapter pushes the change
-  and Google decides (third-party attendee writes are historically unreliable
-  there). Editing is allowed on **any writable calendar** — not gated to local.
-  - **Honest, backend-aware copy is mandatory** (this is the whole point of the
-    decision): on a synced calendar show "Calendula doesn't send invitations —
-    your calendar account may email guests when it syncs"; on a local calendar
-    show "Stored on this device. No one is notified."
-  - Calendula must **not fabricate an ORGANIZER** or otherwise fake scheduling
-    state to coax a send — it writes the guest list faithfully and leaves
-    scheduling entirely to the backend.
-  - The optional "send an .ics invite via your email app" delegate (`ACTION_SEND`,
-    still no INTERNET) was considered and **deferred** — revisit only if users ask
-    to notify guests explicitly.
-- **Out of scope (for now):** RSVP/your-own-response editing, free/busy lookups,
-  resource booking — all carry server round-trips or richer sync semantics.
-
-## Consciously rejected
-
-- Travel time / weather / smart suggestions (network, core-promise conflict)
-- Natural-language quick entry (high effort, locale-fragile; the prefilled
-  form already covers fast entry)
-- Quick-add sheet (the prefilled full form already covers it — cut in v2.0)
-- Drag & drop rescheduling in day/week — **rejected** (owner decision,
-  reaffirmed 2026-06-22): not wanted. Rescheduling stays via the edit form.

.planning/STATE.md

@@ -1,177 +0,0 @@
-# Calendula — Current State
-
-*Last updated: 2026-06-22*
-
-## Status
-
-**Milestone:** 2 (write support) **complete** — v2.0.0 shipped 2026-06-11.
-**Phase:** post-2.x theme-based backlog work (organised in `ROADMAP.md`).
-**Latest released tag: v2.7.5.** The whole Tier 4 (reliability/data-safety/
-interop) arc is now done or in flight:
-- v2.4.0 per-event colors (2026-06-17)
-- v2.5.0 jump-to-date, Agenda view, agenda + month home-screen widgets, "New
-  event" launcher shortcut (2026-06-17)
-- v2.6.0 default reminders (global + per-calendar override, all-day default,
-  battery-exemption row) + system per-app language (2026-06-18)
-- v2.7.0 **`.ics` engine** — single-event share, local-calendar backup export,
-  open/receive `.ics` (single → form, many → bulk import, dedup by UID)
-  (2026-06-18)
-- v2.7.1–v2.7.5 — crash-reporting + F-Droid reproducible-build hardening + fixes
-
-**Next release `release/v2.8.0` (integration branch, not yet cut to main):**
-holds crash reports via the public Codeberg tracker (MR !27) + reminder
-snooze/dismiss notification actions (MR !28). Version bump to 2.8.0 happens at
-release-cut.
-
-## Progress
-
-- [x] Design spec written and committed (`docs/superpowers/specs/2026-06-08-calendar-app-design.md`)
-- [x] V1 design decisions resolved (App name "Calendula", icon, seed color)
-- [x] Plan 01 written and executed — foundation lands (theme, icon, i18n, Hilt, DataStore, CI green)
-- [x] Plan 02 written and executed — data layer + permission flow + debug screen
-- [x] Month view (S1) — 6-week grid, event dots, today marker, swipe nav, three states (replaces debug screen)
-- [x] Week view (S2) — time schedule with overlap-resolved lanes, all-day strip, swipe nav, three states
-- [x] Day view (S3) — single-column slice reusing the week layout
-- [x] View-switcher (M1) wired — cycles Month ↔ Week ↔ Day
-- [x] Event-detail screen (S4) — full-screen, humanized recurrence
-- [x] Filter sheet (M3) — per-calendar visibility, grouped by account, persisted, applied centrally in the repository
-- [x] Settings (M4) — appearance (theme, dynamic colour, week start), language (per-app locales), about
-- [~] Jump-to-date (M2) — **cut from scope**; "Today" half shipped in v0.5, date-picker dropped
-- [x] Full event read (v0.6) — reminders, status, availability, access level,
-  attendee role + self-response, foreign timezone, and linkified description
-  URLs in the detail view; new domain enums + mapper unit tests. (A dedicated
-  URL field was cut — no `CalendarContract` column backs it.)
-
-- [x] v1.1 write foundation — `WRITE_CALENDAR` (onboarding asks READ+WRITE,
-  only READ gates; contextual upgrade for v1.0 installs), read-only-calendar
-  detection (`CALENDAR_ACCESS_LEVEL` → `canModifyContents`, actions hidden for
-  WebCal/birthday calendars), delete from the detail screen (recurring:
-  "only this event" via cancelled exception / "all events in the series"),
-  repository + mapper tests
-
-- [x] v1.2 create event — full-screen `EventEditScreen` (title, all-day,
-  M3 date/time pickers with duration-preserving start moves, writable-only
-  calendar picker preselecting the last-used calendar, location, description),
-  "+" FAB on all three views prefilled with the visible day, `insertEvent`
-  with provider-correct all-day normalisation (UTC midnights, exclusive end),
-  domain/mapper/repository tests
-
-- [x] v1.3 edit event (shipped 2026-06-11) — `EventEditScreen` reused for
-  edit (detail-screen Edit action, `canModify`-gated, contextual WRITE
-  upgrade), dirty-checked partial `update` on the Events row (recurring:
-  series DTSTART moves by the user's delta, DURATION instead of DTEND),
-  reminder diff by minutes (kept rows keep their method), simple recurrence
-  picker (FREQ/INTERVAL/UNTIL/COUNT; complex RRULEs preserved verbatim and
-  shown humanized), `EventFormField.Recurrence` incl. settings default,
-  recurrence also available on create; domain/mapper/repository tests.
-  Review round 1: weekly BYDAY day-toggles in the custom picker ("every week
-  on Mon+Fri"). Review rounds 2–4: occurrence edit pulled forward from v2.0
-  and made three-way like delete ("this" = exception row via
-  `CONTENT_EXCEPTION_URI`, "this and following" = series split, "all" =
-  series update); delete equally three-way (truncation via RRULE UNTIL);
-  the edit-scope question moved to save time (Google model) — dirty
-  recurring saves park in `SaveUiState.AwaitingScope`, a changed rule drops
-  the "only this event" option
-
-- [x] v1.4 reminder notifications (shipped 2026-06-11) — exported
-  `EVENT_REMINDER` receiver → `CalendarAlerts` (SCHEDULED & due) →
-  dedicated channel, tap opens detail (singleTop deep link); best-effort
-  FIRED marking; one-time onboarding step requesting `POST_NOTIFICATIONS`
-  with duplicate-reminders warning; Settings mirror. Provider only fires
-  `METHOD_ALERT` rows (AOSP-verified), so email reminders never reach us
-
-- [x] v2.0 conflict dialog + store polish (shipped 2026-06-11 as v2.0.0) —
-  `EditSnapshot` compare on save (overwrite/discard; deleted → close),
-  quick-add cut, calendar-switch → v3 backlog; F-Droid/README copy
-  refreshed, fastlane screenshots DE+EN captured on-device
-
-- [x] v2.1 (shipped 2026-06-15) — month grid shows real events as
-  continuous multi-day bars; navigation-drawer View section
-  (Month/Week/Day); cursor-jump fix in event text fields
-
-- [x] v2.2 (shipped 2026-06-16) — tap an empty slot in day/week to create
-  (prefilled with that day + tapped hour, snapped to the hour); local
-  calendar management in a full-screen editor from Settings →
-  Calendars: create/rename/recolor/delete device-only calendars
-  (`ACCOUNT_TYPE_LOCAL`, sync-adapter insert) with name, pastel-previewed
-  colour, and description (stored in `CAL_SYNC1`); synced calendars listed
-  read-only grouped by account with a per-account "manage in source app"
-  deep-link (resolved from the account's authenticator: DAVx5/ICSx5/…) and
-  an add-account shortcut. Shared `InlineTextField` extracted to `ui.common`
-
-- [x] v2.3 settings/calendars/drawer redesign (shipped 2026-06-16) — adopted a
-  shared Material 3 grouped-list blueprint, modelled on the ReFra gallery app
-  and extracted to `ui/common/GroupedList.kt` (`CollapsingScaffold` with a
-  `LargeTopAppBar` exit-until-collapsed title; `GroupedRow` with Position-based
-  corner grouping, press-animated corners, `selected` + `minHeight` knobs).
-    - Settings: category hub (About card on top → version mark at the foot) with
-      sliding sub-pages (Appearance / New event form / Notifications); token-
-      based icon chips; theme/week-start/language pickers migrated from
-      `DropdownMenu` to OptionCard dialogs. New `ic_gitea.xml` (Simple Icons,
-      verbatim path) for the About "Source" button; en+de strings.
-    - Calendar manager: same collapsing scaffold + grouped rows; shared
-      `CalendarColorChip` (neutral chip, pastelised calendar glyph).
-    - Navigation drawer: branded header, grouped View switcher (active view
-      highlighted via `secondaryContainer`), the filter list restyled to
-      grouped rows with a trailing checkbox; the whole drawer scrolls as one.
-    - Cards use `surfaceContainerHigh` for readable contrast against `surface`.
-    - Donate button on the About card deferred (target still TBD).
-
-- [x] v2.4 per-event color (shipped 2026-06-17) — an optional "Color" field in
-  the event form. Read/render already resolved `EVENT_COLOR` with a calendar
-  fallback; this adds the write side and the picker. Palette-backed calendars
-  (Google, some CalDAV) pick from the account's `Colors` (`TYPE_EVENT`) and
-  write `EVENT_COLOR_KEY` so the color round-trips through sync; local
-  calendars write a raw `EVENT_COLOR` from the shared `CALENDAR_COLOR_PALETTE`
-  (extracted with the swatch row to `ui/common/ColorSwatchRow.kt`). Switching
-  calendars resets the choice (a key is account-scoped). A settings toggle
-  ("Allow colors on unsupported calendars", off by default) extends the raw
-  path to synced calendars with no palette, with an honest "may not survive
-  sync" warning on the picker and in Settings. Color writes flow through
-  insert / dirty-checked update / occurrence-exception; mapper + form tests.
-
-- [x] v2.5 (shipped 2026-06-17) — Agenda view (4th top-level view),
-  jump-to-date drawer date picker, two home-screen widgets (scrolling
-  "Upcoming" agenda + month grid), and a "New event" launcher long-press
-  shortcut
-
-- [x] v2.6 (shipped 2026-06-18) — default reminders: global timed default +
-  separate all-day default + per-calendar override (timed), applied on create
-  with dirty-flag handling; three pickers + override list in Settings →
-  Notifications; battery-optimisation exemption row (status + system deep-link,
-  no new permission). Plus system per-app language (Android 13+) and an
-  immediate-effect fix for the in-app language picker
-
-- [x] v2.7 (shipped 2026-06-18) — the `.ics` engine: share a single event as
-  `.ics` from the detail screen; back up local calendars (Settings → Calendars
-  → Export) to a SAF file; open/receive an `.ics` — one event prefills the
-  create form, many events open a bulk import into a chosen calendar (dedup by
-  UID, skip-and-report unrepresentable VTIMEZONE / RECURRENCE-ID / guests).
-  Hand-rolled serializer/parser, zero deps. Plus all-day single-day UTC fix and
-  a widget R8 keep-rule crash fix
-
-- [x] v2.7.1–v2.7.5 (2026-06-21) — launch crash fix (listener before grant),
-  user-controlled crash reporting, widget loading-spinner R8 keep rule, and
-  F-Droid reproducible-build cleanups for the official repo
-
-- [~] release/v2.8.0 (not yet cut) — crash reports via the public Codeberg
-  tracker (MR !27) + reminder snooze/dismiss notification actions (MR !28,
-  snooze self-schedules an exact alarm; primary delivery stays provider-broadcast)
-
-## Next
-
-1. Cut **v2.8.0** from `release/v2.8.0` (bump versionName → tag via the
-   merge-driven pipeline) once on-device review signs off
-2. **Attendee editing** — the committed next feature (Tier 5 #12, high-
-   importance, opened 2026-06-22). Attendees are already read & shown on the
-   detail screen since v0.6; the gap is the write side — make guests editable
-   in `EventEditScreen` / `EventForm` (add by typed email, role, remove),
-   persisted by diffing `CalendarContract.Attendees`. No new permission for the
-   typed-email path. **Invitation behavior DECIDED 2026-06-22: record-only on all
-   writable calendars** — Calendula never sends (no INTERNET); honest backend-aware
-   copy ("your account may email guests when it syncs" on synced calendars, "no one
-   is notified" on local). Full sketch in `ROADMAP.md` → "Attendee editing".
-3. Then: the two INTERNET go/no-go calls (OSM autocomplete, remote calendar
-   create/edit) and Tier 2/3 leftovers (quick-settings tile, now-line, week
-   numbers in month, full-text search, accessibility pass). Drag-and-drop
-   rescheduling is **rejected**.

CHANGELOG.md

@@ -5,6 +5,482 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+## [2.17.1] — 2026-07-30
+
+### Added
+- Settings → Calendars now says what is different about a calendar instead of
+  leaving you to guess. Ones you can only view — a subscribed calendar, a
+  calendar shared with you read-only — are marked **Read-only** ([#76]).
+- Calendars your device isn't syncing are marked **Not synced**, moved to the
+  bottom of their account and left without a switch. None of their events are on
+  the device, so the switch they used to have could not have shown you anything
+  — the calendar simply looked broken. They are no longer offered when you pick
+  a calendar for a new or an imported event either: an event saved there would
+  never reach the account. Whether an account syncs a calendar stays that
+  account's own app's decision ([#78]).
+- The birthday and anniversary calendars Calendula fills from your contacts are
+  marked **Filled from your contacts**, which is why they can't be picked for a
+  new event: anything you put there would be removed again on the next sync.
+  Deleting one is held back while special dates are switched on — Calendula
+  would simply create it again — and the calendar's editor says so; turn the
+  feature off under Settings → Special dates and the delete works as usual
+  ([#76]).
+- The calendar picker in the event form and in the .ics import screen now ends
+  with a **"Missing a calendar?"** row that opens Settings → Calendars, where
+  those marks then explain why a calendar isn't offered ([#76]).
+- The agenda widget's text size is yours to set. **Settings → Widgets & tiles →
+  Agenda widget size** offers Small, Medium, Large and Extra large, replacing the guess
+  the widget used to make from its own measurements. Small is what it looks like
+  today, so nothing changes until you turn it up ([#51]).
+- A repeating event now shows you its next few dates, not just a description of
+  the rule. Both the preset list and the custom recurrence picker carry a
+  **Next:** line — "Next: 30 Jul, 6 Aug, 13 Aug" — under the rule they would
+  save. A phrase like "monthly" on the 31st, or "every 2 weeks on Mon & Fri",
+  can mean something other than it sounds like, and only the dates say so. A
+  rule that can never fire says that instead ([#69]).
+- The event visibility options now say who they affect. **Public**, **Private**
+  and **Confidential** each carry a line about what other people on a shared
+  calendar see — the part the four words on their own leave out ([#69]).
+
+### Changed
+- **Settings has been reorganised so each setting sits where you would look for
+  it.** One long undifferentiated list is now three labelled groups — Look &
+  behaviour, Data, and App — whose rows open sub-screens and say what they do
+  rather than only naming themselves. Appearance, Views, New event form,
+  Notifications and the new Widgets & tiles are separate screens now, so the
+  settings for a calendar view are no longer mixed in with the ones for the
+  app's colours or for the home-screen widgets ([#69]).
+- Settings that are hard to picture from their name now show you what they do.
+  The week-start picker rearranges a real month grid as you choose, the
+  past-events setting previews a sample agenda day for Show, Dim and Hide, the
+  font pickers set a specimen line in the face you are choosing, and the Agenda
+  range options carry the dates each one actually covers. Options that follow
+  the system additionally name which way they currently fall ([#69]).
+- **Backup & restore** is now its own Settings entry instead of living inside
+  the calendar manager, where it was easy to miss — keeping a copy of your
+  calendars is a different question from which calendars you have. The calendar
+  manager keeps a row pointing to it, and nothing about how backup or automatic
+  backup works has changed ([#69]).
+- Calendula's source code now lives on **Codeberg**, where its issues already
+  were. The **Source code** and **License** links in Settings → About point
+  there, so reporting a bug and reading the code no longer land on two different
+  sites. Nothing about the app itself changes, and the F-Droid repository is
+  unaffected.
+
+### Fixed
+- A month-grid widget stays a month grid, and draws all seven days again. Since
+  2.16.0 a placed month widget could redraw itself as the agenda widget a little
+  after any change to your events, and could draw only about four day columns
+  with the last one cut off part-way through. Both came from the release build
+  merging the two widgets into a single class, so Android could no longer tell
+  which of them a widget on your home screen was — and the month grid was handed
+  the wrong widget's measurements to lay its columns out against ([#89], [#103]).
+- The back gesture on **Settings → Views** returns to Settings instead of
+  leaving Settings altogether and dropping you on the calendar. Special dates
+  did the same ([#81]).
+- The dots standing in for the events that didn't fit a day in the month view
+  now dim with everything else when **Dim completed events** is on. A past day
+  with four or more events kept its last events at full strength while the rest
+  faded ([#79]).
+- Two accounts that happen to share a name — a Google account and a DAVx5
+  account for the same address, say — are no longer merged into one group.
+  They were listed together in Settings → Calendars and in the drawer's filter,
+  which also meant the group's source icon and its "manage in app" button could
+  send you to the wrong app, "toggle all" spanned both accounts at once, and
+  collapsing one collapsed the other. Where a name really is shared, each group
+  now names the app it comes from ([#77]).
+- In the month view's **Split** style, the new-event button now starts on the
+  day you have selected. It always started on today, whichever day was selected
+  and listed below the grid ([#87]).
+- Search results now show an all-day event's real date. West of UTC — anywhere in
+  the Americas, say — a search hit was dated one day early, disagreeing with the
+  day the month, week and agenda views file the same event under ([#82]).
+- Reminders no longer depend on Android telling Calendula when they are due.
+  Calendula now works out each reminder's time itself and sets its own alarm for
+  it. On some phones — Samsung's among them — the system's calendar storage never
+  sends the signal a calendar app is meant to wake up on, and no amount of
+  battery or notification settings helps: the reminder is simply never announced.
+  None of that is visible from inside an app that waits to be told, which is why
+  it took a second pass to find ([#75]).
+
+  Reminders also survive things that used to lose them quietly. After a restart
+  or an app update Calendula re-arms its alarms, and a reminder whose moment
+  passed while the phone was off still arrives, as long as the event has not
+  ended yet.
+
+- All-day reminders now arrive at the time you chose in **Settings →
+  Notifications**, on every occurrence. A yearly birthday could drift an hour
+  either way depending on daylight saving, and all-day reminders on calendars
+  from an account fired in the middle of the night instead of in the morning
+  ([#75]).
+
+- Reminders now arrive for every calendar you have switched on. A calendar that
+  was hidden at system level — switched off in another calendar app, or never
+  switched on after being added — still showed its events and listed their
+  reminders in Calendula, but never notified: Android only schedules reminder
+  alarms for calendars marked visible, and Calendula kept its own separate
+  on/off list that had no say in it. There is now one switch: **Settings →
+  Calendars** turns a calendar on or off for the whole device, so what you see
+  and what reminds you can no longer disagree ([#75]).
+
+  Calendars you had switched off in Calendula are switched off here too on first
+  launch. Calendars that were already off — hidden in another calendar app, or
+  never switched on after being added — stay off, and Calendula says so once
+  rather than quietly switching them on for every app on your device; you can
+  turn any of them back on in Settings → Calendars.
+
+  If you gave Calendula read-only access to your calendars, the switch still
+  works: your choice is kept in the app until it can be written.
+
+  The drawer's filter is unchanged and still app-only: hiding a calendar there
+  tidies your view without silencing its reminders.
+
+## [2.16.0] — 2026-07-24
+
+### Added
+- Choose how the month view is laid out. A new **Month view style** setting
+  (Settings → Views) offers three ways to read a month, each shown with a
+  preview of the layout it produces:
+  - **Pages** — what you have today: one month at a time, swiped sideways.
+  - **Continuous** — scroll up and down through the weeks without a break
+    between months. Because the weeks run on unbroken, no month is cut off and
+    no day appears twice, where paging repeats a boundary week at the end of one
+    month and the start of the next. The 1st of each month names itself so you
+    always know where you are, and the title bar keeps up as you scroll ([#38]).
+  - **Split** — a compact grid showing coloured dots for the days that have
+    something on them, with the day you tap listed in full underneath. Tap the
+    date above the list to open the whole day ([#53]).
+
+  The Agenda view is untouched by this and stays available in all three styles —
+  the split layout lists a single day, while Agenda remains a rolling multi-day
+  window with its own range settings.
+- Give an event its own time zone. A new **Time zone** field (under "more
+  fields" in the event form) pins an event to a specific zone, so a call set for
+  8:00 AM in New York stays 8:00 AM in New York wherever you open it — and keeps
+  tracking that zone across daylight-saving changes instead of drifting an hour.
+  The form edits the event in its own zone and shows the local equivalent under
+  the times ("2:00 PM – 3:00 PM your time"); the event's details keep your local
+  time first and note the original beneath it, so both are always clear. Pick a
+  zone from a full-screen picker with your device zone and recent choices on top,
+  searching by city ("new york"), IANA id ("europe/berlin"), or abbreviation
+  ("CEST") to gather every matching zone at once. All-day events stay
+  date-anchored and carry no zone, as before ([#31]).
+- Put the "jump to today" button in the toolbar. A new **Today button in
+  toolbar** setting (Settings → Appearance, off by default) swaps the floating
+  button that fades into the corner while you're away from today for a permanent
+  today icon in the top bar — always there, on today or not, matching the
+  familiar calendar-app pattern. Leave it off to keep the floating button as
+  before ([#60]).
+- Choose what Calendula calls itself on your home screen. A new **App name**
+  setting (Settings → Appearance) switches the launcher label between
+  **Calendula** and **Calendar**, for launchers that can't rename apps
+  themselves. Pick from a full-screen chooser that previews both names as
+  launcher marks; the change applies at once ([#44]).
+- Calendula now speaks **Arabic**, laid out right-to-left, and its French and
+  Italian translations have been brought up to date — thanks to the community
+  translators on Weblate. Pick a language under Settings → Language (or leave it
+  on the system default).
+
+### Changed
+- Dates in the Month, Week and Day title bars now follow your language and
+  region instead of one hardcoded layout. Every date was rendered in a fixed
+  German-style order with a trailing dot on the day number, whatever your
+  settings: US English showed "Fri, 17. Jul 2026" where it should read
+  "Fri, Jul 17". The Agenda view already formatted correctly, so the two
+  disagreed about the same date. All four views now share one formatter, and the
+  day/month order, the separators and the ordinal all come from your locale —
+  so English-in-Germany reads "Fri, 17 Jul" and English-in-the-US "Fri, Jul 17",
+  each correct for where you are ([#60]).
+- The title bar drops the year while you're in the current one — "July" rather
+  than "July 2026". The year reappears the moment you page out of the current
+  year, which is when it tells you something you didn't already know.
+- The Week view's title now names the month instead of spelling out the day range.
+  "24. Jun – 31. Jun" restated the day numbers already printed in the column
+  headers right below it, in the widest string in the bar. A week that straddles
+  two months keeps the outgoing month until it is fully gone ([#60]).
+- The custom recurrence picker has been redesigned and tightened up. As you
+  build a rule — "every 2 weeks on Mon & Wed, until a date" — the live summary
+  now describes exactly what will be saved rather than a near-copy that could
+  drift from it, the amount fields accept being left blank (reading as their
+  shown default instead of greying out OK), and the read-out no longer jumps
+  around as you tap weekdays ([#42]).
+
+### Fixed
+- An all-day event no longer shows up again the day after it happened. In time
+  zones east of UTC, an all-day event — a birthday, say — set for one day also
+  appeared under the *next* day's heading in the Agenda (and the agenda widget),
+  because all-day events are anchored to UTC midnight and the following day's
+  window reached back across that boundary and pulled the event forward onto
+  "today". Each all-day event now lists only on the day it actually falls on
+  ([#65]).
+- A multi-day event now shows under every day it spans in the Agenda, not just
+  its first day, so a trip or a multi-day booking appears on each day it covers.
+- The "Upcoming" agenda widget now scales its text and rows to the size you give
+  it. Previously it was laid out once for the smallest size and simply stretched
+  when enlarged, so the text stayed small no matter how big you made the widget.
+  Now a bigger widget gets bigger, more readable type and roomier rows, while the
+  default size looks exactly as before — no new setting; it follows the size you
+  already chose ([#51]).
+- Calendula now appears under other apps' "Add to calendar" / "Save to calendar"
+  actions. Some apps (e.g. DB Navigator) fire the widely-used "insert event"
+  intent with the singular `vnd.android.cursor.item/event` type, which Calendula
+  didn't advertise — so it was left out of the chooser, and if it was your only
+  calendar app the save silently did nothing. It now accepts that form, plus the
+  `INSERT_OR_EDIT` action, and opens the new event prefilled for review ([#74]).
+- Opening a `.ics`/`.vcs` file now works even when another app hands it over
+  mislabelled as a generic download (`application/octet-stream`), as some mail
+  clients, browsers and file managers do — Calendula recognises it by its file
+  extension instead of relying on the declared type ([#74]).
+- A recurrence end date no longer lands a day late. West of UTC, setting a rule
+  to end "until" a given day could save and show the day after the one picked;
+  the end date now reads back as chosen ([#42]).
+- The status- and navigation-bar icons stay legible over full-screen pickers in
+  dark theme. They could render dark-on-dark — a near-invisible black clock
+  against the dark picker — instead of switching to light ([#70]).
+
+## [2.15.0] — 2026-07-15
+
+### Added
+- Show raw calendar colours. Calendula normally softens each calendar and event
+  colour toward a theme-fitting pastel so harsh sync colours read well on both
+  light and dark; a new **Soften calendar colours** setting (Settings → Design,
+  on by default) lets you turn that off and paint the exact colours your calendar
+  source publishes — matching DAVx5/CalDAV and other calendar apps. Thanks to
+  @leonp5 for the report ([#36]).
+- Readable titles on dark event colours. An event bar's title now shows in white
+  on a dark colour and near-black on a light one, chosen automatically from the
+  colour's brightness, so a deep blue or purple event is legible at a glance in
+  the busy Week and Month views instead of dark-on-dark. This applies whether or
+  not colours are softened. Thanks to @ptab for the suggestion ([#21]).
+- A custom snooze duration. The **Snooze duration** setting (Settings →
+  Notifications) gains a **Custom…** option next to the minute presets: pick any
+  amount and switch between minutes and hours, so a snoozed reminder comes back
+  after exactly the delay you want instead of only a preset one ([#40]).
+- Move an event to another calendar. When editing an existing event, the
+  calendar row is now tappable — pick a different calendar and saving moves the
+  event across, instead of having to delete it and recreate it elsewhere.
+  Recurring series move as a whole, keeping their individually-edited and
+  cancelled occurrences, and any reminders and guests come along too. A calendar
+  can't simply be reassigned underneath an event, so Calendula recreates it on
+  the target and removes the original — the same approach other calendar apps
+  take. Thanks to @prismplex for the suggestion ([#39]).
+- Open an event straight into the edit form from another app. Calendula already
+  answered the "new event" and "open this event" hand-offs from other apps and
+  widgets; it now also answers the "edit this event" one, so an assistant, task
+  app, or widget can send an existing event to Calendula and land on its edit
+  screen rather than the read-only details. A hand-off with no event attached
+  opens the same prefilled create form as "new event". Calendula also recognises
+  a couple more file labels the same calendar data arrives under (`.vcs`
+  vCalendar files and the `application/ics` type), so opening or sharing those
+  into Calendula works too.
+- Keep today at the top of the agenda. A new **Always show today** setting
+  (Settings → Agenda, on by default) anchors today as the first entry in both the
+  Agenda screen and its home-screen widget even once nothing is left today —
+  under today's header a "No more events today" note appears — so the first
+  events you see are clearly today's rather than a future day's. Turn it off to
+  keep the agenda purely upcoming. Thanks to @ptab for the suggestion ([#35]).
+- Duplicate an event. The event details now carry a **Duplicate** action that
+  opens the editor pre-filled with a copy of the event as a new, unsaved one, so
+  a one-off like a shift or an appointment can be recreated by just changing the
+  day and time instead of re-typing every field. The copy keeps the original's
+  time, and its title, location, notes, colour, guests and reminders come along;
+  it's saved as its own single event (any repeat is left off — add one in the
+  editor if you want it). Duplicate works from read-only calendars too, dropping
+  the copy into a writable one. Thanks to @internet-rando for the suggestion
+  ([#52]).
+- French and Polish, in early form. Calendula has started speaking French and
+  Polish, both contributed as community translations through
+  [Calendula's Weblate](https://weblate.dev.jeanlucmakiola.de/projects/calendula/).
+  They are partway there, so untranslated parts still show in English until they
+  fill out — you can already pick either under Settings → Language or in Android's
+  per-app language settings. Thanks to Thomas Tref (French) and Bazyli Cyran
+  (Polish) for getting them started; help finishing them is very welcome.
+
+### Fixed
+- Reminders for events on another day no longer read as if they were today. A
+  reminder fired ahead of time — say, the day before — used to show only the
+  event's time, making it look like it was happening now. The notification now
+  says which day: **Tomorrow** or **Yesterday**, the weekday for another day this
+  week, or the date for anything further out. Thanks to @moonj for the report
+  ([#46]).
+- Agenda dates now read in your locale's format. The agenda's range bar and its
+  day headers used a fixed day-month-year layout — and the range span even mixed
+  two orders (e.g. "15 Jul – Aug 13, 2026") — instead of following your language's
+  conventions. Dates across the agenda and its widget now use your locale's own
+  field order, matching the rest of the app. The range bar also no longer repeats
+  the range's name from the selector button beside it, showing just the dates.
+- Calendar gutters line up with the menu button. The Month view's week-number
+  column, and the Week and Day views' hour labels, sat a few pixels left of the
+  hamburger menu above them; they now line up with it. In Month view the day
+  cells also sit squarely under their weekday letters.
+
+## [2.14.1] — 2026-07-13
+
+### Fixed
+- Deleting one occurrence of a repeating event no longer breaks the series.
+  Choosing "This event" when deleting an occurrence of a recurring event could
+  wipe out every *other* occurrence while leaving the one you deleted behind as
+  a stale, still-tappable ghost — and deleting it again brought the series back.
+  A single-occurrence delete now removes exactly that occurrence and leaves the
+  rest of the series untouched, and the deleted occurrence disappears from the
+  grid straight away. This holds on every kind of calendar, including the
+  on-device ones Calendula keeps for contact birthdays and anniversaries, where
+  the series is a yearly repeat. Thanks to @moonj for the report ([#47]).
+- Tapping an event in a third-party widget opens it in Calendula. v2.13.1 taught
+  Calendula to answer the "new event" hand-off from other apps and widgets; now
+  it also answers the "open this event" one, so tapping an existing event in a
+  widget such as Todo Agenda offers Calendula and lands on that event's details.
+  Thanks to @bushrang3r for the report ([#48]).
+- Events created from other apps get your default reminder. An event handed over
+  by another app or widget — Google Maps' "add to calendar", the Todo Agenda
+  widget's "+" — opened with no reminder at all, ignoring the default set in
+  Settings. It now starts with your default reminder, the same as an event you
+  create in Calendula. An event opened from an `.ics` file is treated differently,
+  because the file has its own say: Calendula keeps whatever reminders it carries
+  (including none at all) and asks you once whether to apply your default instead
+  — it never quietly overrides the file. If you have no default set, it doesn't
+  ask ([#49]).
+- A tidy colour picker on CalDAV calendars. For calendars synced by a CalDAV
+  app (such as DAVx5), the event colour picker showed every colour the account
+  publishes — nearly 150 swatches in alphabetical order, many of them
+  duplicates or near-identical shades. The picker now shows only visually
+  distinct colours, arranged as a rainbow; near-duplicate shades and the
+  washed-out neutrals are folded away so no two swatches look alike. Picked
+  colours still sync exactly as before, and calendars with hand-picked
+  palettes (like Google's) are unaffected. Thanks to @ptab for the report
+  ([#22]).
+
+## [2.14.0] — 2026-07-06
+
+### Added
+- Restore events from a backup file. The backup section of Settings can now read
+  events back **in** from an `.ics` file, not just write one out: pick a file,
+  choose which calendar to import into, and Calendula adds the events — skipping
+  any that are already there and telling you how many it skipped. Export gained a
+  per-calendar selector at the same time, so you can back up just the calendars
+  you pick instead of everything at once ([#32]).
+- Week numbers in Month view. A new **Week numbers** setting (off by default)
+  adds a slim gutter down the left of the Month grid showing the calendar-week
+  number for each row, sized to match the day cells. Handy if you plan or refer
+  to dates by week number ([#25]).
+- Tap a date header to open that day. In Week and Agenda view, tapping a date
+  header now opens that date in Day view — the same drill-in that Month view and
+  the agenda widget already offered, so every view behaves the same way. It makes
+  jumping to a specific day quicker: switch to Week, swipe to the week you want,
+  then tap the date to open it. Thanks to @ptab for the suggestion ([#37]).
+- An early Simplified Chinese translation. Calendula has started speaking
+  Simplified Chinese, contributed as a community translation through
+  [Calendula's Weblate](https://weblate.dev.jeanlucmakiola.de/projects/calendula/).
+  It is still an early effort, so many parts of the app show in English until it
+  fills out — you can already pick it under Settings → Language or in Android's
+  per-app language settings. Thanks to
+  [zh-cn](https://weblate.dev.jeanlucmakiola.de/user/zh-cn/) for getting it
+  started; help finishing it is very welcome.
+
+### Changed
+- Long event titles wrap in the edit screen. When editing an event, a long title
+  now wraps onto multiple lines instead of being clipped to a single line, so you
+  can see and edit the whole thing ([#33]).
+
+## [2.13.1] — 2026-07-06
+
+### Added
+- Create events from other apps and widgets. Calendula now registers the
+  standard "insert event" intent (`ACTION_INSERT` on the calendar events type),
+  so other apps and home-screen widgets — such as the Todo Agenda widget — can
+  hand off to Calendula to create a new event. It opens the new-event form
+  prefilled with whatever they passed (title, start/end time, all-day, location,
+  description, recurrence), and picks your last-used or first writable calendar.
+  Thanks to @dschuermann for the suggestion ([#30]).
+
+### Fixed
+- Some recurring events could not be opened. Events in a series that started
+  before 1970 — for example yearly birthdays or anniversaries synced over CalDAV
+  — showed "Something went wrong" instead of opening, because their stored start
+  time is a negative value that was wrongly treated as invalid. They now open
+  normally and appear in search again. A related case (an event whose stored end
+  precedes its start) is now kept and openable instead of failing the same way.
+  Thanks to @dschuermann for the report ([#34]).
+- The time picker now follows your 24-hour setting. With Calendula set to
+  24-hour time, the clock dial for choosing an event's start and end time still
+  showed AM/PM instead of a 24-hour dial; it now matches your setting (and the
+  same fix applies to the all-day reminder time in Settings). Thanks to
+  @abrossimow for the report ([#27]).
+
+## [2.13.0] — 2026-07-03
+
+### Added
+- Calendula now speaks Spanish and Italian. Both arrived as community
+  translations through [Calendula's Weblate](https://weblate.dev.jeanlucmakiola.de/projects/calendula/)
+  — a **huge thank you** to
+  [kikerw](https://weblate.dev.jeanlucmakiola.de/user/kikerw/) for the Spanish
+  translation and to
+  [corrent](https://weblate.dev.jeanlucmakiola.de/user/corrent/) for the Italian
+  one! Pick your language under Settings → Language or in Android's per-app
+  language settings. Strings added in this very release may still show in
+  English until the translations catch up. Want Calendula in your language?
+  Translating happens entirely in the browser — every contribution is welcome.
+- See your contacts' birthdays and anniversaries in your calendar. A new,
+  **optional** feature (Settings → Contact special dates) mirrors your contacts'
+  birthdays, anniversaries and other dates into local "Birthdays",
+  "Anniversaries" and "Other dates" calendars that stay in sync as your contacts
+  change. Each is a normal local calendar, so you set its colour, visibility and
+  reminders the usual way — new birthdays even start with a reminder a week before
+  *and* on the day. The title format is yours to customise (`{name}`, `{year}`).
+  This is the first feature to use the contacts permission: it is requested only
+  when you turn the feature on, everything stays on your device (Calendula has no
+  internet access), and your contacts are only ever read, never changed. Thanks
+  to @moonj for the suggestion ([#15]).
+- Set more than one default reminder per calendar. A calendar's default
+  reminders — and the global defaults under Settings → Notifications — can now
+  hold several lead times instead of just one, so new events can start with, say,
+  a reminder a week before *and* one on the day. The reminder pickers are now
+  multi-select; per-calendar overrides can still inherit the global default or
+  turn reminders off entirely. Thanks to @moonj for the suggestion ([#14]).
+- Widget headers now open the app. Tapping the month/year title on the month
+  widget opens the app on the month view, and tapping the "Upcoming" title on
+  the agenda widget opens it on your default view — so there's a one-tap way
+  back into the app that lands where you'd expect, instead of only through a day
+  or event. On the month widget, tapping anywhere on a day — not just the small
+  date number — now opens that day, and the "today" button snaps the grid back
+  to the current month in place. Thanks to @rgz46vic and @ptab for the
+  suggestions ([#18], [#20]).
+- Make Calendula's text your own. Settings → Appearance gains **Headings font**
+  and **Body font** pickers: keep the system default, choose a bundled face
+  (Atkinson Hyperlegible, Lora, JetBrains Mono — each previewed in its own
+  face), or load any `.ttf`/`.otf` file from your device, independently per
+  role. Font size and colour stay with Android's accessibility scaling and the
+  app theme, as discussed on the issue. Thanks to @abrossimow for the
+  suggestion ([#19]).
+- Choose what the view-switch button cycles through. Settings → Appearance now
+  lets you pick which views the top-right quick-switch button rotates between
+  and drag them into your preferred order; views you switch off stay reachable
+  from the navigation menu, which can be reordered the same way. Thanks to
+  @abrossimow for the suggestion ([#24]).
+
+### Fixed
+- Month widget arrows and "today" button work again. On release builds the
+  prev/next-month arrows and the jump-to-today control on the month widget did
+  nothing when tapped — code shrinking had stripped the tap handlers behind
+  them. They respond again. Thanks to @rgz46vic for the report ([#18]).
+- Disabled calendars no longer notify. Reminders for events in a calendar you
+  have disabled (Settings → Calendars) are now suppressed instead of still
+  popping up — matching how a disabled calendar's events already stay hidden
+  everywhere else in the app ([#17]).
+- Editing a single occurrence of a recurring event works again. Choosing **Only
+  this event** and saving a change to one event in a repeating series silently
+  did nothing — the change was rejected and the edit form simply reappeared with
+  nothing applied. The edited occurrence is now stored correctly, so the change
+  lands on just that one event and leaves the rest of the series untouched
+  ([#16]).
+- Every calendar can be picked when creating an event. The event editor's
+  calendar picker was a fixed-height dialog, so with many calendars anything
+  past the first nine or so was simply unreachable. It is now a full-screen,
+  scrollable list grouped by account, with each calendar's colour shown.
+  Thanks to @dschuermann for the report ([#29]).
+
 ## [2.12.0] — 2026-06-28
 
 ### Added
@@ -729,3 +1205,51 @@ automatically, with zero telemetry and no internet permission.
 [#10]: https://codeberg.org/jlmakiola/calendula/issues/10
 [#12]: https://codeberg.org/jlmakiola/calendula/issues/12
 [#13]: https://codeberg.org/jlmakiola/calendula/issues/13
+[#14]: https://codeberg.org/jlmakiola/calendula/issues/14
+[#15]: https://codeberg.org/jlmakiola/calendula/issues/15
+[#16]: https://codeberg.org/jlmakiola/calendula/issues/16
+[#17]: https://codeberg.org/jlmakiola/calendula/issues/17
+[#18]: https://codeberg.org/jlmakiola/calendula/issues/18
+[#19]: https://codeberg.org/jlmakiola/calendula/issues/19
+[#20]: https://codeberg.org/jlmakiola/calendula/issues/20
+[#22]: https://codeberg.org/jlmakiola/calendula/issues/22
+[#24]: https://codeberg.org/jlmakiola/calendula/issues/24
+[#25]: https://codeberg.org/jlmakiola/calendula/issues/25
+[#27]: https://codeberg.org/jlmakiola/calendula/issues/27
+[#29]: https://codeberg.org/jlmakiola/calendula/issues/29
+[#21]: https://codeberg.org/jlmakiola/calendula/issues/21
+[#30]: https://codeberg.org/jlmakiola/calendula/issues/30
+[#31]: https://codeberg.org/jlmakiola/calendula/issues/31
+[#32]: https://codeberg.org/jlmakiola/calendula/issues/32
+[#33]: https://codeberg.org/jlmakiola/calendula/issues/33
+[#34]: https://codeberg.org/jlmakiola/calendula/issues/34
+[#36]: https://codeberg.org/jlmakiola/calendula/issues/36
+[#37]: https://codeberg.org/jlmakiola/calendula/issues/37
+[#39]: https://codeberg.org/jlmakiola/calendula/issues/39
+[#35]: https://codeberg.org/jlmakiola/calendula/issues/35
+[#40]: https://codeberg.org/jlmakiola/calendula/issues/40
+[#46]: https://codeberg.org/jlmakiola/calendula/issues/46
+[#47]: https://codeberg.org/jlmakiola/calendula/issues/47
+[#48]: https://codeberg.org/jlmakiola/calendula/issues/48
+[#49]: https://codeberg.org/jlmakiola/calendula/issues/49
+[#51]: https://codeberg.org/jlmakiola/calendula/issues/51
+[#52]: https://codeberg.org/jlmakiola/calendula/issues/52
+[#38]: https://codeberg.org/jlmakiola/calendula/issues/38
+[#53]: https://codeberg.org/jlmakiola/calendula/issues/53
+[#60]: https://codeberg.org/jlmakiola/calendula/issues/60
+[#65]: https://codeberg.org/jlmakiola/calendula/issues/65
+[#74]: https://codeberg.org/jlmakiola/calendula/issues/74
+[#42]: https://codeberg.org/jlmakiola/calendula/issues/42
+[#44]: https://codeberg.org/jlmakiola/calendula/issues/44
+[#70]: https://codeberg.org/jlmakiola/calendula/issues/70
+[#75]: https://codeberg.org/jlmakiola/calendula/issues/75
+[#76]: https://codeberg.org/jlmakiola/calendula/issues/76
+[#78]: https://codeberg.org/jlmakiola/calendula/issues/78
+[#77]: https://codeberg.org/jlmakiola/calendula/issues/77
+[#79]: https://codeberg.org/jlmakiola/calendula/issues/79
+[#81]: https://codeberg.org/jlmakiola/calendula/issues/81
+[#82]: https://codeberg.org/jlmakiola/calendula/issues/82
+[#87]: https://codeberg.org/jlmakiola/calendula/issues/87
+[#89]: https://codeberg.org/jlmakiola/calendula/issues/89
+[#103]: https://codeberg.org/jlmakiola/calendula/issues/103
+[#69]: https://codeberg.org/jlmakiola/calendula/issues/69

CONTRIBUTING.md

@@ -0,0 +1,184 @@
+# Contributing to Calendula
+
+Calendula is a Material 3 Expressive calendar app that lives strictly on top of
+Android's `CalendarContract` — no app database, no sync stack, no network access.
+That constraint shapes most review comments, so
+[`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) is worth skimming before you write
+code. This file is the practical how.
+
+**[Codeberg](https://codeberg.org/jlmakiola/calendula) is the canonical home** —
+issues, pull requests, releases. The self-hosted Gitea instance referenced in the
+release docs is build infrastructure only; there is nothing to contribute there.
+Be decent to the people you meet in the tracker.
+
+## Start with an issue
+
+| You want to | Do this |
+|---|---|
+| Add a feature | **Open an issue first** and wait for a go-ahead |
+| Fix a bug | Open an issue, then a pull request |
+| Fix a typo, a comment, or docs | Just open the pull request |
+| Add or fix a translation | **Don't** — [use Weblate](#translations) |
+
+Features get an opinion before they get code: whether Calendula should do a
+thing at all is the one decision a patch can't make. A feature PR that arrives
+without a discussed issue may be closed unmerged even when the code is good —
+please don't spend a weekend on one first.
+
+Bugs are more straightforward, but still start with an issue: it's what carries
+the milestone and gives the changelog something to link.
+
+Issue templates cover bug, crash, feature and question. For a crash, let the app
+do the work — **Settings → Report a problem**, or the prompt shown after a crash,
+captures the stack trace and prefills the form. The report contains app, Android
+and device versions plus the trace; no calendar content, no personal data.
+
+## Which branch to target
+
+Calendula releases by merging a version bump into `main`, so `main` is a release
+trigger rather than a staging area. Work is assembled on release branches first.
+
+Once your issue has a milestone, that milestone names your branch:
+
+| Milestone | Target branch |
+|---|---|
+| `2.18.0` | `release/v2.18.0` |
+
+Every milestone has a matching branch. If it's somehow missing, target `main` and
+mention it in the PR — it will be retargeted. Don't pick an older release branch:
+they're kept after shipping, so the newest one isn't necessarily yours.
+
+## Translations
+
+**Never edit a `values-*/strings.xml` file in a pull request** — German included.
+Translations are owned by a self-hosted Weblate that writes to this repository
+directly, and a hand-edit is overwritten on the next sync.
+
+→ **[Translate Calendula on Weblate](https://weblate.dev.jeanlucmakiola.de/engage/calendula/)**
+
+Adding a *new* English string to `values/strings.xml` is normal PR work; Weblate
+picks it up and offers it to translators. Partial translations are expected and
+fine — missing keys are informational. Stale and orphaned keys are not, so run
+
+```sh
+python3 scripts/check_translations.py
+```
+
+before pushing. It reports those more clearly than lint's `MissingTranslation`
+does.
+
+## Build & test
+
+```sh
+git clone --recurse-submodules https://codeberg.org/jlmakiola/calendula.git
+```
+
+The `floret-kit` submodule is a composite build compiled from source. An
+existing clone needs `git submodule update --init --recursive`, or nothing
+resolves.
+
+- **JDK 17** — not newer; the Android Gradle Plugin requires exactly 17. Set
+  `JAVA_HOME` if your default differs.
+- **Android SDK** — platform 37 (`compileSdk`) and build-tools 36.0.0, located
+  via `ANDROID_HOME` or a gitignored `local.properties` with `sdk.dir`. If you
+  go the `local.properties` route the included build needs its own copy at
+  `floret-kit/local.properties`; `ANDROID_HOME` covers both at once and is the
+  easier path.
+
+The Gradle wrapper is checked in, so no system Gradle is needed.
+
+```sh
+./gradlew lint test assembleDebug     # roughly what CI runs
+```
+
+A single test class, or a pattern:
+
+```sh
+./gradlew testDebugUnitTest --tests "de.jeanlucmakiola.calendula.domain.SimpleRecurrenceTest"
+./gradlew testDebugUnitTest --tests "*SimpleRecurrence*"
+```
+
+CI reports one `CI` check per pull request: `lintDebug`, `testDebugUnitTest`,
+`assembleDebug`, and a Trivy scan. Pull requests touching only docs, F-Droid
+metadata or the licence skip the Android build and go green quickly. More detail
+in [`docs/BUILDING.md`](docs/BUILDING.md).
+
+## The rules
+
+These are the ones that turn into review comments.
+
+1. **No network.** Calendula holds no `INTERNET` permission, and that's a
+   feature rather than an oversight. Anything that would need one is a product
+   decision before it's a patch — the crash reporter deliberately opens a
+   prefilled web issue instead of posting anything itself.
+2. **The provider is the only database.** No Room, no cache, no local mirror of
+   events. `CalendarContract` is the single source of truth, which is also why
+   externally synced changes work for free.
+3. **Don't patch UI state after a write.** A `ContentObserver` re-queries and
+   views recompose from fresh provider state. Hand-patching a list after saving
+   appears to work, then quietly diverges from what the provider actually stored.
+4. **`domain/` has no Android imports.** Models, validation, recurrence
+   rendering, conflict snapshots and the `.ics` codec stay pure Kotlin so they
+   remain JVM-testable.
+5. **Tests run on the JVM.** JUnit 5 + Truth + Turbine. The seams exist for you:
+   fake the data source (`FakeCalendarDataSource`), and feed mappers plain maps
+   through `ColumnReader` instead of cursors. Instrumented tests are a last
+   resort, not a default.
+6. **Read before touching the subtle pipelines.** Recurring writes (UNTIL vs
+   DURATION, exception URIs, series splits), save-conflict detection and reminder
+   delivery (post-before-mark) follow provider-driven rules that are documented
+   in [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) and are not guessable from
+   the code alone.
+7. **Don't break reproducible builds.** `vcsInfo`, `dependenciesInfo` and the AGP
+   metadata block are disabled on purpose so the official F-Droid repo can verify
+   our binary against a from-source rebuild.
+   `scripts/check_reproducible_release.sh` runs on every pull request, including
+   docs-only ones.
+
+## UI conventions
+
+Material 3 Expressive throughout, built from the system's own tokens and
+components — colour-scheme tokens rather than hardcoded colours, `ListItem` for
+settings rows.
+
+**Selection pickers are full-screen.** Every browse-style "choose one" surface
+uses floret-kit's `FullScreenPicker` / `OptionPicker`; one that needs a commit or
+extra action passes it through the picker's `actions` slot. The exception is the
+recurring-scope chooser (*this / this and following / all*), which stays a
+compact dialog — a two- or three-option decision reads better as a popup than as
+a nearly empty screen. `AlertDialog` is for plain confirmations only, and radio-
+or text-list dialogs aren't used at all.
+
+Shared UI machinery lives in the `floret-kit` submodule and has
+[its own contributing guide](https://codeberg.org/jlmakiola/floret-kit/src/branch/main/CONTRIBUTING.md);
+changing it means a pull request against that repository plus a submodule bump
+here.
+
+## Commits & pull requests
+
+Conventional commits, scoped to the area you touched:
+
+```
+fix(calendars): keep an event's own calendar when it is switched off
+feat(month): pull-to-expand the split view (#38)
+docs(architecture): record what the second review pass changed
+```
+
+Types in use: `feat` `fix` `docs` `refactor` `style` `chore` `ci` `build`
+`revert`. Reference the issue in the subject or the body. Keep commits small —
+small commits revert cleanly, which matters more here than a tidy history.
+
+If your change is user-visible, add an entry under `## [Unreleased]` in
+[`CHANGELOG.md`](CHANGELOG.md). Match the surrounding voice: entries describe
+what changed *for the person using the app*, and why, not what changed in the
+code. Link the issue and add its reference at the bottom of the file. It may get
+reworded when the release is cut, so don't agonise over it.
+
+Please don't commit planning or design documents. Code, tests, architecture notes
+and the changelog land; the reasoning belongs in the commit message and the
+issue.
+
+## Licence
+
+Calendula is [MIT](LICENSE). By contributing you agree your changes ship under
+the same licence.

Gemfile

@@ -0,0 +1,10 @@
+source "https://rubygems.org"
+
+# fastlane is used ONLY to upload the release bundle to Google Play
+# (see fastlane/Fastfile). It is not part of the build or the signing path, so
+# it never runs on a PR — only in release.yaml's `play` job.
+#
+# Pinned exactly; Renovate's bundler manager keeps it bumped. No Gemfile.lock is
+# committed on purpose: this resolves an uploader's transitive deps, not the
+# app's, and none of it affects the reproducible release build.
+gem "fastlane", "2.237.0"

README.md

@@ -8,7 +8,7 @@
 Reads, writes, and reminds — on top of the system calendar, with zero network access.</p>
 
 <p>
-<a href="https://gitea.jeanlucmakiola.de/makiolaj/calendula/actions"><img src="https://gitea.jeanlucmakiola.de/makiolaj/calendula/actions/workflows/ci.yaml/badge.svg?branch=main" alt="CI"></a>
+<a href="https://codeberg.org/jlmakiola/calendula/actions"><img src="https://codeberg.org/jlmakiola/calendula/actions/workflows/ci.yaml/badge.svg?branch=main" alt="CI"></a>
 <img src="https://img.shields.io/badge/Android-10%2B-3DDC84?logo=android&logoColor=white" alt="Android 10+">
 <img src="https://img.shields.io/badge/Kotlin-Compose-7F52FF?logo=kotlin&logoColor=white" alt="Kotlin + Compose">
 <img src="https://img.shields.io/badge/Material%203-Expressive-4285F4" alt="Material 3 Expressive">
@@ -18,15 +18,18 @@ Reads, writes, and reminds — on top of the system calendar, with zero network
 <p>
 <a href="https://f-droid.org/packages/de.jeanlucmakiola.calendula/"><img src="https://fdroid.gitlab.io/artwork/badge/get-it-on.png" alt="Get it on F-Droid" height="56"></a>
 &nbsp;
+<a href="https://apps.obtainium.imranr.dev/redirect?r=obtainium://add/https://codeberg.org/jlmakiola/calendula"><img src="https://github.com/ImranR98/Obtainium/blob/main/assets/graphics/badge_obtainium.png?raw=true" alt="Get it on Obtainium" height="56"></a>
+&nbsp;
 <a href="https://ko-fi.com/jeanlucmakiola"><img src="https://storage.ko-fi.com/cdn/brandasset/v2/support_me_on_kofi_badge_beige.png" alt="Support me on Ko-fi" height="56"></a>
 </p>
 
 <p>
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/01-week.png" width="19%" alt="Week view">&nbsp;
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/02-month.png" width="19%" alt="Month view">&nbsp;
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/04-detail.png" width="19%" alt="Event detail">&nbsp;
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/05-edit.png" width="19%" alt="Event form">&nbsp;
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/06-onboarding.png" width="19%" alt="Reminder onboarding">
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/01-week.png" width="16%" alt="Week view">&nbsp;
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/02-month.png" width="16%" alt="Month view">&nbsp;
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/03-day.png" width="16%" alt="Day view">&nbsp;
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/04-detail.png" width="16%" alt="Event detail">&nbsp;
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/05-agenda.png" width="16%" alt="Agenda view">&nbsp;
+<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/06-onboarding.png" width="16%" alt="Reminder onboarding">
 </p>
 
 </div>
@@ -68,24 +71,38 @@ database, no sync stack reinvented.
 
 - Real Material 3 Expressive throughout — dynamic color (Android 12+),
   expressive motion and shapes, light/dark theme
-- German and English UI, per-app language setting — and [open to community
-  translations](#-translations)
+- English and German UI plus community translations (Spanish, French, Italian,
+  Polish, and more in progress), per-app language setting — and [open to more
+  languages](#-translations)
 - **Zero telemetry, zero analytics, no internet permission** — your data
   never leaves the device
 
 ## 📦 Install
 
+Pick whichever channel you already use — they all install the same app:
+
+| Channel | Updates | Notes |
+| --- | --- | --- |
+| [Official F-Droid](#f-droid-recommended) | On F-Droid's build schedule | Recommended; no extra setup |
+| [Self-hosted F-Droid repo](#self-hosted-f-droid-repo-fastest-updates) | Minutes after a release | Fastest; needs the repo added once |
+| [Codeberg release / Obtainium](#codeberg-release--obtainium) | Per release | Plain APK download, or automated by Obtainium |
+| [Google Play](#google-play-coming-soon) | — | Coming soon |
+| [Build from source](#build-from-source) | Whenever you build | Full control |
+
 ### F-Droid (recommended)
 
 Calendula is on the **official [F-Droid](https://f-droid.org) repository** —
 just search for **Calendula** in any F-Droid client, or
 [install it from f-droid.org](https://f-droid.org/packages/de.jeanlucmakiola.calendula/).
 
-### Self-hosted repo (latest builds)
+F-Droid rebuilds from source on its own schedule, so a new version usually
+shows up there a few days after release.
 
-New versions are built, signed, and published to a self-hosted repository the
-moment each tag lands — usually a few days ahead of the official repo, which
-rebuilds on F-Droid's own schedule. Add it for the freshest builds:
+### Self-hosted F-Droid repo (fastest updates)
+
+Every release is built, signed, and published to a self-hosted F-Droid
+repository as part of the release pipeline, so it lands there first. Add it once
+and your F-Droid client handles updates from then on:
 
 1. In your F-Droid client, open *Settings → Repositories → Add* (or open the
    link below on your phone):
@@ -100,19 +117,71 @@ rebuilds on F-Droid's own schedule. Add it for the freshest builds:
 
 2. Refresh, search for **Calendula**, install.
 
-Both channels share the same signing key, so you can switch between them
-without reinstalling. Or build from source — see below.
+### Codeberg release / Obtainium
+
+If you'd rather not use F-Droid at all, every release is also published on
+**[Codeberg](https://codeberg.org/jlmakiola/calendula/releases)** with the
+signed APK (`calendula_vX.Y.Z.apk`) and a `.sha256` checksum attached — download
+and install it directly.
+
+For automatic updates from that channel, use
+**[Obtainium](https://github.com/ImranR98/Obtainium)** — on the phone,
+**[add Calendula in one tap](https://apps.obtainium.imranr.dev/redirect?r=obtainium://add/https://codeberg.org/jlmakiola/calendula)**,
+or do it by hand: *Add App* → paste `https://codeberg.org/jlmakiola/calendula`
+→ *Add*. Either way, Obtainium tracks the releases and prompts you when a new
+one appears.
+
+### Google Play (coming soon)
+
+Calendula is on its way to Google Play as an additional channel. It isn't live
+yet — this section gets a link once it is. Play builds will be signed with
+Google's key rather than mine, so switching between Play and any other channel
+will require an uninstall.
+
+> **Testers wanted.** Play requires a round of closed testing before the app can
+> go public, and I'm still looking for testers. If you'd like to help, email
+> **[business@jeanlucmakiola.de](mailto:business@jeanlucmakiola.de)** with the
+> Google account address you want to use — that address is what I need to add you
+> to the closed test.
+
+### Build from source
+
+The build is a plain Gradle build with no proprietary dependencies — see
+**[docs/BUILDING.md](docs/BUILDING.md)** (note the `floret-kit` submodule).
+
+<sub>Official F-Droid, the self-hosted repo, and the Codeberg releases all share
+the same signing key, so you can switch freely between them without
+reinstalling.</sub>
 
 ## 📚 Documentation
 
+- **[Contributing](CONTRIBUTING.md)** — how to report, propose, and patch
 - **[Building from source](docs/BUILDING.md)** — requirements and Gradle tasks
 - **[Architecture](docs/ARCHITECTURE.md)** — the layered design and key pipelines
-- **[Roadmap](.planning/ROADMAP.md)** — what's shipped and what's next
+- **[Milestones](https://codeberg.org/jlmakiola/calendula/milestones)** — what's shipped and what's next
+
+## 🤝 Contributing
+
+Bug reports, ideas, and patches are all welcome on
+**[Codeberg](https://codeberg.org/jlmakiola/calendula/issues)**.
+
+The short version: **start with an issue.** Features get a yes-or-no before they
+get code, and both features and bugs are assigned a milestone whose
+`release/vX.Y.Z` branch your pull request then targets. Typo and docs fixes can
+skip straight to a pull request. Translations don't go through pull requests at
+all — [Weblate owns them](#-translations).
+
+Read **[CONTRIBUTING.md](CONTRIBUTING.md)** before writing code: it covers the
+workflow, the build (note the `floret-kit` submodule), and the architectural
+rules a change is reviewed against.
 
 ## 🌍 Translations
 
-Calendula ships in German and English, and you're warmly invited to add your
-language. Translations are managed on a self-hosted **Weblate**:
+Calendula ships in English and German, with community translations in Arabic,
+Chinese, French, Italian, Polish, Portuguese, Russian, and Spanish at varying
+degrees of completeness — partial is fine, untranslated strings simply fall back
+to English. You're warmly invited to add or finish your language. Translations
+are managed on a self-hosted **Weblate**:
 
 **→ [Help translate Calendula](https://weblate.dev.jeanlucmakiola.de/engage/calendula/)**
 

app/build.gradle.kts

@@ -28,8 +28,8 @@ android {
         // which builds this version and then creates the matching vX.Y.Z tag +
         // release itself (versionCode is pinned to MAJOR*10000 + MINOR*100 +
         // PATCH from versionName, e.g. 2.7.2 -> 20702). See docs/RELEASING.md.
-        versionCode = 21200
-        versionName = "2.12.0"
+        versionCode = 21701
+        versionName = "2.17.1"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -90,6 +90,8 @@ android {
 
     buildFeatures {
         compose = true
+        // BuildConfig.DEBUG gates the in-app debug ribbon (see DebugRibbon).
+        buildConfig = true
     }
 
     // Don't embed AGP's dependency-metadata block in the APK signing block. It's
@@ -111,10 +113,13 @@ android {
     lint {
         // Community translations are expected to be partial — a missing string
         // falls back to the English base at runtime — so don't fail the build on
-        // it. Stale/extra keys (ExtraTranslation) stay fatal; scripts/
+        // it. Likewise a translated <plurals> may not fill every CLDR quantity
+        // form its locale defines (e.g. Arabic needs "zero"); the missing form
+        // falls back to "other" at runtime, so MissingQuantity is informational
+        // too. Stale/extra keys (ExtraTranslation) stay fatal; scripts/
         // check_translations.py guards the same invariants with clearer,
         // translator-facing messages.
-        informational += "MissingTranslation"
+        informational += listOf("MissingTranslation", "MissingQuantity")
     }
 
     testOptions {
@@ -159,6 +164,12 @@ dependencies {
     implementation(libs.androidx.glance.material3)
 
     implementation(libs.kotlinx.datetime)
+    implementation("de.jeanlucmakiola.floret:core-time")
+    implementation("de.jeanlucmakiola.floret:core-locale")
+    implementation("de.jeanlucmakiola.floret:core-crash")
+    implementation("de.jeanlucmakiola.floret:core-reminders")
+    implementation("de.jeanlucmakiola.floret:identity")
+    implementation("de.jeanlucmakiola.floret:components")
     implementation(libs.kotlinx.coroutines.core)
 
     debugImplementation(libs.androidx.ui.tooling)

app/proguard-rules.pro

@@ -16,6 +16,18 @@
 -keep class * extends androidx.room.RoomDatabase { *; }
 -dontwarn androidx.room.paging.**
 
+# Glance runs an @Composable's `actionRunCallback<T>()` by persisting the
+# callback's fully-qualified class name into the click PendingIntent, then
+# reflectively instantiating it (Class.forName(name).newInstance()) when the tap
+# fires. Under R8 full mode (AGP 9 default) these ActionCallback classes — only
+# ever referenced reflectively — get renamed or have their no-arg constructor
+# stripped, so the lookup fails silently and the tap does nothing. In the month
+# and agenda widgets that broke every run-callback control (the prev/next/today
+# month arrows and the agenda refresh) in release builds while actionStartActivity
+# taps, which ride a PendingIntent and need no reflection, kept working. Keep
+# every ActionCallback's name and constructor intact.
+-keep class * implements androidx.glance.appwidget.action.ActionCallback { <init>(...); }
+
 # WorkManager instantiates an InputMerger reflectively (Class.newInstance) from
 # the fully-qualified class name persisted in the WorkSpec, so the class must
 # keep both its name and a no-arg constructor. Glance renders every widget
@@ -26,3 +38,15 @@
 # SessionWorker never ran, and widgets were stuck on their loading layout
 # (a blank spinner) in release builds. Keep every InputMerger's name + ctor.
 -keep class * extends androidx.work.InputMerger { <init>(...); }
+
+# Glance identifies a widget by its GlanceAppWidget subclass's *canonical name*:
+# GlanceAppWidgetManager persists a providerName -> receivers map under that
+# string, and `updateAll` looks the widget's app-widget ids up through it. Under
+# R8 full mode (AGP 9 default) MonthWidget and AgendaWidget — same supertype,
+# same overrides, no distinguishing members — were horizontally merged into one
+# class, so both receivers registered under the *same* provider name and
+# `AgendaWidget().updateAll()` resolved the month widget's id too, redrawing a
+# placed month widget as the agenda one on the next data change (#89). Keeping
+# the real names also survives app updates, which would otherwise renumber the
+# obfuscated name and orphan the stored mapping.
+-keep class * extends androidx.glance.appwidget.GlanceAppWidget

app/src/androidTest/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositorySmokeTest.kt

@@ -9,6 +9,7 @@ import androidx.test.platform.app.InstrumentationRegistry
 import androidx.test.rule.GrantPermissionRule
 import com.google.common.truth.Truth.assertThat
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
@@ -31,7 +32,12 @@ class CalendarRepositorySmokeTest {
         val store: DataStore<Preferences> = PreferenceDataStoreFactory.create(
             produceFile = { context.cacheDir.resolve("smoke_test_prefs.preferences_pb") },
         )
-        return CalendarRepositoryImpl(dataSource, CalendarPrefs(store), Dispatchers.IO)
+        return CalendarRepositoryImpl(
+            dataSource,
+            CalendarPrefs(store),
+            SettingsPrefs(store),
+            Dispatchers.IO,
+        )
     }
 
     @Test

app/src/debug/res/values/colors.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Debug-only launcher-icon background. Production is slate (#5C6B7A); the
+    debug build paints the adaptive-icon background burnt orange instead, so the
+    debug icon reads at a glance as "not the real app" on the home screen. The
+    off-white foreground mark contrasts on both. See drawable/ic_launcher_background.
+-->
+<resources>
+    <color name="ic_launcher_background">#FFB23B00</color>
+</resources>

app/src/debug/res/values/strings.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Debug-build resource overrides. Merged on top of src/main for the `debug`
+    build type only (release/releaseTest keep the production values), so the
+    debug app is unmistakable on the launcher: its own label, alongside the
+    real app thanks to the `.debug` applicationId suffix.
+-->
+<resources>
+    <string name="app_name">Calendula Debug</string>
+</resources>

app/src/main/AndroidManifest.xml

@@ -5,6 +5,15 @@
     <uses-permission android:name="android.permission.READ_CALENDAR" />
     <uses-permission android:name="android.permission.WRITE_CALENDAR" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <!--
+      Optional and feature-gated: only the "Contact special dates" feature reads
+      contacts, and only after the user enables it and grants this at runtime
+      (never requested at startup). Everything stays offline — birthdays and
+      other contact dates are mirrored one-way into local calendars; contacts
+      are never written and nothing leaves the device (the app has no INTERNET
+      permission). See docs/design/contact-special-dates.md.
+    -->
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
     <!--
       Lets the "Reliable delivery" setting open the direct system dialog to
       exempt Calendula from battery optimisation (so reminder broadcasts aren't
@@ -24,6 +33,14 @@
         android:maxSdkVersion="32" />
     <uses-permission android:name="android.permission.USE_EXACT_ALARM" />
 
+    <!--
+      A reboot clears every pending alarm, including the one holding the next
+      reminder. Now that the app schedules that alarm itself (#75) rather than
+      leaning on the provider's, it has to hear about the reboot to re-arm it —
+      otherwise reminders simply stop after a restart.
+    -->
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
+
     <!-- Package visibility (Android 11+): without this, getLaunchIntentForPackage
          returns null and the calendar manager's per-account "manage" button can't
          open the source sync app (DAVx5, ICSx5, Google Calendar, …). The LAUNCHER
@@ -54,10 +71,9 @@
             android:exported="true"
             android:launchMode="singleTop"
             android:windowSoftInputMode="adjustResize">
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
+            <!-- The MAIN/LAUNCHER entry (the launcher icon + its label) lives on
+                 the two <activity-alias> below, so the app name can be switched at
+                 runtime (issue #44). MainActivity keeps every other filter. -->
 
             <!-- Be selectable as the system calendar app. Android has no API for
                  an app to make itself the default, so registering the filters
@@ -88,26 +104,156 @@
                 <data android:mimeType="time/epoch" />
             </intent-filter>
 
-            <!-- Open a .ics file (file manager / email attachment / browser). -->
+            <!-- Open a .ics/.vcs file (file manager / email attachment / browser).
+                 The three MIME types cover the common labels the same calendar
+                 data arrives under: iCalendar 2.0 (text/calendar), the older
+                 vCalendar 1.0 / .vcs (text/x-vcalendar), and application/ics some
+                 mail apps emit — Android cross-products the scheme and mimeType
+                 tags, so each MIME is accepted on both schemes (matches Etar). -->
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
-                <data android:scheme="content" android:mimeType="text/calendar" />
-                <data android:scheme="file" android:mimeType="text/calendar" />
+                <data android:scheme="content" />
+                <data android:scheme="file" />
+                <data android:mimeType="text/calendar" />
+                <data android:mimeType="text/x-vcalendar" />
+                <data android:mimeType="application/ics" />
             </intent-filter>
-            <!-- Receive a .ics shared from another app. -->
+            <!-- Same .ics/.vcs data arriving mislabelled as a generic download —
+                 application/octet-stream — the way many mail clients, browsers and
+                 file managers hand off attachments. Matched by file extension, so
+                 this stays a separate filter: a pathPattern here must not narrow
+                 the MIME-typed VIEW filter above (that one has no path and must
+                 keep matching regardless of name). The import handler ignores the
+                 MIME type, so a let-through octet-stream .ics imports normally.
+                 Best-effort: pathPattern is reliable for file:// (and content://
+                 whose path carries the filename); content:// URIs that expose no
+                 name still fall back to the MIME-typed filter above. -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="content" />
+                <data android:scheme="file" />
+                <data android:host="*" />
+                <data android:mimeType="application/octet-stream" />
+                <data android:pathPattern=".*\\.ics" />
+                <data android:pathPattern=".*\\.vcs" />
+            </intent-filter>
+
+            <!-- Receive a .ics/.vcs shared from another app (same MIME set). -->
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="text/calendar" />
+                <data android:mimeType="text/x-vcalendar" />
+                <data android:mimeType="application/ics" />
             </intent-filter>
 
-            <!-- Launcher long-press shortcuts (e.g. "New event"). -->
+            <!-- Let another app or widget (e.g. the Todo Agenda widget) launch us
+                 to create a new event, the way the AOSP calendar accepts it:
+                 ACTION_INSERT on the events *dir* mime type, carrying the new
+                 event's fields as CalendarContract extras
+                 (MainActivity.insertFormOrNull, issue #30). ACTION_EDIT on the
+                 dir mime is AOSP's "edit a new event" — i.e. create — so it maps
+                 to the same prefilled create form. (The far more common *item*-
+                 typed INSERT — the form the Android docs' example and apps like
+                 DB Navigator use — is the item filter below, issue #74.) -->
+            <intent-filter>
+                <action android:name="android.intent.action.INSERT" />
+                <action android:name="android.intent.action.EDIT" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="vnd.android.cursor.dir/event" />
+            </intent-filter>
+
+            <!-- Create or edit an event another app/assistant/widget points at,
+                 addressed by the provider's *item* MIME type. Three actions share
+                 this filter, told apart at runtime by the intent's data:
+
+                 • ACTION_INSERT — create. This is the form the Android docs'
+                   "insert an event" example and many apps use
+                   (setType("vnd.android.cursor.item/event")), e.g. DB Navigator's
+                   "Save to calendar". The dir-typed filter above alone missed it,
+                   so Calendula never showed in the chooser — and, when it was the
+                   only calendar app, the intent resolved to nothing (issue #74).
+                 • ACTION_INSERT_OR_EDIT — the third "add to calendar" action AOSP
+                   and Google Calendar register; a create, or an edit when it
+                   carries an event id.
+                 • ACTION_EDIT — edit the existing event at
+                   content://com.android.calendar/events/<id> (an id-less EDIT is a
+                   create). Opens the occurrence in the edit form, not the
+                   read-only detail — that's the VIEW filter above.
+
+                 Create fields ride as CalendarContract extras; an edit's
+                 occurrence times ride as EXTRA_EVENT_BEGIN_TIME /
+                 EXTRA_EVENT_END_TIME when supplied (MainActivity.insertFormOrNull
+                 / editEventKeyOrNull). -->
+            <intent-filter>
+                <action android:name="android.intent.action.INSERT" />
+                <action android:name="android.intent.action.INSERT_OR_EDIT" />
+                <action android:name="android.intent.action.EDIT" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="vnd.android.cursor.item/event" />
+            </intent-filter>
+
+            <!-- Open an existing event another app/widget points at (e.g. tapping
+                 an event in the Todo Agenda widget): ACTION_VIEW on
+                 content://com.android.calendar/events/<id>, the way AOSP fires it.
+                 Matched by the provider's item MIME type, not the path — a
+                 content: VIEW intent carries the resolved type
+                 (vnd.android.cursor.item/event) and a path-only filter wouldn't
+                 match it. The occurrence's times ride as EXTRA_EVENT_BEGIN_TIME /
+                 EXTRA_EVENT_END_TIME when the launcher supplies them
+                 (MainActivity.viewEventKeyOrNull, issue #48). -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:mimeType="vnd.android.cursor.item/event" />
+            </intent-filter>
+
+        </activity>
+
+        <!-- Launcher entry for MainActivity, split into two aliases so the app's
+             launcher name can be switched at runtime between "Calendula" and
+             "Calendar" (issue #44). Exactly one is enabled at a time; the app
+             flips them via PackageManager.setComponentEnabledSetting
+             (LauncherNameManager). The shortcuts meta-data lives here, not on
+             MainActivity, because static shortcuts are published by whichever
+             component owns the MAIN/LAUNCHER filter. -->
+        <activity-alias
+            android:name=".DefaultNameAlias"
+            android:enabled="true"
+            android:exported="true"
+            android:icon="@mipmap/ic_launcher"
+            android:label="@string/app_name"
+            android:roundIcon="@mipmap/ic_launcher_round"
+            android:targetActivity=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
             <meta-data
                 android:name="android.app.shortcuts"
                 android:resource="@xml/shortcuts" />
-        </activity>
+        </activity-alias>
+        <activity-alias
+            android:name=".CalendarNameAlias"
+            android:enabled="false"
+            android:exported="true"
+            android:icon="@mipmap/ic_launcher"
+            android:label="@string/app_name_calendar_alias"
+            android:roundIcon="@mipmap/ic_launcher_round"
+            android:targetActivity=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+            <meta-data
+                android:name="android.app.shortcuts"
+                android:resource="@xml/shortcuts" />
+        </activity-alias>
 
         <!-- Standalone surface for a captured crash report. MainActivity routes
              here on a startup crash-loop, so it stays clear of the app's Hilt
@@ -132,17 +278,22 @@
             </intent-filter>
         </service>
 
-        <!-- The provider broadcasts EVENT_REMINDER at reminder time but posts
-             no notification itself — a calendar app must (v1.4, Etar model).
-             Exported: the broadcast arrives from the provider's process. -->
+        <!-- Reminder delivery is the app's own (#75): it plans the alarms from
+             Instances + Reminders instead of waiting for the provider's
+             EVENT_REMINDER broadcast, which OEM-modified providers demonstrably
+             retarget or never send. This receiver takes our scan alarm plus
+             every outside event that invalidates it — boot and package-replace
+             wipe pending alarms, and a clock or timezone change moves every
+             reminder relative to the one that is armed.
+             Exported: the system broadcasts arrive from outside the app. -->
         <receiver
-            android:name=".data.reminders.EventReminderReceiver"
+            android:name=".data.reminders.ReminderScheduleReceiver"
             android:exported="true">
             <intent-filter>
-                <action android:name="android.intent.action.EVENT_REMINDER" />
-                <data
-                    android:host="com.android.calendar"
-                    android:scheme="content" />
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
+                <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
+                <action android:name="android.intent.action.TIME_SET" />
+                <action android:name="android.intent.action.TIMEZONE_CHANGED" />
             </intent-filter>
         </receiver>
 

app/src/main/java/de/jeanlucmakiola/calendula/CalendulaApp.kt

@@ -4,8 +4,14 @@ import android.app.Application
 import dagger.hilt.android.EntryPointAccessors
 import dagger.hilt.android.HiltAndroidApp
 import de.jeanlucmakiola.calendula.data.backup.BackupScheduler
+import de.jeanlucmakiola.calendula.data.calendar.CalendarVisibilityReconciler
 import de.jeanlucmakiola.calendula.data.backup.BackupWorker
-import de.jeanlucmakiola.calendula.data.crash.CrashReporter
+import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesScheduler
+import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesSyncWorker
+import de.jeanlucmakiola.calendula.data.reminders.ReminderMaintenanceScheduler
+import de.jeanlucmakiola.calendula.data.reminders.ReminderMaintenanceWorker
+import de.jeanlucmakiola.floret.crash.CrashConfig
+import de.jeanlucmakiola.floret.crash.CrashReporter
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -22,9 +28,51 @@ class CalendulaApp : Application() {
     override fun onCreate() {
         super.onCreate()
         // Install first thing so startup crashes are captured too (privacy-
-        // respecting, on-device; the user submits the report by hand).
-        CrashReporter.install(this)
+        // respecting, on-device; the user submits the report by hand). The
+        // capture/loop-detection/report machinery lives in floret-kit's
+        // core-crash; only the app label + issue-tracker URLs are app-specific.
+        CrashReporter.install(
+            this,
+            CrashConfig(
+                appLabel = getString(R.string.app_name),
+                newIssueUrl = getString(R.string.report_issue_url),
+                chooseIssueUrl = getString(R.string.report_issue_choose_url),
+                issueTitle = getString(R.string.crash_report_issue_title),
+            ),
+        )
         reconcileAutoBackup()
+        reconcileSpecialDates()
+        reconcileCalendarVisibility()
+        startReminderDelivery()
+    }
+
+    /**
+     * Bring reminder delivery up with the process (#75): a scan re-arms whatever
+     * the system dropped and posts what a missed alarm still owes, then the
+     * provider watch keeps edits re-planned. The daily worker is the backstop.
+     */
+    private fun startReminderDelivery() {
+        val deps = EntryPointAccessors.fromApplication(
+            this, ReminderMaintenanceWorker.Deps::class.java,
+        )
+        val scanner = deps.reminderScanner()
+        scanner.startWatchingProvider()
+        scanner.scanInBackground()
+        ReminderMaintenanceScheduler.apply(this)
+    }
+
+    /**
+     * Flush any calendar switch-off not yet written to `Calendars.VISIBLE`,
+     * including the set inherited from the retired app-local model (#75). A
+     * no-op in the steady state; `RootScreen` re-runs it after a later grant.
+     */
+    private fun reconcileCalendarVisibility() {
+        val deps = EntryPointAccessors.fromApplication(
+            this, CalendarVisibilityReconciler.Deps::class.java,
+        )
+        CoroutineScope(SupervisorJob() + Dispatchers.Default).launch {
+            deps.calendarVisibilityReconciler().run()
+        }
     }
 
     /**
@@ -44,4 +92,19 @@ class CalendulaApp : Application() {
             )
         }
     }
+
+    /**
+     * Re-arm (or cancel) the daily special-dates reconcile from the saved
+     * settings, like [reconcileAutoBackup]. The on-open refresh is RootScreen's
+     * ON_RESUME trigger, so no immediate run is needed here.
+     */
+    private fun reconcileSpecialDates() {
+        val deps = EntryPointAccessors.fromApplication(this, SpecialDatesSyncWorker.Deps::class.java)
+        CoroutineScope(SupervisorJob() + Dispatchers.Default).launch {
+            SpecialDatesScheduler.apply(
+                context = this@CalendulaApp,
+                enabled = deps.settingsPrefs().specialDatesEnabled.first(),
+            )
+        }
+    }
 }

app/src/main/java/de/jeanlucmakiola/calendula/MainActivity.kt

@@ -4,10 +4,12 @@ import android.content.Context
 import android.content.Intent
 import android.net.Uri
 import android.os.Bundle
+import android.provider.CalendarContract
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
@@ -21,22 +23,31 @@ import androidx.core.net.toUri
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import dagger.hilt.android.AndroidEntryPoint
-import de.jeanlucmakiola.calendula.data.crash.CrashReporter
 import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
 import de.jeanlucmakiola.calendula.data.prefs.is24Hour
+import de.jeanlucmakiola.calendula.domain.EventForm
+import de.jeanlucmakiola.calendula.domain.buildInsertEventForm
 import de.jeanlucmakiola.calendula.ui.RootScreen
 import de.jeanlucmakiola.calendula.ui.common.LocalShowHourLines
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.WidgetNavRequest
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.detail.EventDetailViewModel.Companion.NO_OCCURRENCE_TIME
+import de.jeanlucmakiola.floret.components.DebugRibbon
 import de.jeanlucmakiola.calendula.ui.crash.CrashReportActivity
-import de.jeanlucmakiola.calendula.ui.crash.CrashReportDialog
-import de.jeanlucmakiola.calendula.ui.crash.submitCrashReport
+import de.jeanlucmakiola.calendula.domain.FontRole
 import de.jeanlucmakiola.calendula.ui.settings.SettingsViewModel
+import de.jeanlucmakiola.floret.crash.CrashReportDialog
+import de.jeanlucmakiola.floret.crash.CrashReporter
+import de.jeanlucmakiola.floret.crash.submitCrashReport
 import de.jeanlucmakiola.calendula.ui.theme.CalendulaTheme
+import de.jeanlucmakiola.calendula.ui.theme.calendulaTypography
+import de.jeanlucmakiola.calendula.ui.theme.resolveFontFamily
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
 import kotlin.time.Instant
 
 @AndroidEntryPoint
@@ -55,6 +66,16 @@ class MainActivity : AppCompatActivity() {
     // by CalendarHost's import flow.
     private var requestedImportUri by mutableStateOf<Uri?>(null)
 
+    // A prefilled new-event form from an external ACTION_INSERT launch (another
+    // app/widget asking us to create an event, issue #30). Consumed once by
+    // CalendarHost, which opens it in the create form for review.
+    private var requestedInsertForm by mutableStateOf<EventForm?>(null)
+
+    // An external "edit this event" (ACTION_EDIT on content://.../events/<id>):
+    // opens the occurrence in the edit form. Same occurrence-key shape as the
+    // detail channel; consumed once by CalendarHost.
+    private var requestedEditKey by mutableStateOf<LongArray?>(null)
+
     // A captured crash report awaiting the user's decision, surfaced as a dialog
     // over the calendar on the next launch (the single-crash path). A startup
     // crash-loop is handled out of band, before setContent — see below.
@@ -76,9 +97,11 @@ class MainActivity : AppCompatActivity() {
         }
 
         enableEdgeToEdge()
-        requestedDetailKey = intent.detailKeyOrNull()
+        requestedDetailKey = intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull()
         requestedNav = intent.navRequestOrNull()
         requestedImportUri = intent.importUriOrNull()
+        requestedInsertForm = intent.insertFormOrNull()
+        requestedEditKey = intent.editEventKeyOrNull()
         if (CrashReporter.shouldPrompt(this)) pendingCrashReport = CrashReporter.pendingReport(this)
         setContent {
             // One activity-scoped SettingsViewModel drives both the theme here
@@ -97,23 +120,46 @@ class MainActivity : AppCompatActivity() {
             val use24Hour = remember(settings.timeFormat, context) {
                 settings.timeFormat.is24Hour(android.text.format.DateFormat.is24HourFormat(context))
             }
+            // The user's custom-font choice, resolved to a Material typography
+            // (issue #19). Recomputed only when a token — or the custom-font
+            // re-import stamp AppFontSettings carries, so replacing the file
+            // behind an active "custom" token still refreshes — changes;
+            // "system for both" returns the default scale untouched.
+            val fonts by settingsViewModel.fontState.collectAsStateWithLifecycle()
+            val typography = remember(fonts, context) {
+                calendulaTypography(
+                    brand = resolveFontFamily(fonts.brand, FontRole.BRAND, context),
+                    plain = resolveFontFamily(fonts.plain, FontRole.PLAIN, context),
+                )
+            }
             CalendulaTheme(
                 darkTheme = darkTheme,
                 dynamicColor = settings.dynamicColor,
+                typography = typography,
             ) {
-                CompositionLocalProvider(
-                    LocalUse24HourFormat provides use24Hour,
-                    LocalShowHourLines provides settings.showHourLines,
-                ) {
-                    RootScreen(
-                        modifier = Modifier.fillMaxSize(),
-                        requestedDetailKey = requestedDetailKey,
-                        onDetailKeyConsumed = { requestedDetailKey = null },
-                        widgetNavRequest = requestedNav,
-                        onWidgetNavConsumed = { requestedNav = null },
-                        requestedImportUri = requestedImportUri,
-                        onImportConsumed = { requestedImportUri = null },
-                    )
+                Box(modifier = Modifier.fillMaxSize()) {
+                    CompositionLocalProvider(
+                        LocalUse24HourFormat provides use24Hour,
+                        LocalShowHourLines provides settings.showHourLines,
+                        LocalSoftenColors provides settings.softenColors,
+                    ) {
+                        RootScreen(
+                            modifier = Modifier.fillMaxSize(),
+                            requestedDetailKey = requestedDetailKey,
+                            onDetailKeyConsumed = { requestedDetailKey = null },
+                            widgetNavRequest = requestedNav,
+                            onWidgetNavConsumed = { requestedNav = null },
+                            requestedImportUri = requestedImportUri,
+                            onImportConsumed = { requestedImportUri = null },
+                            requestedInsertForm = requestedInsertForm,
+                            onInsertConsumed = { requestedInsertForm = null },
+                            requestedEditKey = requestedEditKey,
+                            onEditKeyConsumed = { requestedEditKey = null },
+                        )
+                    }
+                    // A persistent corner marker so a debug build is never
+                    // mistaken for the production app; compiled out of release.
+                    if (BuildConfig.DEBUG) DebugRibbon()
                 }
                 pendingCrashReport?.let { report ->
                     CrashReportDialog(
@@ -143,9 +189,11 @@ class MainActivity : AppCompatActivity() {
 
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
-        intent.detailKeyOrNull()?.let { requestedDetailKey = it }
+        (intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull())?.let { requestedDetailKey = it }
         intent.navRequestOrNull()?.let { requestedNav = it }
         intent.importUriOrNull()?.let { requestedImportUri = it }
+        intent.insertFormOrNull()?.let { requestedInsertForm = it }
+        intent.editEventKeyOrNull()?.let { requestedEditKey = it }
     }
 
     /**
@@ -165,6 +213,39 @@ class MainActivity : AppCompatActivity() {
         return uri.takeIf { it.scheme == "content" || it.scheme == "file" }
     }
 
+    /**
+     * A prefilled new-event form from an external launch asking us to create an
+     * event — another app or widget (e.g. Todo Agenda) firing `ACTION_INSERT`
+     * (issue #30), or `ACTION_EDIT` with no concrete event id (AOSP's "edit a new
+     * event", i.e. create). The new event's fields ride as CalendarContract
+     * extras; anything omitted falls back to the in-app "new event" defaults in
+     * [buildInsertEventForm].
+     */
+    private fun Intent.insertFormOrNull(): EventForm? {
+        // ACTION_EDIT / ACTION_INSERT_OR_EDIT on an existing event route to the
+        // edit form instead ([editEventKeyOrNull]); an id-less one is a create,
+        // as is any plain ACTION_INSERT.
+        val isCreate = action == Intent.ACTION_INSERT ||
+            ((action == Intent.ACTION_EDIT || action == Intent.ACTION_INSERT_OR_EDIT) &&
+                editEventKeyOrNull() == null)
+        if (!isCreate) return null
+        return buildInsertEventForm(
+            beginMillis = longExtraOrNull(CalendarContract.EXTRA_EVENT_BEGIN_TIME),
+            endMillis = longExtraOrNull(CalendarContract.EXTRA_EVENT_END_TIME),
+            isAllDay = getBooleanExtra(CalendarContract.EXTRA_EVENT_ALL_DAY, false),
+            title = getStringExtra(CalendarContract.Events.TITLE),
+            description = getStringExtra(CalendarContract.Events.DESCRIPTION),
+            location = getStringExtra(CalendarContract.Events.EVENT_LOCATION),
+            rrule = getStringExtra(CalendarContract.Events.RRULE),
+            zone = TimeZone.currentSystemDefault(),
+            now = Clock.System.now(),
+        )
+    }
+
+    /** A Long extra's value, or null when the extra is absent. */
+    private fun Intent.longExtraOrNull(key: String): Long? =
+        if (hasExtra(key)) getLongExtra(key, 0L) else null
+
     /**
      * The date a launcher/clock date tap points at, parsed from the AOSP calendar
      * "view time" intent: ACTION_VIEW on `content://com.android.calendar/time/
@@ -186,6 +267,12 @@ class MainActivity : AppCompatActivity() {
         // An external date tap (launcher/clock) has no widget source, so it opens
         // the day view rooted over the default home view (OpenDate source = null).
         calendarTimeDateOrNull()?.let { return WidgetNavRequest.OpenDate(it.toString(), source = null) }
+        // A widget header tap: open a top-level view with no date drill-in. The
+        // empty string carried by [openViewIntent] means "the default home view".
+        if (hasExtra(EXTRA_OPEN_VIEW)) {
+            val name = getStringExtra(EXTRA_OPEN_VIEW).orEmpty()
+            return WidgetNavRequest.OpenView(CalendarView.entries.firstOrNull { it.name == name })
+        }
         val source = sourceViewOrNull()
         val eventId = getLongExtra(EXTRA_EVENT_ID, -1L)
         return when {
@@ -226,6 +313,56 @@ class MainActivity : AppCompatActivity() {
         )
     }
 
+    /**
+     * The detail key for an external "open this event" — ACTION_VIEW on
+     * `content://com.android.calendar/events/<id>`, the way AOSP fires it (e.g.
+     * tapping an existing event in the Todo Agenda widget, issue #48). Reuses the
+     * same occurrence-key channel as reminder taps. The launcher passes the
+     * occurrence's times as `EXTRA_EVENT_BEGIN_TIME` / `EXTRA_EVENT_END_TIME` when
+     * it has them; a bare URI omits them, so we carry [NO_OCCURRENCE_TIME] and
+     * [EventDetailViewModel] falls back to the event row's own DTSTART/DTEND
+     * rather than rendering at the epoch.
+     */
+    private fun Intent.viewEventKeyOrNull(): LongArray? {
+        if (action != Intent.ACTION_VIEW) return null
+        val uri = data ?: return null
+        if (uri.host != CALENDAR_PROVIDER_HOST) return null
+        val segments = uri.pathSegments
+        if (segments.firstOrNull() != "events") return null
+        val eventId = segments.getOrNull(1)?.toLongOrNull() ?: return null
+        return longArrayOf(
+            eventId,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_BEGIN_TIME) ?: NO_OCCURRENCE_TIME,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_END_TIME) ?: NO_OCCURRENCE_TIME,
+        )
+    }
+
+    /**
+     * The occurrence key for an external "edit this event" — `ACTION_EDIT` on
+     * `content://com.android.calendar/events/<id>`, the way AOSP fires it (e.g.
+     * an assistant, task app, or widget that wants to open the event for editing
+     * rather than viewing). Opens it in the edit form. Reuses the same
+     * occurrence-key channel as reminder/view taps; the caller passes the
+     * occurrence's times as `EXTRA_EVENT_BEGIN_TIME` / `EXTRA_EVENT_END_TIME`
+     * when it has them, otherwise we carry [NO_OCCURRENCE_TIME] and
+     * [EventEditViewModel.openForEdit] falls back to the event row's own
+     * DTSTART/DTEND. An id-less `ACTION_EDIT` — or `ACTION_INSERT_OR_EDIT`, which
+     * some apps fire — is a create instead ([insertFormOrNull]).
+     */
+    private fun Intent.editEventKeyOrNull(): LongArray? {
+        if (action != Intent.ACTION_EDIT && action != Intent.ACTION_INSERT_OR_EDIT) return null
+        val uri = data ?: return null
+        if (uri.host != CALENDAR_PROVIDER_HOST) return null
+        val segments = uri.pathSegments
+        if (segments.firstOrNull() != "events") return null
+        val eventId = segments.getOrNull(1)?.toLongOrNull() ?: return null
+        return longArrayOf(
+            eventId,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_BEGIN_TIME) ?: NO_OCCURRENCE_TIME,
+            longExtraOrNull(CalendarContract.EXTRA_EVENT_END_TIME) ?: NO_OCCURRENCE_TIME,
+        )
+    }
+
     companion object {
         // The calendar provider's authority/host. A date tap arrives as
         // ACTION_VIEW on content://com.android.calendar/time/<epochMillis>.
@@ -237,6 +374,10 @@ class MainActivity : AppCompatActivity() {
         private const val EXTRA_DATE_ISO = "de.jeanlucmakiola.calendula.extra.DATE_ISO"
         private const val EXTRA_CREATE = "de.jeanlucmakiola.calendula.extra.CREATE"
 
+        // A widget header tap asking to open a top-level view (no date drill-in).
+        // Its value is the target [CalendarView] name, or "" for the default view.
+        private const val EXTRA_OPEN_VIEW = "de.jeanlucmakiola.calendula.extra.OPEN_VIEW"
+
         // The [CalendarView] (by name) of the widget a launch came from. Roots the
         // in-app back stack in that view; absent for non-widget launches (reminders).
         private const val EXTRA_SOURCE_VIEW = "de.jeanlucmakiola.calendula.extra.SOURCE_VIEW"
@@ -300,5 +441,19 @@ class MainActivity : AppCompatActivity() {
                 putExtra(EXTRA_DATE_ISO, date.toString())
                 addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
             }
+
+        /**
+         * Open the app on a top-level [view] with no date drill-in — a widget
+         * header tap. A null [view] opens the user's default home view (the agenda
+         * widget's "Upcoming" title); a concrete view roots there over the default
+         * home (the month widget's month/year title → [CalendarView.Month]). The
+         * per-view data URI keeps distinct headers' PendingIntents from collapsing.
+         */
+        fun openViewIntent(context: Context, view: CalendarView?): Intent =
+            Intent(context, MainActivity::class.java).apply {
+                data = "calendula://view/${view?.name ?: "default"}".toUri()
+                putExtra(EXTRA_OPEN_VIEW, view?.name ?: "")
+                addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+            }
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/data/appname/LauncherNameManager.kt

@@ -0,0 +1,109 @@
+package de.jeanlucmakiola.calendula.data.appname
+
+import android.content.ComponentName
+import android.content.Context
+import android.content.pm.PackageManager
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/** The launcher label the app shows for itself (issue #44). */
+enum class LauncherName { CALENDULA, CALENDAR }
+
+/** The two launcher aliases declared in the manifest. */
+enum class LauncherAlias { DEFAULT, CALENDAR }
+
+/** One component-enable change in a [aliasWritePlan]. */
+data class AliasStateChange(val alias: LauncherAlias, val enabled: Boolean)
+
+/**
+ * Interpret the `CalendarNameAlias` component-enabled state as a [LauncherName].
+ * Only [PackageManager.COMPONENT_ENABLED_STATE_ENABLED] means the "Calendar"
+ * name is active; `DEFAULT` (never toggled) and `DISABLED` both resolve to the
+ * manifest default, "Calendula".
+ */
+fun launcherNameFor(calendarAliasState: Int): LauncherName =
+    if (calendarAliasState == PackageManager.COMPONENT_ENABLED_STATE_ENABLED) {
+        LauncherName.CALENDAR
+    } else {
+        LauncherName.CALENDULA
+    }
+
+/**
+ * The ordered enable/disable steps to switch the launcher name to [target].
+ * Always **enables the target alias first, then disables the other** — the two
+ * `setComponentEnabledSetting` calls are not atomic, and this ordering means the
+ * only transient the launcher can observe is a harmless two-entry state, never a
+ * zero-entry one (which would briefly drop the app from the launcher).
+ */
+fun aliasWritePlan(target: LauncherName): List<AliasStateChange> = when (target) {
+    LauncherName.CALENDAR -> listOf(
+        AliasStateChange(LauncherAlias.CALENDAR, enabled = true),
+        AliasStateChange(LauncherAlias.DEFAULT, enabled = false),
+    )
+    LauncherName.CALENDULA -> listOf(
+        AliasStateChange(LauncherAlias.DEFAULT, enabled = true),
+        AliasStateChange(LauncherAlias.CALENDAR, enabled = false),
+    )
+}
+
+/**
+ * Switches the app's launcher label between "Calendula" and "Calendar" by
+ * enabling/disabling the two `<activity-alias>` components (issue #44). The
+ * component-enabled state is the single source of truth — there is no persisted
+ * preference — so [current] reads it straight from [PackageManager] and the two
+ * always agree.
+ *
+ * The decision logic lives in the pure [launcherNameFor] / [aliasWritePlan]
+ * functions above (JVM-tested); this class is only the thin framework seam.
+ */
+@Singleton
+class LauncherNameManager @Inject constructor(
+    @ApplicationContext private val context: Context,
+) {
+    private val packageManager: PackageManager get() = context.packageManager
+
+    // The class portion is namespace-qualified (suffix-free), the package portion
+    // is the applicationId (which carries the .debug / .releasetest suffix). The
+    // manifest's ".CalendarNameAlias" resolves its class against the namespace, so
+    // the real component is <namespace>.CalendarNameAlias registered under the
+    // suffixed applicationId. Do NOT use ComponentName(context, ".CalendarNameAlias")
+    // — its leading-dot form prepends the applicationId to the class too, producing
+    // "<appId>.CalendarNameAlias" and failing on every debug / releaseTest build.
+    private fun component(alias: LauncherAlias): ComponentName {
+        val simpleName = when (alias) {
+            LauncherAlias.DEFAULT -> "DefaultNameAlias"
+            LauncherAlias.CALENDAR -> "CalendarNameAlias"
+        }
+        return ComponentName(context.packageName, "$NAMESPACE.$simpleName")
+    }
+
+    /** The launcher name currently in effect. */
+    fun current(): LauncherName =
+        launcherNameFor(packageManager.getComponentEnabledSetting(component(LauncherAlias.CALENDAR)))
+
+    /** Switch the launcher name to [name] (no-op cost if already active). */
+    fun set(name: LauncherName) {
+        for (change in aliasWritePlan(name)) {
+            val state = if (change.enabled) {
+                PackageManager.COMPONENT_ENABLED_STATE_ENABLED
+            } else {
+                PackageManager.COMPONENT_ENABLED_STATE_DISABLED
+            }
+            packageManager.setComponentEnabledSetting(
+                component(change.alias),
+                state,
+                PackageManager.DONT_KILL_APP,
+            )
+        }
+    }
+
+    private companion object {
+        /**
+         * The app's namespace (R-class package) — NOT `applicationId`, which
+         * carries the build-type suffix. Kept in sync with `namespace` in
+         * `app/build.gradle.kts`.
+         */
+        const val NAMESPACE = "de.jeanlucmakiola.calendula"
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/AllDayReminderEncoding.kt

@@ -1,11 +1,10 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
-import java.time.Instant
+import de.jeanlucmakiola.calendula.domain.reminders.allDayLeadDays
 import java.time.LocalDate
 import java.time.LocalTime
 import java.time.ZoneId
 import java.time.ZoneOffset
-import java.time.temporal.ChronoUnit
 
 /**
  * Translates an all-day reminder between the **semantic** lead time the UI
@@ -50,21 +49,36 @@ internal fun toProviderAllDayMinutes(
     return ((utcMidnight - fire) / MILLIS_PER_MINUTE).toInt()
 }
 
+/**
+ * The next date on or after [today] carrying [month]/[day] — the date to sample
+ * a yearly all-day reminder's UTC offset at. A managed birthday's DTSTART is an
+ * ancient anchor (1972 for year-less dates), a year whose timezone rules
+ * (pre-DST offsets) differ from today's; sampling the offset there skews every
+ * modern occurrence by hours. Sampling at the upcoming occurrence makes the
+ * stored offset correct for it and its neighbours (only ±1h DST drift remains,
+ * the inherent limit). Feb-29 skips forward to the next leap year.
+ */
+internal fun nextYearlyOccurrence(month: Int, day: Int, today: LocalDate): LocalDate {
+    var year = today.year
+    // A Feb-29 date is valid only every ~4 years; 8 tries always reaches one.
+    repeat(8) {
+        val candidate = runCatching { LocalDate.of(year, month, day) }.getOrNull()
+        if (candidate != null && !candidate.isBefore(today)) return candidate
+        year++
+    }
+    // Unreachable for real month/day inputs; fall back to the raw anchor.
+    return LocalDate.of(today.year, month, day)
+}
+
 /**
  * Recover the semantic whole-day lead time from a raw all-day reminder
- * [rawMinutes]. Keys off the **local date** of the encoded fire instant, so it
- * returns the right day count regardless of which [timeOfDayMinutes] wrote the
- * row — including pre-feature rows (raw multiples of 1440, fired at UTC midnight)
- * and rows written under a different timezone. A negative [rawMinutes] (fire
- * after DTSTART) folds to day 0.
+ * [rawMinutes] — the inverse of [toProviderAllDayMinutes], for the form and the
+ * detail screen. Delegates to [allDayLeadDays], so the day displayed is the day
+ * the reminder actually fires on.
  */
 internal fun fromProviderAllDayMinutes(
     rawMinutes: Int,
     startDate: LocalDate,
     zone: ZoneId,
-): Int {
-    val utcMidnight = startDate.atStartOfDay(ZoneOffset.UTC).toInstant().toEpochMilli()
-    val fireLocalDate = Instant.ofEpochMilli(utcMidnight - rawMinutes * MILLIS_PER_MINUTE)
-        .atZone(zone).toLocalDate()
-    return ChronoUnit.DAYS.between(fireLocalDate, startDate).toInt() * MINUTES_PER_DAY
-}
+    timeOfDayMinutes: Int,
+): Int = allDayLeadDays(rawMinutes, startDate, zone, timeOfDayMinutes).toInt() * MINUTES_PER_DAY

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarColorPalette.kt

@@ -0,0 +1,22 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+/**
+ * Google-Calendar-style palette; ARGB ints for a raw `CALENDAR_COLOR` /
+ * `EVENT_COLOR`. The named entries exist for callers that need one specific
+ * hue (the managed special-dates calendars), so they can't drift from the
+ * swatches offered in the colour picker.
+ */
+object CalendarColorPalette {
+    val Red = 0xFFD50000.toInt()
+    val Orange = 0xFFE67C00.toInt()
+    val Amber = 0xFFF6BF26.toInt()
+    val Green = 0xFF33B679.toInt()
+    val DarkGreen = 0xFF0B8043.toInt()
+    val Blue = 0xFF039BE5.toInt()
+    val Indigo = 0xFF3F51B5.toInt()
+    val Purple = 0xFF8E24AA.toInt()
+    val Graphite = 0xFF616161.toInt()
+
+    /** The full palette, in swatch-row order. */
+    val all: List<Int> = listOf(Red, Orange, Amber, Green, DarkGreen, Blue, Indigo, Purple, Graphite)
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarDataSource.kt

@@ -1,5 +1,7 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toEpochMillis
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.Manifest
 import android.content.ContentResolver
 import android.content.ContentUris
@@ -16,18 +18,25 @@ import android.util.Log
 import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.domain.Attendee
+import de.jeanlucmakiola.calendula.domain.AttendeeRelationship
+import de.jeanlucmakiola.calendula.domain.AttendeeType
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventAttendee
 import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventDetail
+import de.jeanlucmakiola.calendula.domain.curatedForPicker
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.Reminder
+import de.jeanlucmakiola.calendula.domain.contacts.MANAGED_UID_PREFIX
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import de.jeanlucmakiola.calendula.domain.rruleTruncatedAt
 import kotlinx.datetime.toJavaLocalDate
+import java.time.Instant
+import java.time.LocalDate
 import java.time.ZoneId
 import java.time.ZoneOffset
 import java.util.UUID
@@ -45,7 +54,12 @@ import javax.inject.Singleton
 interface CalendarDataSource {
     fun calendars(): List<CalendarSource>
     fun instances(beginMillis: Long, endMillis: Long): List<EventInstance>
-    fun eventDetail(eventId: Long): EventDetail?
+    /**
+     * [allDayReminderTimeMinutes]: the hour all-day reminders fire at, needed to
+     * decode their stored offsets back to whole-day lead times (see
+     * [fromProviderAllDayMinutes]).
+     */
+    fun eventDetail(eventId: Long, allDayReminderTimeMinutes: Int): EventDetail?
 
     /**
      * Master/one-off events whose title, description or location contains
@@ -57,19 +71,23 @@ interface CalendarDataSource {
 
     /**
      * The event-colour palette the calendar's account publishes
-     * (`CalendarContract.Colors`, `TYPE_EVENT`), sorted by key. Empty when the
-     * account exposes no palette (most local calendars, some CalDAV) — the
-     * signal that a custom colour can only be written as a raw `EVENT_COLOR`,
-     * which a synced calendar may drop on its next sync.
+     * (`CalendarContract.Colors`, `TYPE_EVENT`), curated for display — deduped,
+     * thinned to visually distinct swatches when oversized (CalDAV adapters
+     * publish all ~147 CSS3 names, #22) and hue-sorted; see [curatedForPicker].
+     * Empty when the account exposes no palette (most local calendars, some
+     * CalDAV) — the signal that a custom colour can only be written as a raw
+     * `EVENT_COLOR`, which a synced calendar may drop on its next sync.
      */
     fun eventColorPalette(calendarId: Long): List<EventColorOption>
 
     /**
      * Every master/one-off event of the writable local calendars, mapped for a
      * whole-calendar `.ics` backup. Modified-occurrence and cancelled-exception
-     * rows are excluded (see [EventExportProjection]).
+     * rows are excluded (see [EventExportProjection]). When [calendarIds] is
+     * given, only those calendars are exported (still intersected with the
+     * eligible set); `null` exports every eligible calendar.
      */
-    fun exportableEvents(): List<IcsEvent>
+    fun exportableEvents(calendarIds: Set<Long>? = null): List<IcsEvent>
 
     /**
      * The non-empty `Events.UID_2445` values present in [calendarId] — used to
@@ -97,6 +115,77 @@ interface CalendarDataSource {
     /** Permanently delete a local calendar the app owns, with all its events. */
     fun deleteCalendar(id: Long)
 
+    /**
+     * Show or hide the calendar device-wide by writing `Calendars.VISIBLE` — the
+     * app's one visibility model (#75), which also gates its reminders. One of
+     * the three columns the platform documents as app-writable, and device-local.
+     */
+    fun setCalendarVisible(id: Long, visible: Boolean)
+
+    /**
+     * Whether one calendar is switched on at system level, without reading every
+     * row — for the reminder gate, which sees only a calendar id. Null when the
+     * answer can't be had: no row, or no read permission.
+     */
+    fun isCalendarVisible(id: Long): Boolean?
+
+    /**
+     * Whether the app holds `WRITE_CALENDAR`, i.e. may write
+     * [setCalendarVisible] at all. Read-only users (READ granted, WRITE denied)
+     * keep their calendar switches app-side instead — see
+     * [de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs.pendingDisabledCalendarIds].
+     */
+    fun canWriteCalendars(): Boolean
+
+    /**
+     * Create a local calendar tagged as the special-dates mirror for [type]
+     * (a marker in `CAL_SYNC2`); returns its `Calendars._ID`. Otherwise a normal
+     * local calendar, so it inherits per-calendar colour/visibility/reminders.
+     */
+    fun createManagedCalendar(displayName: String, color: Int, type: SpecialDateType): Long
+
+    /**
+     * The app's special-dates calendars, found by their `CAL_SYNC2` marker.
+     * Lets the mirror re-adopt its calendars after the stored ids are lost, and
+     * detect when the user deleted one in system settings.
+     */
+    fun findManagedCalendars(): List<ManagedCalendarRow>
+
+    /**
+     * The managed events in [calendarId] (those carrying a `UID_2445`, not
+     * soft-deleted) as [ManagedEventRow]s — the existing side of the sync diff.
+     */
+    fun queryManagedEvents(calendarId: Long): List<ManagedEventRow>
+
+    /**
+     * Insert a managed event carrying the deterministic [uid] in `UID_2445`;
+     * seeds its reminder rows from [form] (never touched again by sync). Returns
+     * the new `Events._ID`. [allDayReminderTimeMinutes]: see [insertEvent].
+     */
+    fun insertManagedEvent(form: EventForm, uid: String, allDayReminderTimeMinutes: Int): Long
+
+    /**
+     * Overwrite exactly the given managed columns on [eventId] (keys are
+     * `CalendarContract.Events` columns; a null value clears the column). A
+     * bare, targeted update — it never reconciles reminders or attendees, so
+     * user-owned data on the event survives every sync. No-ops on an empty map.
+     */
+    fun updateManagedFields(eventId: Long, values: Map<String, Any?>)
+
+    /**
+     * Replace the reminders on **every managed** event in [calendarId] with
+     * [minutes] (all-day lead times), each encoded so it fires at
+     * [allDayReminderTimeMinutes] on its upcoming occurrence. Used by the
+     * special-dates section so a reminder change applies to existing events too,
+     * not just future ones — the managed calendars treat reminders as a
+     * calendar-level setting. Skips any non-managed (user) event in the calendar.
+     */
+    fun applyManagedCalendarReminders(
+        calendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        minutes: List<Int>,
+    )
+
     /**
      * Insert a new event; returns the new `Events._ID`. [allDayReminderTimeMinutes]
      * (minutes from local midnight) is the wall-clock time all-day reminders
@@ -119,6 +208,25 @@ interface CalendarDataSource {
         allDayReminderTimeMinutes: Int,
     )
 
+    /**
+     * Move an event (for recurring events: the whole series, with its modified
+     * and cancelled occurrences) to [targetCalendarId], returning the new
+     * `Events._ID`. `CALENDAR_ID` is sync-adapter-owned and can't be updated in
+     * place, so this is copy+delete: the row is re-inserted on the target (its
+     * `UID_2445` preserved), its exceptions, reminders and editable guests
+     * replayed, the [original]→[updated] field edits applied, then the source
+     * deleted. The source is removed only once the copy fully succeeds; a failure
+     * before that rolls the new event back, leaving the original untouched.
+     * [allDayReminderTimeMinutes]: see [insertEvent].
+     */
+    fun moveEvent(
+        eventId: Long,
+        targetCalendarId: Long,
+        original: EventForm,
+        updated: EventForm,
+        allDayReminderTimeMinutes: Int,
+    ): Long
+
     /**
      * Change a single occurrence of a recurring event by inserting a
      * modified-occurrence exception at [beginMillis] (the occurrence's
@@ -292,6 +400,171 @@ class AndroidCalendarDataSource @Inject constructor(
         if (deleted == 0) throw WriteFailedException("delete calendar id=$id")
     }
 
+    /**
+     * Addressed by appended id on the plain (non-sync-adapter) Calendars URI, one
+     * calendar per call. Both parts are load-bearing:
+     * `CalendarProvider2.updateInTransaction` skips the dirty marking and the
+     * `checkNextAlarm()` reschedule unless the selection is `_id=…`, and the
+     * plain URI is what makes the write apply to synced calendars too.
+     */
+    override fun setCalendarVisible(id: Long, visible: Boolean) {
+        val values = ContentValues().apply {
+            put(CalendarContract.Calendars.VISIBLE, if (visible) 1 else 0)
+        }
+        val rows = resolver.update(
+            ContentUris.withAppendedId(CalendarContract.Calendars.CONTENT_URI, id),
+            values, null, null,
+        )
+        if (rows == 0) throw WriteFailedException("set calendar visibility id=$id")
+    }
+
+    override fun isCalendarVisible(id: Long): Boolean? {
+        if (!hasCalendarPermission()) return null
+        return resolver.query(
+            ContentUris.withAppendedId(CalendarContract.Calendars.CONTENT_URI, id),
+            arrayOf(CalendarContract.Calendars.VISIBLE),
+            null, null, null,
+        )?.use { if (it.moveToFirst()) it.getInt(0) != 0 else null }
+    }
+
+    override fun canWriteCalendars(): Boolean =
+        ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_CALENDAR) ==
+            PackageManager.PERMISSION_GRANTED
+
+    override fun createManagedCalendar(displayName: String, color: Int, type: SpecialDateType): Long {
+        val name = displayName.trim().ifEmpty { Fallbacks.UNNAMED_CALENDAR }
+        val values = ContentValues().apply {
+            put(CalendarContract.Calendars.ACCOUNT_NAME, LOCAL_ACCOUNT_NAME)
+            put(CalendarContract.Calendars.ACCOUNT_TYPE, CalendarContract.ACCOUNT_TYPE_LOCAL)
+            put(CalendarContract.Calendars.OWNER_ACCOUNT, LOCAL_ACCOUNT_NAME)
+            put(CalendarContract.Calendars.NAME, name)
+            put(CalendarContract.Calendars.CALENDAR_DISPLAY_NAME, name)
+            put(CalendarContract.Calendars.CALENDAR_COLOR, color)
+            put(
+                CalendarContract.Calendars.CALENDAR_ACCESS_LEVEL,
+                CalendarContract.Calendars.CAL_ACCESS_OWNER,
+            )
+            put(CalendarContract.Calendars.VISIBLE, 1)
+            put(CalendarContract.Calendars.SYNC_EVENTS, 1)
+            // The marker that identifies this as our special-dates calendar,
+            // independent of the (user-editable) display name. CAL_SYNC1 already
+            // holds the description, so the marker lives in CAL_SYNC2.
+            put(MANAGED_MARKER_COLUMN, markerFor(type))
+        }
+        val uri = resolver.insert(localCalendarsUri(), values)
+            ?: throw WriteFailedException("create managed calendar")
+        return ContentUris.parseId(uri)
+    }
+
+    override fun findManagedCalendars(): List<ManagedCalendarRow> = resolver.query(
+        CalendarContract.Calendars.CONTENT_URI,
+        arrayOf(CalendarContract.Calendars._ID, MANAGED_MARKER_COLUMN),
+        "${CalendarContract.Calendars.ACCOUNT_TYPE} = ? AND " +
+            "${CalendarContract.Calendars.ACCOUNT_NAME} = ? AND " +
+            "$MANAGED_MARKER_COLUMN IS NOT NULL",
+        arrayOf(CalendarContract.ACCOUNT_TYPE_LOCAL, LOCAL_ACCOUNT_NAME),
+        null,
+    )?.use { c ->
+        buildList {
+            while (c.moveToNext()) {
+                val type = typeForMarker(c.getString(1)) ?: continue
+                add(ManagedCalendarRow(id = c.getLong(0), type = type))
+            }
+        }
+    } ?: emptyList()
+
+    override fun queryManagedEvents(calendarId: Long): List<ManagedEventRow> = resolver.query(
+        CalendarContract.Events.CONTENT_URI,
+        arrayOf(
+            CalendarContract.Events._ID,
+            CalendarContract.Events.UID_2445,
+            CalendarContract.Events.TITLE,
+            CalendarContract.Events.DTSTART,
+            CalendarContract.Events.RRULE,
+        ),
+        // Only our own mirror events (UID prefix), so a user event that somehow
+        // landed in this calendar (e.g. an .ics import) is never seen as
+        // "existing but not desired" and deleted by the diff.
+        "${CalendarContract.Events.CALENDAR_ID} = ? AND " +
+            "${CalendarContract.Events.DELETED} = 0 AND " +
+            "${CalendarContract.Events.UID_2445} LIKE ?",
+        arrayOf(calendarId.toString(), "$MANAGED_UID_PREFIX%"),
+        null,
+    )?.use { c ->
+        buildList {
+            while (c.moveToNext()) {
+                val uid = c.getString(1)?.takeIf { it.isNotEmpty() } ?: continue
+                add(
+                    ManagedEventRow(
+                        eventId = c.getLong(0),
+                        uid = uid,
+                        title = c.getString(2).orEmpty(),
+                        dtStartMillis = c.getLong(3),
+                        rrule = c.getString(4)?.takeIf { it.isNotEmpty() },
+                    ),
+                )
+            }
+        }
+    } ?: emptyList()
+
+    override fun insertManagedEvent(form: EventForm, uid: String, allDayReminderTimeMinutes: Int): Long {
+        // Deterministic UID = the reconciliation key. A re-sync reads it back
+        // (queryManagedEvents) and diffs on it, so a contact never doubles.
+        val times = form.toWriteTimes(ZoneId.systemDefault())
+        val values = buildEventInsertValues(form, uid, times)
+        val eventId = resolver.insert(CalendarContract.Events.CONTENT_URI, values.toContentValues())
+            ?.let(ContentUris::parseId)
+            ?: throw WriteFailedException("insert managed event into calendar id=${form.calendarId}")
+        // Seeded once, then never re-touched by sync — so a user who moves a
+        // birthday reminder keeps their change. Encoded against the upcoming
+        // occurrence, not the ancient DTSTART anchor (wrong timezone offset).
+        val anchor = Instant.ofEpochMilli(times.dtStartMillis).atZone(ZoneOffset.UTC).toLocalDate()
+        insertReminderRows(
+            eventId,
+            managedAllDayReminderMinutes(anchor, form.reminders, allDayReminderTimeMinutes),
+        )
+        return eventId
+    }
+
+    override fun updateManagedFields(eventId: Long, values: Map<String, Any?>) {
+        if (values.isEmpty()) return
+        val rows = resolver.update(
+            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+            values.toContentValues(),
+            null, null,
+        )
+        if (rows == 0) throw WriteFailedException("update managed event id=$eventId")
+    }
+
+    override fun applyManagedCalendarReminders(
+        calendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        minutes: List<Int>,
+    ) {
+        resolver.query(
+            CalendarContract.Events.CONTENT_URI,
+            arrayOf(CalendarContract.Events._ID, CalendarContract.Events.DTSTART),
+            // Only our own mirror events, so a stray user event in this calendar
+            // isn't all-day-re-encoded or stripped of its own reminders.
+            "${CalendarContract.Events.CALENDAR_ID} = ? AND " +
+                "${CalendarContract.Events.DELETED} = 0 AND " +
+                "${CalendarContract.Events.UID_2445} LIKE ?",
+            arrayOf(calendarId.toString(), "$MANAGED_UID_PREFIX%"),
+            null,
+        )?.use { c ->
+            while (c.moveToNext()) {
+                val eventId = c.getLong(0)
+                // Managed events are all-day: DTSTART is a UTC midnight anchor.
+                val anchor = Instant.ofEpochMilli(c.getLong(1))
+                    .atZone(ZoneOffset.UTC).toLocalDate()
+                reconcileReminders(
+                    eventId,
+                    managedAllDayReminderMinutes(anchor, minutes, allDayReminderTimeMinutes),
+                )
+            }
+        }
+    }
+
     override fun instances(beginMillis: Long, endMillis: Long): List<EventInstance> {
         ensureObserversRegistered()
         val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
@@ -301,7 +574,13 @@ class AndroidCalendarDataSource @Inject constructor(
         return resolver.query(
             uri,
             InstanceProjection.COLUMNS,
-            null, null,
+            // Hide cancelled occurrences: "delete only this event" writes a
+            // cancelled exception for the one instance (#47). A NULL status is a
+            // normal, un-cancelled event, so it must survive the filter — a bare
+            // `!= CANCELED` would drop it (NULL != 2 is NULL, not true).
+            "${CalendarContract.Instances.STATUS} IS NULL OR " +
+                "${CalendarContract.Instances.STATUS} != ${CalendarContract.Events.STATUS_CANCELED}",
+            null,
             CalendarContract.Instances.BEGIN + " ASC",
         )?.use { c -> c.mapAllNotNull { CursorColumnReader(c).toEventInstance() } } ?: emptyList()
     }
@@ -389,7 +668,7 @@ class AndroidCalendarDataSource @Inject constructor(
         }
     }
 
-    override fun eventDetail(eventId: Long): EventDetail? {
+    override fun eventDetail(eventId: Long, allDayReminderTimeMinutes: Int): EventDetail? {
         val attendees = queryAttendees(eventId)
         val reminders = queryReminders(eventId)
         return resolver.query(
@@ -398,7 +677,9 @@ class AndroidCalendarDataSource @Inject constructor(
             null, null, null,
         )?.use { c ->
             if (!c.moveToFirst()) null
-            else CursorColumnReader(c).toEventDetailCore(attendees, reminders)
+            else CursorColumnReader(c).toEventDetailCore(
+                attendees, reminders, allDayReminderTimeMinutes,
+            )
         }
     }
 
@@ -420,16 +701,23 @@ class AndroidCalendarDataSource @Inject constructor(
             c.mapAll { EventColorOption(key = it.getString(0).orEmpty(), argb = it.getInt(1)) }
         }
             ?.filter { it.key.isNotEmpty() }
-            ?.sortedBy { it.key }
+            ?.curatedForPicker()
             ?: emptyList()
     }
 
-    override fun exportableEvents(): List<IcsEvent> {
+    override fun exportableEvents(calendarIds: Set<Long>?): List<IcsEvent> {
         // Only the local calendars the app owns and can write — synced calendars
-        // already have a backup (their server). Map id → display name for the
+        // already have a backup (their server). Exclude the managed special-dates
+        // mirror calendars: their events are derived from contacts, not authored
+        // here, and re-materialise from the contact sync — backing them up would
+        // just duplicate them on restore. A non-null [calendarIds] narrows the
+        // export to the user's chosen subset. Map id → display name for the
         // X-CALENDULA-CALENDAR tag a restore uses to fan back out.
         val names = calendars()
-            .filter { it.isLocal && it.canModifyContents }
+            .filter {
+                it.isLocal && it.canModifyContents && !it.isManaged &&
+                    (calendarIds == null || it.id in calendarIds)
+            }
             .associate { it.id to it.displayName }
         if (names.isEmpty()) return emptyList()
 
@@ -575,35 +863,15 @@ class AndroidCalendarDataSource @Inject constructor(
             .distinct()
 
     override fun insertEvent(form: EventForm, allDayReminderTimeMinutes: Int): Long {
-        val times = form.toWriteTimes(ZoneId.systemDefault())
-        val values = ContentValues().apply {
-            put(
-                CalendarContract.Events.CALENDAR_ID,
-                requireNotNull(form.calendarId) { "EventForm.calendarId is required" },
-            )
-            // A globally-unique UID so a later .ics backup/restore can identify
-            // the event and not duplicate it on re-import (the provider leaves
-            // this null for events it didn't sync). Older rows without one fall
-            // back to a stable synthesised UID at export time (deriveIcsUid).
-            put(CalendarContract.Events.UID_2445, "${UUID.randomUUID()}@calendula")
-            put(CalendarContract.Events.TITLE, form.title.trim())
-            put(CalendarContract.Events.ALL_DAY, if (form.isAllDay) 1 else 0)
-            put(CalendarContract.Events.DTSTART, times.dtStartMillis)
-            // The provider's invariant: recurring rows carry RRULE+DURATION
-            // (and no DTEND), one-off rows carry DTEND.
-            if (form.rrule == null) {
-                put(CalendarContract.Events.DTEND, times.dtEndMillis)
-            } else {
-                put(CalendarContract.Events.RRULE, form.rrule)
-                put(CalendarContract.Events.DURATION, times.toRfc2445Duration(form.isAllDay))
-            }
-            put(CalendarContract.Events.EVENT_TIMEZONE, times.timezone)
-            put(CalendarContract.Events.AVAILABILITY, form.availability.toProviderValue())
-            put(CalendarContract.Events.ACCESS_LEVEL, form.accessLevel.toProviderValue())
-            form.location.trim().takeIf { it.isNotEmpty() }
-                ?.let { put(CalendarContract.Events.EVENT_LOCATION, it) }
-            form.description.trim().takeIf { it.isNotEmpty() }
-                ?.let { put(CalendarContract.Events.DESCRIPTION, it) }
+        // A globally-unique UID so a later .ics backup/restore can identify
+        // the event and not duplicate it on re-import (the provider leaves
+        // this null for events it didn't sync). Older rows without one fall
+        // back to a stable synthesised UID at export time (deriveIcsUid).
+        val values = buildEventInsertValues(
+            form,
+            uid = "${UUID.randomUUID()}@calendula",
+            times = form.toWriteTimes(ZoneId.systemDefault()),
+        ).toContentValues().apply {
             // A null colour just leaves both columns unset (the event inherits
             // its calendar's colour), so only the key/raw cases are written.
             when {
@@ -615,19 +883,7 @@ class AndroidCalendarDataSource @Inject constructor(
         val uri = resolver.insert(CalendarContract.Events.CONTENT_URI, values)
             ?: throw WriteFailedException("insert event into calendar id=${form.calendarId}")
         val eventId = ContentUris.parseId(uri)
-        // Best effort (spec §8): the event exists at this point — a reminder
-        // that fails to attach is logged, not surfaced as a failed create.
-        encodedReminders(form, allDayReminderTimeMinutes)
-            .forEach { minutes ->
-                val reminder = ContentValues().apply {
-                    put(CalendarContract.Reminders.EVENT_ID, eventId)
-                    put(CalendarContract.Reminders.MINUTES, minutes)
-                    put(CalendarContract.Reminders.METHOD, CalendarContract.Reminders.METHOD_ALERT)
-                }
-                if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder) == null) {
-                    Log.w(TAG, "Failed to attach reminder ($minutes min) to event $eventId")
-                }
-            }
+        seedReminders(eventId, form, allDayReminderTimeMinutes)
         // Guests are best-effort like reminders: a row that fails to attach is
         // logged, not surfaced as a failed create. Calendula never sends an
         // invitation — it only writes the rows; the backend decides delivery.
@@ -635,6 +891,47 @@ class AndroidCalendarDataSource @Inject constructor(
         return eventId
     }
 
+    /**
+     * Attach [form]'s reminders to a freshly inserted event. Best effort
+     * (spec §8): the event exists at this point — a reminder that fails to
+     * attach is logged, not surfaced as a failed create.
+     */
+    private fun seedReminders(eventId: Long, form: EventForm, allDayReminderTimeMinutes: Int) =
+        insertReminderRows(eventId, encodedReminders(form, allDayReminderTimeMinutes))
+
+    /** Insert one `METHOD_ALERT` reminder row per raw provider offset. */
+    private fun insertReminderRows(eventId: Long, encodedMinutes: List<Int>) {
+        encodedMinutes.forEach { minutes ->
+            val reminder = ContentValues().apply {
+                put(CalendarContract.Reminders.EVENT_ID, eventId)
+                put(CalendarContract.Reminders.MINUTES, minutes)
+                put(CalendarContract.Reminders.METHOD, CalendarContract.Reminders.METHOD_ALERT)
+            }
+            if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder) == null) {
+                Log.w(TAG, "Failed to attach reminder ($minutes min) to event $eventId")
+            }
+        }
+    }
+
+    /**
+     * A managed all-day event's reminders, encoded so they fire at
+     * [allDayReminderTimeMinutes] on its **upcoming** occurrence. The event's
+     * DTSTART is an ancient recurrence anchor (see [nextYearlyOccurrence]); using
+     * it directly would sample a stale timezone offset, so the offset is sampled
+     * at the next occurrence of the anchor's month/day instead.
+     */
+    private fun managedAllDayReminderMinutes(
+        anchor: LocalDate,
+        reminders: List<Int>,
+        allDayReminderTimeMinutes: Int,
+    ): List<Int> {
+        val zone = ZoneId.systemDefault()
+        val onDate = nextYearlyOccurrence(anchor.monthValue, anchor.dayOfMonth, LocalDate.now(zone))
+        return reminders
+            .map { toProviderAllDayMinutes(it, onDate, zone, allDayReminderTimeMinutes) }
+            .distinct()
+    }
+
     override fun updateEvent(
         eventId: Long,
         original: EventForm,
@@ -669,6 +966,190 @@ class AndroidCalendarDataSource @Inject constructor(
         }
     }
 
+    override fun moveEvent(
+        eventId: Long,
+        targetCalendarId: Long,
+        original: EventForm,
+        updated: EventForm,
+        allDayReminderTimeMinutes: Int,
+    ): Long {
+        // CALENDAR_ID can't be updated in place, so re-create the event on the
+        // target calendar and delete the source. Everything that identifies or
+        // hangs off the event is copied first; the source row is removed only
+        // once the copy (including its exceptions) is complete — a failure
+        // anywhere before that rolls the new event back, so the move is
+        // all-or-nothing and never leaves a half-copied duplicate.
+        val master = queryMoveMaster(eventId)
+            ?: throw WriteFailedException("read event to move id=$eventId")
+        // Keep the source UID so an .ics backup dedups and a sync adapter can
+        // recognise the moved event; mint one only if the source carried none.
+        val uid = master.uid?.takeIf { it.isNotEmpty() } ?: "${UUID.randomUUID()}@calendula"
+        val newEventId = resolver.insert(
+            CalendarContract.Events.CONTENT_URI,
+            buildMovedMasterValues(master.event, targetCalendarId, uid).toContentValues(),
+        )?.let(ContentUris::parseId)
+            ?: throw WriteFailedException("insert moved event into calendar id=$targetCalendarId")
+        try {
+            copyReminderRows(fromEventId = eventId, toEventId = newEventId)
+            insertAttendees(newEventId, editableAttendees(eventId))
+            copyExceptions(fromEventId = eventId, toEventId = newEventId)
+            // Apply the user's field edits exactly as a same-calendar "all
+            // events" save would: the moved master carries the source's values,
+            // so the dirty diff against [original] writes only what changed
+            // (including a time or rrule edit made in the same save).
+            updateEvent(newEventId, original, updated, allDayReminderTimeMinutes)
+        } catch (t: Throwable) {
+            // Undo the partial copy so a failed move leaves nothing behind; the
+            // source is still intact (it's deleted only past this point).
+            runCatching { deleteEvent(newEventId) }
+            throw t
+        }
+        deleteEvent(eventId)
+        return newEventId
+    }
+
+    /** The master row of the event to move, as a verbatim-insert snapshot. */
+    private fun queryMoveMaster(eventId: Long): MoveMaster? = resolver.query(
+        ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+        MoveMasterProjection.COLUMNS,
+        null, null, null,
+    )?.use { c ->
+        if (!c.moveToFirst()) return@use null
+        val r = CursorColumnReader(c)
+        MoveMaster(
+            uid = r.getString(MoveMasterProjection.IDX_UID),
+            event = MasterEventSnapshot(
+                title = r.getString(MoveMasterProjection.IDX_TITLE).orEmpty(),
+                isAllDay = r.getInt(MoveMasterProjection.IDX_ALL_DAY) != 0,
+                dtStartMillis = r.getLong(MoveMasterProjection.IDX_DTSTART),
+                dtEndMillis = r.getLong(MoveMasterProjection.IDX_DTEND)
+                    .takeUnless { r.isNull(MoveMasterProjection.IDX_DTEND) },
+                duration = r.getString(MoveMasterProjection.IDX_DURATION),
+                rrule = r.getString(MoveMasterProjection.IDX_RRULE)?.takeIf { it.isNotBlank() },
+                rdate = r.getString(MoveMasterProjection.IDX_RDATE),
+                exdate = r.getString(MoveMasterProjection.IDX_EXDATE),
+                timezone = r.getString(MoveMasterProjection.IDX_EVENT_TIMEZONE),
+                availability = r.getInt(MoveMasterProjection.IDX_AVAILABILITY),
+                accessLevel = r.getInt(MoveMasterProjection.IDX_ACCESS_LEVEL),
+                status = r.getInt(MoveMasterProjection.IDX_STATUS)
+                    .takeUnless { r.isNull(MoveMasterProjection.IDX_STATUS) },
+                location = r.getString(MoveMasterProjection.IDX_LOCATION),
+                description = r.getString(MoveMasterProjection.IDX_DESCRIPTION),
+            ),
+        )
+    }
+
+    private data class MoveMaster(val uid: String?, val event: MasterEventSnapshot)
+
+    /** Copy every stored reminder row (raw offsets and method) onto [toEventId]. */
+    private fun copyReminderRows(fromEventId: Long, toEventId: Long) = resolver.query(
+        CalendarContract.Reminders.CONTENT_URI,
+        arrayOf(CalendarContract.Reminders.MINUTES, CalendarContract.Reminders.METHOD),
+        CalendarContract.Reminders.EVENT_ID + " = ?",
+        arrayOf(fromEventId.toString()),
+        null,
+    )?.use { c ->
+        while (c.moveToNext()) {
+            val values = ContentValues().apply {
+                put(CalendarContract.Reminders.EVENT_ID, toEventId)
+                put(CalendarContract.Reminders.MINUTES, c.getInt(0))
+                put(CalendarContract.Reminders.METHOD, c.getInt(1))
+            }
+            if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, values) == null) {
+                Log.w(TAG, "Failed to copy a reminder to moved event $toEventId")
+            }
+        }
+    } ?: Unit
+
+    /**
+     * The event's editable guests as [EventAttendee]s — the rows the move
+     * re-creates. Mirrors the edit form's filter: the organizer and resource
+     * rows (backend-owned, not user-editable) and any without an email are
+     * dropped; the response status resets to "invited" on re-insert.
+     */
+    private fun editableAttendees(eventId: Long): List<EventAttendee> = queryAttendees(eventId)
+        .filter {
+            it.relationship != AttendeeRelationship.Organizer && it.type != AttendeeType.Resource
+        }
+        .mapNotNull { a ->
+            a.email?.takeIf { it.isNotBlank() }?.let { email ->
+                EventAttendee(email = email, name = a.name, optional = a.type == AttendeeType.Optional)
+            }
+        }
+
+    /**
+     * Replay every exception of the series [fromEventId] against the moved series
+     * [toEventId]. The copy preserved the recurrence skeleton, so each occurrence
+     * time still resolves: a cancelled occurrence is re-hidden with a cancelled
+     * exception, a modified one is re-inserted with its fields (then its reminders
+     * reconciled and editable guests copied). No-op for a non-recurring event.
+     */
+    private fun copyExceptions(fromEventId: Long, toEventId: Long) {
+        queryExceptionRows(fromEventId).forEach { ex ->
+            if (ex.isCancelled) {
+                val values = ContentValues().apply {
+                    put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, ex.originalInstanceMillis)
+                    put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
+                }
+                resolver.insert(
+                    ContentUris.withAppendedId(
+                        CalendarContract.Events.CONTENT_EXCEPTION_URI, toEventId,
+                    ),
+                    values,
+                ) ?: throw WriteFailedException("copy cancelled occurrence to event id=$toEventId")
+            } else {
+                val uri = resolver.insert(
+                    ContentUris.withAppendedId(
+                        CalendarContract.Events.CONTENT_EXCEPTION_URI, toEventId,
+                    ),
+                    buildCopiedExceptionValues(ex).toContentValues(),
+                ) ?: throw WriteFailedException("copy modified occurrence to event id=$toEventId")
+                val newExceptionId = ContentUris.parseId(uri)
+                // The provider may clone the parent's reminders onto the new
+                // exception; reconcile to the source exception's exact set so
+                // they neither double nor drop. Same DTSTART → same all-day
+                // encoding, so the stored offsets match directly.
+                reconcileReminders(
+                    newExceptionId,
+                    queryReminders(ex.exceptionEventId).map { it.minutes },
+                )
+                insertAttendees(newExceptionId, editableAttendees(ex.exceptionEventId))
+            }
+        }
+    }
+
+    /** The series' exception rows (modified + cancelled), oldest occurrence first. */
+    private fun queryExceptionRows(seriesEventId: Long): List<ExceptionRowSnapshot> = resolver.query(
+        CalendarContract.Events.CONTENT_URI,
+        ExceptionProjection.COLUMNS,
+        "${CalendarContract.Events.ORIGINAL_ID} = ? AND ${CalendarContract.Events.DELETED} = 0",
+        arrayOf(seriesEventId.toString()),
+        CalendarContract.Events.ORIGINAL_INSTANCE_TIME + " ASC",
+    )?.use { c ->
+        c.mapAll {
+            val r = CursorColumnReader(c)
+            val status = r.getInt(ExceptionProjection.IDX_STATUS)
+                .takeUnless { r.isNull(ExceptionProjection.IDX_STATUS) }
+            ExceptionRowSnapshot(
+                exceptionEventId = r.getLong(ExceptionProjection.IDX_ID),
+                originalInstanceMillis = r.getLong(ExceptionProjection.IDX_ORIGINAL_INSTANCE_TIME),
+                isCancelled = status == CalendarContract.Events.STATUS_CANCELED,
+                status = status,
+                title = r.getString(ExceptionProjection.IDX_TITLE).orEmpty(),
+                isAllDay = r.getInt(ExceptionProjection.IDX_ALL_DAY) != 0,
+                dtStartMillis = r.getLong(ExceptionProjection.IDX_DTSTART),
+                dtEndMillis = r.getLong(ExceptionProjection.IDX_DTEND)
+                    .takeUnless { r.isNull(ExceptionProjection.IDX_DTEND) },
+                duration = r.getString(ExceptionProjection.IDX_DURATION),
+                timezone = r.getString(ExceptionProjection.IDX_EVENT_TIMEZONE),
+                availability = r.getInt(ExceptionProjection.IDX_AVAILABILITY),
+                accessLevel = r.getInt(ExceptionProjection.IDX_ACCESS_LEVEL),
+                location = r.getString(ExceptionProjection.IDX_LOCATION),
+                description = r.getString(ExceptionProjection.IDX_DESCRIPTION),
+            )
+        }
+    } ?: emptyList()
+
     override fun updateOccurrence(
         eventId: Long,
         beginMillis: Long,
@@ -763,6 +1244,8 @@ class AndroidCalendarDataSource @Inject constructor(
             CalendarContract.Events.EVENT_TIMEZONE,
             CalendarContract.Events.DURATION,
             CalendarContract.Events.ALL_DAY,
+            CalendarContract.Events._SYNC_ID,
+            CalendarContract.Events.EXDATE,
         ),
         null, null, null,
     )?.use { c ->
@@ -773,6 +1256,8 @@ class AndroidCalendarDataSource @Inject constructor(
                 timezone = c.getString(2),
                 duration = c.getString(3),
                 allDay = c.getInt(4),
+                syncId = c.getString(5),
+                exdate = c.getString(6),
             )
         } else {
             null
@@ -785,6 +1270,9 @@ class AndroidCalendarDataSource @Inject constructor(
         val timezone: String?,
         val duration: String?,
         val allDay: Int,
+        /** Null on a local calendar (and before a synced event's first push). */
+        val syncId: String? = null,
+        val exdate: String? = null,
     ) {
         /** UNTIL cutoff for ending the series before the occurrence at [beginMillis]. */
         fun truncationCutoff(beginMillis: Long): Long = previousLocalDayEndUtcMillis(
@@ -975,16 +1463,49 @@ class AndroidCalendarDataSource @Inject constructor(
     }
 
     override fun deleteOccurrence(eventId: Long, beginMillis: Long) {
-        // A cancelled exception row hides exactly this occurrence; the sync
-        // adapter turns it into an EXDATE/cancelled VEVENT upstream.
-        val values = ContentValues().apply {
-            put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, beginMillis)
-            put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
+        val row = querySeriesRow(eventId)
+        if (row.syncId == null) {
+            // No _sync_id — a local calendar, or a synced event not pushed yet.
+            // A cancelled exception can only attach to its parent through
+            // ORIGINAL_SYNC_ID, so with none the link never forms and the
+            // provider's expansion of the *parent* collapses, taking every other
+            // occurrence with it (#47 on a local calendar). EXDATE needs no link.
+            // Calendula's own contact special-date calendars are local and hold
+            // yearly series, so this path is reached in normal use.
+            val values = buildOccurrenceExdateValues(
+                existingExdate = row.exdate,
+                occurrenceMillis = beginMillis,
+                dtStartMillis = row.dtStartMillis,
+                rrule = row.rrule,
+                duration = row.duration,
+                timezone = row.timezone,
+                allDay = row.allDay,
+            )
+            val updated = resolver.update(
+                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+                values.toContentValues(), null, null,
+            )
+            if (updated == 0) {
+                throw WriteFailedException("exdate occurrence event id=$eventId begin=$beginMillis")
+            }
+            return
         }
+        // A cancelled exception row hides exactly this occurrence; the sync
+        // adapter turns it into an EXDATE/cancelled VEVENT upstream. It carries
+        // the full time set (DTSTART + DURATION + zone) so the provider derives a
+        // single instance rather than cloning the master's RRULE — the same trap
+        // the edit path documents (Codeberg #16).
+        val values = buildOccurrenceCancelValues(
+            originalInstanceMillis = beginMillis,
+            dtStartMillis = beginMillis,
+            duration = row.duration,
+            timezone = row.timezone,
+            allDay = row.allDay,
+        )
         val uri = ContentUris.withAppendedId(
             CalendarContract.Events.CONTENT_EXCEPTION_URI, eventId,
         )
-        resolver.insert(uri, values)
+        resolver.insert(uri, values.toContentValues())
             ?: throw WriteFailedException("cancel occurrence event id=$eventId begin=$beginMillis")
     }
 
@@ -1038,6 +1559,17 @@ class AndroidCalendarDataSource @Inject constructor(
         while (moveToNext()) mapper(this@mapAllNotNull)?.let(::add)
     }
 
+    /** The `CAL_SYNC2` marker value identifying a managed calendar's [type]. */
+    private fun markerFor(type: SpecialDateType): String = when (type) {
+        SpecialDateType.Birthday -> "$MANAGED_MARKER_PREFIX:birthday"
+        SpecialDateType.Anniversary -> "$MANAGED_MARKER_PREFIX:anniversary"
+        SpecialDateType.Custom -> "$MANAGED_MARKER_PREFIX:custom"
+    }
+
+    /** Inverse of [markerFor]; null for a value that isn't one of ours. */
+    private fun typeForMarker(marker: String?): SpecialDateType? =
+        SpecialDateType.entries.firstOrNull { markerFor(it) == marker }
+
     private companion object {
         const val TAG = "CalendarDataSource"
 
@@ -1047,6 +1579,14 @@ class AndroidCalendarDataSource @Inject constructor(
          */
         const val LOCAL_ACCOUNT_NAME = "Calendula"
 
+        /**
+         * Column and namespace for the special-dates marker (shared with the
+         * calendar projection, which reads it into [CalendarSource.isManaged]).
+         * CAL_SYNC1 already holds the local-calendar description, so it uses CAL_SYNC2.
+         */
+        val MANAGED_MARKER_COLUMN: String = CalendarProjection.MANAGED_MARKER_COLUMN
+        const val MANAGED_MARKER_PREFIX = CalendarProjection.MANAGED_MARKER_PREFIX
+
         /**
          * How far ahead/behind a search looks for a recurring event's nearest
          * occurrence (~2 years). Wide enough for everyday series; a series that

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarMapper.kt

@@ -24,5 +24,15 @@ internal fun ColumnReader.toCalendarSource(): CalendarSource {
         } else {
             null
         },
+        // A special-dates mirror calendar, recognised by its durable CAL_SYNC2
+        // marker (only meaningful on the local calendars the app owns). This is
+        // the source of truth for the editor lock — independent of any stored
+        // preference that a backup restore could have wiped.
+        isManaged = isLocal &&
+            getString(CalendarProjection.IDX_MANAGED_MARKER)
+                ?.startsWith(CalendarProjection.MANAGED_MARKER_PREFIX) == true,
+        // NULL is treated as syncing — the harmless default.
+        syncsEvents = isNull(CalendarProjection.IDX_SYNC_EVENTS) ||
+            getInt(CalendarProjection.IDX_SYNC_EVENTS) != 0,
     )
 }

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepository.kt

@@ -38,11 +38,22 @@ interface CalendarRepository {
     /** Permanently delete a local calendar the app owns, with all its events. */
     suspend fun deleteCalendar(id: Long)
 
+    /**
+     * Show or hide [ids] device-wide (`Calendars.VISIBLE`), which also gates
+     * their reminders — see [CalendarDataSource.setCalendarVisible]. Written one
+     * at a time, in order; a failure part-way leaves the earlier writes standing.
+     *
+     * Without `WRITE_CALENDAR` the choice is kept app-side instead (see
+     * [de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs.pendingDisabledCalendarIds]).
+     */
+    suspend fun setCalendarsVisible(ids: Collection<Long>, visible: Boolean)
+
     /**
      * Every event of the writable local calendars, ready to serialise into a
      * whole-calendar `.ics` backup (see [CalendarDataSource.exportableEvents]).
+     * [calendarIds] narrows the export to a chosen subset; `null` exports all.
      */
-    suspend fun exportEvents(): List<IcsEvent>
+    suspend fun exportEvents(calendarIds: Set<Long>? = null): List<IcsEvent>
 
     /**
      * Bulk-import parsed `.ics` [events] into [targetCalendarId]. Events whose
@@ -60,6 +71,20 @@ interface CalendarRepository {
      */
     suspend fun updateEvent(eventId: Long, original: EventForm, updated: EventForm)
 
+    /**
+     * Move an event (recurring: the whole series, with its exceptions) to
+     * [targetCalendarId] and apply the [original]→[updated] field edits; returns
+     * the new event's `Events._ID`. Copy+delete under the hood
+     * (see [CalendarDataSource.moveEvent]) — `CALENDAR_ID` can't be updated in
+     * place.
+     */
+    suspend fun moveEvent(
+        eventId: Long,
+        targetCalendarId: Long,
+        original: EventForm,
+        updated: EventForm,
+    ): Long
+
     /**
      * Change a single occurrence of a recurring event (exception row with the
      * form's values); returns the exception's `Events._ID`.

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositoryImpl.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toEpochMillis
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
@@ -15,11 +16,17 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
+import java.util.concurrent.atomic.AtomicLong
 import kotlin.time.Instant
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -46,52 +53,120 @@ class CalendarRepositoryImpl @Inject constructor(
         extraBufferCapacity = 1,
     )
 
+    /**
+     * Bumped on every provider notification, so one tick's calendar read can be
+     * shared by everything that needs it (see [calendarsSnapshot]).
+     */
+    private val generation = AtomicLong(0L)
+
     init {
-        dataSource.registerChangeListener { ticks.tryEmit(Unit) }
+        dataSource.registerChangeListener {
+            generation.incrementAndGet()
+            ticks.tryEmit(Unit)
+        }
     }
 
-    override fun calendars(): Flow<List<CalendarSource>> =
-        ticks
-            .onStart { emit(Unit) }
-            .reQuery { dataSource.calendars() }
-            .flowOn(io)
+    /**
+     * Re-query signal for everything filtered by visibility: the provider's own
+     * notifications, plus every change to the pending switch-off set.
+     */
+    private fun visibilityTicks(): Flow<Unit> = merge(
+        ticks.onStart { emit(Unit) },
+        // drop(1): the current value is already covered by the tick above.
+        prefs.pendingDisabledCalendarIds.drop(1).map {},
+    )
 
-    // Instances are filtered by the app-side hidden ∪ disabled calendar sets
-    // (M3): an event is dropped whenever the user has hidden *or* disabled its
-    // calendar. Re-runs when the provider ticks *or* either set changes —
-    // toggling a calendar in the filter sheet or the calendar manager updates
-    // every view immediately. [calendars] stays unfiltered so those screens can
-    // list and re-enable hidden/disabled calendars.
-    override fun instances(range: ClosedRange<Instant>): Flow<List<EventInstance>> =
-        combine(
-            ticks
-                .onStart { emit(Unit) }
-                .reQuery {
-                    dataSource.instances(
-                        beginMillis = range.start.toEpochMillis(),
-                        endMillis = range.endInclusive.toEpochMillis(),
-                    )
-                },
-            prefs.hiddenCalendarIds,
-            prefs.disabledCalendarIds,
-        ) { instances, hidden, disabled ->
-            val excluded = hidden + disabled
-            if (excluded.isEmpty()) instances
-            else instances.filterNot { it.calendarId in excluded }
+    // A switch-off not yet written to the provider is folded into the flag
+    // itself, so every consumer reads one visibility (#75). The reconciler goes
+    // to the data source directly — it needs the provider's own answer.
+    override fun calendars(): Flow<List<CalendarSource>> =
+        visibilityTicks().reQuery {
+            val calendars = calendarsSnapshot()
+            val pendingDisabled = prefs.pendingDisabledCalendarIds.first()
+            if (pendingDisabled.isEmpty()) calendars
+            else calendars.map {
+                if (it.id in pendingDisabled) it.copy(isVisibleInSystem = false) else it
+            }
         }
-            // hidden and disabled both derive from one DataStore, so toggling
-            // either makes both re-emit and combine briefly surfaces the same
-            // list twice — collapse the duplicate so views don't re-render for it.
             .distinctUntilChanged()
             .flowOn(io)
 
+    // Instances are filtered by the system's VISIBLE flag ∪ the switch-offs
+    // still waiting to be written to it ∪ the app-side hidden set from the
+    // filter sheet. [calendars] stays unfiltered so those screens can list and
+    // re-enable invisible calendars.
+    override fun instances(range: ClosedRange<Instant>): Flow<List<EventInstance>> =
+        combine(
+            visibilityTicks().reQuery {
+                // All three reads in one pass, so a list of instances is never
+                // filtered against a visibility snapshot from another tick.
+                QueriedInstances(
+                    instances = dataSource.instances(
+                        beginMillis = range.start.toEpochMillis(),
+                        endMillis = range.endInclusive.toEpochMillis(),
+                    ),
+                    switchedOffCalendarIds = invisibleCalendarIds() +
+                        prefs.pendingDisabledCalendarIds.first(),
+                )
+            },
+            prefs.hiddenCalendarIds,
+        ) { queried, hidden ->
+            val excluded = hidden + queried.switchedOffCalendarIds
+            if (excluded.isEmpty()) queried.instances
+            else queried.instances.filterNot { it.calendarId in excluded }
+        }
+            // Any DataStore edit re-emits the hidden set even when unchanged;
+            // collapse those so views don't re-render for them.
+            .distinctUntilChanged()
+            .flowOn(io)
+
+    /** One instances query plus the visibility it must be filtered against. */
+    private data class QueriedInstances(
+        val instances: List<EventInstance>,
+        val switchedOffCalendarIds: Set<Long>,
+    )
+
+    /** Calendars switched off at system level — hidden, and never reminded about. */
+    private suspend fun invisibleCalendarIds(): Set<Long> = calendarsSnapshot()
+        .filterNot { it.isVisibleInSystem }
+        .mapTo(mutableSetOf()) { it.id }
+
+    private val calendarsLock = Mutex()
+    private var cachedGeneration = -1L
+    private var cachedPending: Set<Long>? = null
+    private var cachedCalendars: List<CalendarSource> = emptyList()
+
+    /**
+     * The calendar list for the current tick, queried once and shared, so every
+     * open view doesn't pay for its own `Calendars` query and all of them see
+     * one snapshot.
+     *
+     * An empty result is never cached — that is what a read without the calendar
+     * permission returns, and the grant itself doesn't notify the provider. The
+     * pending switch-off set keys the cache alongside the tick, because an id
+     * leaves it before the invalidating observer is dispatched.
+     */
+    private suspend fun calendarsSnapshot(): List<CalendarSource> = calendarsLock.withLock {
+        val current = generation.get()
+        val pending = prefs.pendingDisabledCalendarIds.first()
+        if (current != cachedGeneration || pending != cachedPending || cachedCalendars.isEmpty()) {
+            cachedCalendars = dataSource.calendars()
+            cachedGeneration = current
+            cachedPending = pending
+        }
+        cachedCalendars
+    }
+
     override suspend fun eventDetail(eventId: Long): EventDetail = withContext(io) {
-        dataSource.eventDetail(eventId) ?: throw NoSuchEventException(eventId)
+        dataSource.eventDetail(eventId, allDayReminderTimeMinutes())
+            ?: throw NoSuchEventException(eventId)
     }
 
     override suspend fun searchEvents(query: String): List<EventInstance> = withContext(io) {
         if (query.isBlank()) return@withContext emptyList()
-        val excluded = prefs.hiddenCalendarIds.first() + prefs.disabledCalendarIds.first()
+        val excluded = prefs.hiddenCalendarIds.first() +
+            prefs.pendingDisabledCalendarIds.first() +
+            invisibleCalendarIds()
         dataSource.searchEvents(query)
             .let { if (excluded.isEmpty()) it else it.filterNot { e -> e.calendarId in excluded } }
     }
@@ -117,7 +192,24 @@ class CalendarRepositoryImpl @Inject constructor(
     override suspend fun deleteCalendar(id: Long) =
         withContext(io) { dataSource.deleteCalendar(id) }
 
-    override suspend fun exportEvents() = withContext(io) { dataSource.exportableEvents() }
+    override suspend fun setCalendarsVisible(ids: Collection<Long>, visible: Boolean) =
+        withContext(io) {
+            if (dataSource.canWriteCalendars()) {
+                ids.forEach { dataSource.setCalendarVisible(it, visible) }
+                // Nothing of ours is left waiting for the provider once the
+                // write lands (and switching one back on retires its entry).
+                prefs.removePendingDisabledCalendarIds(ids)
+            } else if (visible) {
+                prefs.removePendingDisabledCalendarIds(ids)
+            } else {
+                // Read-only permission: the switch still works, app-side, and
+                // the reconciler flushes it if WRITE_CALENDAR ever arrives.
+                prefs.addPendingDisabledCalendarIds(ids)
+            }
+        }
+
+    override suspend fun exportEvents(calendarIds: Set<Long>?) =
+        withContext(io) { dataSource.exportableEvents(calendarIds) }
 
     override suspend fun importEvents(
         targetCalendarId: Long,
@@ -155,6 +247,17 @@ class CalendarRepositoryImpl @Inject constructor(
         dataSource.deleteEvent(eventId)
     }
 
+    override suspend fun moveEvent(
+        eventId: Long,
+        targetCalendarId: Long,
+        original: EventForm,
+        updated: EventForm,
+    ): Long = withContext(io) {
+        dataSource.moveEvent(
+            eventId, targetCalendarId, original, updated, allDayReminderTimeMinutes(),
+        )
+    }
+
     override suspend fun updateOccurrence(
         eventId: Long,
         beginMillis: Long,

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarVisibilityReconciler.kt

@@ -0,0 +1,113 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.util.Log
+import androidx.core.content.ContextCompat
+import dagger.hilt.EntryPoint
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import de.jeanlucmakiola.calendula.data.di.IoDispatcher
+import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
+import de.jeanlucmakiola.calendula.domain.calendarVisibilityPlan
+import de.jeanlucmakiola.calendula.domain.hasSystemHiddenCalendars
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.withContext
+import kotlin.coroutines.cancellation.CancellationException
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Keeps [CalendarPrefs.pendingDisabledCalendarIds] and the system's
+ * `Calendars.VISIBLE` in step (#75): the fold-in of the retired app-local
+ * visibility model, and the standing drain for switch-offs made without
+ * `WRITE_CALENDAR`.
+ *
+ * Runs on every launch and on every calendar-permission grant; a no-op once the
+ * pending set is empty and the notice is settled. Only ever hides (see
+ * [calendarVisibilityPlan]); on an upgraded install the first run that sees a
+ * system-hidden calendar arms the one-time explanatory notice.
+ */
+@Singleton
+class CalendarVisibilityReconciler @Inject constructor(
+    @ApplicationContext private val context: Context,
+    private val dataSource: CalendarDataSource,
+    private val prefs: CalendarPrefs,
+    @IoDispatcher private val io: CoroutineDispatcher,
+) {
+
+    suspend fun run() = withContext(io) {
+        // The DataStore reads sit inside the guard too: this runs in a bare
+        // application-scope coroutine, so an IOException from a damaged
+        // preferences file would take the process down on every launch.
+        try {
+            // Settled ahead of the permission gate, so an update installed
+            // before the first grant can't later look like an upgrade.
+            if (!isUpgradeInstall()) settleNoticeOnce(pending = false)
+            if (!hasPermission(Manifest.permission.READ_CALENDAR)) return@withContext
+            val pending = prefs.pendingDisabledCalendarIds.first()
+            val noticeSettled = prefs.visibilityNoticePending.first() != null
+            if (pending.isEmpty() && noticeSettled) return@withContext
+            val calendars = dataSource.calendars()
+            // Empty means "couldn't read" (null cursor), not "no calendars".
+            // Both decisions below are one-way, so leave them to the next run.
+            if (calendars.isEmpty()) return@withContext
+            settleNoticeOnce(hasSystemHiddenCalendars(calendars, pending))
+            if (pending.isEmpty() || !hasPermission(Manifest.permission.WRITE_CALENDAR)) {
+                return@withContext
+            }
+            val plan = calendarVisibilityPlan(calendars, pending)
+            prefs.removePendingDisabledCalendarIds(plan.settled)
+            // One calendar per write: the provider skips its reminder-alarm
+            // reschedule for anything but a single-id update (see
+            // [CalendarDataSource.setCalendarVisible]).
+            for (id in plan.hide) {
+                dataSource.setCalendarVisible(id, false)
+                prefs.removePendingDisabledCalendarIds(setOf(id))
+            }
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: Exception) {
+            Log.w(TAG, "Calendar visibility reconcile failed; will retry", e)
+        }
+    }
+
+    /**
+     * Settle the one-time notice: [pending] arms it, false retires it unshown.
+     * Answered once and stored either way, so it can't resurface later.
+     */
+    private suspend fun settleNoticeOnce(pending: Boolean) {
+        if (prefs.visibilityNoticePending.first() != null) return
+        prefs.setVisibilityNoticePending(pending)
+    }
+
+    /**
+     * Whether this install has ever run an earlier version. The notice explains
+     * a behaviour change, so a first install has nothing to announce.
+     */
+    private fun isUpgradeInstall(): Boolean = try {
+        @Suppress("DEPRECATION")
+        val info = context.packageManager.getPackageInfo(context.packageName, 0)
+        info.lastUpdateTime > info.firstInstallTime
+    } catch (e: PackageManager.NameNotFoundException) {
+        Log.w(TAG, "Own package info unavailable; treating as a fresh install", e)
+        false
+    }
+
+    private fun hasPermission(permission: String): Boolean =
+        ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
+
+    /** Lets non-injectable entry points (the Application) reach the reconciler. */
+    @EntryPoint
+    @InstallIn(SingletonComponent::class)
+    interface Deps {
+        fun calendarVisibilityReconciler(): CalendarVisibilityReconciler
+    }
+
+    private companion object {
+        const val TAG = "CalendarVisibility"
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventDetailMapper.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.provider.CalendarContract
 import android.util.Log
 import de.jeanlucmakiola.calendula.domain.AccessLevel
@@ -13,6 +14,7 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.Reminder
 import de.jeanlucmakiola.calendula.domain.ReminderMethod
+import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
 import java.time.Instant
 import java.time.ZoneId
 import java.time.ZoneOffset
@@ -22,27 +24,34 @@ private const val TAG = "EventDetailMapper"
 internal fun ColumnReader.toEventDetailCore(
     attendees: List<Attendee>,
     reminders: List<Reminder>,
+    allDayReminderTimeMinutes: Int,
 ): EventDetail? {
-    val begin = getLong(EventDetailProjection.IDX_DTSTART)
-
-    if (begin < 0L) {
-        Log.w(TAG, "Dropping event with negative dtstart=$begin")
+    // DTSTART is epoch millis in UTC, so a series anchored before 1970 (common
+    // for yearly birthdays/anniversaries synced over CalDAV) is legitimately
+    // negative — only an *absent* DTSTART marks a malformed row worth dropping.
+    // Dropping negatives made every occurrence of such a series un-openable
+    // (the detail loads the ancient series-master DTSTART), see issue #34.
+    if (isNull(EventDetailProjection.IDX_DTSTART)) {
+        Log.w(TAG, "Dropping event with missing dtstart")
         return null
     }
+    val begin = getLong(EventDetailProjection.IDX_DTSTART)
 
     // Recurring events store DURATION instead of DTEND, so the series row's
-    // DTEND is null. Keep the event (end == begin); callers that opened a
-    // specific occurrence supply the real per-occurrence times from
-    // CalendarContract.Instances. Only a present-but-backwards DTEND is malformed.
+    // DTEND is null — derive the length from DURATION (as SearchMapper and
+    // IcsExportMapper do). Callers that opened a specific occurrence overwrite
+    // both times with the per-occurrence values from CalendarContract.Instances;
+    // a caller that names no occurrence (a bare content://.../events/<id> VIEW
+    // intent, issue #48) keeps this row's own times, so the length has to be
+    // right here or the series renders zero-length. A present-but-backwards
+    // DTEND is malformed, but dropping the row would make the event un-openable
+    // — the same trap as the pre-1970 DTSTART bug above (issue #34): it would
+    // surface as the generic error screen with no way to open the event and fix
+    // it. Clamp to a zero-length event instead (matching SearchMapper).
     val end = if (isNull(EventDetailProjection.IDX_DTEND)) {
-        begin
+        begin + parseRfc2445DurationMillis(getString(EventDetailProjection.IDX_DURATION))
     } else {
-        val rawEnd = getLong(EventDetailProjection.IDX_DTEND)
-        if (rawEnd < begin) {
-            Log.w(TAG, "Dropping event with dtend=$rawEnd < dtstart=$begin")
-            return null
-        }
-        rawEnd
+        getLong(EventDetailProjection.IDX_DTEND).coerceAtLeast(begin)
     }
 
     // Kept raw (no untitled fallback): the detail screen substitutes its own
@@ -81,7 +90,13 @@ internal fun ColumnReader.toEventDetailCore(
     val displayReminders = if (isAllDay) {
         val startDate = Instant.ofEpochMilli(begin).atZone(ZoneOffset.UTC).toLocalDate()
         val zone = ZoneId.systemDefault()
-        reminders.map { it.copy(minutes = fromProviderAllDayMinutes(it.minutes, startDate, zone)) }
+        reminders.map {
+            it.copy(
+                minutes = fromProviderAllDayMinutes(
+                    it.minutes, startDate, zone, allDayReminderTimeMinutes,
+                ),
+            )
+        }
     } else {
         reminders
     }

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapper.kt

@@ -6,9 +6,11 @@ import de.jeanlucmakiola.calendula.domain.Availability
 import de.jeanlucmakiola.calendula.domain.EventForm
 import kotlinx.datetime.toJavaLocalDate
 import kotlinx.datetime.toJavaLocalDateTime
+import java.time.Duration
 import java.time.Instant
 import java.time.ZoneId
 import java.time.ZoneOffset
+import java.time.LocalDateTime as JavaLocalDateTime
 
 /** Provider-ready DTSTART / DTEND / EVENT_TIMEZONE for an event write. */
 internal data class EventWriteTimes(
@@ -20,7 +22,11 @@ internal data class EventWriteTimes(
 /**
  * All-day events live at UTC midnights with an exclusive DTEND (the
  * CalendarContract convention — a one-day event ends at the next midnight);
- * timed events resolve their wall-clock values in [zone].
+ * timed events resolve their wall-clock values in the form's own
+ * [EventForm.timezone], falling back to [zone] (the device) when it doesn't pin
+ * one. Passing the device zone is therefore still correct for an unpinned form —
+ * but it no longer overrides a pinned event's zone, which is what used to
+ * silently re-anchor a foreign-zone event to the device on any time edit.
  */
 internal fun EventForm.toWriteTimes(zone: ZoneId): EventWriteTimes = if (isAllDay) {
     EventWriteTimes(
@@ -31,22 +37,92 @@ internal fun EventForm.toWriteTimes(zone: ZoneId): EventWriteTimes = if (isAllDa
         timezone = "UTC",
     )
 } else {
+    val writeZone = writeZone(zone)
     EventWriteTimes(
-        dtStartMillis = start.toJavaLocalDateTime().atZone(zone).toInstant().toEpochMilli(),
-        dtEndMillis = end.toJavaLocalDateTime().atZone(zone).toInstant().toEpochMilli(),
-        timezone = zone.id,
+        dtStartMillis = start.toJavaLocalDateTime().atZone(writeZone).toInstant().toEpochMilli(),
+        dtEndMillis = end.toJavaLocalDateTime().atZone(writeZone).toInstant().toEpochMilli(),
+        timezone = writeZone.id,
     )
 }
 
+/**
+ * The zone this form's DTSTART is expressed in: UTC for an all-day event (the
+ * provider's date anchor), otherwise the form's own pinned zone, falling back to
+ * [deviceZone] when it doesn't pin one or pins something the tz database can't
+ * parse.
+ */
+private fun EventForm.writeZone(deviceZone: ZoneId): ZoneId = if (isAllDay) {
+    ZoneOffset.UTC
+} else {
+    timezone?.let { runCatching { ZoneId.of(it) }.getOrNull() } ?: deviceZone
+}
+
+/**
+ * The form's start as a bare wall-clock value — what the user sees on the form,
+ * stripped of any zone. All-day events use their date's midnight rather than
+ * [EventForm.start]'s placeholder time-of-day, which exists only so switching the
+ * event back to timed has something to show.
+ */
+private fun EventForm.anchorLocal(): JavaLocalDateTime = if (isAllDay) {
+    start.date.toJavaLocalDate().atStartOfDay()
+} else {
+    start.toJavaLocalDateTime()
+}
+
 /**
  * RFC 2445 duration for a recurring event's row (the provider requires
  * DURATION instead of DTEND when an RRULE is set): whole days for all-day
  * events, seconds otherwise.
  */
-internal fun EventWriteTimes.toRfc2445Duration(isAllDay: Boolean): String = if (isAllDay) {
-    "P${(dtEndMillis - dtStartMillis) / MILLIS_PER_DAY}D"
+internal fun EventWriteTimes.toRfc2445Duration(isAllDay: Boolean): String =
+    rfc2445Duration(dtEndMillis - dtStartMillis, isAllDay)
+
+/**
+ * RFC 2445 duration for a [spanMillis]-long event: whole days for all-day
+ * events (the provider's convention), seconds otherwise. Shared by the write
+ * paths that need a DURATION but start from a raw millisecond span (the series
+ * copy and exception replay of a calendar move) rather than [EventWriteTimes].
+ */
+internal fun rfc2445Duration(spanMillis: Long, isAllDay: Boolean): String = if (isAllDay) {
+    "P${spanMillis / MILLIS_PER_DAY}D"
 } else {
-    "P${(dtEndMillis - dtStartMillis) / 1_000L}S"
+    "P${spanMillis / 1_000L}S"
+}
+
+/**
+ * Column values for a brand-new Events row: identity, times (the provider's
+ * invariant — recurring rows carry RRULE+DURATION and no DTEND, one-off rows
+ * carry DTEND), availability/access level and trimmed optional text. Shared by
+ * the user-event and managed-event insert paths, which differ only in the
+ * [uid] they stamp; colour and attendees are user-event concerns the caller
+ * layers on top.
+ */
+internal fun buildEventInsertValues(
+    form: EventForm,
+    uid: String,
+    times: EventWriteTimes,
+): Map<String, Any?> = buildMap {
+    put(
+        CalendarContract.Events.CALENDAR_ID,
+        requireNotNull(form.calendarId) { "EventForm.calendarId is required" },
+    )
+    put(CalendarContract.Events.UID_2445, uid)
+    put(CalendarContract.Events.TITLE, form.title.trim())
+    put(CalendarContract.Events.ALL_DAY, if (form.isAllDay) 1 else 0)
+    put(CalendarContract.Events.DTSTART, times.dtStartMillis)
+    if (form.rrule == null) {
+        put(CalendarContract.Events.DTEND, times.dtEndMillis)
+    } else {
+        put(CalendarContract.Events.RRULE, form.rrule)
+        put(CalendarContract.Events.DURATION, times.toRfc2445Duration(form.isAllDay))
+    }
+    put(CalendarContract.Events.EVENT_TIMEZONE, times.timezone)
+    put(CalendarContract.Events.AVAILABILITY, form.availability.toProviderValue())
+    put(CalendarContract.Events.ACCESS_LEVEL, form.accessLevel.toProviderValue())
+    form.location.trim().takeIf { it.isNotEmpty() }
+        ?.let { put(CalendarContract.Events.EVENT_LOCATION, it) }
+    form.description.trim().takeIf { it.isNotEmpty() }
+        ?.let { put(CalendarContract.Events.DESCRIPTION, it) }
 }
 
 /**
@@ -59,10 +135,12 @@ internal fun EventWriteTimes.toRfc2445Duration(isAllDay: Boolean): String = if (
  * Time fields travel together (the provider validates them as a unit):
  * - unchanged times, all-day flag and rrule → no time columns at all;
  * - non-recurring result → DTSTART/DTEND, DURATION and RRULE cleared;
- * - recurring result → the *series* DTSTART moves by the same delta the user
- *   applied to the displayed occurrence ([seriesDtStartMillis] is the row's
- *   current DTSTART), DURATION replaces DTEND, RRULE is written. This keeps
- *   past occurrences intact when someone edits a later occurrence's time.
+ * - recurring result → the *series* DTSTART moves by the same **wall-clock**
+ *   shift the user applied to the displayed occurrence and is re-resolved in the
+ *   event's zone ([seriesDtStartMillis] is the row's current DTSTART), DURATION
+ *   replaces DTEND, RRULE is written. This keeps past occurrences intact when
+ *   someone edits a later occurrence's time, and keeps the anchor's time-of-day
+ *   stable across a DST boundary or a zone change between the two.
  */
 internal fun buildEventUpdateValues(
     original: EventForm,
@@ -89,10 +167,14 @@ internal fun buildEventUpdateValues(
         putAll(eventColorColumns(updated.colorKey, updated.color))
     }
 
+    // A zone change counts as a time change even when the wall-clock is
+    // untouched: the same 09:00 in another zone is a different instant, so
+    // DTSTART has to move with it.
     val timesChanged = updated.start != original.start ||
         updated.end != original.end ||
         updated.isAllDay != original.isAllDay ||
-        updated.rrule != original.rrule
+        updated.rrule != original.rrule ||
+        updated.timezone != original.timezone
     if (!timesChanged) return@buildMap
 
     val newTimes = updated.toWriteTimes(zone)
@@ -104,8 +186,23 @@ internal fun buildEventUpdateValues(
         put(CalendarContract.Events.RRULE, null)
         put(CalendarContract.Events.DURATION, null)
     } else {
-        val startDelta = newTimes.dtStartMillis - original.toWriteTimes(zone).dtStartMillis
-        put(CalendarContract.Events.DTSTART, seriesDtStartMillis + startDelta)
+        // Move the series anchor by the *wall-clock* shift the user applied to the
+        // displayed occurrence, then re-resolve it in the event's (possibly new)
+        // zone — never by a millisecond delta. An instant delta silently bakes in
+        // the offset that happened to apply on the edited occurrence's date, which
+        // is a different offset from the series anchor's whenever a DST boundary
+        // sits between them, or whenever the zone itself changed. Working in wall
+        // clock keeps "09:00" meaning 09:00 at both ends.
+        val seriesLocal = Instant.ofEpochMilli(seriesDtStartMillis)
+            .atZone(original.writeZone(zone)).toLocalDateTime()
+        val wallClockShift = Duration.between(original.anchorLocal(), updated.anchorLocal())
+        val shifted = seriesLocal.plus(wallClockShift)
+        // An all-day series anchor must sit on a UTC midnight. A pure day move
+        // already lands there (both ends are midnights), but *switching* a
+        // recurring event to all-day shifts by a time-of-day too, so snap.
+        val newSeriesLocal = if (updated.isAllDay) shifted.toLocalDate().atStartOfDay() else shifted
+        val newSeriesStart = newSeriesLocal.atZone(updated.writeZone(zone))
+        put(CalendarContract.Events.DTSTART, newSeriesStart.toInstant().toEpochMilli())
         put(CalendarContract.Events.DTEND, null)
         put(CalendarContract.Events.RRULE, updated.rrule)
         put(CalendarContract.Events.DURATION, newTimes.toRfc2445Duration(updated.isAllDay))
@@ -118,8 +215,14 @@ internal fun buildEventUpdateValues(
  * provider clone the series row and apply these on top. Unlike the series
  * update there is no dirty check — the exception is a fresh row, so every
  * form-backed column is written (empty optionals as explicit NULLs, since the
- * clone starts from the parent's values). An exception is a single event:
- * DTEND, never RRULE/DURATION.
+ * clone starts from the parent's values).
+ *
+ * The occurrence's length travels as DURATION, never DTEND: the provider
+ * rejects DTEND on an exception outright (`CalendarProvider2`:
+ * "Exceptions can't overwrite dtend") and derives the instance end from
+ * DTSTART + DURATION itself, clearing the inherited RRULE in the process. This
+ * matches how AOSP Calendar/Etar write exceptions; sending DTEND is what made
+ * "only this event" fail on-device (Codeberg #16).
  */
 internal fun buildOccurrenceExceptionValues(
     form: EventForm,
@@ -131,7 +234,7 @@ internal fun buildOccurrenceExceptionValues(
     put(CalendarContract.Events.TITLE, form.title.trim())
     put(CalendarContract.Events.ALL_DAY, if (form.isAllDay) 1 else 0)
     put(CalendarContract.Events.DTSTART, times.dtStartMillis)
-    put(CalendarContract.Events.DTEND, times.dtEndMillis)
+    put(CalendarContract.Events.DURATION, times.toRfc2445Duration(form.isAllDay))
     put(CalendarContract.Events.EVENT_TIMEZONE, times.timezone)
     put(CalendarContract.Events.AVAILABILITY, form.availability.toProviderValue())
     put(CalendarContract.Events.ACCESS_LEVEL, form.accessLevel.toProviderValue())
@@ -140,6 +243,215 @@ internal fun buildOccurrenceExceptionValues(
     putAll(eventColorColumns(form.colorKey, form.color))
 }
 
+/**
+ * Raw provider snapshot of a master/one-off Events row, enough to re-insert it
+ * verbatim on another calendar (a calendar move is copy+delete — `CALENDAR_ID`
+ * is sync-adapter-owned and can't be updated in place). Recurring rows carry
+ * [rrule]/[duration] (and any [rdate]/[exdate]) with a null [dtEndMillis];
+ * one-off rows carry [dtEndMillis]. Colour is deliberately absent: a raw
+ * `EVENT_COLOR` or account-scoped `EVENT_COLOR_KEY` may be invalid on the target
+ * account, so the moved copy inherits the target calendar's colour instead.
+ */
+internal data class MasterEventSnapshot(
+    val title: String,
+    val isAllDay: Boolean,
+    val dtStartMillis: Long,
+    val dtEndMillis: Long?,
+    val duration: String?,
+    val rrule: String?,
+    val rdate: String?,
+    val exdate: String?,
+    val timezone: String?,
+    val availability: Int,
+    val accessLevel: Int,
+    val status: Int?,
+    val location: String?,
+    val description: String?,
+)
+
+/**
+ * Column values re-creating [snapshot] as a fresh Events row on
+ * [targetCalendarId], keeping its [uid] so `.ics` backup dedup and sync identity
+ * survive the move. Preserves the recurrence skeleton (DTSTART/RRULE/DURATION,
+ * RDATE/EXDATE) so the series' generated instances — and therefore the
+ * ORIGINAL_INSTANCE_TIME of every copied exception — line up unchanged. The
+ * caller layers the user's field edits on top with a normal series update.
+ */
+internal fun buildMovedMasterValues(
+    snapshot: MasterEventSnapshot,
+    targetCalendarId: Long,
+    uid: String,
+): Map<String, Any?> = buildMap {
+    put(CalendarContract.Events.CALENDAR_ID, targetCalendarId)
+    put(CalendarContract.Events.UID_2445, uid)
+    put(CalendarContract.Events.TITLE, snapshot.title)
+    put(CalendarContract.Events.ALL_DAY, if (snapshot.isAllDay) 1 else 0)
+    put(CalendarContract.Events.DTSTART, snapshot.dtStartMillis)
+    put(CalendarContract.Events.EVENT_TIMEZONE, snapshot.timezone ?: "UTC")
+    if (snapshot.rrule != null) {
+        put(CalendarContract.Events.RRULE, snapshot.rrule)
+        snapshot.rdate?.takeIf { it.isNotBlank() }?.let { put(CalendarContract.Events.RDATE, it) }
+        snapshot.exdate?.takeIf { it.isNotBlank() }?.let { put(CalendarContract.Events.EXDATE, it) }
+        put(CalendarContract.Events.DURATION, snapshot.movedDuration())
+    } else {
+        snapshot.dtEndMillis?.let { put(CalendarContract.Events.DTEND, it) }
+    }
+    put(CalendarContract.Events.AVAILABILITY, snapshot.availability)
+    put(CalendarContract.Events.ACCESS_LEVEL, snapshot.accessLevel)
+    snapshot.status?.let { put(CalendarContract.Events.STATUS, it) }
+    put(CalendarContract.Events.EVENT_LOCATION, snapshot.location?.ifEmpty { null })
+    put(CalendarContract.Events.DESCRIPTION, snapshot.description?.ifEmpty { null })
+}
+
+/** The recurring copy's DURATION: its own if present, else derived from DTEND. */
+private fun MasterEventSnapshot.movedDuration(): String = duration?.takeIf { it.isNotBlank() }
+    ?: rfc2445Duration((dtEndMillis ?: dtStartMillis) - dtStartMillis, isAllDay)
+
+/**
+ * Raw provider snapshot of one exception row of a recurring series (a modified
+ * or cancelled occurrence, `ORIGINAL_ID` = the series). [originalInstanceMillis]
+ * ties it to the occurrence it overrides; a [isCancelled] row only needs that.
+ */
+internal data class ExceptionRowSnapshot(
+    val exceptionEventId: Long,
+    val originalInstanceMillis: Long,
+    val isCancelled: Boolean,
+    val status: Int?,
+    val title: String,
+    val isAllDay: Boolean,
+    val dtStartMillis: Long,
+    val dtEndMillis: Long?,
+    val duration: String?,
+    val timezone: String?,
+    val availability: Int,
+    val accessLevel: Int,
+    val location: String?,
+    val description: String?,
+)
+
+/**
+ * Column values replaying a *modified* occurrence [snapshot] against the moved
+ * series via `CONTENT_EXCEPTION_URI`. Like [buildOccurrenceExceptionValues] the
+ * length travels as DURATION (the provider rejects DTEND on an exception). A
+ * cancelled occurrence is written separately (ORIGINAL_INSTANCE_TIME +
+ * STATUS_CANCELED) — this builder is only for the modified case.
+ */
+internal fun buildCopiedExceptionValues(snapshot: ExceptionRowSnapshot): Map<String, Any?> =
+    buildMap {
+        put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, snapshot.originalInstanceMillis)
+        put(CalendarContract.Events.TITLE, snapshot.title)
+        put(CalendarContract.Events.ALL_DAY, if (snapshot.isAllDay) 1 else 0)
+        put(CalendarContract.Events.DTSTART, snapshot.dtStartMillis)
+        put(
+            CalendarContract.Events.DURATION,
+            snapshot.duration?.takeIf { it.isNotBlank() }
+                ?: rfc2445Duration(
+                    (snapshot.dtEndMillis ?: snapshot.dtStartMillis) - snapshot.dtStartMillis,
+                    snapshot.isAllDay,
+                ),
+        )
+        put(CalendarContract.Events.EVENT_TIMEZONE, snapshot.timezone ?: "UTC")
+        put(CalendarContract.Events.AVAILABILITY, snapshot.availability)
+        put(CalendarContract.Events.ACCESS_LEVEL, snapshot.accessLevel)
+        put(CalendarContract.Events.EVENT_LOCATION, snapshot.location?.ifEmpty { null })
+        put(CalendarContract.Events.DESCRIPTION, snapshot.description?.ifEmpty { null })
+        snapshot.status?.let { put(CalendarContract.Events.STATUS, it) }
+    }
+
+/**
+ * Column values for a *cancelled*-occurrence exception row ("delete only this
+ * event"): inserting them at `Events.CONTENT_EXCEPTION_URI/<id>` makes the
+ * provider clone the series row and cancel exactly this one instance.
+ *
+ * As with [buildOccurrenceExceptionValues], the occurrence must be anchored with
+ * DTSTART + DURATION so the provider derives a single instance and clears the
+ * inherited RRULE. A STATUS-only cancel skips that: the clone keeps the RRULE, so
+ * the *whole series* is cancelled and every other occurrence disappears
+ * (Codeberg #47). The occurrence's length/zone come straight from the series row
+ * — cancelling never changes them.
+ */
+internal fun buildOccurrenceCancelValues(
+    originalInstanceMillis: Long,
+    dtStartMillis: Long,
+    duration: String?,
+    timezone: String?,
+    allDay: Int,
+): Map<String, Any?> = buildMap {
+    put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, originalInstanceMillis)
+    put(CalendarContract.Events.DTSTART, dtStartMillis)
+    put(CalendarContract.Events.DURATION, duration)
+    put(CalendarContract.Events.EVENT_TIMEZONE, timezone)
+    put(CalendarContract.Events.ALL_DAY, allDay)
+    put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
+}
+
+/**
+ * The master-row columns that drop the occurrence at [occurrenceMillis] from a
+ * series by adding it to `EXDATE` — the path for events that have **no
+ * `_sync_id`** (a local calendar, or a synced event not yet pushed).
+ *
+ * A cancelled exception row (see [buildOccurrenceCancelValues]) only attaches to
+ * its parent through `ORIGINAL_SYNC_ID`. Without a `_sync_id` the link never
+ * forms, and the provider's expansion of the *parent* collapses — every other
+ * occurrence disappears (Codeberg #47, reproduced on a local calendar). EXDATE
+ * needs no link, and is the canonical iCalendar way to drop an occurrence, so a
+ * sync adapter carries it upstream unchanged if the calendar later syncs.
+ *
+ * The whole time/recurrence set is rewritten alongside it on purpose. The
+ * provider does **not** treat an EXDATE-only update as a recurrence change: it
+ * leaves the expanded `Instances` rows untouched, so the occurrence stays visible
+ * (and, symmetrically, un-excluding one leaves it hidden). Writing DTSTART with
+ * it forces the re-expansion — but DTSTART *alone* makes the provider recompute
+ * `lastDate` as if the event were a single instance, collapsing the series to its
+ * first occurrence. Passing DTSTART + DURATION + RRULE + zone together is what
+ * re-expands it correctly. All observed on a Pixel; see the #47 notes.
+ *
+ * EXDATE is a comma-separated list, so an existing one is appended to (a repeat
+ * of the same occurrence is folded away). All-day series take the `VALUE=DATE`
+ * form (`yyyyMMdd`), timed ones the UTC date-time form (`yyyyMMddTHHmmssZ`).
+ */
+internal fun buildOccurrenceExdateValues(
+    existingExdate: String?,
+    occurrenceMillis: Long,
+    dtStartMillis: Long,
+    rrule: String?,
+    duration: String?,
+    timezone: String?,
+    allDay: Int,
+): Map<String, Any?> {
+    val stamp = formatExdateStamp(occurrenceMillis, isAllDay = allDay != 0)
+    val existing = existingExdate?.split(',')
+        ?.map { it.trim() }
+        ?.filter { it.isNotEmpty() }
+        .orEmpty()
+    val merged = (existing + stamp).distinct().joinToString(",")
+    return mapOf(
+        CalendarContract.Events.EXDATE to merged,
+        CalendarContract.Events.DTSTART to dtStartMillis,
+        CalendarContract.Events.RRULE to rrule,
+        CalendarContract.Events.DURATION to duration,
+        CalendarContract.Events.EVENT_TIMEZONE to timezone,
+        CalendarContract.Events.ALL_DAY to allDay,
+    )
+}
+
+/**
+ * One EXDATE entry for the occurrence starting at [occurrenceMillis]. Both forms
+ * are UTC: the provider stores an all-day DTSTART at UTC midnight, so its date
+ * reads off the UTC calendar day.
+ */
+private fun formatExdateStamp(occurrenceMillis: Long, isAllDay: Boolean): String {
+    val utc = Instant.ofEpochMilli(occurrenceMillis).atZone(ZoneOffset.UTC)
+    return if (isAllDay) {
+        "%04d%02d%02d".format(utc.year, utc.monthValue, utc.dayOfMonth)
+    } else {
+        "%04d%02d%02dT%02d%02d%02dZ".format(
+            utc.year, utc.monthValue, utc.dayOfMonth,
+            utc.hour, utc.minute, utc.second,
+        )
+    }
+}
+
 /**
  * The `EVENT_COLOR` / `EVENT_COLOR_KEY` columns for a colour selection. A
  * [colorKey] writes the key alone (the provider derives `EVENT_COLOR` from the

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/IcsExportMapper.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.deriveIcsUid

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/InstanceMapper.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.util.Log
 import de.jeanlucmakiola.calendula.domain.EventInstance
 

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/ManagedCalendar.kt

@@ -0,0 +1,24 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
+
+/**
+ * One of the app's special-dates calendars, discovered by the marker stamped in
+ * its `CAL_SYNC2` column — so the mirror can re-adopt its calendars even if the
+ * stored ids in preferences were lost (e.g. an app-data wipe).
+ */
+data class ManagedCalendarRow(val id: Long, val type: SpecialDateType)
+
+/**
+ * A managed event as read back for the sync diff. [uid] is the deterministic
+ * `Events.UID_2445` (`contact-<type>:<lookupKey>@calendula`) the mirror keys on;
+ * [title], [dtStartMillis] and [rrule] are the managed columns compared against
+ * the desired state to decide whether a targeted update is needed.
+ */
+data class ManagedEventRow(
+    val eventId: Long,
+    val uid: String,
+    val title: String,
+    val dtStartMillis: Long,
+    val rrule: String?,
+)

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/Projections.kt

@@ -15,9 +15,18 @@ internal object CalendarProjection {
         // own we stash one in CAL_SYNC1 (synced rows put their sync token here,
         // so the mapper only reads it for local calendars).
         DESCRIPTION_COLUMN,
+        // The special-dates marker (CAL_SYNC2) — the durable identity the app
+        // uses to recognise its own managed calendars, independent of any
+        // stored preference id (which a backup restore / data wipe can lose).
+        MANAGED_MARKER_COLUMN,
+        CalendarContract.Calendars.SYNC_EVENTS,
     )
 
     const val DESCRIPTION_COLUMN: String = CalendarContract.Calendars.CAL_SYNC1
+    const val MANAGED_MARKER_COLUMN: String = CalendarContract.Calendars.CAL_SYNC2
+
+    /** Namespace prefix of every managed-calendar [MANAGED_MARKER_COLUMN] value. */
+    const val MANAGED_MARKER_PREFIX = "calendula.specialdates"
 
     const val IDX_ID = 0
     const val IDX_DISPLAY_NAME = 1
@@ -27,6 +36,8 @@ internal object CalendarProjection {
     const val IDX_VISIBLE = 5
     const val IDX_ACCESS_LEVEL = 6
     const val IDX_DESCRIPTION = 7
+    const val IDX_MANAGED_MARKER = 8
+    const val IDX_SYNC_EVENTS = 9
 }
 
 internal object InstanceProjection {
@@ -75,6 +86,9 @@ internal object EventDetailProjection {
         CalendarContract.Events.EVENT_TIMEZONE,
         CalendarContract.Events.SELF_ATTENDEE_STATUS,
         CalendarContract.Events.EVENT_COLOR_KEY,
+        // Recurring rows carry DURATION instead of DTEND; the detail screen
+        // needs it to render a series opened without a named occurrence.
+        CalendarContract.Events.DURATION,
     )
 
     const val IDX_EVENT_ID = 0
@@ -95,6 +109,7 @@ internal object EventDetailProjection {
     const val IDX_EVENT_TIMEZONE = 15
     const val IDX_SELF_ATTENDEE_STATUS = 16
     const val IDX_EVENT_COLOR_KEY = 17
+    const val IDX_DURATION = 18
 }
 
 /**
@@ -177,6 +192,86 @@ internal object SearchProjection {
     const val IDX_RDATE = 11
 }
 
+/**
+ * The master/one-off Events row of an event about to be moved to another
+ * calendar, read for a verbatim re-insert (see [MasterEventSnapshot]). Carries
+ * the full recurrence skeleton (RRULE/DURATION, RDATE/EXDATE) so the moved copy
+ * generates the same instances, and `UID_2445` so identity survives the move.
+ */
+internal object MoveMasterProjection {
+    val COLUMNS: Array<String> = arrayOf(
+        CalendarContract.Events.UID_2445,
+        CalendarContract.Events.TITLE,
+        CalendarContract.Events.DTSTART,
+        CalendarContract.Events.DTEND,
+        CalendarContract.Events.DURATION,
+        CalendarContract.Events.RRULE,
+        CalendarContract.Events.RDATE,
+        CalendarContract.Events.EXDATE,
+        CalendarContract.Events.EVENT_TIMEZONE,
+        CalendarContract.Events.ALL_DAY,
+        CalendarContract.Events.AVAILABILITY,
+        CalendarContract.Events.ACCESS_LEVEL,
+        CalendarContract.Events.STATUS,
+        CalendarContract.Events.EVENT_LOCATION,
+        CalendarContract.Events.DESCRIPTION,
+    )
+
+    const val IDX_UID = 0
+    const val IDX_TITLE = 1
+    const val IDX_DTSTART = 2
+    const val IDX_DTEND = 3
+    const val IDX_DURATION = 4
+    const val IDX_RRULE = 5
+    const val IDX_RDATE = 6
+    const val IDX_EXDATE = 7
+    const val IDX_EVENT_TIMEZONE = 8
+    const val IDX_ALL_DAY = 9
+    const val IDX_AVAILABILITY = 10
+    const val IDX_ACCESS_LEVEL = 11
+    const val IDX_STATUS = 12
+    const val IDX_LOCATION = 13
+    const val IDX_DESCRIPTION = 14
+}
+
+/**
+ * The exception rows of a recurring series (`ORIGINAL_ID` = the series), read to
+ * replay them against a moved copy (see [ExceptionRowSnapshot]). Both modified
+ * occurrences and cancellations (`STATUS_CANCELED`) are read; the query filters
+ * `DELETED = 0` so provider tombstones aren't replayed.
+ */
+internal object ExceptionProjection {
+    val COLUMNS: Array<String> = arrayOf(
+        CalendarContract.Events._ID,
+        CalendarContract.Events.ORIGINAL_INSTANCE_TIME,
+        CalendarContract.Events.STATUS,
+        CalendarContract.Events.TITLE,
+        CalendarContract.Events.ALL_DAY,
+        CalendarContract.Events.DTSTART,
+        CalendarContract.Events.DTEND,
+        CalendarContract.Events.DURATION,
+        CalendarContract.Events.EVENT_TIMEZONE,
+        CalendarContract.Events.AVAILABILITY,
+        CalendarContract.Events.ACCESS_LEVEL,
+        CalendarContract.Events.EVENT_LOCATION,
+        CalendarContract.Events.DESCRIPTION,
+    )
+
+    const val IDX_ID = 0
+    const val IDX_ORIGINAL_INSTANCE_TIME = 1
+    const val IDX_STATUS = 2
+    const val IDX_TITLE = 3
+    const val IDX_ALL_DAY = 4
+    const val IDX_DTSTART = 5
+    const val IDX_DTEND = 6
+    const val IDX_DURATION = 7
+    const val IDX_EVENT_TIMEZONE = 8
+    const val IDX_AVAILABILITY = 9
+    const val IDX_ACCESS_LEVEL = 10
+    const val IDX_LOCATION = 11
+    const val IDX_DESCRIPTION = 12
+}
+
 internal object AttendeeProjection {
     val COLUMNS: Array<String> = arrayOf(
         CalendarContract.Attendees.ATTENDEE_NAME,

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/SearchMapper.kt

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
 
@@ -10,8 +11,11 @@ import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
  * of DTEND — reconstruct the end the same way the `.ics` export does.
  */
 internal fun ColumnReader.toSearchResult(): EventInstance? {
+    // A pre-1970 series anchor is a legitimately negative epoch-millis DTSTART
+    // (see EventDetailMapper / issue #34); drop only a genuinely absent one, so
+    // long-running birthdays/anniversaries still surface in search.
+    if (isNull(SearchProjection.IDX_DTSTART)) return null
     val dtStart = getLong(SearchProjection.IDX_DTSTART)
-    if (dtStart < 0L) return null
     val end = when {
         !isNull(SearchProjection.IDX_DTEND) -> getLong(SearchProjection.IDX_DTEND)
         else -> dtStart + parseRfc2445DurationMillis(getString(SearchProjection.IDX_DURATION))

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridge.kt

@@ -1,7 +0,0 @@
-package de.jeanlucmakiola.calendula.data.calendar
-
-import kotlin.time.Instant
-
-fun Long.toKotlinInstantFromEpochMillis(): Instant = Instant.fromEpochMilliseconds(this)
-
-fun Instant.toEpochMillis(): Long = toEpochMilliseconds()

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/AndroidSpecialDatesCalendarSpec.kt

@@ -0,0 +1,42 @@
+package de.jeanlucmakiola.calendula.data.contacts
+
+import android.content.Context
+import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Resolves the localized calendar names/templates and per-type colours the
+ * mirror creates its calendars with. The colours are picked from the shared
+ * palette so managed calendars look native alongside user calendars.
+ */
+@Singleton
+class AndroidSpecialDatesCalendarSpec @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : SpecialDatesCalendarSpec {
+
+    override fun displayName(type: SpecialDateType): String = context.getString(
+        when (type) {
+            SpecialDateType.Birthday -> R.string.special_dates_calendar_birthday
+            SpecialDateType.Anniversary -> R.string.special_dates_calendar_anniversary
+            SpecialDateType.Custom -> R.string.special_dates_calendar_custom
+        },
+    )
+
+    override fun defaultTitleTemplate(type: SpecialDateType): String = context.getString(
+        when (type) {
+            SpecialDateType.Birthday -> R.string.special_dates_default_title_birthday
+            SpecialDateType.Anniversary -> R.string.special_dates_default_title_anniversary
+            SpecialDateType.Custom -> R.string.special_dates_default_title_custom
+        },
+    )
+
+    override fun color(type: SpecialDateType): Int = when (type) {
+        SpecialDateType.Birthday -> CalendarColorPalette.Purple
+        SpecialDateType.Anniversary -> CalendarColorPalette.Red
+        SpecialDateType.Custom -> CalendarColorPalette.Blue
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/ContactSpecialDatesDataSource.kt

@@ -0,0 +1,105 @@
+package de.jeanlucmakiola.calendula.data.contacts
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.provider.ContactsContract
+import android.provider.ContactsContract.CommonDataKinds.Event
+import android.util.Log
+import androidx.core.content.ContextCompat
+import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.domain.contacts.ContactSpecialDate
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
+import de.jeanlucmakiola.calendula.domain.contacts.managedUid
+import de.jeanlucmakiola.calendula.domain.contacts.parseContactEventDate
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Reads the dated `Event` rows (birthdays, anniversaries, custom dates) of the
+ * device's contacts. Read-only and offline — the one-way source for the
+ * special-dates mirror. Requires `READ_CONTACTS`; returns an empty list when
+ * the permission is absent so the sync can degrade to a stalled state rather
+ * than crash.
+ */
+interface ContactSpecialDatesDataSource {
+    fun hasPermission(): Boolean
+
+    /** All usable contact special-dates, deduplicated per contact and type. */
+    fun readSpecialDates(): List<ContactSpecialDate>
+}
+
+/** Whether `READ_CONTACTS` is granted — the gate for every contacts read. */
+fun Context.hasContactsPermission(): Boolean =
+    ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) ==
+        PackageManager.PERMISSION_GRANTED
+
+/** Map a `ContactsContract` event `TYPE` to our calendar bucket. */
+internal fun specialDateTypeForRawEventType(type: Int): SpecialDateType = when (type) {
+    Event.TYPE_BIRTHDAY -> SpecialDateType.Birthday
+    Event.TYPE_ANNIVERSARY -> SpecialDateType.Anniversary
+    else -> SpecialDateType.Custom
+}
+
+@Singleton
+class AndroidContactSpecialDatesDataSource @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : ContactSpecialDatesDataSource {
+
+    override fun hasPermission(): Boolean = context.hasContactsPermission()
+
+    override fun readSpecialDates(): List<ContactSpecialDate> {
+        if (!hasPermission()) return emptyList()
+        val resolver = context.contentResolver
+        // A contact can carry the same date more than once (multiple raw contacts
+        // under one aggregate); dedup on the mirror's reconciliation key so exact
+        // duplicates collapse while genuinely distinct dates (two custom events on
+        // one contact) are all kept. Ordered by Data._ID so which of two truly
+        // conflicting rows wins is stable across syncs (no event ping-pong).
+        val seen = HashSet<String>()
+        val result = ArrayList<ContactSpecialDate>()
+        runCatching {
+            resolver.query(
+                ContactsContract.Data.CONTENT_URI,
+                PROJECTION,
+                "${ContactsContract.Data.MIMETYPE} = ?",
+                arrayOf(Event.CONTENT_ITEM_TYPE),
+                "${ContactsContract.Data._ID} ASC",
+            )?.use { c ->
+                val idxDate = c.getColumnIndexOrThrow(Event.START_DATE)
+                val idxType = c.getColumnIndexOrThrow(Event.TYPE)
+                val idxLabel = c.getColumnIndexOrThrow(Event.LABEL)
+                val idxLookup = c.getColumnIndexOrThrow(ContactsContract.Data.LOOKUP_KEY)
+                val idxName = c.getColumnIndexOrThrow(ContactsContract.Data.DISPLAY_NAME_PRIMARY)
+                while (c.moveToNext()) {
+                    val lookup = c.getString(idxLookup)?.takeIf { it.isNotEmpty() } ?: continue
+                    val parts = parseContactEventDate(c.getString(idxDate)) ?: continue
+                    val type = specialDateTypeForRawEventType(c.getInt(idxType))
+                    val date = ContactSpecialDate(
+                        lookupKey = lookup,
+                        displayName = c.getString(idxName)?.trim().orEmpty(),
+                        type = type,
+                        month = parts.month,
+                        day = parts.day,
+                        year = parts.year,
+                        label = c.getString(idxLabel)?.takeIf { it.isNotBlank() },
+                    )
+                    if (seen.add(date.managedUid())) result += date
+                }
+            }
+        }.onFailure { Log.w(TAG, "Reading contact special-dates failed", it) }
+        return result
+    }
+
+    private companion object {
+        const val TAG = "ContactSpecialDates"
+
+        val PROJECTION = arrayOf(
+            ContactsContract.Data.LOOKUP_KEY,
+            ContactsContract.Data.DISPLAY_NAME_PRIMARY,
+            Event.START_DATE,
+            Event.TYPE,
+            Event.LABEL,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/SpecialDatesScheduler.kt

@@ -0,0 +1,135 @@
+package de.jeanlucmakiola.calendula.data.contacts
+
+import android.content.Context
+import android.util.Log
+import androidx.work.CoroutineWorker
+import androidx.work.Data
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.ExistingWorkPolicy
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import androidx.work.WorkerParameters
+import dagger.hilt.EntryPoint
+import dagger.hilt.InstallIn
+import dagger.hilt.android.EntryPointAccessors
+import dagger.hilt.components.SingletonComponent
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.data.prefs.SpecialDatesStalledReason
+import kotlinx.coroutines.flow.first
+import java.util.concurrent.TimeUnit
+
+/**
+ * Schedules the contact special-dates mirror. Birthdays change rarely, so this
+ * is deliberately cheap: a **daily** periodic reconcile, plus an immediate run
+ * on enable / "Sync now" and a debounced one when the app is foregrounded. No
+ * ContentObserver — it would need the process alive and buys almost nothing for
+ * once-a-year events. Everything stays offline (local contacts → local calendar).
+ */
+object SpecialDatesScheduler {
+
+    private const val WORK_NAME = "special-dates-sync"
+    private const val WORK_NAME_NOW = "special-dates-sync-now"
+    private const val WORK_NAME_FOREGROUND = "special-dates-sync-foreground"
+    private const val KEY_FOREGROUND = "foreground"
+
+    /** Enqueue (or cancel) the daily periodic reconcile to match [enabled]. */
+    fun apply(context: Context, enabled: Boolean) {
+        val workManager = WorkManager.getInstance(context)
+        if (!enabled) {
+            workManager.cancelUniqueWork(WORK_NAME)
+            workManager.cancelUniqueWork(WORK_NAME_NOW)
+            workManager.cancelUniqueWork(WORK_NAME_FOREGROUND)
+            return
+        }
+        val request = PeriodicWorkRequestBuilder<SpecialDatesSyncWorker>(1, TimeUnit.DAYS)
+            // Delay the first periodic run so it never overlaps an immediate run.
+            .setInitialDelay(1, TimeUnit.DAYS)
+            .build()
+        workManager.enqueueUniquePeriodicWork(WORK_NAME, ExistingPeriodicWorkPolicy.UPDATE, request)
+    }
+
+    /**
+     * Run one reconcile immediately. [foreground] runs (the app resuming) are
+     * debounced inside the worker and use their own work name, so a frequent
+     * foreground resync can never REPLACE — and swallow — a pending enable /
+     * "Sync now" run, which always syncs. The engine serializes the two if they
+     * overlap.
+     */
+    fun runNow(context: Context, foreground: Boolean = false) {
+        val request = OneTimeWorkRequestBuilder<SpecialDatesSyncWorker>()
+            .setInputData(Data.Builder().putBoolean(KEY_FOREGROUND, foreground).build())
+            .build()
+        val name = if (foreground) WORK_NAME_FOREGROUND else WORK_NAME_NOW
+        WorkManager.getInstance(context)
+            .enqueueUniqueWork(name, ExistingWorkPolicy.REPLACE, request)
+    }
+
+    internal const val INPUT_FOREGROUND = KEY_FOREGROUND
+}
+
+/**
+ * Runs the [SpecialDatesSyncEngine]. Pulls its collaborators through a Hilt
+ * [EntryPoint] so it works under WorkManager's default worker factory. Records
+ * the run for the settings status line; a missing permission parks the feature
+ * in a stalled state (surfaced in settings) rather than retrying forever.
+ */
+class SpecialDatesSyncWorker(
+    appContext: Context,
+    params: WorkerParameters,
+) : CoroutineWorker(appContext, params) {
+
+    @EntryPoint
+    @InstallIn(SingletonComponent::class)
+    interface Deps {
+        fun settingsPrefs(): SettingsPrefs
+        fun syncEngine(): SpecialDatesSyncEngine
+    }
+
+    override suspend fun doWork(): Result {
+        val deps = EntryPointAccessors.fromApplication(applicationContext, Deps::class.java)
+        val prefs = deps.settingsPrefs()
+
+        val now = System.currentTimeMillis()
+        // A foreground resume can fire often — skip if we synced recently.
+        val foreground = inputData.getBoolean(SpecialDatesScheduler.INPUT_FOREGROUND, false)
+        if (foreground && now - prefs.specialDatesLastForegroundSync.first() < FOREGROUND_DEBOUNCE_MILLIS) {
+            return Result.success()
+        }
+
+        return try {
+            when (val result = deps.syncEngine().sync()) {
+                // The engine re-checks the toggle, so already-queued work never
+                // revives a disabled feature; don't record a run either.
+                SpecialDatesSyncResult.Disabled -> return Result.success()
+                else -> {
+                    val stalled = if (result == SpecialDatesSyncResult.PermissionMissing) {
+                        SpecialDatesStalledReason.PermissionRevoked
+                    } else {
+                        null
+                    }
+                    prefs.recordSpecialDatesRun(now, stalled)
+                }
+            }
+            if (foreground) prefs.setSpecialDatesLastForegroundSync(now)
+            Result.success()
+        } catch (e: SecurityException) {
+            // A revoked calendar/contacts permission won't fix itself on retry —
+            // park the feature in a stalled state (surfaced in settings) instead
+            // of retrying with backoff forever.
+            Log.w(TAG, "Special-dates sync lacks a required permission", e)
+            prefs.recordSpecialDatesRun(now, SpecialDatesStalledReason.PermissionRevoked)
+            Result.success()
+        } catch (e: Exception) {
+            Log.w(TAG, "Special-dates sync failed", e)
+            Result.retry()
+        }
+    }
+
+    companion object {
+        private const val TAG = "SpecialDatesSync"
+
+        /** Skip a foreground-triggered sync if one ran within this window (4h). */
+        private const val FOREGROUND_DEBOUNCE_MILLIS = 4L * 60 * 60 * 1000
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/SpecialDatesSyncEngine.kt

@@ -0,0 +1,304 @@
+package de.jeanlucmakiola.calendula.data.contacts
+
+import android.provider.CalendarContract
+import de.jeanlucmakiola.calendula.data.calendar.CalendarDataSource
+import de.jeanlucmakiola.calendula.data.calendar.ManagedEventRow
+import de.jeanlucmakiola.calendula.data.calendar.toWriteTimes
+import de.jeanlucmakiola.floret.reminders.ReminderOverride
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.domain.Availability
+import de.jeanlucmakiola.calendula.domain.EventForm
+import de.jeanlucmakiola.calendula.domain.RecurrenceFreq
+import de.jeanlucmakiola.calendula.domain.SimpleRecurrence
+import de.jeanlucmakiola.calendula.domain.contacts.ContactSpecialDate
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
+import de.jeanlucmakiola.calendula.domain.contacts.anchorDate
+import de.jeanlucmakiola.calendula.domain.contacts.managedUid
+import de.jeanlucmakiola.calendula.domain.contacts.renderSpecialDateTitle
+import de.jeanlucmakiola.calendula.domain.toRRule
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.LocalTime
+import java.time.ZoneId
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/** Outcome of one mirror reconcile, reported back so the worker can record status. */
+enum class SpecialDatesSyncResult { Success, Disabled, PermissionMissing }
+
+/**
+ * Localized, per-type presentation the engine needs but can't derive purely
+ * (calendar display name, colour, and the default title template). Kept behind
+ * an interface so the engine's diff stays unit-testable without Android
+ * resources.
+ */
+interface SpecialDatesCalendarSpec {
+    fun displayName(type: SpecialDateType): String
+    fun color(type: SpecialDateType): Int
+    fun defaultTitleTemplate(type: SpecialDateType): String
+}
+
+/**
+ * The stored title template for [type], falling back to the localized default
+ * when blank/absent — the one resolution rule shared by the sync (what gets
+ * written) and the settings editor (what gets shown).
+ */
+fun SpecialDatesCalendarSpec.resolveTitleTemplate(
+    type: SpecialDateType,
+    stored: Map<SpecialDateType, String>,
+): String = stored[type]?.takeIf { it.isNotBlank() } ?: defaultTitleTemplate(type)
+
+/**
+ * Mirrors contact birthdays/anniversaries/custom dates into local calendars,
+ * one per type. Every reconcile is an idempotent diff keyed on the deterministic
+ * `UID_2445` ([managedEventUid]): new contacts are inserted (seeding user-owned
+ * fields once), changed contacts get a *targeted* managed-column update, and
+ * removed contacts are deleted — so a user's own edits (reminders, location,
+ * notes) are never clobbered. See docs/design/contact-special-dates.md.
+ */
+@Singleton
+class SpecialDatesSyncEngine @Inject constructor(
+    private val contacts: ContactSpecialDatesDataSource,
+    private val calendars: CalendarDataSource,
+    private val prefs: SettingsPrefs,
+    private val spec: SpecialDatesCalendarSpec,
+) {
+
+    // Serializes calendar-lifecycle work: two overlapping syncs (the daily job
+    // racing a "Sync now"/foreground run) would each see no managed calendar and
+    // both create one; a teardown racing an in-flight sync would delete calendars
+    // the sync then recreates. Holding this for the whole of sync()/teardown()
+    // makes those check-then-act sequences atomic, and — because sync() re-reads
+    // the enabled flag inside the lock — a teardown always wins the race.
+    private val lifecycleMutex = Mutex()
+
+    /**
+     * Reconcile every enabled type against the device's contacts. Returns why it
+     * stopped early (disabled / permission gone) or [SpecialDatesSyncResult.Success].
+     */
+    suspend fun sync(): SpecialDatesSyncResult = lifecycleMutex.withLock {
+        if (!prefs.specialDatesEnabled.first()) return SpecialDatesSyncResult.Disabled
+        if (!contacts.hasPermission()) return SpecialDatesSyncResult.PermissionMissing
+
+        val enabledTypes = prefs.specialDatesTypes.first()
+        val calendarByType = reconcileCalendars(enabledTypes)
+
+        val desiredByType = contacts.readSpecialDates().groupBy { it.type }
+        val reminderCtx = readReminderContext()
+        val templates = prefs.specialDatesTitleTemplates.first()
+        val showYear = prefs.specialDatesShowYear.first()
+
+        calendarByType.forEach { (type, calendarId) ->
+            val template = spec.resolveTitleTemplate(type, templates)
+            syncType(
+                calendarId = calendarId,
+                type = type,
+                contactsOfType = desiredByType[type].orEmpty(),
+                template = template,
+                showYear = showYear,
+                reminderCtx = reminderCtx,
+            )
+        }
+        SpecialDatesSyncResult.Success
+    }
+
+    /**
+     * Set the reminder default for a type's managed calendar and apply it to
+     * **all** its existing events too (not just future ones) — for managed
+     * calendars the reminder is a calendar-level setting. Persists the per-calendar
+     * all-day override so new events keep matching. No-op if the calendar for
+     * [type] doesn't exist yet.
+     */
+    suspend fun applyReminders(type: SpecialDateType, override: ReminderOverride) {
+        val calendarId = prefs.specialDatesCalendars.first()[type] ?: return
+        prefs.setCalendarAllDayReminderOverride(calendarId, override)
+        val minutes = when (override) {
+            ReminderOverride.Inherit -> prefs.defaultAllDayReminderMinutes.first()
+            ReminderOverride.None -> emptyList()
+            is ReminderOverride.Minutes -> override.minutes
+        }
+        calendars.applyManagedCalendarReminders(
+            calendarId = calendarId,
+            allDayReminderTimeMinutes = prefs.allDayReminderTimeMinutes.first(),
+            minutes = minutes,
+        )
+    }
+
+    /** Delete every managed calendar and forget its id — used when the feature is turned off. */
+    suspend fun teardown() = lifecycleMutex.withLock {
+        calendars.findManagedCalendars().forEach { calendars.deleteCalendar(it.id) }
+        SpecialDateType.entries.forEach { prefs.setSpecialDatesCalendarId(it, null) }
+    }
+
+    /**
+     * Ensure each enabled type has exactly one managed calendar (adopting an
+     * existing one, or the stored id if it still exists, else creating one) and
+     * that disabled types have none. Returns the calendar id per enabled type.
+     */
+    private suspend fun reconcileCalendars(enabledTypes: Set<SpecialDateType>): Map<SpecialDateType, Long> {
+        val foundByType = calendars.findManagedCalendars()
+            .groupBy({ it.type }, { it.id })
+            .mapValues { it.value.first() }
+        val stored = prefs.specialDatesCalendars.first()
+        val result = LinkedHashMap<SpecialDateType, Long>()
+        for (type in SpecialDateType.entries) {
+            // A stored id counts only if the calendar still exists (the user may
+            // have deleted it in system settings); otherwise adopt a found one.
+            val existingId = stored[type]?.takeIf { id -> foundByType.containsValue(id) }
+                ?: foundByType[type]
+            if (type in enabledTypes) {
+                val id = existingId ?: createCalendar(type)
+                if (stored[type] != id) prefs.setSpecialDatesCalendarId(type, id)
+                result[type] = id
+            } else {
+                if (existingId != null) calendars.deleteCalendar(existingId)
+                if (stored.containsKey(type)) prefs.setSpecialDatesCalendarId(type, null)
+            }
+        }
+        return result
+    }
+
+    private suspend fun createCalendar(type: SpecialDateType): Long {
+        // reconcileCalendars persists the id — the single place ids are recorded.
+        val id = calendars.createManagedCalendar(spec.displayName(type), spec.color(type), type)
+        // Seed a useful all-day reminder default (on the day + a week before), so
+        // birthdays get lead time out of the box. Per-calendar, user-adjustable —
+        // only set when the user hasn't already configured this calendar.
+        if (!prefs.perCalendarAllDayReminderOverride.first().containsKey(id)) {
+            prefs.setCalendarAllDayReminderOverride(
+                id,
+                ReminderOverride.Minutes(DEFAULT_REMINDER_MINUTES),
+            )
+        }
+        return id
+    }
+
+    private suspend fun syncType(
+        calendarId: Long,
+        type: SpecialDateType,
+        contactsOfType: List<ContactSpecialDate>,
+        template: String,
+        showYear: Boolean,
+        reminderCtx: ReminderContext,
+    ) {
+        val built = contactsOfType.map { sd ->
+            buildManagedEvent(calendarId, type, sd, template, showYear, reminderCtx)
+        }
+        val diff = diffManagedEvents(built.map { it.desired }, calendars.queryManagedEvents(calendarId))
+        val formByUid = built.associate { it.desired.uid to it.form }
+        diff.insertUids.forEach { uid ->
+            calendars.insertManagedEvent(formByUid.getValue(uid), uid, reminderCtx.allDayTimeMinutes)
+        }
+        diff.updates.forEach { calendars.updateManagedFields(it.eventId, it.columns) }
+        diff.deleteEventIds.forEach { calendars.deleteEvent(it) }
+    }
+
+    private fun buildManagedEvent(
+        calendarId: Long,
+        type: SpecialDateType,
+        sd: ContactSpecialDate,
+        template: String,
+        showYear: Boolean,
+        reminderCtx: ReminderContext,
+    ): BuiltManagedEvent {
+        val anchor = sd.anchorDate()
+        val start = LocalDateTime(anchor, LocalTime(0, 0))
+        // The source year is static and correct on every occurrence (unlike age).
+        val year = if (showYear) sd.year else null
+        val title = renderSpecialDateTitle(template, sd.displayName, year)
+        val form = EventForm(
+            calendarId = calendarId,
+            title = title,
+            isAllDay = true,
+            start = start,
+            end = start,
+            reminders = reminderCtx.resolveAllDay(calendarId),
+            availability = Availability.Free,
+            rrule = YEARLY_RRULE,
+        )
+        val dtStartMillis = form.toWriteTimes(ZoneId.systemDefault()).dtStartMillis
+        return BuiltManagedEvent(
+            desired = ManagedEventDesired(
+                uid = sd.managedUid(),
+                title = title,
+                dtStartMillis = dtStartMillis,
+                rrule = YEARLY_RRULE,
+            ),
+            form = form,
+        )
+    }
+
+    // Managed events are always all-day, so only the all-day defaults apply.
+    private suspend fun readReminderContext(): ReminderContext = ReminderContext(
+        allDayGlobal = prefs.defaultAllDayReminderMinutes.first(),
+        allDayOverrides = prefs.perCalendarAllDayReminderOverride.first(),
+        allDayTimeMinutes = prefs.allDayReminderTimeMinutes.first(),
+    )
+
+    private data class ReminderContext(
+        val allDayGlobal: List<Int>,
+        val allDayOverrides: Map<Long, List<Int>>,
+        val allDayTimeMinutes: Int,
+    ) {
+        /** Same semantics as `resolveDefaultReminder`: present-empty = explicit none. */
+        fun resolveAllDay(calendarId: Long): List<Int> =
+            allDayOverrides[calendarId] ?: allDayGlobal
+    }
+
+    private data class BuiltManagedEvent(val desired: ManagedEventDesired, val form: EventForm)
+
+    private companion object {
+        /** "On the day" (0) + one week before (7 days), as all-day lead minutes. */
+        val DEFAULT_REMINDER_MINUTES = listOf(0, 7 * 24 * 60)
+        val YEARLY_RRULE = SimpleRecurrence(freq = RecurrenceFreq.Yearly).toRRule()
+    }
+}
+
+/** The managed columns of a desired event, compared against the existing row. */
+internal data class ManagedEventDesired(
+    val uid: String,
+    val title: String,
+    val dtStartMillis: Long,
+    val rrule: String?,
+)
+
+internal data class ManagedFieldUpdate(val eventId: Long, val columns: Map<String, Any?>)
+
+internal data class ManagedDiff(
+    val insertUids: List<String>,
+    val updates: List<ManagedFieldUpdate>,
+    val deleteEventIds: List<Long>,
+)
+
+/**
+ * The idempotent diff at the heart of the mirror, keyed on `UID_2445`:
+ * desired-not-existing → insert, existing-not-desired → delete, and for events
+ * in both only the *changed* managed columns (title/dtstart/rrule) are emitted —
+ * so a re-run with no contact changes produces nothing, and a managed update
+ * never touches user-owned columns or reminder rows. Pure, so it's unit-tested.
+ */
+internal fun diffManagedEvents(
+    desired: List<ManagedEventDesired>,
+    existing: List<ManagedEventRow>,
+): ManagedDiff {
+    val desiredByUid = desired.associateBy { it.uid }
+    val existingByUid = existing.associateBy { it.uid }
+    val insertUids = desired.filter { it.uid !in existingByUid }.map { it.uid }
+    val deleteEventIds = existing.filter { it.uid !in desiredByUid }.map { it.eventId }
+    val updates = buildList {
+        for (d in desired) {
+            val row = existingByUid[d.uid] ?: continue
+            val columns = buildMap<String, Any?> {
+                if (row.title != d.title) put(CalendarContract.Events.TITLE, d.title)
+                if (row.dtStartMillis != d.dtStartMillis) {
+                    put(CalendarContract.Events.DTSTART, d.dtStartMillis)
+                }
+                if (row.rrule != d.rrule) put(CalendarContract.Events.RRULE, d.rrule)
+            }
+            if (columns.isNotEmpty()) add(ManagedFieldUpdate(row.eventId, columns))
+        }
+    }
+    return ManagedDiff(insertUids, updates, deleteEventIds)
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/crash/CrashReporter.kt

@@ -1,188 +0,0 @@
-package de.jeanlucmakiola.calendula.data.crash
-
-import android.content.Context
-import android.content.pm.PackageInfo
-import android.os.Build
-import androidx.core.content.pm.PackageInfoCompat
-import java.io.File
-import java.io.PrintWriter
-import java.io.StringWriter
-import java.time.Instant
-import java.time.ZoneId
-import java.time.format.DateTimeFormatter
-import java.util.Locale
-
-/**
- * Privacy-respecting crash capture (prod-readiness item 10). On an uncaught
- * exception it writes a self-contained report to the app's private storage and
- * then chains to the platform's default handler, so the process still dies
- * normally (and the OS shows its own "stopped" dialog). Nothing is uploaded —
- * the app holds no `INTERNET` permission. The user submits the report later,
- * by hand, as a Gitea issue (see the ui/crash surfaces).
- *
- * The report is built from a fixed [CrashContext] allowlist — app/Android/device
- * version, locale, time, and the stack trace — and **nothing else**: no device
- * identifiers, no account names, no calendar/event content, no logcat. The user
- * is always shown the full text before it leaves the device.
- */
-object CrashReporter {
-
-    /**
-     * Install the handler. Called first thing in `CalendulaApp.onCreate()` so it
-     * also catches crashes during startup. The handler swallows nothing — it
-     * persists, then delegates to the previously-registered handler.
-     */
-    fun install(context: Context) {
-        val appContext = context.applicationContext
-        val previous = Thread.getDefaultUncaughtExceptionHandler()
-        Thread.setDefaultUncaughtExceptionHandler { thread, throwable ->
-            // Capturing must never mask the original crash, so guard every step.
-            runCatching {
-                val now = System.currentTimeMillis()
-                writeReport(appContext, buildCrashReport(CrashContext.from(appContext), throwable, now))
-                recordCrashTime(appContext, now)
-            }
-            previous?.uncaughtException(thread, throwable)
-        }
-    }
-
-    /** The persisted report from the last crash, or null if there is none. */
-    fun pendingReport(context: Context): String? {
-        val file = reportFile(context)
-        return if (file.exists()) runCatching { file.readText() }.getOrNull()?.takeIf { it.isNotBlank() } else null
-    }
-
-    /**
-     * Whether to surface the report unprompted (on the next launch): a report
-     * exists and the user hasn't already waved this one away. Settings reaches
-     * the report via [pendingReport] regardless, so "Not now" only stops the
-     * auto-prompt — it doesn't discard the report.
-     */
-    fun shouldPrompt(context: Context): Boolean =
-        reportFile(context).exists() && !dismissedFile(context).exists()
-
-    /** Stop auto-prompting for the current report without discarding it. */
-    fun dismissPrompt(context: Context) {
-        runCatching { dismissedFile(context).apply { parentFile?.mkdirs() }.writeText("") }
-    }
-
-    /** Drop the persisted report once the user has reported it (or from Settings). */
-    fun clearReport(context: Context) {
-        runCatching { reportFile(context).delete() }
-        runCatching { dismissedFile(context).delete() }
-    }
-
-    /**
-     * Whether the app appears to be in a startup crash-loop: at least
-     * [LOOP_THRESHOLD] crashes inside [LOOP_WINDOW_MS]. In that case the main UI
-     * can't be trusted to start, so the caller routes straight to the standalone
-     * report screen instead of re-entering the crashing graph.
-     */
-    fun isCrashLoop(context: Context): Boolean {
-        val times = readCrashTimes(context)
-        if (times.size < LOOP_THRESHOLD) return false
-        val recent = times.sortedDescending()
-        return recent[0] - recent[LOOP_THRESHOLD - 1] <= LOOP_WINDOW_MS
-    }
-
-    /**
-     * Mark the app as having started successfully, resetting the loop counter so
-     * an ordinary single crash much later never trips loop detection. The
-     * pending report itself is kept — only the timing trail is cleared.
-     */
-    fun markHealthy(context: Context) {
-        runCatching { timesFile(context).delete() }
-    }
-
-    // --- persistence -------------------------------------------------------
-
-    private fun writeReport(context: Context, report: String) {
-        val file = reportFile(context).apply { parentFile?.mkdirs() }
-        file.writeText(report.take(MAX_REPORT_CHARS))
-        // A fresh crash should prompt again, even if the previous one was waved away.
-        runCatching { dismissedFile(context).delete() }
-    }
-
-    private fun recordCrashTime(context: Context, nowMillis: Long) {
-        val kept = (readCrashTimes(context) + nowMillis).takeLast(MAX_TIMES)
-        timesFile(context).apply { parentFile?.mkdirs() }
-            .writeText(kept.joinToString("\n"))
-    }
-
-    private fun readCrashTimes(context: Context): List<Long> {
-        val file = timesFile(context)
-        if (!file.exists()) return emptyList()
-        return runCatching { file.readLines().mapNotNull { it.trim().toLongOrNull() } }.getOrDefault(emptyList())
-    }
-
-    private fun crashDir(context: Context) = File(context.filesDir, CRASH_DIR)
-    private fun reportFile(context: Context) = File(crashDir(context), REPORT_FILE)
-    private fun timesFile(context: Context) = File(crashDir(context), TIMES_FILE)
-    private fun dismissedFile(context: Context) = File(crashDir(context), DISMISSED_FILE)
-
-    private const val CRASH_DIR = "crash"
-    private const val REPORT_FILE = "last_crash.txt"
-    private const val TIMES_FILE = "crash_times.txt"
-    private const val DISMISSED_FILE = "dismissed"
-    private const val MAX_TIMES = 5
-    private const val MAX_REPORT_CHARS = 64 * 1024
-    private const val LOOP_THRESHOLD = 2
-    private const val LOOP_WINDOW_MS = 10_000L
-}
-
-/**
- * The allowlist of non-personal facts that go into a crash report. Built from
- * [Build] and the app's own [PackageInfo]; deliberately holds no identifiers.
- */
-data class CrashContext(
-    val appVersionName: String,
-    val appVersionCode: Long,
-    val sdkInt: Int,
-    val androidRelease: String,
-    val manufacturer: String,
-    val model: String,
-    val locale: String,
-) {
-    companion object {
-        fun from(context: Context): CrashContext {
-            val pkg = runCatching {
-                context.packageManager.getPackageInfo(context.packageName, 0)
-            }.getOrNull()
-            return CrashContext(
-                appVersionName = pkg?.versionName ?: "?",
-                appVersionCode = pkg?.let { PackageInfoCompat.getLongVersionCode(it) } ?: 0L,
-                sdkInt = Build.VERSION.SDK_INT,
-                androidRelease = Build.VERSION.RELEASE ?: "?",
-                manufacturer = Build.MANUFACTURER ?: "?",
-                model = Build.MODEL ?: "?",
-                locale = Locale.getDefault().toLanguageTag(),
-            )
-        }
-    }
-}
-
-/**
- * Render a crash report from the [ctx] allowlist, the [throwable]'s full stack
- * trace, and the crash [nowMillis]. Pure (no Android, no I/O) so it is unit
- * tested. The leading marker doubles as the file's sanity check in
- * [CrashReporter.pendingReport].
- */
-fun buildCrashReport(ctx: CrashContext, throwable: Throwable, nowMillis: Long): String {
-    val trace = StringWriter().also { throwable.printStackTrace(PrintWriter(it)) }.toString().trim()
-    val time = runCatching {
-        Instant.ofEpochMilli(nowMillis).atZone(ZoneId.systemDefault()).format(TIME_FORMAT)
-    }.getOrDefault(nowMillis.toString())
-    return buildString {
-        appendLine("Calendula crash report")
-        appendLine("App version: ${ctx.appVersionName} (${ctx.appVersionCode})")
-        appendLine("Android: ${ctx.androidRelease} (API ${ctx.sdkInt})")
-        appendLine("Device: ${ctx.manufacturer} ${ctx.model}")
-        appendLine("Locale: ${ctx.locale}")
-        appendLine("Time: $time")
-        appendLine()
-        appendLine("Stack trace:")
-        append(trace)
-    }
-}
-
-private val TIME_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")

app/src/main/java/de/jeanlucmakiola/calendula/data/di/DataModule.kt

@@ -14,8 +14,12 @@ import de.jeanlucmakiola.calendula.data.calendar.AndroidCalendarDataSource
 import de.jeanlucmakiola.calendula.data.calendar.CalendarDataSource
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepositoryImpl
-import de.jeanlucmakiola.calendula.data.reminders.AndroidReminderAlertStore
-import de.jeanlucmakiola.calendula.data.reminders.ReminderAlertStore
+import de.jeanlucmakiola.calendula.data.contacts.AndroidContactSpecialDatesDataSource
+import de.jeanlucmakiola.calendula.data.contacts.AndroidSpecialDatesCalendarSpec
+import de.jeanlucmakiola.calendula.data.contacts.ContactSpecialDatesDataSource
+import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesCalendarSpec
+import de.jeanlucmakiola.calendula.data.reminders.ProviderReminderInstanceSource
+import de.jeanlucmakiola.calendula.data.reminders.ReminderInstanceSource
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 import javax.inject.Singleton
@@ -42,9 +46,21 @@ abstract class DataBindModule {
 
     @Binds
     @Singleton
-    abstract fun bindReminderAlertStore(
-        impl: AndroidReminderAlertStore,
-    ): ReminderAlertStore
+    abstract fun bindReminderInstanceSource(
+        impl: ProviderReminderInstanceSource,
+    ): ReminderInstanceSource
+
+    @Binds
+    @Singleton
+    abstract fun bindContactSpecialDatesDataSource(
+        impl: AndroidContactSpecialDatesDataSource,
+    ): ContactSpecialDatesDataSource
+
+    @Binds
+    @Singleton
+    abstract fun bindSpecialDatesCalendarSpec(
+        impl: AndroidSpecialDatesCalendarSpec,
+    ): SpecialDatesCalendarSpec
 }
 
 @Module

app/src/main/java/de/jeanlucmakiola/calendula/data/fonts/CustomFontStore.kt

@@ -0,0 +1,57 @@
+package de.jeanlucmakiola.calendula.data.fonts
+
+import android.content.Context
+import android.net.Uri
+import de.jeanlucmakiola.calendula.domain.FontRole
+import java.io.File
+import java.util.Locale
+import android.graphics.fonts.Font as PlatformFont
+
+/**
+ * Storage for user-loaded custom fonts (issue #19). A font a user picks via the
+ * system file picker is copied into the app's private storage — one file per
+ * [FontRole] — so the selection survives even if the original is later moved or
+ * deleted, and never leaves the app. The chosen file is validated as a real font
+ * before it replaces the previous one, so a bad pick can't wedge the app-wide
+ * typography.
+ */
+object CustomFontStore {
+
+    private fun dir(context: Context): File = File(context.filesDir, "fonts")
+
+    /** The stored font file for [role] (may not exist yet). */
+    fun file(context: Context, role: FontRole): File =
+        File(dir(context), "${role.name.lowercase(Locale.ROOT)}.ttf")
+
+    fun exists(context: Context, role: FontRole): Boolean =
+        file(context, role).let { it.exists() && it.length() > 0 }
+
+    /**
+     * Copy [uri] into per-role storage, first validating that it parses as a
+     * font. Returns true on success; on any failure the previous file is left
+     * untouched and false is returned (the caller keeps the old selection).
+     */
+    fun import(context: Context, role: FontRole, uri: Uri): Boolean {
+        val target = file(context, role)
+        target.parentFile?.mkdirs()
+        val tmp = File(target.parentFile, "${role.name.lowercase(Locale.ROOT)}.tmp")
+        return try {
+            context.contentResolver.openInputStream(uri)?.use { input ->
+                tmp.outputStream().use { output -> input.copyTo(output) }
+            } ?: return false
+            // Font.Builder throws IOException for anything that isn't a valid
+            // font file (API 29+, which is our minSdk) — a cheap, reliable check.
+            PlatformFont.Builder(tmp).build()
+            if (target.exists() && !target.delete()) return false
+            tmp.renameTo(target)
+        } catch (_: Exception) {
+            tmp.delete()
+            false
+        }
+    }
+
+    /** Forget the custom font for [role] (used when switching away from it). */
+    fun clear(context: Context, role: FontRole) {
+        file(context, role).delete()
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/CalendarPrefs.kt

@@ -1,18 +1,25 @@
 package de.jeanlucmakiola.calendula.data.prefs
 
 import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.MutablePreferences
 import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.longPreferencesKey
 import androidx.datastore.preferences.core.stringPreferencesKey
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.map
 import javax.inject.Inject
 import javax.inject.Singleton
 
 /**
- * App-side preference for "calendars the user has hidden in this app",
- * separate from the system's per-calendar VISIBLE flag.
+ * App-side calendar preferences. [hiddenCalendarIds] is the drawer's filter
+ * sheet — a purely in-app declutter that deliberately does *not* suppress
+ * reminders. Switching a calendar off entirely is the system's
+ * `Calendars.VISIBLE` flag, written straight to the provider (#75);
+ * [pendingDisabledCalendarIds] only holds those switch-offs the app has not been
+ * allowed to write yet.
  *
  * Persisted as a comma-separated string of Long ids; non-numeric tokens are
  * silently dropped (defensive — see CalendarPrefsTest).
@@ -22,46 +29,56 @@ class CalendarPrefs @Inject constructor(
     private val store: DataStore<Preferences>,
 ) {
 
-    val hiddenCalendarIds: Flow<Set<Long>> = store.data.map { prefs ->
-        prefs[HIDDEN_IDS_KEY].orEmpty()
-            .split(',')
-            .mapNotNull { it.trim().toLongOrNull() }
-            .toSet()
-    }
+    // Both id sets are deduped: the store is shared with SettingsPrefs, so any
+    // unrelated write would otherwise re-emit an identical set.
+    val hiddenCalendarIds: Flow<Set<Long>> = store.data
+        .map { prefs -> prefs[HIDDEN_IDS_KEY].parseIds() }
+        .distinctUntilChanged()
 
     suspend fun setHiddenCalendarIds(ids: Set<Long>) {
+        store.edit { prefs -> prefs.writeIds(HIDDEN_IDS_KEY, ids) }
+    }
+
+    /**
+     * Switch-offs the provider does not know about yet, because writing
+     * `Calendars.VISIBLE` needs `WRITE_CALENDAR` (#75). Also inherits the
+     * retired app-local model's set, from the same key.
+     *
+     * Honoured as a display and reminder filter while non-empty, but not a
+     * second visibility model: `CalendarVisibilityReconciler` drains it entry by
+     * entry as soon as the app may write, and nothing adds to it while it may.
+     */
+    val pendingDisabledCalendarIds: Flow<Set<Long>> = store.data
+        .map { prefs -> prefs[DISABLED_IDS_KEY].parseIds() }
+        .distinctUntilChanged()
+
+    suspend fun addPendingDisabledCalendarIds(ids: Collection<Long>) =
+        editPendingDisabled { it + ids }
+
+    /**
+     * Drop [ids] from the pending set, one at a time as the reconciler flushes
+     * them, so a run that fails part-way never re-applies what already landed.
+     */
+    suspend fun removePendingDisabledCalendarIds(ids: Collection<Long>) =
+        editPendingDisabled { it - ids.toSet() }
+
+    private suspend fun editPendingDisabled(transform: (Set<Long>) -> Set<Long>) {
         store.edit { prefs ->
-            if (ids.isEmpty()) {
-                prefs.remove(HIDDEN_IDS_KEY)
-            } else {
-                prefs[HIDDEN_IDS_KEY] = ids.sorted().joinToString(",")
-            }
+            prefs.writeIds(DISABLED_IDS_KEY, transform(prefs[DISABLED_IDS_KEY].parseIds()))
         }
     }
 
     /**
-     * App-side preference for "calendars the user has disabled in this app" — a
-     * heavier level than [hiddenCalendarIds]. A disabled calendar is removed from
-     * every surface (drawer filter, event-form picker, import picker) and its
-     * events never appear; it stays listed only in Settings → Calendars so it can
-     * be re-enabled. Stored exactly like the hidden set; never touches the
-     * system's VISIBLE/SYNC_EVENTS flags, so other calendar apps are unaffected.
+     * Whether the one-time "visibility follows this device" notice is still
+     * owed. Null until the reconciler has evaluated it (which needs the calendar
+     * permission), false once it has been shown or was never needed.
      */
-    val disabledCalendarIds: Flow<Set<Long>> = store.data.map { prefs ->
-        prefs[DISABLED_IDS_KEY].orEmpty()
-            .split(',')
-            .mapNotNull { it.trim().toLongOrNull() }
-            .toSet()
+    val visibilityNoticePending: Flow<Boolean?> = store.data.map { prefs ->
+        prefs[VISIBILITY_NOTICE_KEY]
     }
 
-    suspend fun setDisabledCalendarIds(ids: Set<Long>) {
-        store.edit { prefs ->
-            if (ids.isEmpty()) {
-                prefs.remove(DISABLED_IDS_KEY)
-            } else {
-                prefs[DISABLED_IDS_KEY] = ids.sorted().joinToString(",")
-            }
-        }
+    suspend fun setVisibilityNoticePending(pending: Boolean) {
+        store.edit { prefs -> prefs[VISIBILITY_NOTICE_KEY] = pending }
     }
 
     /**
@@ -79,6 +96,16 @@ class CalendarPrefs @Inject constructor(
     companion object {
         internal val HIDDEN_IDS_KEY = stringPreferencesKey("hidden_calendar_ids")
         internal val DISABLED_IDS_KEY = stringPreferencesKey("disabled_calendar_ids")
+        internal val VISIBILITY_NOTICE_KEY = booleanPreferencesKey("visibility_notice_pending")
         internal val LAST_USED_CALENDAR_KEY = longPreferencesKey("last_used_calendar_id")
     }
 }
+
+private fun String?.parseIds(): Set<Long> = orEmpty()
+    .split(',')
+    .mapNotNull { it.trim().toLongOrNull() }
+    .toSet()
+
+private fun MutablePreferences.writeIds(key: Preferences.Key<String>, ids: Set<Long>) {
+    if (ids.isEmpty()) remove(key) else set(key, ids.sorted().joinToString(","))
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/ReminderStatePrefs.kt

@@ -0,0 +1,36 @@
+package de.jeanlucmakiola.calendula.data.prefs
+
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.longPreferencesKey
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * How far reminder delivery has got — the one number replacing the provider's
+ * `CalendarAlerts.STATE` (#75). A scan posts the reminders falling after this
+ * watermark and up to now, then moves it to now, so a scan running twice cannot
+ * post twice while a late one still catches up.
+ *
+ * Unset means "never scanned", not zero: the first scan after an install would
+ * otherwise treat every reminder since the epoch as overdue.
+ */
+@Singleton
+class ReminderStatePrefs @Inject constructor(
+    private val store: DataStore<Preferences>,
+) {
+
+    /** The watermark, or `null` before the first scan has ever run. */
+    suspend fun lastScanMillis(): Long? = store.data.map { it[LAST_SCAN_KEY] }.first()
+
+    suspend fun setLastScanMillis(millis: Long) {
+        store.edit { prefs -> prefs[LAST_SCAN_KEY] = millis }
+    }
+
+    private companion object {
+        val LAST_SCAN_KEY = longPreferencesKey("reminder_last_scan_millis")
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefs.kt

@@ -7,13 +7,30 @@ import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.intPreferencesKey
 import androidx.datastore.preferences.core.longPreferencesKey
 import androidx.datastore.preferences.core.stringPreferencesKey
+import de.jeanlucmakiola.floret.reminders.ReminderOverride
+import de.jeanlucmakiola.floret.reminders.ReminderOverrideCodec
+import de.jeanlucmakiola.floret.reminders.applyReminderOverride
+import de.jeanlucmakiola.floret.reminders.normalizeReminders
+import de.jeanlucmakiola.floret.reminders.reminderOverrideFor
 import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.domain.FontRole
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.parseAgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
+import de.jeanlucmakiola.calendula.ui.theme.FONT_SYSTEM_TOKEN
+import de.jeanlucmakiola.calendula.widget.WidgetSize
+import java.time.ZoneId
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.DayOfWeek
 import java.time.temporal.WeekFields
 import java.util.Locale
@@ -71,6 +88,24 @@ fun WeekStartPref.resolveFirstDay(locale: Locale): DayOfWeek = when (this) {
     WeekStartPref.Auto -> DayOfWeek(WeekFields.of(locale).firstDayOfWeek.value)
 }
 
+/**
+ * The resolved first day of the week as a hot [StateFlow] — the one shape every
+ * screen that orders or lays out weekdays should use (the month grid, the agenda
+ * "this week" range, the recurrence weekday toggles). Sharing it keeps the
+ * initial-frame value identical everywhere; hand-rolled copies had drifted onto
+ * different `initialValue`s, so two surfaces could disagree for a frame.
+ */
+fun SettingsPrefs.firstDayOfWeek(scope: CoroutineScope): StateFlow<DayOfWeek> =
+    weekStart
+        .map { it.resolveFirstDay(Locale.getDefault()) }
+        .stateIn(
+            scope = scope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            // Seed with the locale convention rather than a hardcoded weekday, so
+            // the first frame is already right for everyone still on Auto.
+            initialValue = WeekStartPref.Auto.resolveFirstDay(Locale.getDefault()),
+        )
+
 /**
  * Display settings (M4) persisted app-side: theme override, Material You
  * dynamic colour, and week start. Language is handled separately through
@@ -104,6 +139,62 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[DYNAMIC_COLOR_KEY] = enabled }
     }
 
+    /**
+     * Whether raw provider colours are softened toward theme-fitting pastels
+     * before display (issue #36). Defaults to ON — the historical look, which
+     * caps harsh sync colours and pins brightness so entries read on both
+     * themes. Turning it off paints the calendar/event colour exactly as the
+     * sync source (DAVx5/CalDAV) publishes it.
+     */
+    val softenCalendarColors: Flow<Boolean> = store.data.map { prefs ->
+        prefs[SOFTEN_COLORS_KEY] ?: true
+    }
+
+    suspend fun setSoftenCalendarColors(enabled: Boolean) {
+        store.edit { it[SOFTEN_COLORS_KEY] = enabled }
+    }
+
+    /**
+     * Custom-font tokens per Material typeface role (issue #19). Stored as opaque
+     * strings — "system", "custom", or a bundled font's token — resolved to a
+     * FontFamily at the theme layer; an unknown token degrades to the default.
+     */
+    val brandFont: Flow<String> = store.data.map { prefs ->
+        prefs[BRAND_FONT_KEY] ?: FONT_SYSTEM_TOKEN
+    }
+
+    val plainFont: Flow<String> = store.data.map { prefs ->
+        prefs[PLAIN_FONT_KEY] ?: FONT_SYSTEM_TOKEN
+    }
+
+    suspend fun setBrandFont(token: String) {
+        store.edit { it[BRAND_FONT_KEY] = token }
+    }
+
+    suspend fun setPlainFont(token: String) {
+        store.edit { it[PLAIN_FONT_KEY] = token }
+    }
+
+    /**
+     * A per-role bump counter for the user-loaded custom font. Re-importing
+     * overwrites the same file under the same "custom" token, so the token alone
+     * can't signal the change; this stamp — carried into AppFontSettings — breaks
+     * value equality so the resolved FontFamily (and its previews) refresh. A
+     * missing key is 0 (existing installs); the first import bumps it to 1.
+     */
+    val brandFontStamp: Flow<Int> = store.data.map { prefs -> prefs[BRAND_FONT_STAMP_KEY] ?: 0 }
+
+    val plainFontStamp: Flow<Int> = store.data.map { prefs -> prefs[PLAIN_FONT_STAMP_KEY] ?: 0 }
+
+    /** Bump [role]'s custom-font stamp after a re-import so equality-keyed caches refresh. */
+    suspend fun bumpCustomFontStamp(role: FontRole) {
+        val key = when (role) {
+            FontRole.BRAND -> BRAND_FONT_STAMP_KEY
+            FontRole.PLAIN -> PLAIN_FONT_STAMP_KEY
+        }
+        store.edit { it[key] = (it[key] ?: 0) + 1 }
+    }
+
     suspend fun setWeekStart(pref: WeekStartPref) {
         store.edit { it[WEEK_START_KEY] = pref.storageValue() }
     }
@@ -154,6 +245,46 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[DIM_COMPLETED_EVENTS_KEY] = enabled }
     }
 
+    /**
+     * Whether the Month grid shows the calendar-week (ISO) number in a left
+     * gutter (#25). Defaults to OFF — users opt in, since it narrows the day
+     * cells slightly. The Week view shows its number unconditionally.
+     */
+    val showWeekNumbers: Flow<Boolean> = store.data.map { prefs ->
+        prefs[SHOW_WEEK_NUMBERS_KEY] ?: false
+    }
+
+    suspend fun setShowWeekNumbers(enabled: Boolean) {
+        store.edit { it[SHOW_WEEK_NUMBERS_KEY] = enabled }
+    }
+
+    /**
+     * How the Month view lays itself out (#38, #53). Defaults to [MonthViewStyle.Paged]
+     * — the historical behaviour, so existing installs see no change until they opt in.
+     */
+    val monthViewStyle: Flow<MonthViewStyle> = store.data.map { prefs ->
+        prefs[MONTH_VIEW_STYLE_KEY].toEnum(MonthViewStyle.Paged)
+    }
+
+    suspend fun setMonthViewStyle(style: MonthViewStyle) {
+        store.edit { it[MONTH_VIEW_STYLE_KEY] = style.name }
+    }
+
+    /**
+     * Where the jump-to-today control lives (issue #60). Default OFF — the
+     * historical layout, where it's an extended FAB that fades in above the "+"
+     * only while the view is off today. Turning it ON moves it to a persistent
+     * icon button in each calendar view's top bar (always shown, on today or
+     * not) and drops the FAB pill.
+     */
+    val todayButtonInToolbar: Flow<Boolean> = store.data.map { prefs ->
+        prefs[TODAY_BUTTON_IN_TOOLBAR_KEY] ?: false
+    }
+
+    suspend fun setTodayButtonInToolbar(enabled: Boolean) {
+        store.edit { it[TODAY_BUTTON_IN_TOOLBAR_KEY] = enabled }
+    }
+
     /**
      * How far ahead the in-app Agenda screen shows events (v2.11). Defaults to
      * [AgendaRange.Month] — a month of upcoming events. Independent of the
@@ -176,6 +307,23 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[AGENDA_WIDGET_RANGE_KEY] = range.storageValue() }
     }
 
+    /**
+     * The size step the agenda widget draws its text at (#51). Defaults to
+     * [WidgetSize.SMALL], which reproduces its original metrics, so an existing
+     * widget is unchanged until its owner turns the size up.
+     *
+     * This replaced deriving a size tier from the widget's measured size, which
+     * the launcher does not report reliably. The month widget takes no size
+     * setting — it divides the width it is given by seven (#103).
+     */
+    val widgetSize: Flow<WidgetSize> = store.data.map { prefs ->
+        prefs[WIDGET_SIZE_KEY].toEnum(WidgetSize.SMALL)
+    }
+
+    suspend fun setWidgetSize(size: WidgetSize) {
+        store.edit { it[WIDGET_SIZE_KEY] = size.name }
+    }
+
     /**
      * Whether the agenda shows its top range bar — the "showing …" header and
      * the session range switcher (v2.11). Default ON.
@@ -188,6 +336,20 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[AGENDA_SHOW_RANGE_BAR_KEY] = enabled }
     }
 
+    /**
+     * Whether the agenda (both the in-app screen and the home-screen widget)
+     * always anchors today at the top with a "nothing left today" placeholder,
+     * even once today has no remaining events (issue #35). Default ON — makes
+     * today's events easy to tell apart from a future day's at a glance.
+     */
+    val agendaShowToday: Flow<Boolean> = store.data.map { prefs ->
+        prefs[AGENDA_SHOW_TODAY_KEY] ?: true
+    }
+
+    suspend fun setAgendaShowToday(enabled: Boolean) {
+        store.edit { it[AGENDA_SHOW_TODAY_KEY] = enabled }
+    }
+
     /**
      * The calendar view the app opens on (M1). Defaults to [CalendarView.Week] —
      * the historical hard-coded startup view — so existing users see no change
@@ -202,6 +364,47 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[DEFAULT_VIEW_KEY] = view.name }
     }
 
+    /**
+     * Quick-switch button customisation (#24): the ordered full view list plus
+     * which views are enabled in the cycle. Stored comma-joined by enum name, a
+     * "!" prefix marking a disabled view (e.g. "Month,Week,!Day,Agenda"). Missing
+     * views are appended enabled and unknown names dropped, so a future view
+     * defaults into the cycle. An absent key means [QuickSwitchConfig.Default].
+     */
+    val quickSwitchConfig: Flow<QuickSwitchConfig> = store.data.map { prefs ->
+        parseQuickSwitch(prefs[QUICK_SWITCH_VIEWS_KEY])
+    }
+
+    suspend fun setQuickSwitchConfig(config: QuickSwitchConfig) {
+        store.edit { it[QUICK_SWITCH_VIEWS_KEY] = serializeQuickSwitch(config) }
+    }
+
+    /**
+     * Atomic read-modify-write of the quick-switch config: [transform] sees the
+     * value currently stored, parsed inside the edit block, not the async-echoed
+     * UI snapshot. Two rapid intents (a toggle then a drag) therefore compose
+     * instead of each re-serialising a stale copy of the other field over it.
+     */
+    suspend fun updateQuickSwitch(transform: (QuickSwitchConfig) -> QuickSwitchConfig) {
+        store.edit { prefs ->
+            val current = parseQuickSwitch(prefs[QUICK_SWITCH_VIEWS_KEY])
+            prefs[QUICK_SWITCH_VIEWS_KEY] = serializeQuickSwitch(transform(current))
+        }
+    }
+
+    /**
+     * Navigation-drawer view order (#24). Comma-joined enum names; missing views
+     * are appended in default order and unknown names dropped. Absent key means
+     * [IMPLEMENTED_VIEWS] (the historical fixed order).
+     */
+    val drawerViewOrder: Flow<List<CalendarView>> = store.data.map { prefs ->
+        parseViewOrder(prefs[DRAWER_VIEW_ORDER_KEY])
+    }
+
+    suspend fun setDrawerViewOrder(order: List<CalendarView>) {
+        store.edit { it[DRAWER_VIEW_ORDER_KEY] = order.joinToString(",") { view -> view.name } }
+    }
+
     /**
      * Optional event-form fields shown by default (the rest hide behind
      * "more fields"). Stored comma-joined by enum name: an absent key means
@@ -220,6 +423,26 @@ class SettingsPrefs @Inject constructor(
         }
     }
 
+    /**
+     * Zones the user picked recently, most recent first — the timezone picker's
+     * default list, since scrolling ~600 zones to re-find the two you actually
+     * use is the whole problem. Stored comma-joined (IANA ids never contain a
+     * comma); unparseable ids are dropped on read, so a zone the tz database
+     * later retires can't wedge the list.
+     */
+    val recentTimeZones: Flow<List<String>> = store.data.map { prefs ->
+        parseRecentTimeZones(prefs[RECENT_TIMEZONES_KEY])
+    }
+
+    suspend fun addRecentTimeZone(zoneId: String) {
+        store.edit { prefs ->
+            val updated = (listOf(zoneId) + parseRecentTimeZones(prefs[RECENT_TIMEZONES_KEY]))
+                .distinct()
+                .take(MAX_RECENT_TIME_ZONES)
+            prefs[RECENT_TIMEZONES_KEY] = updated.joinToString(",")
+        }
+    }
+
     /**
      * Whether opening the new-event form focuses the title field and raises the
      * keyboard straight away (issue #10). Default ON — a new event almost always
@@ -276,35 +499,36 @@ class SettingsPrefs @Inject constructor(
     }
 
     /**
-     * The default reminder lead time (minutes before start) prefilled on new
-     * **timed** events. `null` = no default reminder — the prior behaviour, kept
-     * as the factory default so existing users aren't surprised by reminders they
-     * never asked for. Stored as a string so "none" is distinct from a numeric
-     * value (and from an unset key, which is also "none"). Per-calendar overrides
-     * in [perCalendarReminderOverride] take precedence; all-day events instead use
+     * The default reminder lead times (minutes before start) prefilled on new
+     * **timed** events. The empty list = no default reminder — the prior
+     * behaviour, kept as the factory default so existing users aren't surprised by
+     * reminders they never asked for. Stored as a comma-joined list of minutes, or
+     * "none"/empty for no reminder (also the unset state). A legacy single value
+     * ("30") parses transparently to a one-element list. Per-calendar overrides in
+     * [perCalendarReminderOverride] take precedence; all-day events instead use
      * [defaultAllDayReminderMinutes]. Resolve with [resolveDefaultReminder].
      */
-    val defaultReminderMinutes: Flow<Int?> = store.data.map { prefs ->
-        prefs[DEFAULT_REMINDER_KEY].toReminderMinutes()
+    val defaultReminderMinutes: Flow<List<Int>> = store.data.map { prefs ->
+        prefs[DEFAULT_REMINDER_KEY].toReminderList()
     }
 
-    suspend fun setDefaultReminderMinutes(minutes: Int?) {
-        store.edit { it[DEFAULT_REMINDER_KEY] = minutes?.toString() ?: NONE }
+    suspend fun setDefaultReminderMinutes(minutes: List<Int>) {
+        store.edit { it[DEFAULT_REMINDER_KEY] = minutes.toStoredReminders() }
     }
 
     /**
-     * The default reminder lead time prefilled on new **all-day** events, in
+     * The default reminder lead times prefilled on new **all-day** events, in
      * minutes before the start of the day. All-day events want day-scale lead
      * times ("1 day before"), so they have their own default rather than reusing
-     * the timed one. `null` = no default. Per-calendar overrides do **not** apply
-     * to all-day events — they always use this global value.
+     * the timed one. Empty list = no default. Per-calendar overrides do **not**
+     * apply to all-day events — they always use this global value.
      */
-    val defaultAllDayReminderMinutes: Flow<Int?> = store.data.map { prefs ->
-        prefs[DEFAULT_ALLDAY_REMINDER_KEY].toReminderMinutes()
+    val defaultAllDayReminderMinutes: Flow<List<Int>> = store.data.map { prefs ->
+        prefs[DEFAULT_ALLDAY_REMINDER_KEY].toReminderList()
     }
 
-    suspend fun setDefaultAllDayReminderMinutes(minutes: Int?) {
-        store.edit { it[DEFAULT_ALLDAY_REMINDER_KEY] = minutes?.toString() ?: NONE }
+    suspend fun setDefaultAllDayReminderMinutes(minutes: List<Int>) {
+        store.edit { it[DEFAULT_ALLDAY_REMINDER_KEY] = minutes.toStoredReminders() }
     }
 
     /**
@@ -341,21 +565,21 @@ class SettingsPrefs @Inject constructor(
     /**
      * Per-calendar overrides of [defaultReminderMinutes] for **timed** events,
      * keyed by calendar id. A calendar **present** in the map overrides the global
-     * timed default for its new events: a `null` value means "no reminder", an int
-     * means that lead time. A calendar **absent** from the map inherits the global
-     * default. Serialised as `id=value;id=value`, with `none` for an explicit
-     * no-reminder override. (All-day events ignore this and use
-     * [defaultAllDayReminderMinutes].)
+     * timed default for its new events: an **empty** list means "no reminder", a
+     * non-empty list means those lead times. A calendar **absent** from the map
+     * inherits the global default. Serialised as `id=value;id=value`, where a value
+     * is a comma-joined minute list or `none` for an explicit no-reminder override.
+     * (All-day events ignore this and use [defaultAllDayReminderMinutes].)
      */
-    val perCalendarReminderOverride: Flow<Map<Long, Int?>> = store.data.map { prefs ->
-        parseReminderOverrides(prefs[CALENDAR_REMINDER_OVERRIDE_KEY])
+    val perCalendarReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
+        reminderOverrideCodec.parse(prefs[CALENDAR_REMINDER_OVERRIDE_KEY])
     }
 
-    suspend fun setCalendarReminderOverride(calendarId: Long, override: CalendarReminderOverride) {
+    suspend fun setCalendarReminderOverride(calendarId: Long, override: ReminderOverride) {
         store.edit { prefs ->
-            val current = parseReminderOverrides(prefs[CALENDAR_REMINDER_OVERRIDE_KEY]).toMutableMap()
-            current.applyOverride(calendarId, override)
-            prefs[CALENDAR_REMINDER_OVERRIDE_KEY] = serializeReminderOverrides(current)
+            val current = reminderOverrideCodec.parse(prefs[CALENDAR_REMINDER_OVERRIDE_KEY]).toMutableMap()
+            current.applyReminderOverride(calendarId, override)
+            prefs[CALENDAR_REMINDER_OVERRIDE_KEY] = reminderOverrideCodec.serialize(current)
         }
     }
 
@@ -364,19 +588,19 @@ class SettingsPrefs @Inject constructor(
      * events, with the same semantics as [perCalendarReminderOverride] (absent =
      * inherit the global all-day default; present null = no reminder).
      */
-    val perCalendarAllDayReminderOverride: Flow<Map<Long, Int?>> = store.data.map { prefs ->
-        parseReminderOverrides(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY])
+    val perCalendarAllDayReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
+        reminderOverrideCodec.parse(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY])
     }
 
     suspend fun setCalendarAllDayReminderOverride(
         calendarId: Long,
-        override: CalendarReminderOverride,
+        override: ReminderOverride,
     ) {
         store.edit { prefs ->
             val current =
-                parseReminderOverrides(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY]).toMutableMap()
-            current.applyOverride(calendarId, override)
-            prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY] = serializeReminderOverrides(current)
+                reminderOverrideCodec.parse(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY]).toMutableMap()
+            current.applyReminderOverride(calendarId, override)
+            prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY] = reminderOverrideCodec.serialize(current)
         }
     }
 
@@ -426,6 +650,102 @@ class SettingsPrefs @Inject constructor(
         }
     }
 
+    // --- Contact special dates (issue #15) ------------------------------
+
+    /** Master switch for the contact special-dates mirror. Default OFF (opt-in). */
+    val specialDatesEnabled: Flow<Boolean> = store.data.map { it[SPECIAL_DATES_ENABLED_KEY] ?: false }
+
+    suspend fun setSpecialDatesEnabled(enabled: Boolean) {
+        store.edit { it[SPECIAL_DATES_ENABLED_KEY] = enabled }
+    }
+
+    /** The date types the user wants mirrored (default: all three). */
+    val specialDatesTypes: Flow<Set<SpecialDateType>> = store.data.map { prefs ->
+        SpecialDateType.entries.filterTo(mutableSetOf()) { prefs[typeEnabledKey(it)] ?: true }
+    }
+
+    suspend fun setSpecialDateTypeEnabled(type: SpecialDateType, enabled: Boolean) {
+        store.edit { it[typeEnabledKey(type)] = enabled }
+    }
+
+    /** The managed calendar id per type, for the ones that currently exist. */
+    val specialDatesCalendars: Flow<Map<SpecialDateType, Long>> = store.data.map { prefs ->
+        SpecialDateType.entries.mapNotNull { type ->
+            prefs[calendarIdKey(type)]?.let { type to it }
+        }.toMap()
+    }
+
+    /** Every managed calendar id — the editor locks title/date/recurrence for their events. */
+    val managedCalendarIds: Flow<Set<Long>> = specialDatesCalendars.map { it.values.toSet() }
+
+    suspend fun setSpecialDatesCalendarId(type: SpecialDateType, calendarId: Long?) {
+        store.edit { prefs ->
+            if (calendarId == null) prefs.remove(calendarIdKey(type)) else prefs[calendarIdKey(type)] = calendarId
+        }
+    }
+
+    /**
+     * The title template per type ("{name}'s birthday"); an empty string means
+     * unset, so the settings screen can seed the localized default. `{name}` is
+     * the contact name, `{age}` the age at the upcoming date (empty when the
+     * birth year is unknown or [specialDatesShowAge] is off).
+     */
+    val specialDatesTitleTemplates: Flow<Map<SpecialDateType, String>> = store.data.map { prefs ->
+        SpecialDateType.entries.associateWith { prefs[titleTemplateKey(it)].orEmpty() }
+    }
+
+    suspend fun setSpecialDatesTitleTemplate(type: SpecialDateType, template: String) {
+        store.edit { it[titleTemplateKey(type)] = template }
+    }
+
+    /** Whether `{year}` resolves in the title (only meaningful when the year is known). Default ON. */
+    val specialDatesShowYear: Flow<Boolean> = store.data.map { it[SPECIAL_DATES_SHOW_YEAR_KEY] ?: true }
+
+    suspend fun setSpecialDatesShowYear(enabled: Boolean) {
+        store.edit { it[SPECIAL_DATES_SHOW_YEAR_KEY] = enabled }
+    }
+
+    /** Outcome of the last mirror sync, for the settings status line. */
+    val specialDatesStatus: Flow<SpecialDatesStatus> = store.data.map { prefs ->
+        SpecialDatesStatus(
+            lastRun = prefs[SPECIAL_DATES_LAST_RUN_KEY] ?: 0L,
+            stalled = prefs[SPECIAL_DATES_STALLED_KEY]
+                ?.let { name -> SpecialDatesStalledReason.entries.firstOrNull { it.name == name } },
+        )
+    }
+
+    /** Record a sync outcome; [stalled] non-null marks the feature paused (e.g. permission revoked). */
+    suspend fun recordSpecialDatesRun(atMillis: Long, stalled: SpecialDatesStalledReason?) {
+        store.edit { prefs ->
+            prefs[SPECIAL_DATES_LAST_RUN_KEY] = atMillis
+            if (stalled == null) prefs.remove(SPECIAL_DATES_STALLED_KEY) else prefs[SPECIAL_DATES_STALLED_KEY] = stalled.name
+        }
+    }
+
+    /** Epoch millis of the last foreground-triggered sync, to debounce ON_RESUME. */
+    val specialDatesLastForegroundSync: Flow<Long> =
+        store.data.map { it[SPECIAL_DATES_LAST_FG_SYNC_KEY] ?: 0L }
+
+    suspend fun setSpecialDatesLastForegroundSync(atMillis: Long) {
+        store.edit { it[SPECIAL_DATES_LAST_FG_SYNC_KEY] = atMillis }
+    }
+
+    private fun typeEnabledKey(type: SpecialDateType) =
+        booleanPreferencesKey("special_dates_type_${type.name}")
+
+    private fun calendarIdKey(type: SpecialDateType) =
+        longPreferencesKey("special_dates_calendar_${type.name}")
+
+    private fun titleTemplateKey(type: SpecialDateType) =
+        stringPreferencesKey("special_dates_title_${type.name}")
+
+    private fun parseRecentTimeZones(stored: String?): List<String> =
+        stored?.split(',').orEmpty()
+            .map { it.trim() }
+            .filter { it.isNotEmpty() && runCatching { ZoneId.of(it) }.isSuccess }
+            .distinct()
+            .take(MAX_RECENT_TIME_ZONES)
+
     private fun parseFormFields(stored: String?): Set<EventFormField> = when (stored) {
         null -> DEFAULT_FORM_FIELDS
         else -> stored.split(',')
@@ -433,18 +753,65 @@ class SettingsPrefs @Inject constructor(
             .toSet()
     }
 
+    /** Parse a plain comma-joined view order, completed to every implemented view. */
+    private fun parseViewOrder(stored: String?): List<CalendarView> =
+        completeViewOrder(
+            stored?.split(',').orEmpty()
+                .mapNotNull { name -> CalendarView.entries.firstOrNull { it.name == name.trim() } },
+        )
+
+    /** Parse the quick-switch config; "!"-prefixed names are disabled. */
+    private fun parseQuickSwitch(stored: String?): QuickSwitchConfig {
+        if (stored == null) return QuickSwitchConfig.Default
+        val parsed = stored.split(',').mapNotNull { raw ->
+            val token = raw.trim()
+            val disabled = token.startsWith("!")
+            val name = if (disabled) token.drop(1) else token
+            CalendarView.entries.firstOrNull { it.name == name }?.let { it to disabled }
+        }
+        val order = completeViewOrder(parsed.map { it.first })
+        // Only views explicitly stored disabled are excluded; anything appended
+        // (a view added in a later release) defaults into the cycle.
+        val disabled = parsed.filter { it.second }.map { it.first }.toSet()
+        return QuickSwitchConfig(order, order.filterNot { it in disabled }.toSet())
+    }
+
+    private fun serializeQuickSwitch(config: QuickSwitchConfig): String =
+        completeViewOrder(config.order).joinToString(",") { view ->
+            if (view in config.enabled) view.name else "!${view.name}"
+        }
+
+    /** Keep the given order (de-duplicated), then append any views it omits. */
+    private fun completeViewOrder(seen: List<CalendarView>): List<CalendarView> {
+        val ordered = seen.distinct()
+        return ordered + IMPLEMENTED_VIEWS.filterNot { it in ordered }
+    }
+
     companion object {
         internal val THEME_MODE_KEY = stringPreferencesKey("theme_mode")
         internal val DYNAMIC_COLOR_KEY = booleanPreferencesKey("dynamic_color")
+        internal val SOFTEN_COLORS_KEY = booleanPreferencesKey("soften_calendar_colors")
+        internal val BRAND_FONT_KEY = stringPreferencesKey("brand_font")
+        internal val PLAIN_FONT_KEY = stringPreferencesKey("plain_font")
+        internal val BRAND_FONT_STAMP_KEY = intPreferencesKey("brand_font_stamp")
+        internal val PLAIN_FONT_STAMP_KEY = intPreferencesKey("plain_font_stamp")
         internal val WEEK_START_KEY = stringPreferencesKey("week_start")
         internal val AGENDA_SCREEN_RANGE_KEY = stringPreferencesKey("agenda_screen_range")
         internal val AGENDA_WIDGET_RANGE_KEY = stringPreferencesKey("agenda_widget_range")
         internal val AGENDA_SHOW_RANGE_BAR_KEY = booleanPreferencesKey("agenda_show_range_bar")
+        internal val WIDGET_SIZE_KEY = stringPreferencesKey("widget_size")
+        internal val AGENDA_SHOW_TODAY_KEY =
+            booleanPreferencesKey("agenda_show_today")
         internal val TIME_FORMAT_KEY = stringPreferencesKey("time_format")
         internal val SHOW_HOUR_LINES_KEY = booleanPreferencesKey("show_hour_lines")
         internal val PAST_EVENT_DISPLAY_KEY = stringPreferencesKey("agenda_past_event_display")
         internal val DIM_COMPLETED_EVENTS_KEY = booleanPreferencesKey("dim_completed_events")
+        internal val SHOW_WEEK_NUMBERS_KEY = booleanPreferencesKey("show_week_numbers")
+        internal val MONTH_VIEW_STYLE_KEY = stringPreferencesKey("month_view_style")
+        internal val TODAY_BUTTON_IN_TOOLBAR_KEY = booleanPreferencesKey("today_button_in_toolbar")
         internal val DEFAULT_VIEW_KEY = stringPreferencesKey("default_view")
+        internal val QUICK_SWITCH_VIEWS_KEY = stringPreferencesKey("quick_switch_views")
+        internal val DRAWER_VIEW_ORDER_KEY = stringPreferencesKey("drawer_view_order")
         internal val FORM_FIELDS_KEY = stringPreferencesKey("event_form_default_fields")
         internal val AUTOFOCUS_EVENT_TITLE_KEY = booleanPreferencesKey("autofocus_event_title")
         internal val REMINDERS_ENABLED_KEY = booleanPreferencesKey("reminders_enabled")
@@ -468,6 +835,10 @@ class SettingsPrefs @Inject constructor(
             stringPreferencesKey("per_calendar_allday_reminder_override")
         internal val DEFAULT_FORM_FIELDS =
             setOf(EventFormField.Location, EventFormField.Description)
+        internal val RECENT_TIMEZONES_KEY = stringPreferencesKey("recent_time_zones")
+
+        /** Enough to cover the zones a user actually recurs to, without a wall of rows. */
+        internal const val MAX_RECENT_TIME_ZONES = 5
         internal val AUTO_BACKUP_ENABLED_KEY = booleanPreferencesKey("auto_backup_enabled")
         internal val AUTO_BACKUP_INTERVAL_KEY = longPreferencesKey("auto_backup_interval_minutes")
         internal val AUTO_BACKUP_FOLDER_KEY = stringPreferencesKey("auto_backup_folder_uri")
@@ -478,9 +849,30 @@ class SettingsPrefs @Inject constructor(
         const val DEFAULT_BACKUP_INTERVAL = 1_440L
         /** Floor for the automatic-backup interval (also above WorkManager's 15-min limit). */
         const val MIN_BACKUP_INTERVAL = 30L
+
+        internal val SPECIAL_DATES_ENABLED_KEY = booleanPreferencesKey("special_dates_enabled")
+        internal val SPECIAL_DATES_SHOW_YEAR_KEY = booleanPreferencesKey("special_dates_show_year")
+        internal val SPECIAL_DATES_LAST_RUN_KEY = longPreferencesKey("special_dates_last_run")
+        internal val SPECIAL_DATES_STALLED_KEY = stringPreferencesKey("special_dates_stalled_reason")
+        internal val SPECIAL_DATES_LAST_FG_SYNC_KEY =
+            longPreferencesKey("special_dates_last_foreground_sync")
     }
 }
 
+/** Snapshot of the special-dates mirror's last outcome (see [SettingsPrefs.specialDatesStatus]). */
+data class SpecialDatesStatus(
+    /** Epoch millis of the last sync, or 0 if it has never run. */
+    val lastRun: Long,
+    /** Non-null when the mirror is paused and why; null when healthy. */
+    val stalled: SpecialDatesStalledReason?,
+)
+
+/** Why the special-dates mirror is paused. */
+enum class SpecialDatesStalledReason {
+    /** READ_CONTACTS was revoked in system settings after the feature was enabled. */
+    PermissionRevoked,
+}
+
 /** Snapshot of the automatic backup's last outcome (see [SettingsPrefs.autoBackupStatus]). */
 data class BackupStatus(
     /** Epoch millis of the last run, or 0 if it has never run. */
@@ -489,52 +881,30 @@ data class BackupStatus(
     val consecutiveFailures: Int,
 )
 
-/** A calendar's reminder-default override (see [SettingsPrefs.perCalendarReminderOverride]). */
-sealed interface CalendarReminderOverride {
-    /** No override — the calendar uses the global default. */
-    data object Inherit : CalendarReminderOverride
-    /** Explicit "no reminder" for this calendar, regardless of the global default. */
-    data object None : CalendarReminderOverride
-    /** A specific lead time in minutes before the event start. */
-    data class Minutes(val minutes: Int) : CalendarReminderOverride
-}
-
 /**
- * The lead time to prefill on a new event: the matching per-calendar override
+ * The lead times to prefill on a new event: the matching per-calendar override
  * if [calendarId] has one for this event kind, otherwise the global default for
  * that kind. All-day events consult [allDayOverrides] / [allDayGlobal]; timed
- * events consult [timedOverrides] / [timedGlobal]. `null` = no reminder. Pure so
- * it can be unit-tested.
+ * events consult [timedOverrides] / [timedGlobal]. The empty list = no reminder.
+ * Pure so it can be unit-tested.
  */
 fun resolveDefaultReminder(
-    timedGlobal: Int?,
-    allDayGlobal: Int?,
-    timedOverrides: Map<Long, Int?>,
-    allDayOverrides: Map<Long, Int?>,
+    timedGlobal: List<Int>,
+    allDayGlobal: List<Int>,
+    timedOverrides: Map<Long, List<Int>>,
+    allDayOverrides: Map<Long, List<Int>>,
     calendarId: Long?,
     isAllDay: Boolean,
-): Int? {
+): List<Int> {
     val overrides = if (isAllDay) allDayOverrides else timedOverrides
     val global = if (isAllDay) allDayGlobal else timedGlobal
     return if (calendarId != null && overrides.containsKey(calendarId)) {
-        overrides[calendarId]
+        overrides.getValue(calendarId)
     } else {
         global
     }
 }
 
-/** Apply a [CalendarReminderOverride] to an override map ([Inherit] removes the key). */
-private fun MutableMap<Long, Int?>.applyOverride(
-    calendarId: Long,
-    override: CalendarReminderOverride,
-) {
-    when (override) {
-        CalendarReminderOverride.Inherit -> remove(calendarId)
-        CalendarReminderOverride.None -> put(calendarId, null)
-        is CalendarReminderOverride.Minutes -> put(calendarId, override.minutes)
-    }
-}
-
 /** Sentinel stored for [WeekStartPref.Auto]; days store their [DayOfWeek.name]. */
 private const val WEEK_START_AUTO = "AUTO"
 
@@ -557,24 +927,31 @@ private fun parseWeekStart(stored: String?): WeekStartPref = when (stored) {
 private const val NONE = "none"
 private const val ENTRY_SEP = ";"
 private const val KEY_VALUE_SEP = "="
+private const val LIST_SEP = ","
 
-private fun String?.toReminderMinutes(): Int? = when (this) {
-    null, "", NONE -> null
-    else -> toIntOrNull()
+/**
+ * The per-calendar override map codec, in Calendula's stored dialect
+ * (`id=minutes` entries joined by `;`, minutes comma-joined, `none` for an
+ * explicit no-reminder). The model and codec live in floret-kit; the dialect
+ * (fixed at release) stays here.
+ */
+private val reminderOverrideCodec =
+    ReminderOverrideCodec(entrySep = ENTRY_SEP, keyValueSep = KEY_VALUE_SEP, listSep = LIST_SEP, noneToken = NONE)
+
+/**
+ * Parse a stored reminder value into lead times. `null`/empty/"none" → empty
+ * list; a comma-joined list → its minutes; a legacy single value ("30") → a
+ * one-element list. Non-numeric parts are dropped defensively.
+ */
+private fun String?.toReminderList(): List<Int> = when {
+    this == null || isEmpty() || this == NONE -> emptyList()
+    else -> split(LIST_SEP).mapNotNull { it.trim().toIntOrNull() }.normalizeReminders()
 }
 
-private fun parseReminderOverrides(stored: String?): Map<Long, Int?> {
-    if (stored.isNullOrBlank()) return emptyMap()
-    return stored.split(ENTRY_SEP).mapNotNull { entry ->
-        val parts = entry.split(KEY_VALUE_SEP).takeIf { it.size == 2 } ?: return@mapNotNull null
-        val id = parts[0].toLongOrNull() ?: return@mapNotNull null
-        val value = if (parts[1] == NONE) null else parts[1].toIntOrNull() ?: return@mapNotNull null
-        id to value
-    }.toMap()
-}
+/** Serialise lead times for storage: "none" when empty, else comma-joined. */
+private fun List<Int>.toStoredReminders(): String =
+    if (isEmpty()) NONE else normalizeReminders().joinToString(LIST_SEP) { it.toString() }
 
-private fun serializeReminderOverrides(map: Map<Long, Int?>): String =
-    map.entries.joinToString(ENTRY_SEP) { (id, minutes) -> "$id$KEY_VALUE_SEP${minutes ?: NONE}" }
 
 private inline fun <reified E : Enum<E>> String?.toEnum(default: E): E =
     this?.let { stored -> enumValues<E>().firstOrNull { it.name == stored } } ?: default

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/EventReminderReceiver.kt

@@ -1,57 +0,0 @@
-package de.jeanlucmakiola.calendula.data.reminders
-
-import android.Manifest
-import android.content.BroadcastReceiver
-import android.content.Context
-import android.content.Intent
-import android.content.pm.PackageManager
-import android.provider.CalendarContract
-import androidx.core.content.ContextCompat
-import dagger.hilt.android.AndroidEntryPoint
-import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
-import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.launch
-import javax.inject.Inject
-
-/**
- * Becomes the app that turns the calendar provider's reminder alarms into
- * visible notifications (the Etar model — the provider broadcasts
- * `EVENT_REMINDER` at reminder time but posts nothing itself).
- *
- * The broadcast's data URI only carries the alarm time, so it is ignored:
- * we query every still-scheduled, due `CalendarAlerts` row ourselves, post
- * them, and mark them fired. Posting happens before marking — a crash in
- * between re-posts silently (same tag) rather than losing the reminder.
- */
-@AndroidEntryPoint
-class EventReminderReceiver : BroadcastReceiver() {
-
-    @Inject lateinit var alertStore: ReminderAlertStore
-    @Inject lateinit var notifier: ReminderNotifier
-    @Inject lateinit var settingsPrefs: SettingsPrefs
-
-    override fun onReceive(context: Context, intent: Intent) {
-        if (intent.action != CalendarContract.ACTION_EVENT_REMINDER) return
-        val readGranted = ContextCompat.checkSelfPermission(
-            context, Manifest.permission.READ_CALENDAR,
-        ) == PackageManager.PERMISSION_GRANTED
-        if (!readGranted || !notifier.canPost()) return
-
-        val pendingResult = goAsync()
-        CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
-            try {
-                if (settingsPrefs.remindersEnabled.first()) {
-                    val now = System.currentTimeMillis()
-                    val due = alertStore.dueAlerts(now)
-                    due.forEach { notifier.post(it) }
-                    alertStore.markFired(due.map { it.alertId }, now)
-                }
-            } finally {
-                pendingResult.finish()
-            }
-        }
-    }
-}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderActionReceiver.kt

@@ -3,6 +3,7 @@ package de.jeanlucmakiola.calendula.data.reminders
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
+import androidx.core.net.toUri
 import dagger.hilt.android.AndroidEntryPoint
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import kotlinx.coroutines.CoroutineScope
@@ -18,12 +19,14 @@ import javax.inject.Inject
  * intents (notification action buttons and our own [ReminderSnoozeScheduler]
  * alarm), so the receiver is not exported.
  *
- * - **Dismiss** just cancels the notification — the `CalendarAlerts` row is
- *   already fired, so nothing re-posts it.
+ * - **Dismiss** just cancels the notification — the scan's watermark has moved
+ *   past this reminder, so nothing re-posts it.
  * - **Snooze** cancels the notification and schedules an exact alarm to re-show
  *   it after the user's snooze delay.
  * - **Show** (the alarm) re-posts the same notification, so the user can snooze
- *   or dismiss it again.
+ *   or dismiss it again — unless the calendar was switched off during the
+ *   snooze, which [ReminderNotifier.post] catches — this alarm is its own
+ *   trigger, outside the ordinary scan.
  */
 @AndroidEntryPoint
 class ReminderActionReceiver : BroadcastReceiver() {
@@ -73,20 +76,34 @@ class ReminderActionReceiver : BroadcastReceiver() {
         const val ACTION_DISMISS = "de.jeanlucmakiola.calendula.reminders.DISMISS"
         const val ACTION_SHOW = "de.jeanlucmakiola.calendula.reminders.SHOW"
 
-        private const val EXTRA_ALERT_ID = "alert_id"
+        /**
+         * Not handled here — the notification body opens the detail screen
+         * directly. It only claims a slot in [requestCode] so that intent stays
+         * distinct from the three this receiver does handle.
+         */
+        const val ACTION_OPEN = "de.jeanlucmakiola.calendula.reminders.OPEN"
+
+        private const val EXTRA_ALERT_KEY = "alert_key"
         private const val EXTRA_EVENT_ID = "event_id"
+        private const val EXTRA_CALENDAR_ID = "calendar_id"
         private const val EXTRA_BEGIN = "begin"
         private const val EXTRA_END = "end"
         private const val EXTRA_TITLE = "title"
         private const val EXTRA_LOCATION = "location"
         private const val EXTRA_ALL_DAY = "all_day"
 
-        /** An explicit intent to this receiver carrying [alert] as extras. */
+        /**
+         * An explicit intent to this receiver carrying [alert] as extras. The
+         * data URI duplicates no information but is what keeps two reminders'
+         * `PendingIntent`s apart — `filterEquals` never compares extras.
+         */
         fun intent(context: Context, action: String, alert: ReminderAlert): Intent =
             Intent(context, ReminderActionReceiver::class.java).apply {
                 this.action = action
-                putExtra(EXTRA_ALERT_ID, alert.alertId)
+                data = "calendula://reminder/${alert.key}".toUri()
+                putExtra(EXTRA_ALERT_KEY, alert.key)
                 putExtra(EXTRA_EVENT_ID, alert.eventId)
+                putExtra(EXTRA_CALENDAR_ID, alert.calendarId)
                 putExtra(EXTRA_BEGIN, alert.beginMillis)
                 putExtra(EXTRA_END, alert.endMillis)
                 putExtra(EXTRA_TITLE, alert.title)
@@ -95,24 +112,27 @@ class ReminderActionReceiver : BroadcastReceiver() {
             }
 
         /**
-         * A stable request code per (alert, action) so the three PendingIntents
-         * of one notification stay distinct and don't clobber each other.
+         * A stable request code per (alert, action), so one notification's
+         * PendingIntents stay distinct. The shift keeps the action slot intact;
+         * the top bits it drops are separated by [intent]'s per-reminder URI.
          */
         fun requestCode(alert: ReminderAlert, action: String): Int {
             val actionOffset = when (action) {
                 ACTION_SNOOZE -> 1
                 ACTION_DISMISS -> 2
                 ACTION_SHOW -> 3
+                ACTION_OPEN -> 4
                 else -> 0
             }
-            return alert.alertId.toInt() * 8 + actionOffset
+            return (alert.key.toInt() shl 3) + actionOffset
         }
 
         private fun alertFrom(intent: Intent): ReminderAlert? {
-            if (!intent.hasExtra(EXTRA_ALERT_ID)) return null
+            if (!intent.hasExtra(EXTRA_ALERT_KEY)) return null
             return ReminderAlert(
-                alertId = intent.getLongExtra(EXTRA_ALERT_ID, 0L),
+                key = intent.getLongExtra(EXTRA_ALERT_KEY, 0L),
                 eventId = intent.getLongExtra(EXTRA_EVENT_ID, 0L),
+                calendarId = intent.getLongExtra(EXTRA_CALENDAR_ID, 0L),
                 beginMillis = intent.getLongExtra(EXTRA_BEGIN, 0L),
                 endMillis = intent.getLongExtra(EXTRA_END, 0L),
                 title = intent.getStringExtra(EXTRA_TITLE).orEmpty(),

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlarms.kt

@@ -0,0 +1,64 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import android.app.AlarmManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import androidx.core.content.getSystemService
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * True on API < 31 (no restriction), and on 31+ when the exact-alarm capability
+ * is held — auto-granted via `USE_EXACT_ALARM` on API 33+ (Calendula is a
+ * calendar app), user-revocable on 31–32.
+ */
+internal fun AlarmManager.canScheduleExactCompat(): Boolean =
+    Build.VERSION.SDK_INT < Build.VERSION_CODES.S || canScheduleExactAlarms()
+
+/**
+ * Holds the app's own wake-up for the next reminder (#75). Exactly one alarm
+ * exists at a time, for the earliest reminder ahead; every firing re-scans and
+ * re-arms. Exact, with an inexact allow-while-idle fallback where the OS
+ * withholds the capability (API 31–32 with the permission revoked).
+ */
+@Singleton
+class ReminderAlarmScheduler @Inject constructor(
+    @ApplicationContext private val context: Context,
+) {
+
+    fun scheduleScan(triggerAtMillis: Long) {
+        val alarmManager = context.getSystemService<AlarmManager>() ?: return
+        val pendingIntent = scanPendingIntent(PendingIntent.FLAG_UPDATE_CURRENT)
+        if (alarmManager.canScheduleExactCompat()) {
+            alarmManager.setExactAndAllowWhileIdle(
+                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
+            )
+        } else {
+            alarmManager.setAndAllowWhileIdle(
+                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
+            )
+        }
+    }
+
+    /** Drop the pending wake-up — reminders are off, or there is nothing to wait for. */
+    fun cancelScan() {
+        val alarmManager = context.getSystemService<AlarmManager>() ?: return
+        alarmManager.cancel(scanPendingIntent(PendingIntent.FLAG_UPDATE_CURRENT))
+    }
+
+    private fun scanPendingIntent(flags: Int): PendingIntent = PendingIntent.getBroadcast(
+        context,
+        SCAN_REQUEST_CODE,
+        Intent(context, ReminderScheduleReceiver::class.java)
+            .setAction(ReminderScheduleReceiver.ACTION_SCAN),
+        flags or PendingIntent.FLAG_IMMUTABLE,
+    )
+
+    private companion object {
+        // Fixed: there is only ever one scan alarm, and re-arming must replace it.
+        const val SCAN_REQUEST_CODE = 0x5CA1
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlert.kt

@@ -0,0 +1,32 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import de.jeanlucmakiola.calendula.domain.reminders.PlannedReminder
+
+/**
+ * One reminder as the notification layer needs it: what to show, and the stable
+ * [key] identifying it across a reboot, a re-scan and a reinstall. Derived from
+ * the reminder itself (see [PlannedReminder.key]) — in-house delivery has no
+ * `CalendarAlerts` row to take an id from (#75).
+ */
+data class ReminderAlert(
+    val key: Long,
+    val eventId: Long,
+    val calendarId: Long,
+    val beginMillis: Long,
+    val endMillis: Long,
+    /** Raw event title; may be blank — the notifier substitutes "(no title)". */
+    val title: String,
+    val location: String?,
+    val isAllDay: Boolean,
+)
+
+fun PlannedReminder.toAlert(): ReminderAlert = ReminderAlert(
+    key = key,
+    eventId = instance.eventId,
+    calendarId = instance.calendarId,
+    beginMillis = instance.beginMillis,
+    endMillis = instance.endMillis,
+    title = instance.title,
+    location = instance.location,
+    isAllDay = instance.isAllDay,
+)

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlertStore.kt

@@ -1,112 +0,0 @@
-package de.jeanlucmakiola.calendula.data.reminders
-
-import android.content.ContentValues
-import android.content.Context
-import android.provider.CalendarContract
-import android.util.Log
-import dagger.hilt.android.qualifiers.ApplicationContext
-import javax.inject.Inject
-import javax.inject.Singleton
-
-/**
- * One due row of the provider's `CalendarAlerts` table (a join with Events).
- * Stays in the data layer: alerts feed the notification path only and never
- * reach a screen, so there is no domain model for them.
- */
-data class ReminderAlert(
-    val alertId: Long,
-    val eventId: Long,
-    val beginMillis: Long,
-    val endMillis: Long,
-    /** Raw event title; may be blank — the notifier substitutes "(no title)". */
-    val title: String,
-    val location: String?,
-    val isAllDay: Boolean,
-)
-
-/**
- * Seam over the `CalendarAlerts` table so the receiver logic can be exercised
- * without a ContentResolver. The provider creates these rows itself — only
- * for `METHOD_ALERT` reminders (verified in AOSP `CalendarAlarmManager`), so
- * email reminders never show up here.
- */
-interface ReminderAlertStore {
-
-    /** Alerts that are due (`ALARM_TIME` has passed) and still unhandled. */
-    fun dueAlerts(nowMillis: Long): List<ReminderAlert>
-
-    /**
-     * Mark the given alerts handled (`STATE_FIRED`) so a later broadcast does
-     * not surface them again. Best effort: this write needs `WRITE_CALENDAR`,
-     * which the user may have declined — then re-broadcasts silently replace
-     * the already-posted notifications instead (same tag, alert-once).
-     */
-    fun markFired(alertIds: List<Long>, nowMillis: Long)
-}
-
-@Singleton
-class AndroidReminderAlertStore @Inject constructor(
-    @ApplicationContext private val context: Context,
-) : ReminderAlertStore {
-
-    override fun dueAlerts(nowMillis: Long): List<ReminderAlert> = context.contentResolver.query(
-        CalendarContract.CalendarAlerts.CONTENT_URI,
-        PROJECTION,
-        CalendarContract.CalendarAlerts.STATE + " = ? AND " +
-            CalendarContract.CalendarAlerts.ALARM_TIME + " <= ?",
-        arrayOf(
-            CalendarContract.CalendarAlerts.STATE_SCHEDULED.toString(),
-            nowMillis.toString(),
-        ),
-        CalendarContract.CalendarAlerts.BEGIN + " ASC",
-    )?.use { c ->
-        buildList {
-            while (c.moveToNext()) {
-                add(
-                    ReminderAlert(
-                        alertId = c.getLong(0),
-                        eventId = c.getLong(1),
-                        beginMillis = c.getLong(2),
-                        endMillis = c.getLong(3),
-                        title = c.getString(4).orEmpty(),
-                        location = c.getString(5)?.takeIf { it.isNotBlank() },
-                        isAllDay = c.getInt(6) == 1,
-                    ),
-                )
-            }
-        }
-    } ?: emptyList()
-
-    override fun markFired(alertIds: List<Long>, nowMillis: Long) {
-        if (alertIds.isEmpty()) return
-        val values = ContentValues().apply {
-            put(CalendarContract.CalendarAlerts.STATE, CalendarContract.CalendarAlerts.STATE_FIRED)
-            put(CalendarContract.CalendarAlerts.RECEIVED_TIME, nowMillis)
-            put(CalendarContract.CalendarAlerts.NOTIFY_TIME, nowMillis)
-        }
-        try {
-            context.contentResolver.update(
-                CalendarContract.CalendarAlerts.CONTENT_URI,
-                values,
-                CalendarContract.CalendarAlerts._ID +
-                    " IN (" + alertIds.joinToString(",") + ")",
-                null,
-            )
-        } catch (e: SecurityException) {
-            Log.w(TAG, "Cannot mark alerts fired without WRITE_CALENDAR", e)
-        }
-    }
-
-    private companion object {
-        const val TAG = "ReminderAlertStore"
-        val PROJECTION = arrayOf(
-            CalendarContract.CalendarAlerts._ID,
-            CalendarContract.CalendarAlerts.EVENT_ID,
-            CalendarContract.CalendarAlerts.BEGIN,
-            CalendarContract.CalendarAlerts.END,
-            CalendarContract.CalendarAlerts.TITLE,
-            CalendarContract.CalendarAlerts.EVENT_LOCATION,
-            CalendarContract.CalendarAlerts.ALL_DAY,
-        )
-    }
-}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderInstanceSource.kt

@@ -0,0 +1,121 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import android.content.Context
+import android.content.ContentUris
+import android.provider.CalendarContract
+import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.domain.reminders.ReminderEventInstance
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * The read side of in-house reminder delivery: occurrences and their reminder
+ * offsets, read from `Instances` and `Reminders` rather than `CalendarAlerts`,
+ * which cannot be assumed to be written (#75).
+ *
+ * An interface so [ReminderScanner] can be exercised on the JVM.
+ */
+interface ReminderInstanceSource {
+
+    /** Occurrences overlapping `[fromMillis, toMillis]`, of switched-on calendars. */
+    fun occurrences(fromMillis: Long, toMillis: Long): List<ReminderEventInstance>
+
+    /** `METHOD_ALERT` reminder offsets per event id, for the given events. */
+    fun reminderMinutes(eventIds: Collection<Long>): Map<Long, List<Int>>
+
+    /**
+     * The largest `METHOD_ALERT` offset anywhere in the table, so the query
+     * window can be stretched to cover it and a long-lead reminder is planned
+     * before it comes due rather than firing late.
+     */
+    fun longestReminderMinutes(): Int
+}
+
+@Singleton
+class ProviderReminderInstanceSource @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : ReminderInstanceSource {
+
+    override fun occurrences(fromMillis: Long, toMillis: Long): List<ReminderEventInstance> {
+        val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
+            ContentUris.appendId(this, fromMillis)
+            ContentUris.appendId(this, toMillis)
+        }.build()
+        // `visible` is the flag the app's one visibility model writes (#75).
+        // The status clause mirrors CalendarDataSource.instances: NULL means
+        // "normal", so a bare `!= CANCELED` would drop every ordinary event.
+        val selection = "${CalendarContract.Calendars.VISIBLE} = 1 AND " +
+            "(${CalendarContract.Instances.STATUS} IS NULL OR " +
+            "${CalendarContract.Instances.STATUS} != ${CalendarContract.Events.STATUS_CANCELED})"
+        return context.contentResolver.query(
+            uri, OCCURRENCE_PROJECTION, selection, null, null,
+        )?.use { c ->
+            buildList {
+                while (c.moveToNext()) {
+                    add(
+                        ReminderEventInstance(
+                            eventId = c.getLong(0),
+                            calendarId = c.getLong(1),
+                            beginMillis = c.getLong(2),
+                            endMillis = if (c.isNull(3)) 0L else c.getLong(3),
+                            title = c.getString(4).orEmpty(),
+                            location = c.getString(5)?.takeIf { it.isNotBlank() },
+                            isAllDay = c.getInt(6) == 1,
+                        ),
+                    )
+                }
+            }
+        } ?: emptyList()
+    }
+
+    override fun reminderMinutes(eventIds: Collection<Long>): Map<Long, List<Int>> {
+        if (eventIds.isEmpty()) return emptyMap()
+        val out = mutableMapOf<Long, MutableList<Int>>()
+        // Batched: the ids go into the selection literally, and an unbounded
+        // `IN (...)` would grow the SQL past what SQLite takes.
+        eventIds.distinct().chunked(EVENT_ID_BATCH).forEach { batch ->
+            context.contentResolver.query(
+                CalendarContract.Reminders.CONTENT_URI,
+                REMINDER_PROJECTION,
+                "${CalendarContract.Reminders.METHOD} = " +
+                    "${CalendarContract.Reminders.METHOD_ALERT} AND " +
+                    "${CalendarContract.Reminders.EVENT_ID} IN (${batch.joinToString(",")})",
+                null,
+                null,
+            )?.use { c ->
+                while (c.moveToNext()) {
+                    out.getOrPut(c.getLong(0)) { mutableListOf() } += c.getInt(1)
+                }
+            }
+        }
+        return out
+    }
+
+    override fun longestReminderMinutes(): Int = context.contentResolver.query(
+        CalendarContract.Reminders.CONTENT_URI,
+        arrayOf(CalendarContract.Reminders.MINUTES),
+        "${CalendarContract.Reminders.METHOD} = ${CalendarContract.Reminders.METHOD_ALERT}",
+        null,
+        // One row is enough: the provider passes the sort order to SQLite.
+        "${CalendarContract.Reminders.MINUTES} DESC",
+    )?.use { c -> if (c.moveToFirst()) c.getInt(0) else 0 } ?: 0
+
+    private companion object {
+        const val EVENT_ID_BATCH = 50
+
+        val OCCURRENCE_PROJECTION = arrayOf(
+            CalendarContract.Instances.EVENT_ID,
+            CalendarContract.Instances.CALENDAR_ID,
+            CalendarContract.Instances.BEGIN,
+            CalendarContract.Instances.END,
+            CalendarContract.Instances.TITLE,
+            CalendarContract.Instances.EVENT_LOCATION,
+            CalendarContract.Instances.ALL_DAY,
+        )
+
+        val REMINDER_PROJECTION = arrayOf(
+            CalendarContract.Reminders.EVENT_ID,
+            CalendarContract.Reminders.MINUTES,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderMaintenanceWorker.kt

@@ -0,0 +1,62 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import android.content.Context
+import android.util.Log
+import androidx.work.CoroutineWorker
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import androidx.work.WorkerParameters
+import dagger.hilt.EntryPoint
+import dagger.hilt.InstallIn
+import dagger.hilt.android.EntryPointAccessors
+import dagger.hilt.components.SingletonComponent
+import java.util.concurrent.TimeUnit
+
+/**
+ * The backstop under the alarm: a daily scan that runs whether or not the alarm
+ * survived. Finds nothing to do in the steady state; it exists for the device
+ * that quietly drops the alarm without a reboot to announce it (#75).
+ */
+object ReminderMaintenanceScheduler {
+
+    private const val WORK_NAME = "reminder-scan-maintenance"
+
+    /** Enqueue the daily backstop; idempotent, so every launch may call it. */
+    fun apply(context: Context) {
+        val request = PeriodicWorkRequestBuilder<ReminderMaintenanceWorker>(1, TimeUnit.DAYS)
+            // The launch scan covers now; let the first periodic run wait.
+            .setInitialDelay(1, TimeUnit.DAYS)
+            .build()
+        WorkManager.getInstance(context)
+            .enqueueUniquePeriodicWork(WORK_NAME, ExistingPeriodicWorkPolicy.UPDATE, request)
+    }
+}
+
+class ReminderMaintenanceWorker(
+    appContext: Context,
+    params: WorkerParameters,
+) : CoroutineWorker(appContext, params) {
+
+    @EntryPoint
+    @InstallIn(SingletonComponent::class)
+    interface Deps {
+        fun reminderScanner(): ReminderScanner
+    }
+
+    override suspend fun doWork(): Result = try {
+        EntryPointAccessors.fromApplication(applicationContext, Deps::class.java)
+            .reminderScanner()
+            .scan()
+        Result.success()
+    } catch (e: Exception) {
+        // The scan swallows its own failures, so anything reaching here is the
+        // entry point itself — a retry will not mend it.
+        Log.w(TAG, "Reminder maintenance scan failed", e)
+        Result.success()
+    }
+
+    private companion object {
+        const val TAG = "ReminderMaintenance"
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderNotifier.kt

@@ -14,25 +14,35 @@ import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.MainActivity
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.calendar.CalendarDataSource
+import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.is24Hour
+import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
 import kotlinx.coroutines.flow.first
+import kotlinx.datetime.isoDayNumber
+import java.time.DayOfWeek
+import java.time.Instant
 import java.time.ZoneId
 import java.util.Locale
 import javax.inject.Inject
 import javax.inject.Singleton
 
 /**
- * Posts one notification per due reminder alert on a dedicated channel.
- * Tapping opens the event's detail screen; the tag is the alert id, so a
- * re-broadcast of an alert we couldn't mark fired replaces its notification
- * silently ([NotificationCompat.Builder.setOnlyAlertOnce]) instead of
- * duplicating it.
+ * Posts one notification per due reminder on a dedicated channel. Tapping opens
+ * the event's detail screen.
+ *
+ * The tag is the reminder's stable key, so a scan that posts the same reminder
+ * again — a catch-up pass overlapping the alarm that already fired — replaces
+ * its notification silently ([NotificationCompat.Builder.setOnlyAlertOnce])
+ * instead of stacking a second one.
  */
 @Singleton
 class ReminderNotifier @Inject constructor(
     @ApplicationContext private val context: Context,
     private val settingsPrefs: SettingsPrefs,
+    private val calendarPrefs: CalendarPrefs,
+    private val calendarDataSource: CalendarDataSource,
 ) {
 
     /** False when the user declined `POST_NOTIFICATIONS` or muted the app. */
@@ -43,18 +53,43 @@ class ReminderNotifier @Inject constructor(
         return granted && NotificationManagerCompat.from(context).areNotificationsEnabled()
     }
 
-    suspend fun post(alert: ReminderAlert) {
+    /**
+     * The single choke point for "this calendar is switched off", covering the
+     * two paths that reach [post] around the scan's own filter: a snooze armed
+     * before the switch-off, and a read-only install whose switch lives in
+     * [CalendarPrefs].
+     */
+    private suspend fun isSilenced(calendarId: Long): Boolean =
+        calendarId in calendarPrefs.pendingDisabledCalendarIds.first() ||
+            calendarDataSource.isCalendarVisible(calendarId) == false
+
+    /**
+     * Post [alert], unless its calendar is switched off. Returns whether the
+     * notification was put up, which the snooze re-show path uses to tell a
+     * silenced reminder from a delivered one.
+     */
+    suspend fun post(alert: ReminderAlert): Boolean {
+        if (isSilenced(alert.calendarId)) return false
         ensureChannel()
         val title = alert.title.ifBlank { context.getString(R.string.event_untitled) }
         val is24Hour = settingsPrefs.timeFormat.first()
             .is24Hour(android.text.format.DateFormat.is24HourFormat(context))
+        val zone = ZoneId.systemDefault()
+        val locale = Locale.getDefault()
+        // resolveFirstDay yields a kotlinx.datetime day; bridge it to java.time by
+        // its shared ISO number (1..7) for the date math in reminderTimeText.
+        val firstDayOfWeek = DayOfWeek.of(settingsPrefs.weekStart.first().resolveFirstDay(locale).isoDayNumber)
         val time = reminderTimeText(
             beginMillis = alert.beginMillis,
             endMillis = alert.endMillis,
             isAllDay = alert.isAllDay,
-            zone = ZoneId.systemDefault(),
-            locale = Locale.getDefault(),
+            zone = zone,
+            locale = locale,
             is24Hour = is24Hour,
+            today = Instant.now().atZone(zone).toLocalDate(),
+            firstDayOfWeek = firstDayOfWeek,
+            tomorrowLabel = context.getString(R.string.reminder_day_tomorrow),
+            yesterdayLabel = context.getString(R.string.reminder_day_yesterday),
         )
         val text = listOfNotNull(time, alert.location).joinToString(" · ")
         val notification = NotificationCompat.Builder(context, CHANNEL_ID)
@@ -81,16 +116,18 @@ class ReminderNotifier @Inject constructor(
             .build()
         try {
             NotificationManagerCompat.from(context)
-                .notify(alert.alertId.toString(), NOTIFICATION_ID, notification)
+                .notify(alert.key.toString(), NOTIFICATION_ID, notification)
         } catch (e: SecurityException) {
             // POST_NOTIFICATIONS was revoked between canPost() and here.
             Log.w(TAG, "Could not post reminder for event ${alert.eventId}", e)
         }
+        // Handled either way — a retry hits the same revoked permission.
+        return true
     }
 
     /** Remove a posted reminder (snooze re-shows it later; dismiss is final). */
     fun cancel(alert: ReminderAlert) {
-        NotificationManagerCompat.from(context).cancel(alert.alertId.toString(), NOTIFICATION_ID)
+        NotificationManagerCompat.from(context).cancel(alert.key.toString(), NOTIFICATION_ID)
     }
 
     private fun actionIntent(alert: ReminderAlert, action: String): PendingIntent =
@@ -103,7 +140,10 @@ class ReminderNotifier @Inject constructor(
 
     private fun detailIntent(alert: ReminderAlert): PendingIntent = PendingIntent.getActivity(
         context,
-        /* requestCode = */ alert.alertId.toInt(),
+        // Shares the per-(alert, action) request-code scheme with the buttons.
+        /* requestCode = */ ReminderActionReceiver.requestCode(
+            alert, ReminderActionReceiver.ACTION_OPEN,
+        ),
         MainActivity.eventDetailIntent(context, alert.eventId, alert.beginMillis, alert.endMillis),
         PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
     )

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderScanner.kt

@@ -0,0 +1,158 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.util.Log
+import androidx.core.content.ContextCompat
+import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.data.calendar.CalendarDataSource
+import de.jeanlucmakiola.calendula.data.di.IoDispatcher
+import de.jeanlucmakiola.calendula.data.prefs.ReminderStatePrefs
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.domain.reminders.planReminders
+import de.jeanlucmakiola.calendula.domain.reminders.reminderQueryHorizon
+import de.jeanlucmakiola.calendula.domain.reminders.reminderWatermark
+import de.jeanlucmakiola.calendula.domain.reminders.scheduleReminders
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.CoroutineStart
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.debounce
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import java.time.ZoneId
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * One pass of in-house reminder delivery: read what is planned, post what has
+ * come due, and arm the next wake-up. Every trigger runs the same [scan], and
+ * re-running is always safe — the watermark in [ReminderStatePrefs] decides what
+ * is owed, not the trigger.
+ */
+@Singleton
+class ReminderScanner @Inject constructor(
+    @ApplicationContext private val context: Context,
+    private val source: ReminderInstanceSource,
+    private val calendarDataSource: CalendarDataSource,
+    private val notifier: ReminderNotifier,
+    private val alarms: ReminderAlarmScheduler,
+    private val state: ReminderStatePrefs,
+    private val settingsPrefs: SettingsPrefs,
+    @IoDispatcher private val io: kotlinx.coroutines.CoroutineDispatcher,
+) {
+
+    // Triggers overlap freely (an alarm during a burst of edits); serialize so
+    // two passes can't both read the same watermark and post the same reminder.
+    private val scanLock = Mutex()
+
+    private val scope = CoroutineScope(SupervisorJob() + io)
+    private val providerChanges = MutableSharedFlow<Unit>(
+        replay = 0, extraBufferCapacity = 1, onBufferOverflow = BufferOverflow.DROP_OLDEST,
+    )
+    private var watching = false
+
+    suspend fun scan() = withContext(io) {
+        scanLock.withLock {
+            try {
+                runScan()
+            } catch (e: SecurityException) {
+                // Permission revoked mid-flight; the next grant re-scans.
+                Log.w(TAG, "Reminder scan lacks the calendar permission", e)
+            } catch (e: Exception) {
+                Log.w(TAG, "Reminder scan failed", e)
+            }
+        }
+    }
+
+    private suspend fun runScan() {
+        val now = System.currentTimeMillis()
+        if (!hasReadCalendar()) return
+
+        if (!settingsPrefs.remindersEnabled.first()) {
+            // Reminders off: drop the wake-up, but keep the watermark moving
+            // so switching them back on doesn't replay the backlog.
+            alarms.cancelScan()
+            state.setLastScanMillis(now)
+            return
+        }
+
+        val lookahead = reminderQueryHorizon(LOOKAHEAD_MILLIS, source.longestReminderMinutes())
+        // Reach into the past too: an all-day "at time of event" encodes to a
+        // negative offset, and a catch-up pass needs the occurrences it missed.
+        val occurrences = source.occurrences(now - PAST_WINDOW_MILLIS, now + lookahead)
+        val planned = planReminders(
+            instances = occurrences,
+            minutesByEvent = source.reminderMinutes(occurrences.map { it.eventId }),
+            zone = ZoneId.systemDefault(),
+            allDayTimeMinutes = settingsPrefs.allDayReminderTimeMinutes.first(),
+        )
+
+        val schedule = scheduleReminders(
+            planned = planned,
+            lastFiredMillis = reminderWatermark(state.lastScanMillis(), now),
+            nowMillis = now,
+            horizonMillis = now + MAX_ALARM_INTERVAL_MILLIS,
+        )
+
+        if (notifier.canPost()) {
+            schedule.due.forEach { notifier.post(it.toAlert()) }
+        }
+        // Advance even when nothing could be posted, so muting notifications
+        // doesn't build a backlog.
+        state.setLastScanMillis(now)
+        alarms.scheduleScan(schedule.nextAlarmMillis)
+    }
+
+    private fun hasReadCalendar(): Boolean = ContextCompat.checkSelfPermission(
+        context, Manifest.permission.READ_CALENDAR,
+    ) == PackageManager.PERMISSION_GRANTED
+
+    /**
+     * Re-scan when the provider changes, so a saved or deleted event re-arms the
+     * alarm at once. Debounced, since a single save lands as several
+     * notifications. Process-lifetime only; other triggers cover the rest.
+     */
+    fun startWatchingProvider() {
+        if (watching) return
+        watching = true
+        providerChanges
+            .debounce(PROVIDER_CHANGE_DEBOUNCE_MILLIS)
+            .onEach { scan() }
+            .launchIn(scope)
+        calendarDataSource.registerChangeListener { providerChanges.tryEmit(Unit) }
+    }
+
+    /** Fire-and-forget scan for callers that are not in a coroutine already. */
+    fun scanInBackground() {
+        scope.launch(start = CoroutineStart.DEFAULT) { scan() }
+    }
+
+    private companion object {
+        const val TAG = "ReminderScanner"
+
+        /**
+         * How far ahead occurrences are read. Stretched further by the longest
+         * reminder offset in the table, so this is only the floor.
+         */
+        const val LOOKAHEAD_MILLIS = 7L * 24 * 60 * 60 * 1000
+
+        /** How far back to look for occurrences that may still owe a reminder. */
+        const val PAST_WINDOW_MILLIS = 24L * 60 * 60 * 1000
+
+        /**
+         * Never wait longer than a day for the next pass: it rolls the lookahead
+         * window forward and re-arms an alarm the system may have dropped.
+         */
+        const val MAX_ALARM_INTERVAL_MILLIS = 24L * 60 * 60 * 1000
+
+        const val PROVIDER_CHANGE_DEBOUNCE_MILLIS = 2_000L
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderScheduleReceiver.kt

@@ -0,0 +1,53 @@
+package de.jeanlucmakiola.calendula.data.reminders
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import dagger.hilt.android.AndroidEntryPoint
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * Every out-of-process reason to re-run a reminder scan: our own [ACTION_SCAN]
+ * alarm, boot and package-replaced (both wipe pending alarms), and time or
+ * timezone changes (both move reminders relative to the armed alarm). All do the
+ * same thing, since [ReminderScanner.scan] is idempotent.
+ *
+ * Exported for the system broadcasts; an early scan triggered by another app is
+ * harmless.
+ */
+@AndroidEntryPoint
+class ReminderScheduleReceiver : BroadcastReceiver() {
+
+    @Inject lateinit var scanner: ReminderScanner
+
+    override fun onReceive(context: Context, intent: Intent) {
+        // Checked despite every action doing the same thing: the receiver is
+        // exported and the broadcasts it takes are protected, so any other
+        // action did not come from where it claims to.
+        if (intent.action !in HANDLED_ACTIONS) return
+        val pendingResult = goAsync()
+        CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
+            try {
+                scanner.scan()
+            } finally {
+                pendingResult.finish()
+            }
+        }
+    }
+
+    companion object {
+        const val ACTION_SCAN = "de.jeanlucmakiola.calendula.reminders.SCAN"
+
+        private val HANDLED_ACTIONS = setOf(
+            ACTION_SCAN,
+            Intent.ACTION_BOOT_COMPLETED,
+            Intent.ACTION_MY_PACKAGE_REPLACED,
+            Intent.ACTION_TIME_CHANGED,
+            Intent.ACTION_TIMEZONE_CHANGED,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderSnoozeScheduler.kt

@@ -10,14 +10,13 @@ import javax.inject.Inject
 import javax.inject.Singleton
 
 /**
- * Schedules a one-off exact alarm that re-shows a snoozed reminder.
+ * Schedules a one-off exact alarm that re-shows a snoozed reminder. Separate
+ * from [ReminderAlarmScheduler]'s single moving scan alarm: a snooze is pinned
+ * to one reminder and has to outlive the watermark moving past it, so it carries
+ * the reminder in its own intent.
  *
- * The app otherwise relies entirely on the calendar provider's `EVENT_REMINDER`
- * broadcast (the Etar model), but a snoozed reminder has no provider backing —
- * its `CalendarAlerts` row is already fired — so we must re-fire it ourselves.
- * A snooze that lands late is a broken snooze, hence an *exact* alarm; we fall
- * back to an inexact allow-while-idle alarm only if the OS withholds the
- * exact-alarm capability (API 31–32 where the user revoked it).
+ * Falls back to an inexact allow-while-idle alarm where the OS withholds the
+ * exact-alarm capability (API 31–32 with the permission revoked).
  */
 @Singleton
 class ReminderSnoozeScheduler @Inject constructor(
@@ -37,8 +36,8 @@ class ReminderSnoozeScheduler @Inject constructor(
                 AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
             )
         } else {
-            // Exact alarms revoked (API 31–32): an inexact wake is the honest
-            // best we can do without nagging for SCHEDULE_EXACT_ALARM.
+            // Exact alarms revoked (API 31–32); an inexact wake is the best
+            // available without nagging for SCHEDULE_EXACT_ALARM.
             alarmManager.setAndAllowWhileIdle(
                 AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
             )

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderTimeText.kt

@@ -1,23 +1,37 @@
 package de.jeanlucmakiola.calendula.data.reminders
 
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
+import java.time.DayOfWeek
 import java.time.Instant
+import java.time.LocalDate
 import java.time.ZoneId
 import java.time.ZoneOffset
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
+import java.time.format.TextStyle
+import java.time.temporal.ChronoUnit
 import java.util.Locale
 
 /**
  * The one line of time context in a reminder notification. Pure so it can be
- * JVM-tested:
+ * JVM-tested.
  *
- * - timed, same day:      "09:30 – 10:00"
- * - timed, crossing days: "11 Jun, 23:30 – 12 Jun, 00:30" (medium date + short time)
+ * Timed events that fall on a day other than [today] are prefixed with that
+ * day, so a reminder fired ahead of time no longer reads as if the event were
+ * today (issue #46). The prefix prefers natural language and stays short:
+ *
+ * - today:                "09:30 – 10:00"                 (no prefix)
+ * - tomorrow / yesterday: "Tomorrow, 09:30 – 10:00"       ([tomorrowLabel] / [yesterdayLabel])
+ * - elsewhere this week:  "Thu, 09:30 – 10:00"            (localized short weekday)
+ * - further out:          "16 Jul, 09:30 – 10:00"         (medium date — a weekday
+ *                                                          alone would be ambiguous)
+ * - timed, crossing days: "11 Jun, 23:30 – 12 Jun, 00:30" (medium date + short time,
+ *                                                          already unambiguous)
  * - all-day, one day:     "11 Jun 2026"
  * - all-day, multi-day:   "11 Jun 2026 – 12 Jun 2026"
  *
- * All-day instances store UTC midnights with an exclusive end, so they are
+ * All-day instances already carry an explicit date, so they never gain a
+ * relative prefix. They store UTC midnights with an exclusive end, so they are
  * read in UTC and the end day is the last *covered* day.
  */
 fun reminderTimeText(
@@ -27,6 +41,10 @@ fun reminderTimeText(
     zone: ZoneId,
     locale: Locale,
     is24Hour: Boolean,
+    today: LocalDate,
+    firstDayOfWeek: DayOfWeek,
+    tomorrowLabel: String,
+    yesterdayLabel: String,
 ): String {
     if (isAllDay) {
         val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
@@ -43,18 +61,70 @@ fun reminderTimeText(
     }
 
     val timeFormat = timeOfDayFormatter(is24Hour, locale)
+    val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
     val begin = Instant.ofEpochMilli(beginMillis).atZone(zone)
     val end = Instant.ofEpochMilli(endMillis).atZone(zone)
     return if (begin.toLocalDate() == end.toLocalDate()) {
-        timeFormat.format(begin) + RANGE + timeFormat.format(end)
+        val range = timeFormat.format(begin) + RANGE + timeFormat.format(end)
+        val prefix = relativeDayPrefix(
+            day = begin.toLocalDate(),
+            today = today,
+            firstDayOfWeek = firstDayOfWeek,
+            locale = locale,
+            dateFormat = dateFormat,
+            tomorrowLabel = tomorrowLabel,
+            yesterdayLabel = yesterdayLabel,
+        )
+        if (prefix == null) range else "$prefix, $range"
     } else {
         // Cross-day: medium date + the chosen short time, joined per side. Built
         // from the two formatters (not ofLocalizedDateTime) so the 12/24h choice
-        // applies to the time portion too.
-        val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
+        // applies to the time portion too. The explicit dates already say which
+        // day, so no relative prefix is layered on top.
         val dateTime = { z: java.time.ZonedDateTime -> "${dateFormat.format(z)}, ${timeFormat.format(z)}" }
         dateTime(begin) + RANGE + dateTime(end)
     }
 }
 
+/**
+ * A short label for [day] relative to [today], or `null` when it *is* today (the
+ * common case, which needs no prefix). Weekday names are used only within the
+ * current week — a "next Wednesday" would be indistinguishable from this one, so
+ * anything past this week falls back to the exact date.
+ */
+private fun relativeDayPrefix(
+    day: LocalDate,
+    today: LocalDate,
+    firstDayOfWeek: DayOfWeek,
+    locale: Locale,
+    dateFormat: DateTimeFormatter,
+    tomorrowLabel: String,
+    yesterdayLabel: String,
+): String? = when (ChronoUnit.DAYS.between(today, day)) {
+    0L -> null
+    1L -> tomorrowLabel
+    -1L -> yesterdayLabel
+    else -> if (isSameWeek(day, today, firstDayOfWeek)) {
+        day.dayOfWeek.getDisplayName(TextStyle.SHORT, locale)
+    } else {
+        dateFormat.format(day)
+    }
+}
+
+/**
+ * True when [day] and [today] share the same week. The week boundary honours the
+ * user's *week starts on* setting (already resolved to a concrete [firstDayOfWeek],
+ * with [firstDayOfWeek] falling back to the locale default upstream).
+ */
+private fun isSameWeek(day: LocalDate, today: LocalDate, firstDayOfWeek: DayOfWeek): Boolean {
+    val startOfWeek = today.previousOrSame(firstDayOfWeek)
+    return !day.isBefore(startOfWeek) && day.isBefore(startOfWeek.plusWeeks(1))
+}
+
+/** The most recent [target] on or before this date (this date itself when it matches). */
+private fun LocalDate.previousOrSame(target: DayOfWeek): LocalDate {
+    val backtrack = (dayOfWeek.value - target.value + 7) % 7
+    return minusDays(backtrack.toLong())
+}
+
 private const val RANGE = " – "

app/src/main/java/de/jeanlucmakiola/calendula/domain/CalendarRowState.kt

@@ -0,0 +1,60 @@
+package de.jeanlucmakiola.calendula.domain
+
+/**
+ * The ways a calendar can behave unlike a plain, writable one — each a reason it
+ * is missing from the event and import pickers (#76).
+ */
+enum class CalendarStateLabel {
+    /**
+     * A special-dates mirror the app fills from contacts. Writable and visible,
+     * yet no event target: anything authored here is deleted by the next sync.
+     */
+    MANAGED,
+
+    /** Contents can't be modified: a WebCal subscription, a read-only share. */
+    READ_ONLY,
+
+    /** The account holds the events, but this device isn't syncing them down. */
+    NOT_SYNCED,
+}
+
+/**
+ * Whether the account keeps this calendar's events off the device
+ * (`Calendars.SYNC_EVENTS = 0`) — empty by construction. Device-local calendars
+ * are excluded: nothing syncs them by definition, and one from another app can
+ * hold real events at `sync_events = 0`.
+ */
+val CalendarSource.isNotSynced: Boolean
+    get() = !syncsEvents && !isLocal
+
+/**
+ * Whether a visibility switch on this calendar can change anything the user
+ * would see — it can't for a non-syncing one, with no events on the device.
+ */
+val CalendarSource.hasVisibilitySwitch: Boolean
+    get() = !isNotSynced
+
+/**
+ * Whether this calendar can be offered as a target for a new or imported event.
+ * The one predicate behind both pickers, so the states [CalendarStateLabel]
+ * names on a manager row are exactly the states that keep a calendar out of them
+ * (#76). An event already living in an excluded calendar keeps it; the editor
+ * adds that calendar back to its picker.
+ */
+val CalendarSource.isEventTarget: Boolean
+    get() = canModifyContents && isVisibleInSystem && !isManaged && !isNotSynced
+
+/** Every state worth naming on this calendar's row, in reading order. */
+fun CalendarSource.stateLabels(): List<CalendarStateLabel> = buildList {
+    if (isManaged) add(CalendarStateLabel.MANAGED)
+    if (!canModifyContents) add(CalendarStateLabel.READ_ONLY)
+    if (isNotSynced) add(CalendarStateLabel.NOT_SYNCED)
+}
+
+/**
+ * Calendar-manager order within one group: the ones you can actually act on
+ * first, the non-syncing ones after them. Stable otherwise, so the provider's
+ * display-name ordering survives.
+ */
+fun List<CalendarSource>.orderedForManager(): List<CalendarSource> =
+    sortedBy { it.isNotSynced }

app/src/main/java/de/jeanlucmakiola/calendula/domain/CalendarVisibilityPlan.kt

@@ -0,0 +1,48 @@
+package de.jeanlucmakiola.calendula.domain
+
+/**
+ * The `Calendars.VISIBLE` writes that flush the app's pending "switched off"
+ * set into the provider, plus the ids that need no write at all.
+ */
+data class CalendarVisibilityPlan(
+    val hide: Set<Long> = emptySet(),
+    val settled: Set<Long> = emptySet(),
+) {
+    val isEmpty: Boolean get() = hide.isEmpty() && settled.isEmpty()
+}
+
+/**
+ * Reconcile [pendingDisabledIds] — switch-offs the app could not write, plus
+ * what the retired app-local visibility model left behind (#75) — against the
+ * calendars actually on the device.
+ *
+ * Only ever *hides*: switching a system-hidden calendar back on would un-hide it
+ * in every other calendar app too. Calendula follows the flag and explains
+ * itself once (see [hasSystemHiddenCalendars]).
+ *
+ * [CalendarVisibilityPlan.settled] carries the ids needing no write — already
+ * hidden, or gone from the device.
+ */
+fun calendarVisibilityPlan(
+    calendars: List<CalendarSource>,
+    pendingDisabledIds: Set<Long>,
+): CalendarVisibilityPlan {
+    val byId = calendars.associateBy { it.id }
+    val hide = mutableSetOf<Long>()
+    val settled = mutableSetOf<Long>()
+    for (id in pendingDisabledIds) {
+        val calendar = byId[id]
+        // Gone from the device, or already invisible — nothing to write.
+        if (calendar != null && calendar.isVisibleInSystem) hide += id else settled += id
+    }
+    return CalendarVisibilityPlan(hide = hide, settled = settled)
+}
+
+/**
+ * Whether any calendar is switched off at system level without Calendula having
+ * asked for it — the condition the one-time notice explains.
+ */
+fun hasSystemHiddenCalendars(
+    calendars: List<CalendarSource>,
+    pendingDisabledIds: Set<Long>,
+): Boolean = calendars.any { !it.isVisibleInSystem && it.id !in pendingDisabledIds }

app/src/main/java/de/jeanlucmakiola/calendula/domain/EventColorPalette.kt

@@ -0,0 +1,185 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlin.math.abs
+import kotlin.math.atan2
+import kotlin.math.cbrt
+import kotlin.math.hypot
+import kotlin.math.pow
+import kotlin.math.roundToInt
+import kotlin.math.sqrt
+
+/**
+ * Curates an account's published event palette for the colour picker.
+ *
+ * Sync adapters differ wildly in what they publish: Google exposes a
+ * hand-picked two-dozen set, while CalDAV adapters (DAVx5) dump all ~147 CSS3
+ * named colours — including exact-value aliases (aqua/cyan, the gray/grey
+ * spelling pairs) and dozens of visually indistinguishable whites and grays
+ * (#22).
+ *
+ * Crucially, curation runs against the colour the picker actually *paints*, not
+ * the raw provider value. The picker softens every swatch through [pastelArgb]:
+ * it pins lightness to a constant and caps saturation, so the raw palette's
+ * lightness axis is invisible on screen. Two raw colours that look different —
+ * a navy and a mid blue — paint as one swatch, and every neutral (black, the
+ * grays, white) paints as the same pale tint. Judging distinctness in raw
+ * space, as before, left near-identical painted swatches and stranded the
+ * neutrals as a run of look-alike "pinks" at the end of the grid.
+ *
+ * Three steps, all in painted space:
+ *  1. Collapse swatches that paint identically to one (alphabetically-first key
+ *     wins, deterministically) — this folds aliases, dark/light shades of a
+ *     hue, and all the neutrals together.
+ *  2. Oversized palettes (> [CURATION_TRIGGER_SIZE]) drop the washed-out
+ *     neutral-origin tints (painted chroma < [PASTEL_CHROMA_FLOOR]) and are
+ *     then thinned to visually distinct colours: most vivid first, a colour is
+ *     kept only when at least [MIN_DELTA_E] (CIE76, painted Lab) from every
+ *     colour already kept. Small palettes are already curated by their adapter
+ *     and pass through whole.
+ *  3. The survivors are ordered like a rainbow — continuously by painted hue —
+ *     with the wheel cut at its single widest empty gap so the one unavoidable
+ *     seam lands in dead space and no hue family is torn across both ends.
+ *
+ * Every surviving option keeps its provider [EventColorOption.key], so a pick
+ * still round-trips through sync.
+ */
+fun List<EventColorOption>.curatedForPicker(): List<EventColorOption> {
+    val painted = sortedBy { it.key }
+        .distinctBy { pastelArgb(it.argb) }
+        .map { it to Lab.of(pastelArgb(it.argb)) }
+    val kept = if (painted.size <= CURATION_TRIGGER_SIZE) {
+        painted
+    } else {
+        thin(painted.filter { (_, lab) -> lab.chroma >= PASTEL_CHROMA_FLOOR })
+    }
+    return orderAroundWheel(kept).map { (option, _) -> option }
+}
+
+/**
+ * Orders swatches continuously around the (painted) hue wheel, then cuts the
+ * circle at its widest angular gap so the single seam lands in empty space
+ * instead of mid-family. Saturation breaks ties, vivid first.
+ */
+private fun orderAroundWheel(
+    swatches: List<Pair<EventColorOption, Lab>>,
+): List<Pair<EventColorOption, Lab>> {
+    if (swatches.size < 2) return swatches
+    val byHue = swatches.sortedWith(
+        compareBy({ (_, lab) -> lab.hue }, { (_, lab) -> -lab.chroma }),
+    )
+    // Split the wheel after the largest empty arc between neighbouring hues;
+    // the default is the wrap gap (last hue back round to the first), i.e. the
+    // familiar 0→360 order, and we only rotate away from it for a wider void.
+    var cutAfter = byHue.lastIndex
+    var widestGap = 360.0 - byHue.last().second.hue + byHue.first().second.hue
+    for (i in 0 until byHue.lastIndex) {
+        val gap = byHue[i + 1].second.hue - byHue[i].second.hue
+        if (gap > widestGap) {
+            widestGap = gap
+            cutAfter = i
+        }
+    }
+    return byHue.subList(cutAfter + 1, byHue.size) + byHue.subList(0, cutAfter + 1)
+}
+
+/** Greedy max-distance filter: vivid colours stake out clusters first. */
+private fun thin(
+    swatches: List<Pair<EventColorOption, Lab>>,
+): List<Pair<EventColorOption, Lab>> {
+    val byVividness = swatches
+        .sortedWith(compareByDescending<Pair<EventColorOption, Lab>> { it.second.chroma }.thenBy { it.first.key })
+    val kept = mutableListOf<Pair<EventColorOption, Lab>>()
+    for (candidate in byVividness) {
+        if (kept.none { it.second.deltaE(candidate.second) < MIN_DELTA_E }) kept += candidate
+    }
+    return kept
+}
+
+/**
+ * The softening the colour picker paints over every swatch: keep the hue, scale
+ * and clamp saturation into a gentle band, and pin value to a constant so
+ * nothing screams and everything reads on the surface. Value is fixed here so
+ * curation is theme-independent — only hue and saturation distinguish painted
+ * swatches.
+ *
+ * This is a self-contained mirror of floret-kit's `pastelize` hue/saturation
+ * shaping (`de.jeanlucmakiola.floret.components.pastelize`), with value pinned
+ * rather than theme-picked. Curation must reason about the colour the picker
+ * paints, so the two shapings have to agree: if floret's saturation band or
+ * curve changes, update this in step.
+ */
+fun pastelArgb(rawArgb: Int): Int {
+    val r = ((rawArgb shr 16) and 0xFF) / 255f
+    val g = ((rawArgb shr 8) and 0xFF) / 255f
+    val b = (rawArgb and 0xFF) / 255f
+    val max = maxOf(r, g, b)
+    val min = minOf(r, g, b)
+    val delta = max - min
+    val hue = when {
+        delta == 0f -> 0f
+        max == r -> 60f * (((g - b) / delta) % 6f)
+        max == g -> 60f * (((b - r) / delta) + 2f)
+        else -> 60f * (((r - g) / delta) + 4f)
+    }.let { if (it < 0f) it + 360f else it }
+    val sat = (if (max == 0f) 0f else delta / max) * 0.6f
+    val s = sat.coerceIn(0.25f, 0.65f)
+    val v = PASTEL_VALUE
+    val c = v * s
+    val x = c * (1f - abs((hue / 60f) % 2f - 1f))
+    val m = v - c
+    val (rr, gg, bb) = when {
+        hue < 60f -> Triple(c, x, 0f)
+        hue < 120f -> Triple(x, c, 0f)
+        hue < 180f -> Triple(0f, c, x)
+        hue < 240f -> Triple(0f, x, c)
+        hue < 300f -> Triple(x, 0f, c)
+        else -> Triple(c, 0f, x)
+    }
+    fun channel(value: Float) = ((value + m) * 255f).roundToInt().coerceIn(0, 255)
+    return (0xFF shl 24) or (channel(rr) shl 16) or (channel(gg) shl 8) or channel(bb)
+}
+
+/** Reference lightness for curation; the picker paints at this on dark surfaces. */
+private const val PASTEL_VALUE = 0.82f
+
+/** Palettes at most this big skip the thinning (Google's ~26 pass through). */
+private const val CURATION_TRIGGER_SIZE = 36
+
+/** Minimum CIE76 ΔE between surviving painted swatches. */
+private const val MIN_DELTA_E = 13.0
+
+/**
+ * Painted-chroma floor for oversized palettes: below this a swatch is a washed-
+ * out tint — the neutrals and near-whites the saturation clamp muddies — so it
+ * is dropped rather than shown as pale filler.
+ */
+private const val PASTEL_CHROMA_FLOOR = 22.0
+
+/** CIE Lab (D65) — the space where Euclidean distance ≈ perceived difference. */
+private class Lab(val l: Double, val a: Double, val b: Double) {
+    val chroma: Double get() = hypot(a, b)
+
+    /** Hue angle in degrees, 0–360, around the Lab a-b plane. */
+    val hue: Double get() = (Math.toDegrees(atan2(b, a)) + 360.0) % 360.0
+
+    fun deltaE(other: Lab): Double =
+        sqrt((l - other.l).pow(2) + (a - other.a).pow(2) + (b - other.b).pow(2))
+
+    companion object {
+        fun of(argb: Int): Lab {
+            fun linear(shift: Int): Double {
+                val c = ((argb shr shift) and 0xFF) / 255.0
+                return if (c <= 0.04045) c / 12.92 else ((c + 0.055) / 1.055).pow(2.4)
+            }
+            val r = linear(16)
+            val g = linear(8)
+            val b = linear(0)
+            val x = (0.4124 * r + 0.3576 * g + 0.1805 * b) / 0.95047
+            val y = 0.2126 * r + 0.7152 * g + 0.0722 * b
+            val z = (0.0193 * r + 0.1192 * g + 0.9505 * b) / 1.08883
+            fun f(t: Double) = if (t > 0.008856) cbrt(t) else 7.787 * t + 16.0 / 116.0
+            val fy = f(y)
+            return Lab(116 * fy - 16, 500 * (f(x) - fy), 200 * (fy - f(z)))
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/domain/EventForm.kt

@@ -4,13 +4,14 @@ import kotlinx.datetime.LocalDate
 import kotlinx.datetime.LocalDateTime
 import kotlinx.datetime.LocalTime
 import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Instant
 
 /**
  * User input for creating an event (and, from v1.3, editing one). Times are
- * wall-clock values in the device zone; the data layer translates them to
- * provider millis (all-day events normalise to UTC midnights there).
+ * wall-clock values in [timezone]; the data layer translates them to provider
+ * millis (all-day events normalise to UTC midnights there).
  */
 data class EventForm(
     val calendarId: Long?,
@@ -18,6 +19,23 @@ data class EventForm(
     val isAllDay: Boolean = false,
     val start: LocalDateTime,
     val end: LocalDateTime,
+    /**
+     * The zone [start]/[end] are wall-clock values in, or null to follow the
+     * device — null is not "no zone", it is "whichever zone the device is in
+     * when this is saved", which is what an event authored and lived in one
+     * place wants. The data layer resolves it at write time and always stamps a
+     * concrete `EVENT_TIMEZONE`.
+     *
+     * A non-null value pins the event to a zone regardless of where the device
+     * is, so it keeps tracking that zone's offset across DST. [toEditForm] only
+     * sets it when the stored zone differs from the device's, so merely opening
+     * a local event never reveals the field — and re-opening a pinned one in
+     * another zone round-trips it rather than silently re-anchoring it.
+     *
+     * Always null for all-day events: those are date-anchored, not zone-anchored
+     * (see [EventFormField.Timezone] and the data layer's UTC-midnight rule).
+     */
+    val timezone: String? = null,
     val location: String = "",
     val description: String = "",
     /** Reminder lead times in minutes before the start, deduplicated. */
@@ -66,11 +84,19 @@ data class EventAttendee(
 
 /**
  * The form's optional sections. Which ones show by default is a user setting;
- * the rest unfold behind a "more fields" button.
+ * the rest unfold behind a "more fields" button. Declaration order is the order
+ * they're offered in, so a new constant goes where it belongs on the form, not
+ * at the end.
  */
 enum class EventFormField {
     Location,
     Description,
+    /**
+     * Pins the event's wall-clock times to a zone. Offered right after the time
+     * fields it qualifies, and suppressed entirely for all-day events, whose
+     * dates are deliberately zone-free.
+     */
+    Timezone,
     Reminders,
     Recurrence,
     Availability,
@@ -100,8 +126,25 @@ enum class EventFormProblem {
  * All-day provider times are UTC midnights with an exclusive end; the form
  * shows the last covered day and keeps placeholder wall-clock times in case
  * the user switches the event to timed.
+ *
+ * A timed event stored in a zone other than [zone] is prefilled *in its own
+ * zone* and keeps it pinned, so the wall-clock the form shows is the one the
+ * event means ("the New York 09:00 call") and a later save re-anchors it to the
+ * same zone rather than the device's.
  */
 fun EventDetail.toEditForm(beginMillis: Long, endMillis: Long, zone: TimeZone): EventForm {
+    // All-day events are date-anchored and carry a nominal "UTC" that is an
+    // anchor, not a location, so they never pin a zone.
+    val pinnedZone = if (instance.isAllDay) {
+        null
+    } else {
+        eventTimezone
+            ?.takeIf { it != zone.id }
+            // An unparseable id (a malformed sync row) can't be honoured or
+            // shown; fall back to the device zone rather than failing the open.
+            ?.takeIf { runCatching { TimeZone.of(it) }.isSuccess }
+    }
+    val formZone = pinnedZone?.let { TimeZone.of(it) } ?: zone
     val (start, end) = if (instance.isAllDay) {
         val startDate = Instant.fromEpochMilliseconds(beginMillis)
             .toLocalDateTime(TimeZone.UTC).date
@@ -110,8 +153,8 @@ fun EventDetail.toEditForm(beginMillis: Long, endMillis: Long, zone: TimeZone):
         val endDate = maxOf(startDate, LocalDate.fromEpochDays(endExclusive.toEpochDays() - 1))
         LocalDateTime(startDate, LocalTime(9, 0)) to LocalDateTime(endDate, LocalTime(10, 0))
     } else {
-        Instant.fromEpochMilliseconds(beginMillis).toLocalDateTime(zone) to
-            Instant.fromEpochMilliseconds(endMillis).toLocalDateTime(zone)
+        Instant.fromEpochMilliseconds(beginMillis).toLocalDateTime(formZone) to
+            Instant.fromEpochMilliseconds(endMillis).toLocalDateTime(formZone)
     }
     return EventForm(
         calendarId = instance.calendarId,
@@ -119,6 +162,7 @@ fun EventDetail.toEditForm(beginMillis: Long, endMillis: Long, zone: TimeZone):
         isAllDay = instance.isAllDay,
         start = start,
         end = end,
+        timezone = pinnedZone,
         location = instance.location.orEmpty(),
         description = description.orEmpty(),
         reminders = reminders.map { it.minutes }.distinct().sorted(),
@@ -176,6 +220,23 @@ fun EventDetail.toEditSnapshot(beginMillis: Long, endMillis: Long, zone: TimeZon
         rowEnd = instance.end,
     )
 
+/**
+ * The form's times as they land in [target] — what a pinned event's wall-clock
+ * actually means where the user is standing. Null when there's nothing to
+ * disambiguate: an unpinned event (already in [target]), one pinned to [target]
+ * itself, an all-day event (no zone), or an unparseable pinned zone.
+ *
+ * The form edits a pinned event in its own zone, so this is what lets the UI
+ * show the other side of the pair rather than making the user do the arithmetic.
+ */
+fun EventForm.timesIn(target: TimeZone): Pair<LocalDateTime, LocalDateTime>? {
+    if (isAllDay) return null
+    val pinned = timezone?.let { runCatching { TimeZone.of(it) }.getOrNull() } ?: return null
+    if (pinned.id == target.id) return null
+    return start.toInstant(pinned).toLocalDateTime(target) to
+        end.toInstant(pinned).toLocalDateTime(target)
+}
+
 /**
  * The optional sections that hold a value in [form] — when editing, these
  * must be visible regardless of the user's default-fields setting, or the
@@ -184,6 +245,7 @@ fun EventDetail.toEditSnapshot(beginMillis: Long, endMillis: Long, zone: TimeZon
 fun EventForm.populatedFields(): Set<EventFormField> = buildSet {
     if (location.isNotBlank()) add(EventFormField.Location)
     if (description.isNotBlank()) add(EventFormField.Description)
+    if (timezone != null) add(EventFormField.Timezone)
     if (reminders.isNotEmpty()) add(EventFormField.Reminders)
     if (rrule != null) add(EventFormField.Recurrence)
     if (availability != Availability.Busy) add(EventFormField.Availability)

app/src/main/java/de/jeanlucmakiola/calendula/domain/FontRole.kt

@@ -0,0 +1,8 @@
+package de.jeanlucmakiola.calendula.domain
+
+/**
+ * The two Material 3 typeface roles a user can set independently (issue #19):
+ * [BRAND] drives the display/headline styles (expression), [PLAIN] the
+ * title/body/label styles (readability). Each defaults to the system typeface.
+ */
+enum class FontRole { BRAND, PLAIN }

app/src/main/java/de/jeanlucmakiola/calendula/domain/InsertEventForm.kt

@@ -0,0 +1,76 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.LocalTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Duration.Companion.hours
+import kotlin.time.Instant
+
+/**
+ * Build a prefilled [EventForm] from an `ACTION_INSERT` intent's extras (issue
+ * #30). External apps and widgets (e.g. the Todo Agenda widget) launch the
+ * calendar this way to create a new event, passing the fields as
+ * [android.provider.CalendarContract] extras. Any field the intent omits falls
+ * back to the same defaults the in-app "new event" uses — a timed start at the
+ * next full hour and a one-hour duration. [EventForm.calendarId] is left null so
+ * it resolves to the last-used / first-writable calendar, exactly like the
+ * `.ics` single-event and plain new-event paths.
+ *
+ * Pure (no Android types) so it is unit-testable; the intent parsing that reads
+ * the extras lives in `MainActivity.insertFormOrNull`.
+ */
+fun buildInsertEventForm(
+    beginMillis: Long?,
+    endMillis: Long?,
+    isAllDay: Boolean,
+    title: String?,
+    description: String?,
+    location: String?,
+    rrule: String?,
+    zone: TimeZone,
+    now: Instant,
+): EventForm {
+    val (start, end) = if (isAllDay) {
+        // All-day provider times are UTC midnights with an exclusive end; show
+        // the last covered day and keep placeholder wall-clock times in case the
+        // user switches the event to timed (mirrors EventDetail.toEditForm).
+        val startDate = beginMillis
+            ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(TimeZone.UTC).date }
+            ?: now.toLocalDateTime(zone).date
+        val endDate = endMillis
+            ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(TimeZone.UTC).date }
+            ?.let { exclusive -> maxOf(startDate, LocalDate.fromEpochDays(exclusive.toEpochDays() - 1)) }
+            ?: startDate
+        LocalDateTime(startDate, LocalTime(9, 0)) to LocalDateTime(endDate, LocalTime(10, 0))
+    } else {
+        val startTime = beginMillis
+            ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(zone) }
+            ?: nextFullHour(now, zone)
+        val endTime = endMillis
+            ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(zone) }
+            ?.takeIf { it >= startTime }
+            ?: (startTime.toInstant(zone) + 1.hours).toLocalDateTime(zone)
+        startTime to endTime
+    }
+    return EventForm(
+        calendarId = null,
+        title = title.orEmpty(),
+        isAllDay = isAllDay,
+        start = start,
+        end = end,
+        location = location.orEmpty(),
+        description = description.orEmpty(),
+        // Bare RRULE value (Events.RRULE convention); tolerate a leading "RRULE:"
+        // some callers include.
+        rrule = rrule?.removePrefix("RRULE:")?.takeIf { it.isNotBlank() },
+    )
+}
+
+private fun nextFullHour(now: Instant, zone: TimeZone): LocalDateTime {
+    val hourMillis = 3_600_000L
+    val rounded = (now.toEpochMilliseconds() / hourMillis + 1) * hourMillis
+    return Instant.fromEpochMilliseconds(rounded).toLocalDateTime(zone)
+}

app/src/main/java/de/jeanlucmakiola/calendula/domain/Models.kt

@@ -1,5 +1,9 @@
 package de.jeanlucmakiola.calendula.domain
 
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Instant
 
 data class CalendarSource(
@@ -8,6 +12,11 @@ data class CalendarSource(
     val accountName: String,
     val accountType: String,
     val color: Int,
+    /**
+     * The system's `Calendars.VISIBLE` flag — the single visibility model,
+     * deciding both what Calendula shows and whether this calendar plans
+     * reminders (#75). The drawer's filter sheet is a separate in-app declutter.
+     */
     val isVisibleInSystem: Boolean,
     /**
      * Whether events in this calendar can be created/edited/deleted
@@ -26,6 +35,21 @@ data class CalendarSource(
      * owns for its own calendars). Always null for synced calendars.
      */
     val description: String? = null,
+    /**
+     * A special-dates mirror calendar the app manages (birthdays/anniversaries
+     * from contacts). Its events' title/date/recurrence are owned by the sync,
+     * so it's hidden from the new-event calendar picker and its events lock those
+     * fields in the editor. Recognised by a durable provider marker, so it holds
+     * even after a backup restore clears the app's stored ids.
+     */
+    val isManaged: Boolean = false,
+    /**
+     * Whether the provider keeps this calendar's events on the device
+     * (`Calendars.SYNC_EVENTS`), independent of [isVisibleInSystem]. Says
+     * nothing about device-local calendars, which can hold events with it off.
+     * Read for the "not synced" row label (#76).
+     */
+    val syncsEvents: Boolean = true,
 )
 
 data class EventInstance(
@@ -48,6 +72,31 @@ data class EventInstance(
  */
 fun EventInstance.hasEnded(now: Instant): Boolean = end <= now
 
+/**
+ * The zone this event's calendar dates live in: the device [zone] for timed
+ * events, UTC for all-day ones, whose midnights would otherwise shift day
+ * boundaries (#65, #82). Every surface naming an all-day date goes through here.
+ */
+fun EventInstance.dateZone(zone: TimeZone): TimeZone =
+    if (isAllDay) TimeZone.UTC else zone
+
+/** The first calendar day this event occupies. */
+fun EventInstance.spanFirstDay(zone: TimeZone): LocalDate =
+    start.toLocalDateTime(dateZone(zone)).date
+
+/**
+ * The last calendar day this event occupies. An event ending exactly at midnight
+ * does not reach into that day, so resolve just before [EventInstance.end].
+ */
+fun EventInstance.spanLastDay(zone: TimeZone): LocalDate {
+    val lastInstant = if (end > start) end - 1.milliseconds else start
+    return lastInstant.toLocalDateTime(dateZone(zone)).date
+}
+
+/** Whether this event occupies more than one calendar day in [zone]. */
+fun EventInstance.spansMultipleDays(zone: TimeZone): Boolean =
+    spanFirstDay(zone) != spanLastDay(zone)
+
 data class EventDetail(
     val instance: EventInstance,
     val description: String?,

app/src/main/java/de/jeanlucmakiola/calendula/domain/RecurrenceOccurrences.kt

@@ -0,0 +1,106 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.isoDayNumber
+import kotlinx.datetime.minus
+import kotlinx.datetime.number
+import kotlinx.datetime.plus
+
+/**
+ * The first [limit] dates a [SimpleRecurrence] fires on, starting at [start]
+ * (DTSTART), for previewing a rule as dates instead of as words. A preview only,
+ * kept to the shapes the picker can build; the provider stays the authority.
+ *
+ * Mirrors RFC 5545: [start] is always the first occurrence (§3.8.5.3), even when
+ * the rule's own picks miss it; a monthly or yearly rule *skips* a period the
+ * start day doesn't exist in rather than clamping; a weekly rule repeats in
+ * blocks of `interval` weeks beginning on Monday (the default WKST, since
+ * [toRRule] never writes one); [RecurrenceEnd.Count] counts real occurrences and
+ * [RecurrenceEnd.Until] is inclusive.
+ *
+ * Returns fewer than [limit] dates when the series ends first, and an empty list
+ * only when the rule yields nothing at all (an UNTIL before [start]).
+ */
+fun SimpleRecurrence.upcomingOccurrences(start: LocalDate, limit: Int): List<LocalDate> {
+    if (limit <= 0) return emptyList()
+    val until = (end as? RecurrenceEnd.Until)?.date
+    val maxCount = (end as? RecurrenceEnd.Count)?.times ?: Int.MAX_VALUE
+    val wanted = minOf(limit, maxCount)
+    if (wanted <= 0) return emptyList()
+    if (until != null && start > until) return emptyList()
+
+    // DTSTART is in the recurrence set whatever the rule picks, so seed with it
+    // and let the walk skip anything landing on or before it.
+    val result = mutableListOf(start)
+    var period = 0
+    // Periods can yield nothing (a skipped 31st), so the cap counts periods
+    // examined rather than dates found.
+    while (result.size < wanted && period < MAX_PERIODS) {
+        for (date in occurrencesInPeriod(period, start)) {
+            if (date <= start) continue
+            if (until != null && date > until) return result
+            result += date
+            if (result.size == wanted) return result
+        }
+        period++
+    }
+    return result
+}
+
+/** The dates this rule's [period]-th repetition yields (empty when skipped). */
+private fun SimpleRecurrence.occurrencesInPeriod(period: Int, start: LocalDate): List<LocalDate> =
+    when (freq) {
+        RecurrenceFreq.Daily -> listOf(start.plus(period * interval, DateTimeUnit.DAY))
+        RecurrenceFreq.Weekly -> weeklyOccurrences(period, start)
+        RecurrenceFreq.Monthly -> {
+            val month = start.plus(period * interval, DateTimeUnit.MONTH)
+            // plus() clamps into the shorter month, but the rule skips such a
+            // period — so a clamped date means "not this month".
+            listOfNotNull(dateOrNull(month.year, month.month.number, start.day))
+        }
+        RecurrenceFreq.Yearly ->
+            listOfNotNull(dateOrNull(start.year + period * interval, start.month.number, start.day))
+    }
+
+/**
+ * One weekly block: every picked weekday inside the week that begins
+ * `period * interval` weeks after the start's own week, in weekday order. With
+ * no picks the rule simply repeats the start's weekday.
+ */
+private fun SimpleRecurrence.weeklyOccurrences(period: Int, start: LocalDate): List<LocalDate> {
+    if (byDays.isEmpty()) return listOf(start.plus(period * interval, DateTimeUnit.WEEK))
+    val daysIntoWeek = (start.dayOfWeek.isoDayNumber - DayOfWeek.MONDAY.isoDayNumber + DAYS_PER_WEEK) %
+        DAYS_PER_WEEK
+    val weekStart = start
+        .minus(daysIntoWeek, DateTimeUnit.DAY)
+        .plus(period * interval, DateTimeUnit.WEEK)
+    return byDays.sortedBy { it.isoDayNumber }.map { day ->
+        weekStart.plus(
+            (day.isoDayNumber - DayOfWeek.MONDAY.isoDayNumber + DAYS_PER_WEEK) % DAYS_PER_WEEK,
+            DateTimeUnit.DAY,
+        )
+    }
+}
+
+/**
+ * Whether a run of [occurrences] starting at [start] leaves its starting year,
+ * i.e. whether showing them without a year would be ambiguous — a yearly rule
+ * would otherwise read as the same date repeated.
+ */
+fun occurrencesSpanYears(occurrences: List<LocalDate>, start: LocalDate): Boolean =
+    occurrences.any { it.year != start.year } || occurrences.map { it.year }.distinct().size > 1
+
+/** [LocalDate] for a day-of-month that may not exist in that month; null if it doesn't. */
+private fun dateOrNull(year: Int, month: Int, day: Int): LocalDate? =
+    runCatching { LocalDate(year, month, day) }.getOrNull()
+
+private const val DAYS_PER_WEEK = 7
+
+/**
+ * How many repetitions to examine before giving up: generous enough for the
+ * sparsest rule the picker can build, bounded so a rule whose occurrences all
+ * fall outside its own UNTIL can't spin.
+ */
+private const val MAX_PERIODS = 2_000

app/src/main/java/de/jeanlucmakiola/calendula/domain/TimeZoneCatalog.kt

@@ -0,0 +1,225 @@
+package de.jeanlucmakiola.calendula.domain
+
+import java.text.Normalizer
+import java.time.Instant
+import java.time.ZoneId
+import java.time.format.TextStyle
+import java.util.Locale
+
+/**
+ * One selectable zone, resolved for display at a given instant. [id] is the IANA
+ * id we store in `EVENT_TIMEZONE` and show as the primary label (via [label]);
+ * [shortName] its abbreviation ("CET", "WET", "UTC", or a "GMT+05:30" fallback);
+ * [offsetMinutes] its offset. Both the abbreviation and the offset shift with
+ * DST, so they're only meaningful next to the moment they were resolved for.
+ *
+ * [displayName] is the long localized name ("Central European Time"). It's kept
+ * for search only — matching on it lets someone type "pacific" — and is *not*
+ * displayed: spelled out next to the id it made the field too wide to fit.
+ */
+data class TimeZoneOption(
+    val id: String,
+    val displayName: String,
+    val shortName: String,
+    val offsetMinutes: Int,
+) {
+    /** The id as the primary label, underscores undone ("America/New York"). */
+    val label: String get() = id.replace('_', ' ')
+
+    /** The trailing segment of the id ("Europe/Berlin" -> "Berlin"), underscores undone. */
+    val city: String get() = id.substringAfterLast('/').replace('_', ' ')
+
+    /** The leading segment ("Europe/Berlin" -> "Europe"); empty for bare ids like "UTC". */
+    val region: String get() = id.substringBeforeLast('/', missingDelimiterValue = "")
+
+    /**
+     * The four fields [filterTimeZones] matches on, normalized once here rather
+     * than per query. Normalizing is not cheap — NFD decomposition plus a combining-
+     * mark strip — and a search re-examines every option on every keystroke, so
+     * doing it at construction turns ~2400 normalizations per character into a few
+     * hundred plain `startsWith`/`contains` calls.
+     *
+     * Declared in the class body, so it stays out of `equals`/`hashCode`/`copy`:
+     * it is derived state, and two options with the same id are the same option.
+     */
+    internal val searchKeys: TimeZoneSearchKeys = TimeZoneSearchKeys(
+        city = city.normalizeForSearch(),
+        id = id.normalizeForSearch(),
+        displayName = displayName.normalizeForSearch(),
+        shortName = shortName.normalizeForSearch(),
+    )
+}
+
+/** Pre-normalized match targets for one [TimeZoneOption]. */
+internal data class TimeZoneSearchKeys(
+    val city: String,
+    val id: String,
+    val displayName: String,
+    val shortName: String,
+)
+
+private fun optionFor(
+    zone: ZoneId,
+    locale: Locale,
+    at: Instant,
+    regionOf: (String) -> String?,
+): TimeZoneOption = TimeZoneOption(
+    id = zone.id,
+    displayName = zone.getDisplayName(TextStyle.FULL, locale),
+    shortName = resolveAbbreviation(zone.id, zone.rules.isDaylightSavings(at), locale, regionOf),
+    offsetMinutes = zone.rules.getOffset(at).totalSeconds / 60,
+)
+
+/**
+ * The zone abbreviation ("EDT", "CEST"), DST-correct at the resolved instant, or
+ * a "GMT+05:30" form when no name exists.
+ *
+ * Two things make this fiddlier than it looks. First, it goes through
+ * java.util.TimeZone, NOT java.time's "zzz" formatter: on Android the latter has
+ * no short specific-zone names and degrades every zone to a "GMT-4" form (it
+ * agrees with java.util only on desktop, which is why desktop can't catch it).
+ * Second, ICU only surfaces the short name *commonly used in the display
+ * locale's region* — a German-region English phone (en-DE) is shown "CEST" but
+ * not "EDT", and an en-US phone the reverse. So ask in the display *language*
+ * but the *zone's* region ("America/New_York" in en-US, "Europe/Berlin" in
+ * en-DE) via [regionOf]. That covers almost everything; where a region still
+ * yields no name (Athens in en-GR) the plain device locale sometimes does, so
+ * try that next; failing both, the caller shows the offset.
+ *
+ * [regionOf] maps an IANA id to an ISO 3166 region and is injected because it
+ * needs `android.icu`, which this pure-JVM module can't import. The default
+ * (no region) leaves only the device-locale path — which is all a JVM test has
+ * anyway, and enough there since desktop ICU isn't region-gated the same way.
+ */
+private fun resolveAbbreviation(
+    id: String,
+    dst: Boolean,
+    locale: Locale,
+    regionOf: (String) -> String?,
+): String {
+    fun shortIn(loc: Locale): String =
+        java.util.TimeZone.getTimeZone(id).getDisplayName(dst, java.util.TimeZone.SHORT, loc)
+    val regional = regionOf(id)
+        ?.takeIf { it.length == 2 }
+        ?.let { shortIn(Locale(locale.language, it)) }
+    if (regional != null && !regional.looksLikeOffset()) return regional
+    // Either no region, or the region has no name for this zone: the device
+    // locale is the next-best shot, and the offset the last resort.
+    return shortIn(locale)
+}
+
+/** True for the offset-style names ICU returns when a zone has no abbreviation. */
+private fun String.looksLikeOffset(): Boolean = this == "UTC" || startsWith("GMT")
+
+/**
+ * Every zone the JVM knows, resolved at [at]. [regionOf] (see
+ * [resolveAbbreviation]) supplies the zone's region for the abbreviation.
+ *
+ * This is ~600 entries, each costing a localized display name plus up to two ICU
+ * short-name lookups, so it is **not** cheap enough for the main thread — build
+ * it off-thread once and filter the result with [filterTimeZones] rather than
+ * rebuilding per keystroke.
+ *
+ * Bare three-letter ids ("EST", "CST6CDT") and the legacy SystemV tree are
+ * dropped: they're aliases the tz database keeps for compatibility, they'd
+ * double up the real zones in the list, and none of them is what a user means
+ * when they pick a place.
+ */
+fun timeZoneOptions(
+    locale: Locale = Locale.getDefault(),
+    at: Instant = Instant.now(),
+    regionOf: (String) -> String? = { null },
+): List<TimeZoneOption> = ZoneId.getAvailableZoneIds()
+    .asSequence()
+    .filter { it.contains('/') && !it.startsWith("SystemV/") }
+    .map { optionFor(ZoneId.of(it), locale, at, regionOf) }
+    .sortedWith(compareBy({ it.region }, { it.city }))
+    .toList()
+
+/**
+ * Resolve a single [id] the same way [timeZoneOptions] would, or null if the tz
+ * database doesn't know it — for labelling one known zone without paying to
+ * build the whole catalogue.
+ */
+fun timeZoneOptionOf(
+    id: String,
+    locale: Locale = Locale.getDefault(),
+    at: Instant = Instant.now(),
+    regionOf: (String) -> String? = { null },
+): TimeZoneOption? {
+    val zone = runCatching { ZoneId.of(id) }.getOrNull() ?: return null
+    return optionFor(zone, locale, at, regionOf)
+}
+
+/**
+ * The short descriptor shown beneath the id, e.g. "CET · GMT+01:00". "UTC" reads
+ * fine alone; any other offset-shaped name is normalised to our own GMT form so
+ * the offset isn't stated twice in ICU's spelling and ours.
+ */
+fun zoneDescriptor(option: TimeZoneOption): String {
+    val abbrev = option.shortName
+    return when {
+        abbrev == "UTC" -> "UTC"
+        abbrev.startsWith("GMT") -> formatGmtOffset(option.offsetMinutes)
+        else -> "$abbrev · ${formatGmtOffset(option.offsetMinutes)}"
+    }
+}
+
+/**
+ * [options] matching [query], best matches first; a blank query returns the list
+ * unchanged. Matching is accent- and case-insensitive and treats underscores as
+ * spaces, so "sao paulo" finds "America/Sao_Paulo".
+ *
+ * Ranking puts a city that *starts with* the query above one that merely
+ * contains it — typing "col" should reach Colombo before Turks_and_Caicos —
+ * and the id is matched ahead of the localized name so a user who knows the
+ * IANA id gets it first. An exact abbreviation hit ("CEST") ranks just under a
+ * city prefix, so typing an abbreviation surfaces every zone that shows it
+ * (all the CEST zones together); the abbreviation is the one resolved for the
+ * display region, i.e. what the row actually shows.
+ */
+fun filterTimeZones(options: List<TimeZoneOption>, query: String): List<TimeZoneOption> {
+    val needle = query.normalizeForSearch()
+    if (needle.isEmpty()) return options
+    return options
+        .mapNotNull { option ->
+            val keys = option.searchKeys
+            val rank = when {
+                keys.city.startsWith(needle) -> 0
+                keys.shortName == needle -> 1
+                keys.displayName.startsWith(needle) -> 2
+                keys.shortName.startsWith(needle) -> 3
+                keys.city.contains(needle) -> 4
+                keys.id.contains(needle) -> 5
+                keys.displayName.contains(needle) -> 6
+                else -> return@mapNotNull null
+            }
+            rank to option
+        }
+        .sortedWith(compareBy({ it.first }, { it.second.city }))
+        .map { it.second }
+}
+
+/** Unicode combining marks — what NFD decomposition leaves an accent as. */
+private val COMBINING_MARKS = Regex("\\p{Mn}+")
+
+/**
+ * Lowercased, accent-stripped, underscores and slashes flattened to spaces, so
+ * a query types the way a place is spoken rather than the way the tz database
+ * spells it.
+ */
+private fun String.normalizeForSearch(): String =
+    Normalizer.normalize(this, Normalizer.Form.NFD)
+        .replace(COMBINING_MARKS, "")
+        .replace('_', ' ')
+        .replace('/', ' ')
+        .lowercase(Locale.ROOT)
+        .trim()
+
+/** "GMT+02:00" / "GMT-05:30" / "GMT" — the offset as shown next to a zone. */
+fun formatGmtOffset(offsetMinutes: Int): String {
+    if (offsetMinutes == 0) return "GMT"
+    val sign = if (offsetMinutes < 0) '-' else '+'
+    val abs = kotlin.math.abs(offsetMinutes)
+    return "GMT%c%02d:%02d".format(sign, abs / 60, abs % 60)
+}

app/src/main/java/de/jeanlucmakiola/calendula/domain/contacts/ContactSpecialDate.kt

@@ -0,0 +1,122 @@
+package de.jeanlucmakiola.calendula.domain.contacts
+
+import java.time.LocalDate
+
+/**
+ * The kinds of contact "special date" Calendula mirrors into local calendars.
+ * Each kind gets its own local calendar, so it inherits per-calendar colour,
+ * visibility and reminder defaults for free. See
+ * docs/design/contact-special-dates.md.
+ */
+enum class SpecialDateType {
+    Birthday,
+    Anniversary,
+
+    /** Everything else — a contact "Event" that is neither birthday nor anniversary. */
+    Custom,
+}
+
+/**
+ * One dated event read from a device contact (a `ContactsContract` `Event`
+ * row). The [lookupKey] is the stable contact identity used to reconcile the
+ * mirror without duplicating; [year] is null when the contact stored the date
+ * without one (`--MM-dd`), in which case age can't be shown.
+ */
+data class ContactSpecialDate(
+    val lookupKey: String,
+    val displayName: String,
+    val type: SpecialDateType,
+    val month: Int,
+    val day: Int,
+    val year: Int?,
+    /** The contact's custom label for a [SpecialDateType.Custom] date, if any. */
+    val label: String? = null,
+)
+
+/** The parsed month/day (+ optional year) of a contact date. */
+data class ContactDateParts(val year: Int?, val month: Int, val day: Int)
+
+/**
+ * A fixed leap year to validate and anchor year-less dates against, so that a
+ * `--02-29` birthday is representable (and, once anchored, only recurs in leap
+ * years — matching how the calendar provider expands a yearly Feb-29 series).
+ */
+const val YEARLESS_ANCHOR_YEAR = 1972
+
+/**
+ * Parse a `ContactsContract.CommonDataKinds.Event.START_DATE` value into its
+ * calendar parts, or null if it isn't a usable date. Handles the three shapes
+ * seen in the wild:
+ * - full `yyyy-MM-dd` (year known),
+ * - year-less `--MM-dd` (year null),
+ * - compact `yyyyMMdd`.
+ *
+ * A date that names an impossible day (e.g. `1999-02-29`) is rejected. Pure, so
+ * it's unit-tested without a device.
+ */
+fun parseContactEventDate(raw: String?): ContactDateParts? {
+    val s = raw?.trim().orEmpty()
+    if (s.isEmpty()) return null
+
+    // Year-less: "--MM-dd" or "--MMdd".
+    if (s.startsWith("--")) {
+        val (m, d) = parseMonthDay(s.substring(2)) ?: return null
+        return validated(null, m, d)
+    }
+
+    if (s.contains('-')) {
+        val parts = s.split('-').filter { it.isNotEmpty() }
+        return when (parts.size) {
+            // "yyyy-MM-dd" — but a leading '-' would have dropped the empty
+            // first part, so require the first token to look like a year.
+            3 -> if (s.startsWith('-')) null else validated(
+                year = parts[0].toIntOrNull() ?: return null,
+                month = parts[1].toIntOrNull() ?: return null,
+                day = parts[2].toIntOrNull() ?: return null,
+            )
+            // Year-less "MM-dd" without the "--" prefix.
+            2 -> validated(
+                year = null,
+                month = parts[0].toIntOrNull() ?: return null,
+                day = parts[1].toIntOrNull() ?: return null,
+            )
+            else -> null
+        }
+    }
+
+    // Compact "yyyyMMdd".
+    if (s.length == 8 && s.all { it.isDigit() }) {
+        return validated(
+            year = s.substring(0, 4).toInt(),
+            month = s.substring(4, 6).toInt(),
+            day = s.substring(6, 8).toInt(),
+        )
+    }
+
+    return null
+}
+
+/** "MM-dd" or compact "MMdd". */
+private fun parseMonthDay(rest: String): Pair<Int, Int>? {
+    if (rest.contains('-')) {
+        val p = rest.split('-').filter { it.isNotEmpty() }
+        if (p.size != 2) return null
+        return (p[0].toIntOrNull() ?: return null) to (p[1].toIntOrNull() ?: return null)
+    }
+    if (rest.length == 4 && rest.all { it.isDigit() }) {
+        return rest.substring(0, 2).toInt() to rest.substring(2, 4).toInt()
+    }
+    return null
+}
+
+/**
+ * Confirm month/day form a real calendar date (validated against the actual
+ * year when known, otherwise the leap anchor so `02-29` survives).
+ */
+private fun validated(year: Int?, month: Int, day: Int): ContactDateParts? {
+    if (month !in 1..12 || day !in 1..31) return null
+    val checkYear = year ?: YEARLESS_ANCHOR_YEAR
+    return runCatching { LocalDate.of(checkYear, month, day) }
+        .map { ContactDateParts(year, month, day) }
+        .getOrNull()
+}

app/src/main/java/de/jeanlucmakiola/calendula/domain/contacts/SpecialDateFormatting.kt

@@ -0,0 +1,65 @@
+package de.jeanlucmakiola.calendula.domain.contacts
+
+import kotlinx.datetime.LocalDate
+
+/**
+ * Prefix of every managed-event `UID_2445`. Distinguishes mirror events from
+ * user-created ones (which carry a random `<uuid>@calendula` UID), so the sync
+ * only ever reconciles — and never deletes — events it actually owns.
+ */
+const val MANAGED_UID_PREFIX = "contact-"
+
+/**
+ * The deterministic `Events.UID_2445` that ties a mirrored event to its source
+ * contact date. Stable across syncs (the reconciliation key), namespaced by
+ * type so the same contact's birthday and anniversary never collide, and — when
+ * a [discriminator] is given — by it too, so two Custom dates on one contact
+ * (e.g. "Wedding" and "Graduation") get distinct events instead of clobbering
+ * each other.
+ */
+fun managedEventUid(type: SpecialDateType, lookupKey: String, discriminator: String? = null): String {
+    val disc = discriminator?.takeIf { it.isNotBlank() }?.let { ":$it" }.orEmpty()
+    return "$MANAGED_UID_PREFIX${type.name.lowercase()}:$lookupKey$disc@calendula"
+}
+
+/**
+ * The reconciliation key for this date's mirrored event. Birthdays/anniversaries
+ * are one-per-contact, so they key on the contact alone; a [SpecialDateType.Custom]
+ * date adds a discriminator (its label, else its month-day) so distinct custom
+ * dates on one contact don't collapse into a single event.
+ */
+fun ContactSpecialDate.managedUid(): String =
+    managedEventUid(type, lookupKey, customDiscriminator())
+
+private fun ContactSpecialDate.customDiscriminator(): String? =
+    if (type == SpecialDateType.Custom) {
+        label?.trim()?.lowercase()?.ifBlank { null } ?: "%02d-%02d".format(month, day)
+    } else {
+        null
+    }
+
+/**
+ * The all-day date the recurring `FREQ=YEARLY` series is anchored at: the real
+ * date when the year is known (so age can be derived), otherwise the month/day
+ * on a fixed leap anchor year so a `--02-29` date stays representable and the
+ * anchor never drifts between syncs.
+ */
+fun ContactSpecialDate.anchorDate(): LocalDate =
+    LocalDate(year ?: YEARLESS_ANCHOR_YEAR, month, day)
+
+/**
+ * Render a title [template] for a contact, substituting `{name}` and `{year}`
+ * (the source year — a birthday's birth year or an anniversary's start year;
+ * empty when [year] is null). Unlike an age, the year is static and correct on
+ * every occurrence of the yearly event. Collapses the whitespace an empty
+ * `{year}` may leave behind, so "{name}'s birthday ({year})" degrades cleanly to
+ * "Jane's birthday" when no year is known.
+ */
+fun renderSpecialDateTitle(template: String, name: String, year: Int?): String =
+    template
+        .replace("{name}", name)
+        .replace("{year}", year?.toString().orEmpty())
+        // Drop an empty "()" left by an unresolved {year}, then tidy spacing.
+        .replace(Regex("""\(\s*\)"""), "")
+        .replace(Regex("""\s+"""), " ")
+        .trim()

app/src/main/java/de/jeanlucmakiola/calendula/domain/reminders/ReminderPlan.kt

@@ -0,0 +1,191 @@
+package de.jeanlucmakiola.calendula.domain.reminders
+
+import java.time.Instant
+import java.time.LocalDate
+import java.time.LocalTime
+import java.time.ZoneId
+import java.time.ZoneOffset
+import java.time.temporal.ChronoUnit
+
+/**
+ * Pure decision layer of in-house reminder delivery (#75): instances and reminder
+ * offsets in, fire instants out. No provider, no clock. See docs/ARCHITECTURE.md.
+ */
+
+/** An occurrence that reminders can hang off, flattened out of `Instances`. */
+data class ReminderEventInstance(
+    val eventId: Long,
+    val calendarId: Long,
+    val beginMillis: Long,
+    val endMillis: Long,
+    val title: String,
+    val location: String?,
+    val isAllDay: Boolean,
+)
+
+/**
+ * One occurrence paired with one of its reminder offsets, and the instant that
+ * pairing has to fire at.
+ */
+data class PlannedReminder(
+    val instance: ReminderEventInstance,
+    val minutes: Int,
+    val alarmMillis: Long,
+) {
+    /**
+     * Stable identity, keying the notification tag and the snooze/dismiss
+     * `PendingIntent`s. Survives reboot, re-scan and reinstall.
+     */
+    val key: Long = key(instance.eventId, instance.beginMillis, minutes)
+
+    private companion object {
+        fun key(eventId: Long, beginMillis: Long, minutes: Int): Long {
+            var h = eventId * 1_000_003L
+            h = (h xor beginMillis) * 31L
+            return h + minutes
+        }
+    }
+}
+
+/** What one scan concluded: post these now, and wake up again at [nextAlarmMillis]. */
+data class ReminderSchedule(
+    val due: List<PlannedReminder>,
+    val nextAlarmMillis: Long,
+)
+
+private const val MILLIS_PER_MINUTE = 60_000L
+private const val MINUTES_PER_DAY = 1_440
+
+/**
+ * Pair every instance with each of its event's reminder offsets.
+ *
+ * Timed occurrences fire at `begin − minutes`. All-day ones read the offset only
+ * for *which day* it means ([allDayLeadDays]) and take the hour from
+ * [allDayTimeMinutes], recomposed against each occurrence's own date in [zone].
+ * Duplicate offsets in [minutesByEvent] collapse.
+ */
+fun planReminders(
+    instances: List<ReminderEventInstance>,
+    minutesByEvent: Map<Long, List<Int>>,
+    zone: ZoneId,
+    allDayTimeMinutes: Int,
+): List<PlannedReminder> = instances.flatMap { instance ->
+    minutesByEvent[instance.eventId].orEmpty().distinct().map { minutes ->
+        PlannedReminder(
+            instance = instance,
+            minutes = minutes,
+            alarmMillis = if (instance.isAllDay) {
+                allDayAlarmMillis(instance.beginMillis, minutes, zone, allDayTimeMinutes)
+            } else {
+                instance.beginMillis - minutes * MILLIS_PER_MINUTE
+            },
+        )
+    }
+}
+
+/** UTC midnight of an all-day occurrence, as the calendar date it stands for. */
+private fun allDayDate(beginMillis: Long): LocalDate =
+    Instant.ofEpochMilli(beginMillis).atZone(ZoneOffset.UTC).toLocalDate()
+
+/**
+ * How many whole days before its occurrence a raw all-day offset means.
+ *
+ * Our own rows fold the wanted hour into the offset, so the local date of the
+ * encoded instant is the answer. A plain multiple of 1440 is a foreign bare lead
+ * time and taken at face value instead — unless the instant lands on the hour the
+ * setting names (within [NAMED_HOUR_TOLERANCE_MINUTES], for DST drift), where the
+ * encodings collide and the tie goes to our own reading.
+ *
+ * Also used by
+ * [de.jeanlucmakiola.calendula.data.calendar.fromProviderAllDayMinutes] for
+ * display, so screen and notification agree.
+ */
+internal fun allDayLeadDays(
+    rawMinutes: Int,
+    startDate: LocalDate,
+    zone: ZoneId,
+    allDayTimeMinutes: Int,
+): Long {
+    val utcMidnight = startDate.atStartOfDay(ZoneOffset.UTC).toInstant().toEpochMilli()
+    val encoded = Instant.ofEpochMilli(utcMidnight - rawMinutes * MILLIS_PER_MINUTE).atZone(zone)
+    val minutesFromNamedHour = encoded.toLocalTime().let {
+        val delta = (it.hour * 60 + it.minute - allDayTimeMinutes).mod(MINUTES_PER_DAY)
+        minOf(delta, MINUTES_PER_DAY - delta)
+    }
+    if (rawMinutes % MINUTES_PER_DAY == 0 && minutesFromNamedHour > NAMED_HOUR_TOLERANCE_MINUTES) {
+        return (rawMinutes / MINUTES_PER_DAY).toLong()
+    }
+    return ChronoUnit.DAYS.between(encoded.toLocalDate(), startDate)
+}
+
+/** DST drift a row written in the other phase carries, rounded up past Lord Howe's half hour. */
+private const val NAMED_HOUR_TOLERANCE_MINUTES = 90
+
+private fun allDayAlarmMillis(
+    beginMillis: Long,
+    rawMinutes: Int,
+    zone: ZoneId,
+    allDayTimeMinutes: Int,
+): Long = allDayDate(beginMillis)
+    .minusDays(allDayLeadDays(rawMinutes, allDayDate(beginMillis), zone, allDayTimeMinutes))
+    .atTime(LocalTime.of(allDayTimeMinutes / 60, allDayTimeMinutes % 60))
+    .atZone(zone)
+    .toInstant()
+    .toEpochMilli()
+
+/**
+ * Split [planned] into what is due now and when to wake up next.
+ *
+ * Due means the fire instant falls in `(lastFiredMillis, nowMillis]`, so a scan
+ * running twice cannot post twice while a late one still catches up. Reminders
+ * whose event has ended are dropped ([isStillRelevant]). [nextAlarmMillis] is
+ * capped at [horizonMillis] so the lookahead window keeps rolling forward.
+ */
+fun scheduleReminders(
+    planned: List<PlannedReminder>,
+    lastFiredMillis: Long,
+    nowMillis: Long,
+    horizonMillis: Long,
+): ReminderSchedule {
+    val due = planned
+        .filter { it.alarmMillis in (lastFiredMillis + 1)..nowMillis }
+        .filter { it.instance.isStillRelevant(nowMillis) }
+        .distinctBy { it.key }
+        .sortedWith(compareBy({ it.instance.beginMillis }, { it.key }))
+    val nextPending = planned
+        .filter { it.alarmMillis > nowMillis }
+        .minOfOrNull { it.alarmMillis }
+    return ReminderSchedule(
+        due = due,
+        nextAlarmMillis = minOf(nextPending ?: horizonMillis, horizonMillis),
+    )
+}
+
+/**
+ * Still worth showing while the occurrence has not ended. Falls back to the
+ * begin time when the end is unknown (0L).
+ */
+fun ReminderEventInstance.isStillRelevant(nowMillis: Long): Boolean =
+    (endMillis.takeIf { it > 0L } ?: beginMillis) >= nowMillis
+
+/**
+ * The watermark a scan at [nowMillis] should measure against. A first-ever scan
+ * claims the present rather than replaying everything since the epoch; a
+ * watermark in the future (clock moved back) is clamped so it can't silence
+ * every reminder until real time catches up.
+ */
+fun reminderWatermark(lastScanMillis: Long?, nowMillis: Long): Long =
+    lastScanMillis?.coerceAtMost(nowMillis) ?: nowMillis
+
+/**
+ * How far ahead instances must be queried: the plain lookahead plus the longest
+ * reminder offset, so a "two weeks before" is planned before it comes due. The
+ * stretch is capped at [MAX_REMINDER_LEAD_MILLIS] — `maxReminderMinutes` is the
+ * largest row in the whole provider, and a nonsense one would otherwise make
+ * every scan expand every series over years.
+ */
+fun reminderQueryHorizon(lookaheadMillis: Long, maxReminderMinutes: Int): Long =
+    lookaheadMillis + (maxReminderMinutes * MILLIS_PER_MINUTE).coerceIn(0L, MAX_REMINDER_LEAD_MILLIS)
+
+/** Longest reminder offset a scan stretches its query window for — one year. */
+const val MAX_REMINDER_LEAD_MILLIS = 365L * 24 * 60 * 60 * 1000

app/src/main/java/de/jeanlucmakiola/calendula/ui/CalendarHost.kt

@@ -23,8 +23,9 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaScreen
+import de.jeanlucmakiola.calendula.ui.calendars.BackupScreen
 import de.jeanlucmakiola.calendula.ui.calendars.CalendarsScreen
-import de.jeanlucmakiola.calendula.ui.common.calendarFadeThrough
+import de.jeanlucmakiola.floret.identity.fadeThrough
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.drillToDay
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
@@ -33,6 +34,7 @@ import de.jeanlucmakiola.calendula.ui.common.viewBaseStack
 import de.jeanlucmakiola.calendula.ui.day.DayScreen
 import de.jeanlucmakiola.calendula.ui.detail.EventDetailScreen
 import de.jeanlucmakiola.calendula.ui.edit.EventEditScreen
+import de.jeanlucmakiola.calendula.ui.edit.ImportSource
 import de.jeanlucmakiola.calendula.ui.imports.ImportScreen
 import de.jeanlucmakiola.calendula.ui.month.MonthScreen
 import de.jeanlucmakiola.calendula.ui.search.SearchScreen
@@ -72,6 +74,10 @@ fun CalendarHost(
     onWidgetNavConsumed: () -> Unit = {},
     requestedImportUri: android.net.Uri? = null,
     onImportConsumed: () -> Unit = {},
+    requestedInsertForm: EventForm? = null,
+    onInsertConsumed: () -> Unit = {},
+    requestedEditKey: LongArray? = null,
+    onEditKeyConsumed: () -> Unit = {},
     viewModel: CalendarHostViewModel = hiltViewModel(),
 ) {
     // Wait for the persisted default view before seeding the stack, so the app
@@ -79,6 +85,13 @@ fun CalendarHost(
     // correcting it. Brief blank first frame, matching the onboarding gate above.
     val defaultView = viewModel.defaultView.collectAsStateWithLifecycle().value ?: return
 
+    // View customisation (#24): the quick-switch cycle and drawer order. Both have
+    // sensible non-empty initial values, so they're ready before the first frame.
+    val quickSwitchViews = viewModel.quickSwitchViews.collectAsStateWithLifecycle().value
+    val drawerViewOrder = viewModel.drawerViewOrder.collectAsStateWithLifecycle().value
+    // Whether the jump-to-today control sits in each view's top bar or the FAB (#60).
+    val todayInToolbar = viewModel.todayButtonInToolbar.collectAsStateWithLifecycle().value
+
     var viewStack by rememberSaveable(stateSaver = viewStackSaver) {
         mutableStateOf(listOf(defaultView))
     }
@@ -136,6 +149,10 @@ fun CalendarHost(
     // over Settings and survives view switches.
     var showCalendars by rememberSaveable { mutableStateOf(false) }
 
+    // Backup & restore (#69) — hoisted like the manager, being driven by the
+    // calendar list rather than by preferences. Reached from both.
+    var showBackup by rememberSaveable { mutableStateOf(false) }
+
     // Event form (v1.2 create) — same held-key pattern as the detail screen:
     // [heldCreateIso] keeps the prefill date alive through the slide-out.
     // [createStartMinutes] is the tapped slot's start (minutes from midnight)
@@ -165,12 +182,32 @@ fun CalendarHost(
     // picker (many). A plain conditional overlay (no slide) — it's transient.
     var importUri by remember { mutableStateOf<android.net.Uri?>(null) }
     var importForm by remember { mutableStateOf<EventForm?>(null) }
+    // Which channel filled [importForm]: an .ics file (prompt to apply the default
+    // reminder) or an ACTION_INSERT intent (apply it automatically) — #49.
+    var importFormSource by remember { mutableStateOf(ImportSource.File) }
+    // A restore (in-app "Restore from .ics" button) always runs the full import
+    // flow — picker + summary — even for a single-event file, because the intent
+    // is "restore a backup", not "add this one event". An externally opened .ics
+    // keeps routing a single event straight into the prefilled create form.
+    var importForceMany by remember { mutableStateOf(false) }
     LaunchedEffect(requestedImportUri) {
         if (requestedImportUri != null) {
             importUri = requestedImportUri
+            importForceMany = false
             onImportConsumed()
         }
     }
+    // An external ACTION_INSERT launch (another app/widget creating an event,
+    // issue #30) arrives already prefilled — open it in the same create form the
+    // single-event .ics path uses. [importForm] is the topmost overlay, so it
+    // reveals on top of whatever was open without extra dismissal.
+    LaunchedEffect(requestedInsertForm) {
+        if (requestedInsertForm != null) {
+            importFormSource = ImportSource.Insert
+            importForm = requestedInsertForm
+            onInsertConsumed()
+        }
+    }
 
     // Close every overlay that can sit over the calendar, so an externally
     // requested destination (a widget/shortcut/QS-tile launch) is revealed on
@@ -178,12 +215,27 @@ fun CalendarHost(
     fun dismissCoveringOverlays() {
         showSettings = false
         showCalendars = false
+        showBackup = false
         detailKey = null
         editKey = null
         importUri = null
         importForm = null
     }
 
+    // An external "edit this event" (ACTION_EDIT, e.g. an assistant/task app or
+    // widget) opens the occurrence straight in the edit form. Drop any covering
+    // overlay first — the edit overlay sits below Settings/import in the Box, so
+    // without this it would open hidden underneath them. Same held-key pattern as
+    // a detail-screen "Edit" tap; a saved edit just returns to the calendar.
+    LaunchedEffect(requestedEditKey) {
+        if (requestedEditKey != null) {
+            dismissCoveringOverlays()
+            heldEditKey = requestedEditKey
+            editKey = requestedEditKey
+            onEditKeyConsumed()
+        }
+    }
+
     // A home-screen widget launch asks to open a date (→ day view), open an
     // event's detail, or start a create. Handled once and cleared, mirroring
     // [requestedDetailKey]. Date/event opens root the stack in the widget's own
@@ -212,6 +264,17 @@ fun CalendarHost(
                 detailKey = key
                 onWidgetNavConsumed()
             }
+            is WidgetNavRequest.OpenView -> {
+                // A widget header tap: land on a top-level view with no date
+                // drill-in. Reveal it by dropping any covering overlay, then root
+                // the stack on the target (null → the default home) over the
+                // default home — so backing out returns to the default, then exits.
+                dismissCoveringOverlays()
+                createDateIso = null
+                pendingDayIso = null
+                viewStack = viewBaseStack(defaultView, req.view ?: defaultView)
+                onWidgetNavConsumed()
+            }
             is WidgetNavRequest.Create -> {
                 // External "new event" entries (QS tile / launcher shortcut /
                 // widget) must land on top of whatever is open — the form overlay
@@ -236,8 +299,8 @@ fun CalendarHost(
     // owns its own BackHandler and takes precedence). Disabled at the home view,
     // so back there falls through to the system and exits the app.
     val anyOverlayVisible = showSearch || detailKey != null || createDateIso != null ||
-        editKey != null || showSettings || showCalendars || importUri != null ||
-        importForm != null
+        editKey != null || showSettings || showCalendars || showBackup ||
+        importUri != null || importForm != null
     BackHandler(enabled = !anyOverlayVisible && viewStack.size > 1) {
         viewStack = viewStack.dropLast(1)
     }
@@ -246,7 +309,7 @@ fun CalendarHost(
         // Switching between the peer views (month/week/day/agenda) is lateral
         // navigation, so it fades through rather than sliding — paging *within* a
         // view keeps the directional slide. AnimatedContent keyed on the view type.
-        val viewSwitch = calendarFadeThrough()
+        val viewSwitch = fadeThrough()
         AnimatedContent(
             targetState = view,
             transitionSpec = { viewSwitch },
@@ -256,10 +319,14 @@ fun CalendarHost(
                 CalendarView.Week -> WeekScreen(
                     selectedView = currentView,
                     onSelectView = onSelectView,
+                    onOpenDay = onOpenDay,
                     onEventClick = onEventClick,
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Day -> DayScreen(
                     selectedView = currentView,
@@ -269,22 +336,33 @@ fun CalendarHost(
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
                     initialDateIso = pendingDayIso,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Month -> MonthScreen(
                     selectedView = currentView,
                     onSelectView = onSelectView,
                     onOpenDay = onOpenDay,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
-                    onCreateEvent = onCreateEvent,
-                )
-                CalendarView.Agenda -> AgendaScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
                     onEventClick = onEventClick,
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
+                )
+                CalendarView.Agenda -> AgendaScreen(
+                    selectedView = currentView,
+                    onSelectView = onSelectView,
+                    onOpenDay = onOpenDay,
+                    onEventClick = onEventClick,
+                    onOpenSettings = onOpenSettings,
+                    onOpenSearch = onOpenSearch,
+                    onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
             }
         }
@@ -319,6 +397,14 @@ fun CalendarHost(
                         heldEditKey = key
                         editKey = key
                     },
+                    onDuplicate = { form ->
+                        // Reuse the prefilled-create overlay: a duplicate is a
+                        // fresh event, so it applies the default reminder like an
+                        // in-app new event (#52).
+                        importFormSource = ImportSource.Insert
+                        importForm = form
+                        detailKey = null
+                    },
                 )
             }
         }
@@ -335,6 +421,7 @@ fun CalendarHost(
                     initialStartMinutes = createStartMinutes ?: heldCreateMinutes,
                     onClose = { createDateIso = null },
                     onSaved = { createDateIso = null },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -354,6 +441,7 @@ fun CalendarHost(
                         editKey = null
                         detailKey = null
                     },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -367,26 +455,21 @@ fun CalendarHost(
             SettingsScreen(
                 onBack = { showSettings = false },
                 onManageCalendars = { showCalendars = true },
+                onOpenBackup = { showBackup = true },
             )
         }
 
-        // Calendar manager — slides over Settings.
-        AnimatedVisibility(
-            visible = showCalendars,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
-        ) {
-            CalendarsScreen(onBack = { showCalendars = false })
-        }
-
         // Import flow for an opened/received .ics file. A single event routes
         // into the create form (prefilled, for review); many open the picker.
         importUri?.let { uri ->
             ImportScreen(
                 uri = uri,
+                forceMany = importForceMany,
                 onClose = { importUri = null },
+                onManageCalendars = { showCalendars = true },
                 onOpenSingle = { form ->
                     importUri = null
+                    importFormSource = ImportSource.File
                     importForm = form
                 },
             )
@@ -395,8 +478,43 @@ fun CalendarHost(
             EventEditScreen(
                 initialDateIso = null,
                 initialForm = form,
+                initialFormSource = importFormSource,
                 onClose = { importForm = null },
                 onSaved = { importForm = null },
+                onManageCalendars = { showCalendars = true },
+            )
+        }
+
+        // Declared last so it covers every overlay that can open it: Settings,
+        // both event forms, and the .ics import picker (#76).
+        AnimatedVisibility(
+            visible = showCalendars,
+            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
+            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+        ) {
+            CalendarsScreen(
+                onBack = { showCalendars = false },
+                onOpenBackup = { showBackup = true },
+            )
+        }
+
+        // Backup & restore — over the manager, since the manager links into it.
+        AnimatedVisibility(
+            visible = showBackup,
+            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
+            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+        ) {
+            BackupScreen(
+                onBack = { showBackup = false },
+                // Restore runs the normal .ics import, and both this screen and
+                // the manager that can have opened it are declared above the
+                // import overlays — so both have to step aside.
+                onImport = {
+                    importUri = it
+                    importForceMany = true
+                    showBackup = false
+                    showCalendars = false
+                },
             )
         }
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/CalendarHostViewModel.kt

@@ -5,8 +5,10 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import javax.inject.Inject
 
@@ -26,4 +28,29 @@ class CalendarHostViewModel @Inject constructor(
         started = SharingStarted.WhileSubscribed(5_000L),
         initialValue = null,
     )
+
+    /** Views the top-bar quick-switch pill cycles through, in the user's order (#24). */
+    val quickSwitchViews: StateFlow<List<CalendarView>> = prefs.quickSwitchConfig
+        .map { it.cycle }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = IMPLEMENTED_VIEWS,
+        )
+
+    /** Order of the views in the navigation drawer (#24); every view always shown. */
+    val drawerViewOrder: StateFlow<List<CalendarView>> = prefs.drawerViewOrder
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = IMPLEMENTED_VIEWS,
+        )
+
+    /** Whether each view's jump-to-today control lives in the top bar, not the FAB (#60). */
+    val todayButtonInToolbar: StateFlow<Boolean> = prefs.todayButtonInToolbar
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = false,
+        )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/RootScreen.kt

@@ -7,6 +7,7 @@ import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -19,6 +20,10 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
+import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesScheduler
+import de.jeanlucmakiola.calendula.data.contacts.hasContactsPermission
+import de.jeanlucmakiola.calendula.ui.calendars.CalendarVisibilityNoticeDialog
+import de.jeanlucmakiola.calendula.ui.calendars.CalendarVisibilityNoticeViewModel
 import de.jeanlucmakiola.calendula.ui.permission.PermissionScreen
 import de.jeanlucmakiola.calendula.ui.permission.ReminderOnboardingScreen
 import de.jeanlucmakiola.calendula.ui.permission.ReminderOnboardingViewModel
@@ -33,6 +38,10 @@ fun RootScreen(
     onWidgetNavConsumed: () -> Unit = {},
     requestedImportUri: android.net.Uri? = null,
     onImportConsumed: () -> Unit = {},
+    requestedInsertForm: de.jeanlucmakiola.calendula.domain.EventForm? = null,
+    onInsertConsumed: () -> Unit = {},
+    requestedEditKey: LongArray? = null,
+    onEditKeyConsumed: () -> Unit = {},
 ) {
     val context = LocalContext.current
     var hasPermission by remember {
@@ -42,6 +51,10 @@ fun RootScreen(
         )
     }
 
+    // A launch scan already covers the app coming up with the permission, so
+    // only a grant made during this session owes a re-scan.
+    val grantedAtLaunch = remember { hasPermission }
+
     val lifecycle = LocalLifecycleOwner.current.lifecycle
     DisposableEffect(lifecycle) {
         val obs = LifecycleEventObserver { _, event ->
@@ -49,6 +62,12 @@ fun RootScreen(
                 hasPermission = ContextCompat.checkSelfPermission(
                     context, Manifest.permission.READ_CALENDAR
                 ) == PackageManager.PERMISSION_GRANTED
+                // Refresh the contact special-dates mirror on foreground (the
+                // worker is debounced and no-ops when the feature is off). Gated
+                // on the permission so users without the opt-in never enqueue it.
+                if (context.hasContactsPermission()) {
+                    SpecialDatesScheduler.runNow(context, foreground = true)
+                }
             }
         }
         lifecycle.addObserver(obs)
@@ -66,6 +85,19 @@ fun RootScreen(
             // frame instead of flashing the wrong screen.
             val reminderOnboarding: ReminderOnboardingViewModel = hiltViewModel()
             val onboardingDone by reminderOnboarding.onboardingDone.collectAsStateWithLifecycle()
+            // One-time explainer for the switch to the device's own calendar
+            // visibility (#75), armed by the reconciler.
+            val visibilityNotice: CalendarVisibilityNoticeViewModel = hiltViewModel()
+            val noticePending by visibilityNotice.pending.collectAsStateWithLifecycle()
+            // Runs on entry however the permission was granted, including via
+            // Android's app-settings screen (caught by the ON_RESUME above).
+            LaunchedEffect(Unit) {
+                visibilityNotice.reconcile()
+                if (!grantedAtLaunch) reminderOnboarding.rearmAfterGrant()
+            }
+            if (onboardingDone == true && noticePending) {
+                CalendarVisibilityNoticeDialog(onDismiss = visibilityNotice::dismiss)
+            }
             Crossfade(targetState = onboardingDone, animationSpec = gateSpec, label = "onboardingGate") { done ->
                 when (done) {
                     true -> CalendarHost(
@@ -76,6 +108,10 @@ fun RootScreen(
                         onWidgetNavConsumed = onWidgetNavConsumed,
                         requestedImportUri = requestedImportUri,
                         onImportConsumed = onImportConsumed,
+                        requestedInsertForm = requestedInsertForm,
+                        onInsertConsumed = onInsertConsumed,
+                        requestedEditKey = requestedEditKey,
+                        onEditKeyConsumed = onEditKeyConsumed,
                     )
                     false -> ReminderOnboardingScreen(
                         onFinished = reminderOnboarding::finish,

app/src/main/java/de/jeanlucmakiola/calendula/ui/WidgetNavRequest.kt

@@ -31,4 +31,13 @@ sealed interface WidgetNavRequest {
 
     /** Open the create-event form prefilled for [dateIso] (today when null). */
     data class Create(val dateIso: String?) : WidgetNavRequest
+
+    /**
+     * Open the app rooted on a top-level [view] with no date drill-in — a widget
+     * header tap. A null [view] means "the user's default home view" (the agenda
+     * widget's "Upcoming" title, issue #20); a concrete view roots there over the
+     * default home (the month widget's month/year title → [CalendarView.Month],
+     * issue #18), so backing out returns to the default view, then exits.
+     */
+    data class OpenView(val view: CalendarView?) : WidgetNavRequest
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaRange.kt

@@ -1,10 +1,9 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import java.time.YearMonth
-import java.time.format.DateTimeFormatter
-import java.time.format.FormatStyle
 import java.util.Locale
 
 /**
@@ -87,24 +86,37 @@ fun parseAgendaRange(stored: String?, default: AgendaRange): AgendaRange = when
 
 /**
  * The concrete span the range covers, starting at [start] through [end]
- * (inclusive), for a human-readable header:
- * - [AgendaRange.Day] → a single medium date ("27 Jun 2026")
+ * (inclusive), for a human-readable header. Both ends use the same day-month
+ * order so a span never mixes "15 Jul" with "Aug 13, 2026":
+ * - [AgendaRange.Day] → a single date ("27 Jun 2026")
  * - [AgendaRange.ThisMonth] → month and year ("June 2026")
- * - everything else → "start – end" ("27 Jun – 3 Jul 2026")
+ * - everything else → "start – end" ("27 Jun – 3 Jul 2026"), with the start's
+ *   year shown too only when it differs from the end's.
+ *
+ * [monthAsSpan] puts [AgendaRange.ThisMonth] on the "start – end" form as well.
+ * The agenda's own header browses the whole month, so the month name is right
+ * there; the range picker previews the window an option opens *today*, which for
+ * "This month" is only the rest of it.
  */
 fun agendaRangeWindowSummary(
     range: AgendaRange,
     start: LocalDate,
     end: LocalDate,
     locale: Locale,
+    monthAsSpan: Boolean = false,
 ): String {
     val javaStart = java.time.LocalDate.of(start.year, start.month.ordinal + 1, start.day)
     val javaEnd = java.time.LocalDate.of(end.year, end.month.ordinal + 1, end.day)
-    val medium = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
-    return when (range) {
-        AgendaRange.Day -> medium.format(javaStart)
-        AgendaRange.ThisMonth -> DateTimeFormatter.ofPattern("LLLL yyyy", locale).format(javaStart)
-        else -> "${DateTimeFormatter.ofPattern("d MMM", locale).format(javaStart)} – ${medium.format(javaEnd)}"
+    val dayMonth = localizedDateFormatter(locale, "dMMM")
+    val dayMonthYear = localizedDateFormatter(locale, "dMMMy")
+    return when {
+        range == AgendaRange.Day -> dayMonthYear.format(javaStart)
+        range == AgendaRange.ThisMonth && !monthAsSpan ->
+            localizedDateFormatter(locale, "LLLLy").format(javaStart)
+        else -> {
+            val startFmt = if (start.year == end.year) dayMonth else dayMonthYear
+            "${startFmt.format(javaStart)} – ${dayMonthYear.format(javaEnd)}"
+        }
     }
 }
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaRows.kt

@@ -0,0 +1,206 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Coffee
+import androidx.compose.material3.Card
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.eventFill
+import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.locale.currentLocale
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.plus
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Instant
+import java.util.Locale
+
+// The agenda's row vocabulary, split out of AgendaScreen so the month view's
+// split style can list a day with exactly the same visual language instead of
+// growing a parallel set of event rows.
+
+@Composable
+internal fun AgendaDayHeader(
+    date: LocalDate,
+    today: LocalDate,
+    onOpenDay: (LocalDate) -> Unit,
+) {
+    Surface(
+        color = MaterialTheme.colorScheme.surface,
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable { onOpenDay(date) },
+    ) {
+        Text(
+            text = agendaDayLabel(date, today),
+            style = MaterialTheme.typography.titleSmall,
+            color = if (date == today) {
+                MaterialTheme.colorScheme.primary
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            },
+            modifier = Modifier.padding(start = 28.dp, end = 28.dp, top = 16.dp, bottom = 8.dp),
+        )
+    }
+}
+
+/**
+ * A card standing in for a day with no events — the same coffee-cup motif as the
+ * agenda's full-screen empty state, boxed into a card so the day keeps a visible slot
+ * rather than a bare header. Used for an anchored, event-less today (#35) and for
+ * an empty selected day in the month view's split style.
+ */
+@Composable
+internal fun AgendaEmptyDayRow(text: String, onClick: () -> Unit) {
+    Card(
+        // Match a single event row's resting corner radius (floret groupedShape).
+        shape = RoundedCornerShape(22.dp),
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp, vertical = 4.dp)
+            .clickable(onClick = onClick),
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(vertical = 18.dp, horizontal = 16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            Icon(
+                imageVector = Icons.Filled.Coffee,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.size(36.dp),
+            )
+            Spacer(Modifier.height(8.dp))
+            Text(
+                text = text,
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                textAlign = TextAlign.Center,
+            )
+        }
+    }
+}
+
+@Composable
+internal fun AgendaEventRow(
+    event: EventInstance,
+    day: LocalDate,
+    zone: TimeZone,
+    position: Position,
+    dimmed: Boolean,
+    modifier: Modifier = Modifier,
+    onClick: () -> Unit,
+) {
+    val dark = isSystemInDarkTheme()
+    val soften = LocalSoftenColors.current
+    val title = event.title.ifBlank { stringResource(R.string.event_untitled) }
+    GroupedRow(
+        modifier = if (dimmed) modifier.alpha(EventDimAlpha) else modifier,
+        title = title,
+        summary = agendaTimeSummary(event, day, zone),
+        position = position,
+        minHeight = 64.dp,
+        leading = {
+            Box(
+                modifier = Modifier
+                    .size(width = 6.dp, height = 36.dp)
+                    .clip(RoundedCornerShape(3.dp))
+                    .background(eventFill(event.color, dark, soften)),
+            )
+        },
+        onClick = onClick,
+    )
+}
+
+/** "Today · Wed, 17. Jun 2026" — relative word for today/tomorrow, else the date. */
+@Composable
+internal fun agendaDayLabel(date: LocalDate, today: LocalDate): String {
+    val relative = when (date) {
+        today -> stringResource(R.string.agenda_header_today)
+        today.plus(1, DateTimeUnit.DAY) -> stringResource(R.string.agenda_header_tomorrow)
+        else -> null
+    }
+    val formatted = formatAgendaDate(date)
+    return if (relative != null) "$relative · $formatted" else formatted
+}
+
+/**
+ * Time line under the title: "09:00 – 10:00 · Location", "All day", etc.
+ *
+ * A multi-day event shows only the part relevant to [day], spelled out so each
+ * day reads on its own: its first day names the start ("Starts 14:00"), its last
+ * day the end ("Ends 10:00"), and any whole day in between reads as "All day".
+ * An all-day multi-day event is simply "All day" on every day it covers.
+ */
+@Composable
+internal fun agendaTimeSummary(event: EventInstance, day: LocalDate, zone: TimeZone): String {
+    val is24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
+
+    val time = when (val label = agendaTimeLabel(event, day, zone)) {
+        AgendaTimeLabel.AllDay -> stringResource(R.string.event_detail_all_day)
+        is AgendaTimeLabel.Starts -> stringResource(
+            R.string.agenda_span_starts,
+            formatTime(label.start, zone, is24Hour, locale),
+        )
+        is AgendaTimeLabel.Ends -> stringResource(
+            R.string.agenda_span_ends,
+            formatTime(label.end, zone, is24Hour, locale),
+        )
+        is AgendaTimeLabel.Range -> "${formatTime(label.start, zone, is24Hour, locale)} – " +
+            formatTime(label.end, zone, is24Hour, locale)
+    }
+
+    val location = event.location?.takeIf { it.isNotBlank() }
+    return if (location != null) "$time · $location" else time
+}
+
+private fun formatTime(
+    instant: Instant,
+    zone: TimeZone,
+    is24Hour: Boolean,
+    locale: Locale,
+): String {
+    val t = instant.toLocalDateTime(zone).time
+    return formatTimeOfDay(t.hour, t.minute, is24Hour, locale)
+}
+
+private fun formatAgendaDate(date: LocalDate): String {
+    val locale = Locale.getDefault()
+    val java = java.time.LocalDate.of(date.year, date.month.ordinal + 1, date.day)
+    // Weekday + date in the locale's own field order (e.g. "Wed, Jun 17, 2026"
+    // vs "Mi., 17. Juni 2026") rather than a hardcoded day-month-year layout.
+    return localizedDateFormatter(locale, "EEEdMMMy").format(java)
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaScreen.kt

@@ -1,9 +1,6 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
 import androidx.compose.foundation.ExperimentalFoundationApi
-import androidx.compose.foundation.background
-import androidx.compose.foundation.clickable
-import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -15,23 +12,21 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
-import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Coffee
-import androidx.compose.material.icons.filled.DateRange
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.DrawerValue
+import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalNavigationDrawer
 import androidx.compose.material3.Scaffold
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
@@ -45,8 +40,6 @@ import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.alpha
-import androidx.compose.ui.draw.clip
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
@@ -59,49 +52,48 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.hasEnded
 import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
-import de.jeanlucmakiola.calendula.ui.common.calendarAnimateItem
+import de.jeanlucmakiola.floret.identity.animateItemMotion
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
+import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
-import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
-import de.jeanlucmakiola.calendula.ui.common.GroupedRow
-import de.jeanlucmakiola.calendula.ui.common.Position
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.next
-import de.jeanlucmakiola.calendula.ui.common.pastelize
-import de.jeanlucmakiola.calendula.ui.common.positionOf
+import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
-import de.jeanlucmakiola.calendula.ui.common.currentLocale
-import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
-import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
+import de.jeanlucmakiola.floret.locale.currentLocale
 import kotlinx.coroutines.launch
-import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.plus
-import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Instant
-import java.time.format.TextStyle as JavaTextStyle
-import java.util.Locale
 
-private val zone = TimeZone.currentSystemDefault()
+// No file-level zone constant here on purpose: it would be fixed for the process
+// lifetime and drift from the zone AgendaViewModel groups in after a device
+// time-zone change. The zone travels on AgendaUiState.Success instead.
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun AgendaScreen(
     selectedView: CalendarView,
     onSelectView: (CalendarView) -> Unit,
+    onOpenDay: (LocalDate) -> Unit,
     onEventClick: (EventInstance) -> Unit,
     onOpenSettings: () -> Unit,
     onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
+    quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
+    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
+    todayInToolbar: Boolean = false,
     modifier: Modifier = Modifier,
     viewModel: AgendaViewModel = hiltViewModel(),
 ) {
     val state by viewModel.state.collectAsStateWithLifecycle()
     val anchor by viewModel.anchor.collectAsStateWithLifecycle()
     val pastDisplay by viewModel.pastEventDisplay.collectAsStateWithLifecycle()
+    val showToday by viewModel.showToday.collectAsStateWithLifecycle()
+    val weekStart by viewModel.weekStart.collectAsStateWithLifecycle()
 
     val scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior()
     val drawerState = rememberDrawerState(DrawerValue.Closed)
@@ -120,6 +112,7 @@ fun AgendaScreen(
             CalendarDrawer(
                 currentView = selectedView,
                 currentDate = anchor,
+                viewOrder = drawerViewOrder,
                 onSelectView = { view ->
                     onSelectView(view)
                     scope.launch { drawerState.close() }
@@ -140,15 +133,17 @@ fun AgendaScreen(
             topBar = {
                 AgendaTopBar(
                     selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next()) },
+                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
+                    showTodayButton = todayInToolbar,
+                    onToday = viewModel::goToToday,
                     scrollBehavior = scrollBehavior,
                 )
             },
             floatingActionButton = {
                 CalendarFabColumn(
-                    todayVisible = !isOnToday,
+                    todayVisible = !isOnToday && !todayInToolbar,
                     todayText = stringResource(R.string.agenda_today_action),
                     onToday = viewModel::goToToday,
                     onCreate = { onCreateEvent(anchor, null) },
@@ -165,9 +160,11 @@ fun AgendaScreen(
                 successState?.takeIf { it.showRangeBar }?.let { s ->
                     Row(
                         verticalAlignment = Alignment.CenterVertically,
+                        // end aligns the selector's right edge with the top-bar view
+                        // switcher (its 8.dp margin + the app bar's 4.dp inset).
                         modifier = Modifier
                             .fillMaxWidth()
-                            .padding(start = 28.dp, end = 16.dp, top = 8.dp, bottom = 8.dp),
+                            .padding(start = 28.dp, end = 12.dp, top = 8.dp, bottom = 8.dp),
                     ) {
                         AgendaRangeBanner(
                             range = s.range,
@@ -185,8 +182,10 @@ fun AgendaScreen(
                 AgendaContent(
                     state = state,
                     pastDisplay = pastDisplay,
+                    showToday = showToday,
                     onRetry = viewModel::goToToday,
                     onEventClick = onEventClick,
+                    onOpenDay = onOpenDay,
                     modifier = Modifier
                         .weight(1f)
                         .fillMaxWidth(),
@@ -200,6 +199,7 @@ fun AgendaScreen(
             title = stringResource(R.string.settings_agenda_range),
             description = stringResource(R.string.agenda_range_override_hint),
             selected = successState?.range ?: AgendaRange.Month,
+            weekStart = weekStart,
             onSelect = viewModel::setRangeOverride,
             onDismiss = { showRangePicker = false },
         )
@@ -207,9 +207,11 @@ fun AgendaScreen(
 }
 
 /**
- * A compact tonal pill showing the agenda's current range. Tapping it opens the
- * range picker as a session-only override. Filled with the primary container
- * while an override is active, so the temporary state is obvious.
+ * The agenda's current range, tapped to open the range picker as a session-only
+ * override. Shares the top-bar view switcher's button shape so the two read as a
+ * family, but stays low-emphasis — a subtle neutral surface tint rather than the
+ * switcher's secondary container, so it doesn't compete. Fills with the primary
+ * container only while an override is active, to make that temporary state clear.
  */
 @Composable
 private fun AgendaRangePill(
@@ -218,43 +220,34 @@ private fun AgendaRangePill(
     onClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
-    val container = if (isOverride) {
-        MaterialTheme.colorScheme.primaryContainer
-    } else {
-        MaterialTheme.colorScheme.surfaceContainerHigh
-    }
-    val content = if (isOverride) {
-        MaterialTheme.colorScheme.onPrimaryContainer
-    } else {
-        MaterialTheme.colorScheme.onSurfaceVariant
-    }
-    Surface(
-        color = container,
-        contentColor = content,
-        shape = RoundedCornerShape(50),
-        modifier = modifier.clickable(onClick = onClick),
+    FilledTonalButton(
+        onClick = onClick,
+        shape = MaterialTheme.shapes.large,
+        colors = ButtonDefaults.filledTonalButtonColors(
+            containerColor = if (isOverride) {
+                MaterialTheme.colorScheme.primaryContainer
+            } else {
+                MaterialTheme.colorScheme.surfaceContainerHigh
+            },
+            contentColor = if (isOverride) {
+                MaterialTheme.colorScheme.onPrimaryContainer
+            } else {
+                MaterialTheme.colorScheme.onSurfaceVariant
+            },
+        ),
+        modifier = modifier,
     ) {
-        Row(
-            verticalAlignment = Alignment.CenterVertically,
-            modifier = Modifier.padding(horizontal = 16.dp, vertical = 10.dp),
-        ) {
-            Icon(
-                imageVector = Icons.Filled.DateRange,
-                contentDescription = null,
-                modifier = Modifier.size(18.dp),
-            )
-            Spacer(Modifier.width(8.dp))
-            Text(
-                text = agendaRangeLabel(range),
-                style = MaterialTheme.typography.labelLarge,
-            )
-        }
+        Text(
+            text = agendaRangeLabel(range),
+            style = MaterialTheme.typography.labelLarge,
+        )
     }
 }
 
 /**
- * A header naming the concrete window currently shown, e.g. "Showing all events
- * for · Today, 27 Jun 2026" / "This week, 27 Jun – 3 Jul" / "This month, June 2026".
+ * A header naming the concrete window currently shown under a "showing …" label,
+ * e.g. "27 Jun 2026" / "27 Jun – 3 Jul 2026" / "June 2026". The range's name
+ * lives on the selector button beside it, so it isn't repeated here.
  */
 @Composable
 private fun AgendaRangeBanner(
@@ -271,8 +264,10 @@ private fun AgendaRangeBanner(
             style = MaterialTheme.typography.labelMedium,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
+        // Just the concrete dates — the range's name ("Next 30 days") already
+        // sits on the selector button to the right, so repeating it here is noise.
         Text(
-            text = "${agendaRangeLabel(range)}, $window",
+            text = window,
             style = MaterialTheme.typography.titleMedium,
             color = MaterialTheme.colorScheme.onSurface,
         )
@@ -283,8 +278,10 @@ private fun AgendaRangeBanner(
 private fun AgendaContent(
     state: AgendaUiState,
     pastDisplay: PastEventDisplay,
+    showToday: Boolean,
     onRetry: () -> Unit,
     onEventClick: (EventInstance) -> Unit,
+    onOpenDay: (LocalDate) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     when (state) {
@@ -297,7 +294,7 @@ private fun AgendaContent(
             // Hiding drops finished events — and any day they leave empty; dimming
             // keeps them but fades the row. Recomputed each minute so events fall
             // away (or fade) as they end while the screen stays open.
-            val days = if (pastDisplay == PastEventDisplay.HIDE) {
+            val filtered = if (pastDisplay == PastEventDisplay.HIDE) {
                 state.days.mapNotNull { day ->
                     val remaining = day.events.filterNot { it.hasEnded(now) }
                     if (remaining.isEmpty()) null else day.copy(events = remaining)
@@ -305,15 +302,25 @@ private fun AgendaContent(
             } else {
                 state.days
             }
+            // Anchor today with a "nothing left today" placeholder — but only when
+            // the window actually starts on today; a jumped-to date has no today in
+            // it, so anchoring there would be misleading (#35).
+            val days = anchorTodayIfMissing(
+                days = filtered,
+                today = state.today,
+                enabled = showToday && state.anchor == state.today,
+            )
             if (days.isEmpty()) {
                 AgendaEmpty(modifier)
             } else {
                 AgendaList(
                     days = days,
                     today = state.today,
+                    zone = state.zone,
                     dimPast = pastDisplay == PastEventDisplay.DIM,
                     now = now,
                     onEventClick = onEventClick,
+                    onOpenDay = onOpenDay,
                     modifier = modifier,
                 )
             }
@@ -326,9 +333,11 @@ private fun AgendaContent(
 private fun AgendaList(
     days: List<AgendaDay>,
     today: LocalDate,
+    zone: TimeZone,
     dimPast: Boolean,
     now: Instant,
     onEventClick: (EventInstance) -> Unit,
+    onOpenDay: (LocalDate) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     LazyColumn(
@@ -338,72 +347,40 @@ private fun AgendaList(
     ) {
         days.forEach { day ->
             stickyHeader(key = "header-${day.date}") {
-                AgendaDayHeader(date = day.date, today = today)
+                AgendaDayHeader(date = day.date, today = today, onOpenDay = onOpenDay)
             }
-            itemsIndexed(
-                items = day.events,
-                key = { _, event -> event.instanceId },
-            ) { index, event ->
-                AgendaEventRow(
-                    event = event,
-                    position = positionOf(index, day.events.size),
-                    dimmed = dimPast && event.hasEnded(now),
-                    modifier = calendarAnimateItem(),
-                    onClick = { onEventClick(event) },
-                )
+            if (day.events.isEmpty()) {
+                // An anchored, event-less today (#35) — "nothing left today".
+                item(key = "placeholder-${day.date}") {
+                    AgendaEmptyDayRow(
+                        text = stringResource(R.string.agenda_no_more_today),
+                        onClick = { onOpenDay(day.date) },
+                    )
+                }
+            } else {
+                itemsIndexed(
+                    items = day.events,
+                    // Scope the key by day: a multi-day event appears under every
+                    // day it spans, so its instanceId alone is not unique across
+                    // the list (LazyColumn requires unique keys).
+                    key = { _, event -> "${day.date}-${event.instanceId}" },
+                ) { index, event ->
+                    AgendaEventRow(
+                        event = event,
+                        day = day.date,
+                        zone = zone,
+                        position = positionOf(index, day.events.size),
+                        dimmed = dimPast && event.hasEnded(now),
+                        modifier = animateItemMotion(),
+                        onClick = { onEventClick(event) },
+                    )
+                }
             }
             item(key = "gap-${day.date}") { Spacer(Modifier.height(8.dp)) }
         }
     }
 }
 
-@Composable
-private fun AgendaDayHeader(date: LocalDate, today: LocalDate) {
-    Surface(
-        color = MaterialTheme.colorScheme.surface,
-        modifier = Modifier.fillMaxWidth(),
-    ) {
-        Text(
-            text = agendaDayLabel(date, today),
-            style = MaterialTheme.typography.titleSmall,
-            color = if (date == today) {
-                MaterialTheme.colorScheme.primary
-            } else {
-                MaterialTheme.colorScheme.onSurfaceVariant
-            },
-            modifier = Modifier.padding(start = 28.dp, end = 28.dp, top = 16.dp, bottom = 8.dp),
-        )
-    }
-}
-
-@Composable
-private fun AgendaEventRow(
-    event: EventInstance,
-    position: Position,
-    dimmed: Boolean,
-    modifier: Modifier = Modifier,
-    onClick: () -> Unit,
-) {
-    val dark = isSystemInDarkTheme()
-    val title = event.title.ifBlank { stringResource(R.string.event_untitled) }
-    GroupedRow(
-        modifier = if (dimmed) modifier.alpha(EventDimAlpha) else modifier,
-        title = title,
-        summary = agendaTimeSummary(event),
-        position = position,
-        minHeight = 64.dp,
-        leading = {
-            Box(
-                modifier = Modifier
-                    .size(width = 6.dp, height = 36.dp)
-                    .clip(RoundedCornerShape(3.dp))
-                    .background(pastelize(event.color, dark)),
-            )
-        },
-        onClick = onClick,
-    )
-}
-
 @Composable
 private fun AgendaEmpty(modifier: Modifier = Modifier) {
     Column(
@@ -433,6 +410,8 @@ private fun AgendaTopBar(
     onCycleView: () -> Unit,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
+    showTodayButton: Boolean,
+    onToday: () -> Unit,
     scrollBehavior: TopAppBarScrollBehavior,
 ) {
     TopAppBar(
@@ -451,6 +430,7 @@ private fun AgendaTopBar(
             }
         },
         actions = {
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,
@@ -470,42 +450,3 @@ private fun AgendaTopBar(
         scrollBehavior = scrollBehavior,
     )
 }
-
-/** "Today · Wed, 17. Jun 2026" — relative word for today/tomorrow, else the date. */
-@Composable
-private fun agendaDayLabel(date: LocalDate, today: LocalDate): String {
-    val relative = when (date) {
-        today -> stringResource(R.string.agenda_header_today)
-        today.plus(1, DateTimeUnit.DAY) -> stringResource(R.string.agenda_header_tomorrow)
-        else -> null
-    }
-    val formatted = formatAgendaDate(date)
-    return if (relative != null) "$relative · $formatted" else formatted
-}
-
-/** Time line under the title: "09:00 – 10:00 · Location", "All day", etc. */
-@Composable
-private fun agendaTimeSummary(event: EventInstance): String {
-    val time = if (event.isAllDay) {
-        stringResource(R.string.event_detail_all_day)
-    } else {
-        val is24Hour = LocalUse24HourFormat.current
-        val locale = currentLocale()
-        "${formatTime(event.start, is24Hour, locale)} – ${formatTime(event.end, is24Hour, locale)}"
-    }
-    val location = event.location?.takeIf { it.isNotBlank() }
-    return if (location != null) "$time · $location" else time
-}
-
-private fun formatTime(instant: Instant, is24Hour: Boolean, locale: Locale): String {
-    val t = instant.toLocalDateTime(zone).time
-    return formatTimeOfDay(t.hour, t.minute, is24Hour, locale)
-}
-
-private fun formatAgendaDate(date: LocalDate): String {
-    val locale = Locale.getDefault()
-    val java = java.time.LocalDate.of(date.year, date.month.ordinal + 1, date.day)
-    val weekday = java.dayOfWeek.getDisplayName(JavaTextStyle.SHORT, locale)
-    val monthName = java.month.getDisplayName(JavaTextStyle.SHORT, locale)
-    return "$weekday, ${date.day}. $monthName ${date.year}"
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaUiState.kt

@@ -2,9 +2,43 @@ package de.jeanlucmakiola.calendula.ui.agenda
 
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import de.jeanlucmakiola.calendula.domain.spanFirstDay
+import de.jeanlucmakiola.calendula.domain.spanLastDay
+import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.toLocalDateTime
+import kotlinx.datetime.plus
+import kotlin.time.Instant
+
+/**
+ * What an agenda row's time line should convey for an event on a given day —
+ * the part of a multi-day span that [day] falls in. Pure and shared so the
+ * agenda screen and the agenda widget label multi-day events identically; each
+ * surface only formats the instants into its own locale/24h string.
+ */
+sealed interface AgendaTimeLabel {
+    /** An all-day event, or a whole in-between day of a multi-day span. */
+    data object AllDay : AgendaTimeLabel
+    /** The first day of a multi-day timed event: when it begins. */
+    data class Starts(val start: Instant) : AgendaTimeLabel
+    /** The last day of a multi-day timed event: when it ends. */
+    data class Ends(val end: Instant) : AgendaTimeLabel
+    /** A single-day timed event: its start–end range. */
+    data class Range(val start: Instant, val end: Instant) : AgendaTimeLabel
+}
+
+/** The [AgendaTimeLabel] for [event] as it appears on [day], resolved in [zone]. */
+fun agendaTimeLabel(event: EventInstance, day: LocalDate, zone: TimeZone): AgendaTimeLabel {
+    if (event.isAllDay) return AgendaTimeLabel.AllDay
+    val firstDay = event.spanFirstDay(zone)
+    val lastDay = event.spanLastDay(zone)
+    return when {
+        firstDay == lastDay -> AgendaTimeLabel.Range(event.start, event.end)
+        day <= firstDay -> AgendaTimeLabel.Starts(event.start)
+        day >= lastDay -> AgendaTimeLabel.Ends(event.end)
+        else -> AgendaTimeLabel.AllDay // a full in-between day
+    }
+}
 
 /** One calendar day with at least one event, for the agenda list. */
 data class AgendaDay(
@@ -15,31 +49,69 @@ data class AgendaDay(
 
 /**
  * Group flat [instances] into forward-looking [AgendaDay]s (only days that
- * actually carry events). An event that began before [anchor] (ongoing or
- * multi-day) is clamped to the anchor day so it still surfaces on top. Within a
- * day, all-day events sort first, then ascending by start time, then title.
+ * actually carry events). A multi-day event surfaces on *every* day it spans,
+ * not just its first — clamped to [[anchor], [windowEnd]] so an event that began
+ * before the window (ongoing) still lists from the anchor day, and one running
+ * past the window stops at the last visible day. Within a day, all-day events
+ * sort first, then ascending by start time, then title.
  *
  * Shared by the Agenda screen and the agenda home-screen widget so both group
  * and order identically.
  */
 fun groupAgendaDays(
     anchor: LocalDate,
+    windowEnd: LocalDate,
     instances: List<EventInstance>,
     zone: TimeZone,
-): List<AgendaDay> =
-    instances
-        .groupBy { it.start.toLocalDateTime(zone).date.coerceAtLeast(anchor) }
-        .toSortedMap()
-        .map { (date, dayEvents) ->
-            AgendaDay(
-                date = date,
-                events = dayEvents.sortedWith(
-                    compareByDescending<EventInstance> { it.isAllDay }
-                        .thenBy { it.start }
-                        .thenBy { it.title },
-                ),
-            )
+): List<AgendaDay> {
+    val byDay = sortedMapOf<LocalDate, MutableList<EventInstance>>()
+    for (instance in instances) {
+        val firstDay = instance.spanFirstDay(zone).coerceAtLeast(anchor)
+        val lastDay = instance.spanLastDay(zone).coerceAtMost(windowEnd)
+        // Skip instances that don't actually occupy any day in [[anchor], [windowEnd]].
+        // The provider returns an event whenever its instant span overlaps the query
+        // window, but all-day events live at UTC midnights with an exclusive end: east
+        // of UTC that end dips just past local midnight, so *yesterday's* all-day event
+        // overlaps today's window start and comes back even though its true last day
+        // (resolved in UTC) is before the anchor. Clamping it up to the anchor would
+        // surface it under "today" (issue #65); drop it instead. The symmetric case —
+        // a next-day all-day event overlapping the window's last instant — drops too.
+        if (lastDay < firstDay) continue
+        var day = firstDay
+        while (day <= lastDay) {
+            byDay.getOrPut(day) { mutableListOf() }.add(instance)
+            day = day.plus(1, DateTimeUnit.DAY)
         }
+    }
+    return byDay.map { (date, dayEvents) ->
+        AgendaDay(
+            date = date,
+            events = dayEvents.sortedWith(
+                compareByDescending<EventInstance> { it.isAllDay }
+                    .thenBy { it.start }
+                    .thenBy { it.title },
+            ),
+        )
+    }
+}
+
+/**
+ * Ensure [today] surfaces as the first agenda day even when it carries no
+ * (remaining) events, by prepending an empty-event [AgendaDay] the agenda widget
+ * renders as a "nothing left today" placeholder. A no-op unless [enabled], and
+ * when today already has its own day in [days]. Keeps today anchored at the top
+ * so a glance tells today's events apart from a future day's (issue #35).
+ */
+fun anchorTodayIfMissing(
+    days: List<AgendaDay>,
+    today: LocalDate,
+    enabled: Boolean,
+): List<AgendaDay> =
+    if (enabled && days.none { it.date == today }) {
+        listOf(AgendaDay(today, emptyList())) + days
+    } else {
+        days
+    }
 
 /**
  * State for the Agenda view: a flat, forward-looking list of upcoming events
@@ -61,5 +133,12 @@ sealed interface AgendaUiState {
         val rangeEnd: LocalDate,
         /** Whether to show the top range bar — header + switcher (toggle, on by default). */
         val showRangeBar: Boolean,
+        /**
+         * The zone [days] were grouped in. Carried in the state rather than
+         * re-read by the screen so labelling and grouping cannot disagree: an
+         * event's "Starts …/Ends …/All day" line is only correct relative to the
+         * same zone that decided which day it was filed under.
+         */
+        val zone: TimeZone,
     ) : AgendaUiState
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaViewModel.kt

@@ -7,7 +7,7 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
-import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
+import de.jeanlucmakiola.calendula.data.prefs.firstDayOfWeek
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
@@ -20,13 +20,11 @@ import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import java.util.Locale
 import kotlinx.datetime.atStartOfDayIn
 import kotlinx.datetime.atTime
 import kotlinx.datetime.plus
@@ -50,9 +48,12 @@ class AgendaViewModel @Inject constructor(
         settingsPrefs.agendaShowRangeBar,
     ) { range, showBar -> AgendaSettings(range, showBar) }
 
-    // First day of the week, for the calendar-aligned "this week" range.
-    private val weekStartDay = settingsPrefs.weekStart
-        .map { it.resolveFirstDay(Locale.getDefault()) }
+    /**
+     * First day of the week, for the calendar-aligned "this week" range. Public
+     * because the range picker resolves each option to real dates, which needs
+     * the same week start the window is built from.
+     */
+    val weekStart: StateFlow<DayOfWeek> = settingsPrefs.firstDayOfWeek(viewModelScope)
 
     /**
      * How to treat events that already ended today (show / dim / hide). A display
@@ -66,6 +67,19 @@ class AgendaViewModel @Inject constructor(
             initialValue = PastEventDisplay.SHOW,
         )
 
+    /**
+     * Whether to keep today anchored at the top with a "nothing left today"
+     * placeholder even once it has no remaining events (#35). A display concern
+     * applied in the composition (after past-event filtering), so it rides
+     * alongside the data state like [pastEventDisplay] rather than re-querying.
+     */
+    val showToday: StateFlow<Boolean> = settingsPrefs.agendaShowToday
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = true,
+        )
+
     private val zone = TimeZone.currentSystemDefault()
 
     private val todayDate: LocalDate
@@ -80,7 +94,7 @@ class AgendaViewModel @Inject constructor(
     private val _rangeOverride = MutableStateFlow<AgendaRange?>(null)
 
     val state: StateFlow<AgendaUiState> =
-        combine(_anchor, agendaSettings, _rangeOverride, weekStartDay) { anchor, settings, override, weekStart ->
+        combine(_anchor, agendaSettings, _rangeOverride, weekStart) { anchor, settings, override, weekStart ->
             AgendaParams(
                 anchor = anchor,
                 range = override ?: settings.range,
@@ -146,11 +160,11 @@ class AgendaViewModel @Inject constructor(
             return AgendaUiState.Failure(FailureReason.NoCalendarsConfigured)
         }
         val anchor = params.anchor
-        val days = groupAgendaDays(anchor, instances, zone)
         val rangeEnd = anchor.plus(
             params.range.dayCount(anchor, params.weekStart) - 1,
             DateTimeUnit.DAY,
         )
+        val days = groupAgendaDays(anchor, rangeEnd, instances, zone)
         return AgendaUiState.Success(
             anchor = anchor,
             today = todayDate,
@@ -159,6 +173,7 @@ class AgendaViewModel @Inject constructor(
             rangeIsOverride = params.rangeIsOverride,
             rangeEnd = rangeEnd,
             showRangeBar = params.showRangeBar,
+            zone = zone,
         )
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/BackupScreen.kt

@@ -0,0 +1,373 @@
+package de.jeanlucmakiola.calendula.ui.calendars
+
+import android.net.Uri
+import android.text.format.DateUtils
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.FileDownload
+import androidx.compose.material.icons.filled.FileUpload
+import androidx.compose.material.icons.filled.Schedule
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.listSaver
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringArrayResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.core.net.toUri
+import androidx.documentfile.provider.DocumentFile
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.domain.CalendarSource
+import de.jeanlucmakiola.calendula.domain.isEventTarget
+import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.DialogAmountField
+import de.jeanlucmakiola.floret.components.DialogUnitDropdown
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.positionOf
+import java.time.LocalDate
+
+// SAF mime filter for the restore picker. Source apps hand `.ics` files out
+// under several mimes, so accept the common set.
+private val RESTORE_MIME_TYPES = arrayOf(
+    "text/calendar",
+    "application/octet-stream",
+    "text/plain",
+)
+
+/**
+ * Backup & restore (#69): `.ics` export and restore for local calendars, with
+ * optional automatic backup. Shares [CalendarsViewModel] with the manager.
+ *
+ * A full-screen destination hoisted in `CalendarHost`; [onBack] pops it,
+ * [onImport] hands a picked file to the app's normal .ics import flow.
+ */
+@Composable
+fun BackupScreen(
+    onBack: () -> Unit,
+    onImport: (Uri) -> Unit,
+    viewModel: CalendarsViewModel = hiltViewModel(),
+) {
+    val calendars by viewModel.calendars.collectAsStateWithLifecycle()
+    val backupResult by viewModel.backupResult.collectAsStateWithLifecycle()
+    val autoBackup by viewModel.autoBackup.collectAsStateWithLifecycle()
+
+    val context = LocalContext.current
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    // Export covers local calendars only; managed special-dates mirrors are
+    // rebuilt from contacts. Restore can target anything the import picker offers.
+    val exportable = calendars.filter { it.isLocal && it.canModifyContents && !it.isManaged }
+    val canImport = calendars.any { it.isEventTarget }
+
+    // Exports everything eligible (null); the per-calendar selector owns its
+    // own launcher.
+    val createBackup = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.CreateDocument("text/calendar"),
+    ) { uri -> uri?.let { viewModel.exportBackup(it, null) } }
+    var showExportPicker by rememberSaveable { mutableStateOf(false) }
+
+    // Restore runs the picked file through the normal .ics import flow.
+    val openBackup = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocument(),
+    ) { uri -> uri?.let(onImport) }
+
+    // The VM persists the write grant so background runs can keep writing.
+    val pickFolder = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocumentTree(),
+    ) { uri -> uri?.let(viewModel::setAutoBackupFolder) }
+    var showInterval by remember { mutableStateOf(false) }
+
+    val backupFailedText = stringResource(R.string.calendars_backup_failed)
+    LaunchedEffect(backupResult) {
+        when (val r = backupResult) {
+            is BackupResult.Success -> {
+                snackbarHostState.showSnackbar(
+                    context.resources.getQuantityString(
+                        R.plurals.calendars_backup_done, r.eventCount, r.eventCount,
+                    ),
+                )
+                viewModel.consumeBackupResult()
+            }
+            BackupResult.Failure -> {
+                snackbarHostState.showSnackbar(backupFailedText)
+                viewModel.consumeBackupResult()
+            }
+            null -> Unit
+        }
+    }
+
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_backup),
+        onBack = onBack,
+        snackbarHost = { SnackbarHost(snackbarHostState) },
+        predictiveBack = true,
+    ) {
+        HintText(stringResource(R.string.calendars_backup_hint))
+
+        if (exportable.isNotEmpty()) {
+            GroupedRow(
+                title = stringResource(R.string.calendars_backup_action),
+                position = Position.Top,
+                leading = { LeadingAvatar(Icons.Default.FileDownload) },
+                onClick = {
+                    // A single exportable calendar skips the selector.
+                    if (exportable.size == 1) {
+                        runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
+                    } else {
+                        showExportPicker = true
+                    }
+                },
+            )
+            GroupedRow(
+                title = stringResource(R.string.calendars_restore_action),
+                summary = stringResource(R.string.calendars_restore_hint),
+                position = Position.Middle,
+                leading = { LeadingAvatar(Icons.Default.FileUpload) },
+                onClick = { runCatching { openBackup.launch(RESTORE_MIME_TYPES) } },
+            )
+            GroupedRow(
+                title = stringResource(R.string.calendars_auto_backup),
+                summary = stringResource(R.string.calendars_auto_backup_hint),
+                position = if (autoBackup.enabled) Position.Middle else Position.Bottom,
+                leading = { LeadingAvatar(Icons.Default.Schedule) },
+                trailing = {
+                    Switch(checked = autoBackup.enabled, onCheckedChange = viewModel::setAutoBackupEnabled)
+                },
+                onClick = { viewModel.setAutoBackupEnabled(!autoBackup.enabled) },
+            )
+            if (autoBackup.enabled) {
+                GroupedRow(
+                    title = stringResource(R.string.calendars_auto_backup_folder),
+                    summary = rememberFolderName(autoBackup.folderUri)
+                        ?: stringResource(R.string.calendars_auto_backup_folder_unset),
+                    position = Position.Middle,
+                    onClick = { runCatching { pickFolder.launch(null) } },
+                )
+                GroupedRow(
+                    title = stringResource(R.string.calendars_auto_backup_interval),
+                    summary = backupIntervalLabel(autoBackup.intervalMinutes),
+                    position = Position.Bottom,
+                    onClick = { showInterval = true },
+                )
+                HintText(backupStatusText(autoBackup.status))
+            }
+        } else if (canImport) {
+            // Nothing to back up, but restore is still possible — don't hide
+            // it behind export eligibility.
+            SectionHeader(stringResource(R.string.calendars_restore_header))
+            HintText(stringResource(R.string.calendars_restore_hint))
+            GroupedRow(
+                title = stringResource(R.string.calendars_restore_action),
+                position = Position.Alone,
+                leading = { LeadingAvatar(Icons.Default.FileUpload) },
+                onClick = { runCatching { openBackup.launch(RESTORE_MIME_TYPES) } },
+            )
+        }
+    }
+
+    if (showExportPicker) {
+        ExportCalendarPicker(
+            calendars = exportable,
+            onExport = viewModel::exportBackup,
+            onDismiss = { showExportPicker = false },
+        )
+    }
+    if (showInterval) {
+        BackupIntervalDialog(
+            currentMinutes = autoBackup.intervalMinutes,
+            onConfirm = viewModel::setAutoBackupIntervalMinutes,
+            onDismiss = { showInterval = false },
+        )
+    }
+}
+
+/**
+ * Choose which local calendars to include in a one-time `.ics` export. Defaults
+ * to all selected; the Export action opens the SAF save dialog and hands back
+ * the picked file with the chosen calendar ids.
+ */
+@Composable
+private fun ExportCalendarPicker(
+    calendars: List<CalendarSource>,
+    onExport: (Uri, Set<Long>?) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    // Deliberately not keyed on [calendars]: that list is observer-driven, so
+    // keying it would reset the user's de-selections on every provider re-emit.
+    var selected by rememberSaveable(
+        stateSaver = listSaver(
+            save = { it.toList() },
+            restore = { it.toSet() },
+        ),
+    ) {
+        mutableStateOf(calendars.map { it.id }.toSet())
+    }
+    val createBackup = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.CreateDocument("text/calendar"),
+    ) { uri ->
+        if (uri != null) {
+            onExport(uri, selected)
+            onDismiss()
+        }
+    }
+
+    FullScreenPicker(
+        title = stringResource(R.string.calendars_export_title),
+        onDismiss = onDismiss,
+    ) {
+        HintText(stringResource(R.string.calendars_export_hint))
+        calendars.forEachIndexed { index, calendar ->
+            val isSelected = calendar.id in selected
+            GroupedRow(
+                title = calendar.displayName,
+                summary = calendar.description,
+                position = positionOf(index, calendars.size),
+                leading = { CalendarColorChip(calendar.color) },
+                trailing = {
+                    Checkbox(
+                        checked = isSelected,
+                        onCheckedChange = { checked ->
+                            selected = if (checked) selected + calendar.id else selected - calendar.id
+                        },
+                    )
+                },
+                onClick = {
+                    selected = if (isSelected) selected - calendar.id else selected + calendar.id
+                },
+            )
+        }
+        Button(
+            onClick = {
+                runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
+            },
+            enabled = selected.isNotEmpty(),
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 16.dp, vertical = 16.dp),
+        ) {
+            Text(stringResource(R.string.calendars_export_action))
+        }
+    }
+}
+
+/** Readable name of the persisted backup folder, resolved from its tree Uri. */
+@Composable
+private fun rememberFolderName(uriString: String?): String? {
+    val context = LocalContext.current
+    return remember(uriString) {
+        uriString?.let {
+            runCatching { DocumentFile.fromTreeUri(context, it.toUri())?.name }.getOrNull()
+        }
+    }
+}
+
+/** "Every 30 minutes" / "Every 2 hours" / "Every day" — the interval in its largest whole unit. */
+@Composable
+private fun backupIntervalLabel(minutes: Long): String {
+    val duration = when {
+        minutes % MINUTES_PER_WEEK == 0L ->
+            pluralStringResource(R.plurals.duration_weeks, (minutes / MINUTES_PER_WEEK).toInt(), (minutes / MINUTES_PER_WEEK).toInt())
+        minutes % MINUTES_PER_DAY == 0L ->
+            pluralStringResource(R.plurals.duration_days, (minutes / MINUTES_PER_DAY).toInt(), (minutes / MINUTES_PER_DAY).toInt())
+        minutes % 60L == 0L ->
+            pluralStringResource(R.plurals.duration_hours, (minutes / 60L).toInt(), (minutes / 60L).toInt())
+        else ->
+            pluralStringResource(R.plurals.duration_minutes, minutes.toInt(), minutes.toInt())
+    }
+    return stringResource(R.string.calendars_auto_backup_every, duration)
+}
+
+/** "Last backup: 5 minutes ago" / "… failed" / "No automatic backup yet". */
+@Composable
+private fun backupStatusText(status: BackupStatus): String {
+    if (status.lastRun == 0L) return stringResource(R.string.calendars_auto_backup_status_never)
+    val relative = DateUtils.getRelativeTimeSpanString(
+        status.lastRun, System.currentTimeMillis(), DateUtils.MINUTE_IN_MILLIS,
+    ).toString()
+    return if (status.lastSuccess) {
+        stringResource(R.string.calendars_auto_backup_status_ok, relative)
+    } else {
+        stringResource(R.string.calendars_auto_backup_status_failed, relative)
+    }
+}
+
+/** Amount + unit picker for the backup interval (floored at 30 minutes). */
+@Composable
+private fun BackupIntervalDialog(
+    currentMinutes: Long,
+    onConfirm: (Long) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    // Pick the largest unit the current value divides into.
+    val unitMinutes = remember { listOf(1L, 60L, MINUTES_PER_DAY, MINUTES_PER_WEEK) }
+    val units = stringArrayResource(R.array.backup_interval_units).toList()
+    val initialUnit = unitMinutes.indexOfLast { currentMinutes % it == 0L }.coerceAtLeast(0)
+    var amount by rememberSaveable { mutableStateOf((currentMinutes / unitMinutes[initialUnit]).toString()) }
+    var unitIndex by rememberSaveable { mutableStateOf(initialUnit) }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.calendars_auto_backup_interval)) },
+        text = {
+            Column {
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    DialogAmountField(value = amount, onValueChange = { amount = it }, placeholder = "1")
+                    Spacer(Modifier.width(12.dp))
+                    DialogUnitDropdown(label = units[unitIndex], entries = units) { unitIndex = it }
+                }
+                Spacer(Modifier.height(8.dp))
+                Text(
+                    text = stringResource(R.string.calendars_auto_backup_interval_min),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = {
+                val value = amount.toLongOrNull()?.coerceAtLeast(1L) ?: 1L
+                onConfirm((value * unitMinutes[unitIndex]).coerceAtLeast(SettingsPrefs.MIN_BACKUP_INTERVAL))
+                onDismiss()
+            }) { Text(stringResource(R.string.reminder_custom_set)) }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text(stringResource(R.string.dialog_cancel)) }
+        },
+    )
+}
+
+private const val MINUTES_PER_DAY = 1_440L
+private const val MINUTES_PER_WEEK = 10_080L

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarVisibilityNotice.kt

@@ -0,0 +1,71 @@
+package de.jeanlucmakiola.calendula.ui.calendars
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.calendar.CalendarVisibilityReconciler
+import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * The one-time notice that Calendula now follows the device's per-calendar
+ * visibility (#75), armed by `CalendarVisibilityReconciler`. The app does not
+ * switch those calendars back on — that would un-hide them everywhere else too.
+ */
+@HiltViewModel
+class CalendarVisibilityNoticeViewModel @Inject constructor(
+    private val prefs: CalendarPrefs,
+    private val reconciler: CalendarVisibilityReconciler,
+) : ViewModel() {
+
+    /**
+     * Reconcile whenever the app comes up with the calendar permission held,
+     * rather than off one grant route: a permission granted on Android's
+     * app-settings screen never reaches the permission screen's callback.
+     */
+    fun reconcile() {
+        viewModelScope.launch { reconciler.run() }
+    }
+
+    val pending: StateFlow<Boolean> = prefs.visibilityNoticePending
+        .map { it == true }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = false,
+        )
+
+    fun dismiss() {
+        viewModelScope.launch { prefs.setVisibilityNoticePending(false) }
+    }
+}
+
+/** Plain informational dialog — one acknowledgement, nothing to decide. */
+@Composable
+fun CalendarVisibilityNoticeDialog(onDismiss: () -> Unit) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        icon = { Icon(Icons.Default.VisibilityOff, contentDescription = null) },
+        title = { Text(stringResource(R.string.calendars_visibility_notice_title)) },
+        text = { Text(stringResource(R.string.calendars_visibility_notice_message)) },
+        confirmButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.dialog_ok))
+            }
+        },
+    )
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarsScreen.kt

@@ -4,11 +4,7 @@ import android.accounts.AccountManager
 import android.content.Context
 import android.content.Intent
 import android.provider.Settings
-import android.text.format.DateUtils
-import androidx.activity.compose.rememberLauncherForActivityResult
-import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
@@ -24,23 +20,21 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
 import androidx.compose.material.icons.automirrored.filled.Notes
 import androidx.compose.material.icons.automirrored.filled.OpenInNew
 import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Backup
 import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material.icons.filled.Close
-import androidx.compose.material.icons.filled.Cloud
 import androidx.compose.material.icons.filled.Delete
-import androidx.compose.material.icons.filled.FileDownload
+import androidx.compose.material.icons.filled.Info
 import androidx.compose.material.icons.filled.MoreVert
 import androidx.compose.material.icons.filled.Palette
 import androidx.compose.material.icons.filled.PhoneAndroid
-import androidx.compose.material.icons.filled.Schedule
 import androidx.compose.material.icons.filled.Visibility
 import androidx.compose.material.icons.filled.VisibilityOff
 import androidx.compose.material3.AlertDialog
@@ -71,64 +65,63 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
-import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.ImageBitmap
-import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.graphics.vector.ImageVector
-import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.res.pluralStringResource
-import androidx.compose.ui.res.stringArrayResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.input.KeyboardCapitalization
 import androidx.compose.ui.unit.dp
-import androidx.core.graphics.drawable.toBitmap
-import androidx.core.net.toUri
-import androidx.documentfile.provider.DocumentFile
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
-import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
-import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
-import de.jeanlucmakiola.calendula.ui.common.CALENDAR_COLOR_PALETTE
+import de.jeanlucmakiola.calendula.domain.CalendarStateLabel
+import de.jeanlucmakiola.calendula.domain.hasVisibilitySwitch
+import de.jeanlucmakiola.calendula.domain.isNotSynced
+import de.jeanlucmakiola.calendula.domain.orderedForManager
+import de.jeanlucmakiola.calendula.domain.stateLabels
+import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
+import de.jeanlucmakiola.calendula.ui.common.AccountKey
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
-import de.jeanlucmakiola.calendula.ui.common.DialogAmountField
-import de.jeanlucmakiola.calendula.ui.common.DialogUnitDropdown
-import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
-import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
-import de.jeanlucmakiola.calendula.ui.common.predictiveBack
-import de.jeanlucmakiola.calendula.ui.common.CollapsingScaffold
+import de.jeanlucmakiola.calendula.ui.common.accountGroupTitle
+import de.jeanlucmakiola.calendula.ui.common.groupByAccount
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
+import de.jeanlucmakiola.calendula.ui.common.eventFill
+import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
+import de.jeanlucmakiola.calendula.ui.common.SourceLogo
+import de.jeanlucmakiola.calendula.ui.common.curatedSourcePackage
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.identity.collapseExit
+import de.jeanlucmakiola.floret.identity.expandEnter
+import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
-import de.jeanlucmakiola.calendula.ui.common.GroupedRow
-import de.jeanlucmakiola.calendula.ui.common.InlineTextField
-import de.jeanlucmakiola.calendula.ui.common.Position
-import de.jeanlucmakiola.calendula.ui.common.pastelize
-import java.time.LocalDate
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.InlineTextField
+import de.jeanlucmakiola.floret.components.Position
 
 /** Sentinel [editorId] meaning "the editor is composing a new calendar". */
 private const val NEW_CALENDAR_ID = Long.MIN_VALUE
 
 /**
  * Calendar manager (reached from Settings). Lists the app's own device-only
- * calendars with create / rename / recolor / delete (via a full-screen editor),
- * and lists synced calendars read-only with a per-account "manage in the source
- * app" deep-link — the app never touches a synced calendar's server. A
- * full-screen destination; [onBack] pops it.
+ * calendars with create / rename / recolor / delete, and synced calendars
+ * read-only with a per-account "manage in the source app" deep-link.
+ *
+ * Export/import lives in its own Settings entry ([BackupScreen], #69); this
+ * screen only points at it. [onBack] pops the destination.
  */
 @Composable
 fun CalendarsScreen(
     onBack: () -> Unit,
+    onOpenBackup: () -> Unit,
     viewModel: CalendarsViewModel = hiltViewModel(),
 ) {
     val calendars by viewModel.calendars.collectAsStateWithLifecycle()
-    val disabledIds by viewModel.disabledCalendarIds.collectAsStateWithLifecycle()
+    val deleteLockedIds by viewModel.deleteLockedCalendarIds.collectAsStateWithLifecycle()
     val error by viewModel.error.collectAsStateWithLifecycle()
-    val backupResult by viewModel.backupResult.collectAsStateWithLifecycle()
-    val autoBackup by viewModel.autoBackup.collectAsStateWithLifecycle()
 
     // null = list; NEW_CALENDAR_ID = create; any other id = edit that calendar.
     // [editorSession] bumps on every open so the editor's field state resets for
@@ -142,8 +135,9 @@ fun CalendarsScreen(
             sessionKey = editorSession,
             isNew = editorId == NEW_CALENDAR_ID,
             initialName = editing?.displayName.orEmpty(),
-            initialColor = editing?.color ?: CALENDAR_COLOR_PALETTE.first(),
+            initialColor = editing?.color ?: CalendarColorPalette.all.first(),
             initialDescription = editing?.description.orEmpty(),
+            deleteLocked = editing != null && editing.id in deleteLockedIds,
             onSave = { name, color, description ->
                 val id = editorId
                 if (id == null || id == NEW_CALENDAR_ID) {
@@ -163,21 +157,14 @@ fun CalendarsScreen(
         CalendarsList(
             local = calendars.filter { it.isLocal },
             synced = calendars.filterNot { it.isLocal },
-            disabledIds = disabledIds,
             error = error,
             onConsumeError = viewModel::consumeError,
-            backupResult = backupResult,
-            onExportBackup = viewModel::exportBackup,
-            onConsumeBackupResult = viewModel::consumeBackupResult,
-            autoBackup = autoBackup,
-            onSetAutoBackupEnabled = viewModel::setAutoBackupEnabled,
-            onSetAutoBackupInterval = viewModel::setAutoBackupIntervalMinutes,
-            onSetAutoBackupFolder = viewModel::setAutoBackupFolder,
+            onOpenBackup = onOpenBackup,
             onBack = onBack,
             onAdd = { editorSession++; editorId = NEW_CALENDAR_ID },
             onEdit = { calendar -> editorSession++; editorId = calendar.id },
-            onSetDisabled = viewModel::setDisabled,
-            onSetAccountDisabled = viewModel::setAccountDisabled,
+            onSetVisible = viewModel::setCalendarVisible,
+            onSetAccountVisible = viewModel::setAccountVisible,
         )
     }
 }
@@ -186,27 +173,20 @@ fun CalendarsScreen(
 private fun CalendarsList(
     local: List<CalendarSource>,
     synced: List<CalendarSource>,
-    disabledIds: Set<Long>,
     error: Boolean,
     onConsumeError: () -> Unit,
-    backupResult: BackupResult?,
-    onExportBackup: (android.net.Uri) -> Unit,
-    onConsumeBackupResult: () -> Unit,
-    autoBackup: AutoBackupUiState,
-    onSetAutoBackupEnabled: (Boolean) -> Unit,
-    onSetAutoBackupInterval: (Long) -> Unit,
-    onSetAutoBackupFolder: (android.net.Uri) -> Unit,
+    onOpenBackup: () -> Unit,
     onBack: () -> Unit,
     onAdd: () -> Unit,
     onEdit: (CalendarSource) -> Unit,
-    onSetDisabled: (Long, Boolean) -> Unit,
-    onSetAccountDisabled: (Collection<Long>, Boolean) -> Unit,
+    onSetVisible: (Long, Boolean) -> Unit,
+    onSetAccountVisible: (Collection<Long>, Boolean) -> Unit,
 ) {
     val context = LocalContext.current
     val snackbarHostState = remember { SnackbarHostState() }
     // Accounts the user has folded shut; empty = all expanded (keeps every
     // calendar visible by default, the section is collapsible for tidiness).
-    var collapsedAccounts by remember { mutableStateOf(emptySet<String>()) }
+    var collapsedAccounts by remember { mutableStateOf(emptySet<AccountKey>()) }
     var localExpanded by remember { mutableStateOf(true) }
     val writeErrorText = stringResource(R.string.calendars_write_error)
 
@@ -217,50 +197,19 @@ private fun CalendarsList(
         }
     }
 
-    // SAF "create document" target for the backup file. The picked Uri is handed
-    // to the VM to stream the .ics into.
-    val createBackup = rememberLauncherForActivityResult(
-        contract = ActivityResultContracts.CreateDocument("text/calendar"),
-    ) { uri -> uri?.let(onExportBackup) }
-
-    // SAF folder picker for the automatic-backup destination; the VM persists the
-    // write grant so background runs can keep writing to it.
-    val pickFolder = rememberLauncherForActivityResult(
-        contract = ActivityResultContracts.OpenDocumentTree(),
-    ) { uri -> uri?.let(onSetAutoBackupFolder) }
-    var showInterval by remember { mutableStateOf(false) }
-
-    val backupFailedText = stringResource(R.string.calendars_backup_failed)
-    LaunchedEffect(backupResult) {
-        when (val r = backupResult) {
-            is BackupResult.Success -> {
-                snackbarHostState.showSnackbar(
-                    context.resources.getQuantityString(
-                        R.plurals.calendars_backup_done, r.eventCount, r.eventCount,
-                    ),
-                )
-                onConsumeBackupResult()
-            }
-            BackupResult.Failure -> {
-                snackbarHostState.showSnackbar(backupFailedText)
-                onConsumeBackupResult()
-            }
-            null -> Unit
-        }
-    }
-
     CollapsingScaffold(
         title = stringResource(R.string.calendars_title),
         onBack = onBack,
         snackbarHost = { SnackbarHost(snackbarHostState) },
+        predictiveBack = true,
     ) {
         // What the per-calendar / per-account switches below actually do.
-        HintText(stringResource(R.string.calendars_disable_hint))
+        HintText(stringResource(R.string.calendars_visibility_hint))
 
         // Local (device-only) calendars — one collapsible group. The header's
         // "+" adds a calendar; the switch enables/disables them all at once;
         // tapping a calendar row opens its editor.
-        val localDisabled = local.isNotEmpty() && local.all { it.id in disabledIds }
+        val localDisabled = local.isNotEmpty() && local.none { it.isVisibleInSystem }
         CalendarGroup(
             title = stringResource(R.string.calendars_local_header),
             expanded = localExpanded,
@@ -272,17 +221,17 @@ private fun CalendarsList(
             onManage = onAdd,
             onToggleExpand = { localExpanded = !localExpanded },
             showToggleAll = local.isNotEmpty(),
-            allEnabled = local.none { it.id in disabledIds },
-            onToggleAll = { enabled -> onSetAccountDisabled(local.map { it.id }, !enabled) },
+            allEnabled = local.all { it.isVisibleInSystem },
+            onToggleAll = { enabled -> onSetAccountVisible(local.map { it.id }, enabled) },
         ) {
             if (local.isEmpty()) {
                 HintText(stringResource(R.string.calendars_local_empty))
             } else {
                 local.forEachIndexed { index, calendar ->
-                    val disabled = calendar.id in disabledIds
+                    val disabled = !calendar.isVisibleInSystem
                     GroupedRow(
                         title = calendar.displayName,
-                        summary = calendar.description,
+                        summary = calendarRowSummary(calendar),
                         position = if (index == local.lastIndex) Position.Bottom else Position.Middle,
                         container = MaterialTheme.colorScheme.surfaceContainerHighest,
                         dimmed = disabled,
@@ -291,7 +240,7 @@ private fun CalendarsList(
                             EnableSwitch(
                                 calendarName = calendar.displayName,
                                 enabled = !disabled,
-                                onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
+                                onToggle = { enabled -> onSetVisible(calendar.id, enabled) },
                             )
                         },
                         onClick = { onEdit(calendar) },
@@ -300,49 +249,22 @@ private fun CalendarsList(
             }
         }
 
-        // Backup — local calendars have no sync, so a .ics export is their only
-        // safety net. Offered only when there is something to back up.
-        if (local.isNotEmpty()) {
-            Spacer(Modifier.height(16.dp))
-            SectionHeader(stringResource(R.string.calendars_backup_header))
-            HintText(stringResource(R.string.calendars_backup_hint))
-            // One connected card: the one-time export on top, then automatic
-            // backup (and its folder/interval rows when on).
-            GroupedRow(
-                title = stringResource(R.string.calendars_backup_action),
-                position = Position.Top,
-                leading = { LeadingAvatar(Icons.Default.FileDownload) },
-                onClick = {
-                    runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
-                },
-            )
-            GroupedRow(
-                title = stringResource(R.string.calendars_auto_backup),
-                summary = stringResource(R.string.calendars_auto_backup_hint),
-                position = if (autoBackup.enabled) Position.Middle else Position.Bottom,
-                leading = { LeadingAvatar(Icons.Default.Schedule) },
-                trailing = {
-                    Switch(checked = autoBackup.enabled, onCheckedChange = onSetAutoBackupEnabled)
-                },
-                onClick = { onSetAutoBackupEnabled(!autoBackup.enabled) },
-            )
-            if (autoBackup.enabled) {
-                GroupedRow(
-                    title = stringResource(R.string.calendars_auto_backup_folder),
-                    summary = rememberFolderName(autoBackup.folderUri)
-                        ?: stringResource(R.string.calendars_auto_backup_folder_unset),
-                    position = Position.Middle,
-                    onClick = { runCatching { pickFolder.launch(null) } },
+        // Pointer to the Backup entry (#69), so it stays findable from here.
+        Spacer(Modifier.height(16.dp))
+        GroupedRow(
+            title = stringResource(R.string.settings_section_backup),
+            summary = stringResource(R.string.settings_backup_subtitle),
+            position = Position.Alone,
+            leading = { LeadingAvatar(Icons.Default.Backup) },
+            trailing = {
+                Icon(
+                    imageVector = Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
-                GroupedRow(
-                    title = stringResource(R.string.calendars_auto_backup_interval),
-                    summary = backupIntervalLabel(autoBackup.intervalMinutes),
-                    position = Position.Bottom,
-                    onClick = { showInterval = true },
-                )
-                HintText(backupStatusText(autoBackup.status))
-            }
-        }
+            },
+            onClick = onOpenBackup,
+        )
 
         Spacer(Modifier.height(16.dp))
 
@@ -352,14 +274,19 @@ private fun CalendarsList(
         SectionHeader(stringResource(R.string.calendars_synced_header))
         HintText(stringResource(R.string.calendars_synced_hint))
         synced
-            .groupBy { it.accountName.ifBlank { it.accountType } }
-            .forEach { (account, cals) ->
-                val expanded = account !in collapsedAccounts
-                val accountType = cals.first().accountType
-                val accountDisabled = cals.all { it.id in disabledIds }
+            .groupByAccount()
+            .forEach { group ->
+                val cals = group.calendars
+                val expanded = group.key !in collapsedAccounts
+                val accountType = group.accountType
+                // A non-syncing calendar has no switch, so it neither counts
+                // towards "the whole account is off" nor moves with toggle-all.
+                val switchable = cals.filter { it.hasVisibilitySwitch }
+                val accountDisabled = switchable.isNotEmpty() &&
+                    switchable.none { it.isVisibleInSystem }
                 Spacer(Modifier.height(16.dp))
                 CalendarGroup(
-                    title = account,
+                    title = accountGroupTitle(group),
                     expanded = expanded,
                     bodyHasRows = true,
                     headerDisabled = accountDisabled,
@@ -371,29 +298,41 @@ private fun CalendarsList(
                     },
                     onToggleExpand = {
                         collapsedAccounts = if (expanded) {
-                            collapsedAccounts + account
+                            collapsedAccounts + group.key
                         } else {
-                            collapsedAccounts - account
+                            collapsedAccounts - group.key
                         }
                     },
-                    showToggleAll = true,
-                    allEnabled = cals.none { it.id in disabledIds },
-                    onToggleAll = { enabled -> onSetAccountDisabled(cals.map { it.id }, !enabled) },
+                    showToggleAll = switchable.isNotEmpty(),
+                    allEnabled = switchable.all { it.isVisibleInSystem },
+                    onToggleAll = { enabled ->
+                        onSetAccountVisible(switchable.map { it.id }, enabled)
+                    },
                 ) {
-                    cals.forEachIndexed { index, calendar ->
-                        val disabled = calendar.id in disabledIds
+                    // Actionable calendars first; non-syncing ones at the
+                    // bottom, dimmed and switchless.
+                    val ordered = cals.orderedForManager()
+                    ordered.forEachIndexed { index, calendar ->
+                        val disabled = !calendar.isVisibleInSystem || calendar.isNotSynced
                         GroupedRow(
                             title = calendar.displayName,
-                            position = if (index == cals.lastIndex) Position.Bottom else Position.Middle,
+                            summary = calendarRowSummary(calendar),
+                            position = if (index == ordered.lastIndex) Position.Bottom else Position.Middle,
                             container = MaterialTheme.colorScheme.surfaceContainerHighest,
                             dimmed = disabled,
                             leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
-                            trailing = {
-                                EnableSwitch(
-                                    calendarName = calendar.displayName,
-                                    enabled = !disabled,
-                                    onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
-                                )
+                            trailing = if (calendar.hasVisibilitySwitch) {
+                                {
+                                    EnableSwitch(
+                                        calendarName = calendar.displayName,
+                                        enabled = calendar.isVisibleInSystem,
+                                        onToggle = { enabled ->
+                                            onSetVisible(calendar.id, enabled)
+                                        },
+                                    )
+                                }
+                            } else {
+                                null
                             },
                         )
                     }
@@ -401,13 +340,6 @@ private fun CalendarsList(
             }
     }
 
-    if (showInterval) {
-        BackupIntervalDialog(
-            currentMinutes = autoBackup.intervalMinutes,
-            onConfirm = onSetAutoBackupInterval,
-            onDismiss = { showInterval = false },
-        )
-    }
 }
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -421,12 +353,14 @@ private fun CalendarEditor(
     onSave: (name: String, color: Int, description: String?) -> Unit,
     onDelete: () -> Unit,
     onClose: () -> Unit,
+    deleteLocked: Boolean = false,
 ) {
     var name by rememberSaveable(sessionKey) { mutableStateOf(initialName) }
     var color by rememberSaveable(sessionKey) { mutableStateOf(initialColor) }
     var description by rememberSaveable(sessionKey) { mutableStateOf(initialDescription) }
     var confirmDelete by remember { mutableStateOf(false) }
     val dark = isSystemInDarkTheme()
+    val soften = LocalSoftenColors.current
 
     Scaffold(
         modifier = Modifier
@@ -453,11 +387,20 @@ private fun CalendarEditor(
                 },
                 actions = {
                     if (!isNew) {
-                        IconButton(onClick = { confirmDelete = true }) {
+                        // Disabled rather than hidden while the special-dates
+                        // sync owns this calendar; the card below says why.
+                        IconButton(
+                            onClick = { confirmDelete = true },
+                            enabled = !deleteLocked,
+                        ) {
                             Icon(
                                 Icons.Default.Delete,
                                 contentDescription = stringResource(R.string.event_detail_delete),
-                                tint = MaterialTheme.colorScheme.error,
+                                tint = if (deleteLocked) {
+                                    MaterialTheme.colorScheme.onSurface.copy(alpha = 0.38f)
+                                } else {
+                                    MaterialTheme.colorScheme.error
+                                },
                             )
                         }
                     }
@@ -486,7 +429,20 @@ private fun CalendarEditor(
                 .padding(horizontal = 16.dp, vertical = 8.dp),
             verticalArrangement = Arrangement.spacedBy(12.dp),
         ) {
-            EditorCard(icon = Icons.Default.CalendarMonth, iconTint = pastelize(color, dark)) {
+            if (deleteLocked) {
+                EditorCard(
+                    icon = Icons.Default.Info,
+                    iconTint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    iconAtTop = true,
+                ) {
+                    Text(
+                        text = stringResource(R.string.calendars_managed_delete_locked),
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+            EditorCard(icon = Icons.Default.CalendarMonth, iconTint = eventFill(color, dark, soften)) {
                 InlineTextField(
                     value = name,
                     onValueChange = { name = it },
@@ -507,7 +463,7 @@ private fun CalendarEditor(
                 )
                 Spacer(Modifier.height(12.dp))
                 ColorSwatchRow(
-                    colors = CALENDAR_COLOR_PALETTE,
+                    colors = CalendarColorPalette.all,
                     selected = color,
                     onSelect = { color = it },
                     dark = dark,
@@ -558,10 +514,28 @@ private fun CalendarEditor(
 }
 
 /**
- * The per-row enable/disable control. Checked = the calendar is shown in the
- * app; unchecking disables it (events, filters and pickers all drop it) without
- * touching any provider data. Carries its own content description so the toggle
- * is self-describing to screen readers even on a dimmed row.
+ * The row's supporting line: the states that make this calendar behave unlike a
+ * plain writable one (#76), then its own description.
+ */
+@Composable
+private fun calendarRowSummary(calendar: CalendarSource): String? {
+    val states = calendar.stateLabels().map { label ->
+        stringResource(
+            when (label) {
+                CalendarStateLabel.MANAGED -> R.string.calendars_state_managed
+                CalendarStateLabel.READ_ONLY -> R.string.calendars_state_read_only
+                CalendarStateLabel.NOT_SYNCED -> R.string.calendars_state_not_synced
+            },
+        )
+    }
+    val parts = states + listOfNotNull(calendar.description?.takeIf { it.isNotBlank() })
+    return parts.joinToString(" · ").ifEmpty { null }
+}
+
+/**
+ * The per-row on/off control, writing the system's device-local
+ * `Calendars.VISIBLE`. Unchecked drops the calendar out of every surface and
+ * stops its reminders. Carries its own content description.
  */
 @Composable
 private fun EnableSwitch(
@@ -569,7 +543,7 @@ private fun EnableSwitch(
     enabled: Boolean,
     onToggle: (Boolean) -> Unit,
 ) {
-    val label = stringResource(R.string.calendars_show_in_app_a11y, calendarName)
+    val label = stringResource(R.string.calendars_visibility_a11y, calendarName)
     Switch(
         checked = enabled,
         onCheckedChange = onToggle,
@@ -664,8 +638,8 @@ private fun CalendarGroup(
     )
     AnimatedVisibility(
         visible = expanded,
-        enter = calendarExpandEnter(),
-        exit = calendarCollapseExit(),
+        enter = expandEnter(),
+        exit = collapseExit(),
     ) {
         Column(content = body)
     }
@@ -741,175 +715,33 @@ private fun CalendarGroupMenu(
     }
 }
 
-/**
- * The source app's launcher icon (Google Calendar, DAVx5, Nextcloud, …) as a
- * round 40dp chip, so each synced account is recognisable at a glance. We load
- * whatever app owns the account from [PackageManager] rather than bundling brand
- * logos — always accurate, nothing to license. Falls back to a neutral cloud
- * chip when no installed app resolves for the account.
- */
-@Composable
-private fun SourceLogo(accountType: String) {
-    val context = LocalContext.current
-    val logo = remember(accountType) { sourceAppLogo(context, accountType) }
-    if (logo != null) {
-        Image(
-            bitmap = logo,
-            contentDescription = null,
-            contentScale = ContentScale.Crop,
-            modifier = Modifier
-                .size(40.dp)
-                .clip(CircleShape),
-        )
-    } else {
-        LeadingAvatar(Icons.Default.Cloud)
-    }
-}
-
-/** The launcher icon of the app backing [accountType], preferring the human-facing app. */
-private fun sourceAppLogo(context: Context, accountType: String): ImageBitmap? {
-    val pm = context.packageManager
-    val candidates = buildList {
-        curatedSourcePackage(accountType)?.let { add(it) }
-        AccountManager.get(context).authenticatorTypes
-            .firstOrNull { it.type.equals(accountType, ignoreCase = true) }
-            ?.packageName
-            ?.let { add(it) }
-    }
-    for (pkg in candidates) {
-        val bitmap = runCatching { pm.getApplicationIcon(pkg).toBitmap() }.getOrNull()
-        if (bitmap != null) return bitmap.asImageBitmap()
-    }
-    return null
-}
-
-/** Neutral circular chip carrying an arbitrary icon (e.g. the local-device mark). */
-@Composable
-private fun LeadingAvatar(icon: ImageVector) {
-    Box(
-        modifier = Modifier
-            .size(40.dp)
-            .clip(CircleShape)
-            .background(MaterialTheme.colorScheme.surfaceContainerHighest),
-        contentAlignment = Alignment.Center,
-    ) {
-        Icon(
-            icon,
-            contentDescription = null,
-            tint = MaterialTheme.colorScheme.onSurfaceVariant,
-            modifier = Modifier.size(22.dp),
-        )
-    }
-}
 
 @Composable
-private fun SectionHeader(text: String) {
+internal fun SectionHeader(text: String) {
     Text(
         text = text,
         style = MaterialTheme.typography.labelLarge,
         color = MaterialTheme.colorScheme.primary,
-        modifier = Modifier.padding(start = 24.dp, end = 24.dp, top = 16.dp, bottom = 4.dp),
+        // The cards' own edge, so header and group share a left margin.
+        modifier = Modifier.padding(
+            start = GroupedListInset,
+            end = GroupedListInset,
+            top = 16.dp,
+            bottom = 4.dp,
+        ),
     )
 }
 
 @Composable
-private fun HintText(text: String) {
+internal fun HintText(text: String) {
     Text(
         text = text,
         style = MaterialTheme.typography.bodySmall,
         color = MaterialTheme.colorScheme.onSurfaceVariant,
-        modifier = Modifier.padding(horizontal = 24.dp, vertical = 4.dp),
+        modifier = Modifier.padding(horizontal = GroupedListInset, vertical = 4.dp),
     )
 }
 
-/** Readable name of the persisted backup folder, resolved from its tree Uri. */
-@Composable
-private fun rememberFolderName(uriString: String?): String? {
-    val context = LocalContext.current
-    return remember(uriString) {
-        uriString?.let {
-            runCatching { DocumentFile.fromTreeUri(context, it.toUri())?.name }.getOrNull()
-        }
-    }
-}
-
-/** "Every 30 minutes" / "Every 2 hours" / "Every day" — the interval in its largest whole unit. */
-@Composable
-private fun backupIntervalLabel(minutes: Long): String {
-    val duration = when {
-        minutes % MINUTES_PER_WEEK == 0L ->
-            pluralStringResource(R.plurals.duration_weeks, (minutes / MINUTES_PER_WEEK).toInt(), (minutes / MINUTES_PER_WEEK).toInt())
-        minutes % MINUTES_PER_DAY == 0L ->
-            pluralStringResource(R.plurals.duration_days, (minutes / MINUTES_PER_DAY).toInt(), (minutes / MINUTES_PER_DAY).toInt())
-        minutes % 60L == 0L ->
-            pluralStringResource(R.plurals.duration_hours, (minutes / 60L).toInt(), (minutes / 60L).toInt())
-        else ->
-            pluralStringResource(R.plurals.duration_minutes, minutes.toInt(), minutes.toInt())
-    }
-    return stringResource(R.string.calendars_auto_backup_every, duration)
-}
-
-/** "Last backup: 5 minutes ago" / "… failed" / "No automatic backup yet". */
-@Composable
-private fun backupStatusText(status: BackupStatus): String {
-    if (status.lastRun == 0L) return stringResource(R.string.calendars_auto_backup_status_never)
-    val relative = DateUtils.getRelativeTimeSpanString(
-        status.lastRun, System.currentTimeMillis(), DateUtils.MINUTE_IN_MILLIS,
-    ).toString()
-    return if (status.lastSuccess) {
-        stringResource(R.string.calendars_auto_backup_status_ok, relative)
-    } else {
-        stringResource(R.string.calendars_auto_backup_status_failed, relative)
-    }
-}
-
-/** Amount + unit picker for the backup interval (floored at 30 minutes). */
-@Composable
-private fun BackupIntervalDialog(
-    currentMinutes: Long,
-    onConfirm: (Long) -> Unit,
-    onDismiss: () -> Unit,
-) {
-    // minutes-per-unit for each entry; pick the largest unit the current value divides into.
-    val unitMinutes = remember { listOf(1L, 60L, MINUTES_PER_DAY, MINUTES_PER_WEEK) }
-    val units = stringArrayResource(R.array.backup_interval_units).toList()
-    val initialUnit = unitMinutes.indexOfLast { currentMinutes % it == 0L }.coerceAtLeast(0)
-    var amount by rememberSaveable { mutableStateOf((currentMinutes / unitMinutes[initialUnit]).toString()) }
-    var unitIndex by rememberSaveable { mutableStateOf(initialUnit) }
-
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        title = { Text(stringResource(R.string.calendars_auto_backup_interval)) },
-        text = {
-            Column {
-                Row(verticalAlignment = Alignment.CenterVertically) {
-                    DialogAmountField(value = amount, onValueChange = { amount = it }, placeholder = "1")
-                    Spacer(Modifier.width(12.dp))
-                    DialogUnitDropdown(label = units[unitIndex], entries = units) { unitIndex = it }
-                }
-                Spacer(Modifier.height(8.dp))
-                Text(
-                    text = stringResource(R.string.calendars_auto_backup_interval_min),
-                    style = MaterialTheme.typography.bodySmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                )
-            }
-        },
-        confirmButton = {
-            TextButton(onClick = {
-                val value = amount.toLongOrNull()?.coerceAtLeast(1L) ?: 1L
-                onConfirm((value * unitMinutes[unitIndex]).coerceAtLeast(SettingsPrefs.MIN_BACKUP_INTERVAL))
-                onDismiss()
-            }) { Text(stringResource(R.string.reminder_custom_set)) }
-        },
-        dismissButton = {
-            TextButton(onClick = onDismiss) { Text(stringResource(R.string.dialog_cancel)) }
-        },
-    )
-}
-
-private const val MINUTES_PER_DAY = 1_440L
-private const val MINUTES_PER_WEEK = 10_080L
 
 /**
  * Pick the app to open for managing a synced calendar's account. The account's
@@ -935,9 +767,3 @@ private fun sourceAppIntent(context: Context, accountType: String): Intent {
     return Intent(Settings.ACTION_SYNC_SETTINGS)
 }
 
-/** Preferred app for account types whose authenticator isn't the app to open. */
-private fun curatedSourcePackage(accountType: String): String? = when {
-    accountType.equals("com.google", ignoreCase = true) -> "com.google.android.calendar"
-    else -> null
-}
-

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarsViewModel.kt

@@ -12,7 +12,6 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
-import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
@@ -43,7 +42,6 @@ class CalendarsViewModel @Inject constructor(
     @ApplicationContext private val context: Context,
     private val repository: CalendarRepository,
     private val icsExporter: IcsExporter,
-    private val prefs: CalendarPrefs,
     private val settingsPrefs: SettingsPrefs,
     @IoDispatcher private val io: CoroutineDispatcher,
 ) : ViewModel() {
@@ -58,20 +56,6 @@ class CalendarsViewModel @Inject constructor(
                 initialValue = emptyList(),
             )
 
-    /**
-     * Calendars the user has disabled in the app. This screen is the only
-     * surface that lists them, so it both reads the set (to dim the rows) and
-     * toggles it. Every other surface simply excludes these ids.
-     */
-    val disabledCalendarIds: StateFlow<Set<Long>> =
-        prefs.disabledCalendarIds
-            .flowOn(io)
-            .stateIn(
-                scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
-                initialValue = emptySet(),
-            )
-
     /** Automatic-backup settings + last-run status, for the Backup section UI. */
     val autoBackup: StateFlow<AutoBackupUiState> = combine(
         settingsPrefs.autoBackupEnabled,
@@ -88,6 +72,25 @@ class CalendarsViewModel @Inject constructor(
             initialValue = AutoBackupUiState(),
         )
 
+    /**
+     * Managed special-dates calendars whose deletion would not stick: while the
+     * feature is on, `SpecialDatesSyncEngine.reconcileCalendars` undoes it on
+     * the next pass. Read off each calendar's durable [CalendarSource.isManaged]
+     * marker rather than the stored ids, which lag a sync pass behind.
+     */
+    val deleteLockedCalendarIds: StateFlow<Set<Long>> = combine(
+        calendars,
+        settingsPrefs.specialDatesEnabled,
+    ) { sources, enabled ->
+        if (!enabled) emptySet() else sources.filter { it.isManaged }.map { it.id }.toSet()
+    }
+        .flowOn(io)
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = emptySet(),
+        )
+
     private val _error = MutableStateFlow(false)
     val error: StateFlow<Boolean> = _error.asStateFlow()
 
@@ -103,11 +106,11 @@ class CalendarsViewModel @Inject constructor(
      * document [uri] as one `VCALENDAR`. Result (event count, or failure) lands
      * in [backupResult] for a one-shot message.
      */
-    fun exportBackup(uri: Uri) {
+    fun exportBackup(uri: Uri, calendarIds: Set<Long>? = null) {
         viewModelScope.launch {
             _backupResult.value = try {
                 val count = withContext(io) {
-                    val events = repository.exportEvents()
+                    val events = repository.exportEvents(calendarIds)
                     icsExporter.writeDocument(
                         uri = uri,
                         content = IcsWriter().writeCalendar(events, Clock.System.now()),
@@ -136,29 +139,21 @@ class CalendarsViewModel @Inject constructor(
     }
 
     /**
-     * Enable or disable a calendar app-side. Disabling removes it from every
-     * surface but Settings → Calendars (and hides its events) without touching
-     * provider data — purely a reversible Calendula-local view choice.
+     * Switch a calendar on or off — the app's one visibility model, writing the
+     * system's `Calendars.VISIBLE`. A reminder that came due while the calendar
+     * was off stays gone when it is switched back on: the watermark has already
+     * moved past it (#75).
      */
-    fun setDisabled(id: Long, disabled: Boolean) {
-        viewModelScope.launch {
-            val current = prefs.disabledCalendarIds.first()
-            val next = if (disabled) current + id else current - id
-            if (next != current) prefs.setDisabledCalendarIds(next)
-        }
+    fun setCalendarVisible(id: Long, visible: Boolean) = write {
+        repository.setCalendarsVisible(listOf(id), visible)
     }
 
     /**
-     * Enable or disable every calendar of one account in a single write — the
-     * "toggle all" affordance on an account header. Done as one set update so the
-     * per-calendar [setDisabled] calls can't race each other.
+     * Switch every calendar of one account on or off. Each row is written on its
+     * own, in one coroutine so the writes can't race.
      */
-    fun setAccountDisabled(ids: Collection<Long>, disabled: Boolean) {
-        viewModelScope.launch {
-            val current = prefs.disabledCalendarIds.first()
-            val next = if (disabled) current + ids else current - ids.toSet()
-            if (next != current) prefs.setDisabledCalendarIds(next)
-        }
+    fun setAccountVisible(ids: Collection<Long>, visible: Boolean) = write {
+        repository.setCalendarsVisible(ids, visible)
     }
 
     // --- Automatic backup (issue #8) ------------------------------------

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/AccountGroups.kt

@@ -0,0 +1,80 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.CalendarSource
+
+/**
+ * One account's calendars, as every surface that lists calendars by account
+ * shows them. An account is identified by name **and** type (#77): a Google and
+ * a DAVx5 account can share an address and still be two separate accounts.
+ */
+data class CalendarAccountGroup(
+    /** Stable identity: what makes two calendars belong to the same account. */
+    val key: AccountKey,
+    /** The account's own name, as shown when it is unambiguous. */
+    val label: String,
+    /** True when another group shows the same [label] under a different type. */
+    val ambiguous: Boolean,
+    val calendars: List<CalendarSource>,
+) {
+    val accountType: String get() = key.type
+}
+
+/** The pair a group is keyed on. */
+data class AccountKey(val name: String, val type: String)
+
+/**
+ * Group [calendars] under their owning account, preserving the provider's order
+ * within each group and ordering groups by first appearance.
+ *
+ * The label falls back through name → type → the first calendar's own name, so
+ * a calendar with no account still lands somewhere sensible.
+ */
+fun List<CalendarSource>.groupByAccount(): List<CalendarAccountGroup> {
+    val grouped = groupBy { AccountKey(it.accountName, it.accountType) }
+    val labels = grouped.mapValues { (key, cals) ->
+        key.name.ifBlank { key.type }.ifBlank { cals.first().displayName }
+    }
+    val shared = labels.values.groupingBy { it }.eachCount()
+    return grouped.map { (key, cals) ->
+        val label = labels.getValue(key)
+        CalendarAccountGroup(
+            key = key,
+            label = label,
+            ambiguous = shared.getValue(label) > 1,
+            calendars = cals,
+        )
+    }
+}
+
+/**
+ * What to write above a group: its account name, qualified with the app the
+ * account comes from when another account shares the name (#77).
+ */
+@Composable
+fun accountGroupTitle(group: CalendarAccountGroup): String =
+    if (!group.ambiguous) {
+        group.label
+    } else {
+        stringResource(R.string.calendars_account_from_source, group.label, sourceAppName(group.accountType))
+    }
+
+/**
+ * The human name of the app backing [accountType], falling back to the raw
+ * account type when no installed app resolves for it.
+ */
+@Composable
+fun sourceAppName(accountType: String): String {
+    val context = LocalContext.current
+    return remember(accountType) {
+        val pm = context.packageManager
+        val packages = sourceAppPackages(context, accountType)
+        packages.firstNotNullOfOrNull { pkg ->
+            runCatching { pm.getApplicationLabel(pm.getApplicationInfo(pkg, 0)).toString() }.getOrNull()
+        } ?: accountType
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarColors.kt

@@ -13,31 +13,18 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 
-/**
- * Soften a raw calendar color toward a pastel that fits the active theme.
- *  - Keeps the hue (so users still recognise their calendars)
- *  - Caps saturation so harsh provider colors stop screaming
- *  - Pins value/brightness to a band that reads on both light and dark surfaces
- */
-fun pastelize(rawArgb: Int, dark: Boolean): Color {
-    val hsv = FloatArray(3)
-    android.graphics.Color.colorToHSV(rawArgb, hsv)
-    hsv[1] = (hsv[1] * 0.6f).coerceIn(0.25f, 0.65f)
-    hsv[2] = if (dark) 0.82f else 0.72f
-    return Color(android.graphics.Color.HSVToColor(hsv))
-}
-
 /**
  * Leading avatar for a calendar: a neutral chip holding a calendar glyph tinted
- * in the calendar's (pastelised) colour. Shared by the calendar manager and the
- * visibility filter so they read identically.
+ * in the calendar's colour — softened to a pastel, or raw when the softener is
+ * off (issue #36). Shared by the calendar manager and the visibility filter so
+ * they read identically.
  */
 @Composable
 fun CalendarColorChip(color: Int, modifier: Modifier = Modifier) {
     val dark = isSystemInDarkTheme()
+    val soften = LocalSoftenColors.current
     Box(
         modifier = modifier
             .size(40.dp)
@@ -48,7 +35,7 @@ fun CalendarColorChip(color: Int, modifier: Modifier = Modifier) {
         Icon(
             Icons.Filled.CalendarMonth,
             contentDescription = null,
-            tint = pastelize(color, dark),
+            tint = eventFill(color, dark, soften),
             modifier = Modifier.size(22.dp),
         )
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarDrawer.kt

@@ -37,6 +37,9 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.ui.filter.CalendarFilterList
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.positionOf
 import kotlinx.datetime.LocalDate
 
 /**
@@ -59,6 +62,7 @@ fun CalendarDrawer(
     onSelectView: (CalendarView) -> Unit,
     onJumpToDate: (LocalDate) -> Unit,
     onSettings: () -> Unit,
+    viewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
 ) {
     var showDatePicker by remember { mutableStateOf(false) }
 
@@ -73,10 +77,10 @@ fun CalendarDrawer(
             DrawerHeader()
 
             DrawerSectionHeader(stringResource(R.string.view_section))
-            IMPLEMENTED_VIEWS.forEachIndexed { index, view ->
+            viewOrder.forEachIndexed { index, view ->
                 GroupedRow(
                     title = stringResource(view.labelRes),
-                    position = positionOf(index, IMPLEMENTED_VIEWS.size),
+                    position = positionOf(index, viewOrder.size),
                     selected = view == currentView,
                     minHeight = 56.dp,
                     leading = { Icon(view.icon, contentDescription = null) },

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarPickerGroups.kt

@@ -0,0 +1,200 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import android.accounts.AccountManager
+import android.content.Context
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
+import androidx.compose.material.icons.filled.Cloud
+import androidx.compose.material.icons.filled.PhoneAndroid
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.core.graphics.drawable.toBitmap
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.CalendarSource
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+
+/**
+ * The app's single "which calendar" selection list, shared by the event editor
+ * and the .ics import screen. Renders the same grouped-card system as the
+ * calendar-manager screen: a category header per source — the device chip for
+ * the app's own calendars, the owning app's launcher icon for each synced
+ * account — with the calendars beneath it as a connected card, a colour chip on
+ * each and a check on the selected one. Emits into the caller's [ColumnScope]
+ * (a scrolling column), so the caller owns the surrounding chrome.
+ *
+ * The list holds event *targets* only, so a switched-off, read-only or managed
+ * calendar is absent (#76). [onManageCalendars], when given, adds the footer row
+ * naming the possible reasons and opening the calendar manager.
+ */
+@Composable
+fun ColumnScope.CalendarPickerGroups(
+    calendars: List<CalendarSource>,
+    selectedId: Long?,
+    onSelect: (Long) -> Unit,
+    onManageCalendars: (() -> Unit)? = null,
+) {
+    val local = remember(calendars) { calendars.filter { it.isLocal } }
+    val syncedGroups = remember(calendars) {
+        calendars.filterNot { it.isLocal }.groupByAccount()
+    }
+
+    if (local.isNotEmpty()) {
+        CalendarPickerGroup(
+            title = stringResource(R.string.calendars_local_header),
+            leading = { LeadingAvatar(Icons.Default.PhoneAndroid) },
+            calendars = local,
+            selectedId = selectedId,
+            onSelect = onSelect,
+        )
+    }
+    syncedGroups.forEachIndexed { index, group ->
+        if (local.isNotEmpty() || index > 0) Spacer(Modifier.height(16.dp))
+        CalendarPickerGroup(
+            title = accountGroupTitle(group),
+            leading = { SourceLogo(group.accountType) },
+            calendars = group.calendars,
+            selectedId = selectedId,
+            onSelect = onSelect,
+        )
+    }
+    if (onManageCalendars != null) {
+        Spacer(Modifier.height(16.dp))
+        GroupedRow(
+            title = stringResource(R.string.calendar_picker_missing_title),
+            summary = stringResource(R.string.calendar_picker_missing_summary),
+            position = Position.Alone,
+            leading = { LeadingAvatar(Icons.Default.VisibilityOff) },
+            trailing = {
+                Icon(
+                    Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            },
+            onClick = onManageCalendars,
+        )
+    }
+}
+
+/** One account's category header (avatar + name) atop its selectable calendars. */
+@Composable
+private fun CalendarPickerGroup(
+    title: String,
+    leading: @Composable () -> Unit,
+    calendars: List<CalendarSource>,
+    selectedId: Long?,
+    onSelect: (Long) -> Unit,
+) {
+    GroupedRow(
+        title = title,
+        position = Position.Top,
+        leading = leading,
+    )
+    calendars.forEachIndexed { index, calendar ->
+        val isSelected = calendar.id == selectedId
+        GroupedRow(
+            title = calendar.displayName,
+            position = if (index == calendars.lastIndex) Position.Bottom else Position.Middle,
+            selected = isSelected,
+            leading = { CalendarColorChip(calendar.color) },
+            trailing = if (isSelected) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
+            onClick = { onSelect(calendar.id) },
+        )
+    }
+}
+
+/**
+ * The source app's launcher icon (Google Calendar, DAVx5, Nextcloud, …) as a
+ * round 40dp chip, so each synced account is recognisable at a glance. We load
+ * whatever app owns the account from [android.content.pm.PackageManager] rather
+ * than bundling brand logos — always accurate, nothing to license. Falls back to
+ * a neutral cloud chip when no installed app resolves for the account.
+ */
+@Composable
+fun SourceLogo(accountType: String) {
+    val context = LocalContext.current
+    val logo = remember(accountType) { sourceAppLogo(context, accountType) }
+    if (logo != null) {
+        Image(
+            bitmap = logo,
+            contentDescription = null,
+            contentScale = ContentScale.Crop,
+            modifier = Modifier
+                .size(40.dp)
+                .clip(CircleShape),
+        )
+    } else {
+        LeadingAvatar(Icons.Default.Cloud)
+    }
+}
+
+/** Neutral circular chip carrying an arbitrary icon (e.g. the local-device mark). */
+@Composable
+fun LeadingAvatar(icon: ImageVector) {
+    Box(
+        modifier = Modifier
+            .size(40.dp)
+            .clip(CircleShape)
+            .background(MaterialTheme.colorScheme.surfaceContainerHighest),
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            icon,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.size(22.dp),
+        )
+    }
+}
+
+/** The launcher icon of the app backing [accountType], preferring the human-facing app. */
+private fun sourceAppLogo(context: Context, accountType: String): ImageBitmap? {
+    val pm = context.packageManager
+    for (pkg in sourceAppPackages(context, accountType)) {
+        val bitmap = runCatching { pm.getApplicationIcon(pkg).toBitmap() }.getOrNull()
+        if (bitmap != null) return bitmap.asImageBitmap()
+    }
+    return null
+}
+
+/** Apps that could stand for [accountType], best candidate first. */
+internal fun sourceAppPackages(context: Context, accountType: String): List<String> = buildList {
+    curatedSourcePackage(accountType)?.let { add(it) }
+    AccountManager.get(context).authenticatorTypes
+        .firstOrNull { it.type.equals(accountType, ignoreCase = true) }
+        ?.packageName
+        ?.let { add(it) }
+}
+
+/** Preferred app for account types whose authenticator isn't the app to open. */
+internal fun curatedSourcePackage(accountType: String): String? = when {
+    accountType.equals("com.google", ignoreCase = true) -> "com.google.android.calendar"
+    else -> null
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarSwipe.kt

@@ -0,0 +1,79 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.gestures.detectHorizontalDragGestures
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.dp
+
+/**
+ * Drag distance that turns a calendar page, shared by the month, week and day
+ * views so all three answer a swipe at the same point.
+ *
+ * It was 6dp once, which is inside the distance a tap wanders: brushing the grid
+ * changed the month, and a page that turns on an unintended gesture reads as the
+ * animation misfiring rather than as the gesture being over-eager.
+ */
+val CALENDAR_SWIPE_THRESHOLD = 24.dp
+
+/**
+ * The whole-page horizontal swipe: one page per gesture, committed **the moment
+ * the drag clears [CALENDAR_SWIPE_THRESHOLD]** rather than when the finger lifts.
+ *
+ * Waiting for the lift meant the page sat still under a finger that had already
+ * travelled far enough to ask for it, and the answer only arrived once you let
+ * go — which reads as the view being slow rather than as a deliberate commit.
+ * Firing on the threshold is what makes the gesture feel like it is being
+ * followed. The trade is that a drag can no longer be taken back by dragging the
+ * other way; in practice, once you have moved 24dp deliberately you meant it, and
+ * the page you land on is one swipe back.
+ *
+ * Deliberately **horizontal-only**. The week and day timelines scroll vertically
+ * underneath this, and a two-dimensional detector here would claim those drags
+ * before the inner scroll ever saw them. As it is, a horizontal drag crosses this
+ * detector's slop while a vertical one is consumed below, and the two coexist.
+ * (The month view's split style needs a vertical axis as well, so it keeps its
+ * own axis-locking detector rather than using this.)
+ */
+@Composable
+fun rememberCalendarPageSwipe(
+    onSwipeNext: () -> Unit,
+    onSwipePrev: () -> Unit,
+): Modifier {
+    val threshold = with(LocalDensity.current) { CALENDAR_SWIPE_THRESHOLD.toPx() }
+    return Modifier.pointerInput(onSwipeNext, onSwipePrev) {
+        var accum = 0f
+        // One page per gesture: without this a long drag would keep re-firing
+        // every time the accumulator crossed the threshold again.
+        var fired = false
+        detectHorizontalDragGestures(
+            onDragStart = {
+                accum = 0f
+                fired = false
+            },
+            onDragEnd = {
+                accum = 0f
+                fired = false
+            },
+            onDragCancel = {
+                accum = 0f
+                fired = false
+            },
+            onHorizontalDrag = { _, drag ->
+                accum += drag
+                if (!fired) {
+                    val commit = when {
+                        accum < -threshold -> onSwipeNext
+                        accum > threshold -> onSwipePrev
+                        else -> null
+                    }
+                    if (commit != null) {
+                        fired = true
+                        commit()
+                    }
+                }
+            },
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarTitle.kt

@@ -0,0 +1,34 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
+import java.util.Locale
+
+/**
+ * Formats a calendar title (top bar or widget header): [skeleton]'s fields laid
+ * out in [locale]'s own order, with the year shown only when [date] falls outside
+ * [currentYear].
+ *
+ * Pass [skeleton] *without* a year field — "LLLL" for a month, "EEEdMMM" for a
+ * day. A skeleton is a field list, so wanting the year is just asking for one
+ * more field; the locale still decides where it lands ("July 2026" vs "2026年7月").
+ *
+ * Dropping the year in the current year is the one bit of policy here: the title
+ * sits directly above a grid that already says which year it is, and the year's
+ * *absence* is itself the signal that you're in the current one — it appears the
+ * moment you page out of it, which is when it starts carrying information.
+ *
+ * [forceYear] overrides that for titles whose [date] does not tell the whole
+ * story — a week view's title names only the month its *first* day falls in, so
+ * a week straddling New Year must still show the year even though [date] is in
+ * [currentYear].
+ */
+fun formatCalendarTitle(
+    date: java.time.LocalDate,
+    locale: Locale,
+    currentYear: Int,
+    skeleton: String,
+    forceYear: Boolean = false,
+): String {
+    val fields = if (date.year == currentYear && !forceYear) skeleton else skeleton + "y"
+    return localizedDateFormatter(locale, fields).format(date)
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarTransitions.kt

@@ -1,61 +1,36 @@
 package de.jeanlucmakiola.calendula.ui.common
 
-import android.provider.Settings
-import androidx.activity.BackEventCompat
-import androidx.activity.compose.PredictiveBackHandler
 import androidx.compose.animation.ContentTransform
-import androidx.compose.animation.EnterTransition
-import androidx.compose.animation.ExitTransition
-import androidx.compose.animation.core.Animatable
-import androidx.compose.animation.core.FastOutSlowInEasing
+import androidx.compose.animation.SizeTransform
 import androidx.compose.animation.core.FiniteAnimationSpec
-import androidx.compose.animation.expandVertically
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
-import androidx.compose.animation.shrinkVertically
 import androidx.compose.animation.slideInHorizontally
-import androidx.compose.animation.slideInVertically
 import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.animation.togetherWith
-import androidx.compose.foundation.lazy.LazyItemScope
-import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.graphicsLayer
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.IntOffset
-import androidx.compose.ui.unit.dp
-import kotlin.coroutines.cancellation.CancellationException
 
 /**
- * Whether the user has asked the system to remove animations (Settings →
- * Accessibility → "Remove animations", which sets the global animator duration
- * scale to 0). Compose animations do *not* honour this platform flag on their
- * own, so the shared motion helpers in this file check it and fall back to a
- * quick cross-fade — opacity only, no spatial movement — to respect the
- * vestibular intent of the setting while keeping state changes legible.
- *
- * Read once at composition; the scale changes rarely and only takes full effect
- * after a process restart anyway.
+ * Calendar-specific motion. The family's generic content transitions — section
+ * expand/collapse, item reveal, list relayout, cross-fade, predictive-back, and
+ * the reduce-motion check — now live in floret-kit's identity module
+ * (`expandEnter`, `collapseExit`, `itemEnter`, `animateItemMotion`,
+ * `fadeThrough`, `Modifier.predictiveBack`, `rememberReduceMotion`). What stays
+ * here is only what's specific to paging the calendar grid: the directional
+ * month/week/day slide and the specs that feed it.
  */
-@Composable
-fun rememberReduceMotion(): Boolean {
-    val resolver = LocalContext.current.contentResolver
-    return remember(resolver) {
-        Settings.Global.getFloat(resolver, Settings.Global.ANIMATOR_DURATION_SCALE, 1f) == 0f
-    }
-}
 
 /**
- * The M3 Expressive spatial spring used for the month/week slide: the *fast*
- * spring-physics spec from the active motion scheme — snappy with a subtle
- * springy settle, rather than a fixed easing curve.
+ * The M3 Expressive spatial spring used for the month/week/day slide: the
+ * *default* spring-physics spec from the active motion scheme, rather than a
+ * fixed easing curve.
+ *
+ * Default rather than fast: `fastSpatialSpec` is tuned for small, incidental
+ * movement, and driving a whole calendar page with it made the settle read as a
+ * twitch instead of a glide.
  *
  * Read it in a composable scope (this helper) so it can be captured by the
  * non-composable `AnimatedContent` transitionSpec lambda.
@@ -63,27 +38,34 @@ fun rememberReduceMotion(): Boolean {
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun rememberCalendarSlideSpec(): FiniteAnimationSpec<IntOffset> =
-    MaterialTheme.motionScheme.fastSpatialSpec()
+    MaterialTheme.motionScheme.defaultSpatialSpec()
 
 /**
- * The fast effects spec from the active motion scheme, for opacity (fade)
- * transitions. Captured in composable scope alongside [rememberCalendarSlideSpec]
- * for use in non-composable transition lambdas and as the reduced-motion fallback.
+ * The effects spec from the active motion scheme, for the opacity half of the
+ * transition. Captured in composable scope alongside [rememberCalendarSlideSpec]
+ * for use in non-composable transition lambdas, and reused on its own as the
+ * reduced-motion fallback.
+ *
+ * Opacity gets its own spec on purpose: M3 Expressive springs *position* and
+ * eases *opacity*, and a fade that bounced with the slide would shimmer.
  */
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun rememberCalendarFadeSpec(): FiniteAnimationSpec<Float> =
-    MaterialTheme.motionScheme.fastEffectsSpec()
+    MaterialTheme.motionScheme.defaultEffectsSpec()
 
 /**
- * Horizontal slide for navigating between adjacent months/weeks/days.
+ * Navigating between adjacent months/weeks/days, as M3's shared-axis X: the
+ * outgoing page slides and fades one way while the incoming one arrives from the
+ * other, position on a spring and opacity on an easing curve.
  *
  * @param slideDir     +1 = forward (incoming from the right), -1 = back, 0 = jump
  *                     (e.g. "today"); a jump reuses the forward direction.
  * @param spec         spatial animation spec, typically [rememberCalendarSlideSpec].
- * @param fadeSpec     effects spec for the reduced-motion fade, typically
+ * @param fadeSpec     effects spec for the opacity half, and for the whole
+ *                     transition under reduced motion; typically
  *                     [rememberCalendarFadeSpec].
- * @param reduceMotion when true, swap the directional slide for a plain cross-fade.
+ * @param reduceMotion when true, drop the movement and cross-fade alone.
  */
 fun calendarSlideTransition(
     slideDir: Int,
@@ -95,131 +77,26 @@ fun calendarSlideTransition(
         return fadeIn(fadeSpec).togetherWith(fadeOut(fadeSpec))
     }
     val dir = if (slideDir == 0) 1 else slideDir
-    return slideInHorizontally(spec) { w -> dir * w }
-        .togetherWith(slideOutHorizontally(spec) { w -> -dir * w })
+    return ContentTransform(
+        targetContentEnter =
+            slideInHorizontally(spec) { w -> dir * w / SLIDE_TRAVEL_DIVISOR } + fadeIn(fadeSpec),
+        initialContentExit =
+            slideOutHorizontally(spec) { w -> -dir * w / SLIDE_TRAVEL_DIVISOR } + fadeOut(fadeSpec),
+        // AnimatedContent clips to the animating container by default, which
+        // shears the pages against the viewport edge as they pass. There is no
+        // size change here to contain — both pages are the same grid.
+        sizeTransform = SizeTransform(clip = false),
+    )
 }
 
 /**
- * Cross-fade [ContentTransform] for swapping whole screens or content blocks
- * where there is no meaningful spatial direction (e.g. onboarding gates). Pure
- * opacity, so it doubles as its own reduced-motion form.
- */
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
-@Composable
-fun calendarFadeThrough(): ContentTransform {
-    val fade = MaterialTheme.motionScheme.fastEffectsSpec<Float>()
-    return fadeIn(fade).togetherWith(fadeOut(fade))
-}
-
-/**
- * Enter transition for a vertically-revealed section (expandable rows, inline
- * fields): height grows from the top while fading in. Under reduced motion the
- * height growth is dropped, leaving a quick fade.
+ * How far a page travels, as a fraction of the container width.
  *
- * Pair with [calendarCollapseExit]. This is the promoted form of the pattern
- * originally inlined in the event edit form, so every expandable surface in the
- * app reveals the same way.
+ * A full width was the obvious reading of "paging", but the two pages are
+ * stacked and both opaque, so a full-width slide showed one grid racing across
+ * another — the movement carried the whole transition and had a long way to go.
+ * Under M3's shared-axis pattern the offset only has to *hint* the direction
+ * while the cross-fade does the swapping, so a fifth of the width is plenty and
+ * leaves nothing skating past.
  */
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
-@Composable
-fun calendarExpandEnter(reduceMotion: Boolean = rememberReduceMotion()): EnterTransition {
-    val fade = fadeIn(MaterialTheme.motionScheme.fastEffectsSpec())
-    return if (reduceMotion) {
-        fade
-    } else {
-        expandVertically(MaterialTheme.motionScheme.fastSpatialSpec()) + fade
-    }
-}
-
-/** Exit counterpart to [calendarExpandEnter]: shrink + fade, or fade only under reduced motion. */
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
-@Composable
-fun calendarCollapseExit(reduceMotion: Boolean = rememberReduceMotion()): ExitTransition {
-    val fade = fadeOut(MaterialTheme.motionScheme.fastEffectsSpec())
-    return if (reduceMotion) {
-        fade
-    } else {
-        shrinkVertically(MaterialTheme.motionScheme.fastSpatialSpec()) + fade
-    }
-}
-
-/**
- * Enter transition for content revealed by an `AnimatedContent`/`AnimatedVisibility`
- * (e.g. search results once a query resolves): a gentle rise + fade. Reduced
- * motion keeps the fade only.
- */
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
-@Composable
-fun calendarItemEnter(reduceMotion: Boolean = rememberReduceMotion()): EnterTransition {
-    val fade = fadeIn(MaterialTheme.motionScheme.fastEffectsSpec())
-    return if (reduceMotion) {
-        fade
-    } else {
-        fade + slideInVertically(MaterialTheme.motionScheme.fastSpatialSpec()) { h -> h / 6 }
-    }
-}
-
-/**
- * Shared [LazyItemScope.animateItem] wiring so list rows fade/relocate with the
- * app's motion scheme instead of Compose's default spring. Returns a bare
- * [Modifier] under reduced motion so rows snap into place. Requires the list to
- * supply stable item keys.
- */
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
-@Composable
-fun LazyItemScope.calendarAnimateItem(reduceMotion: Boolean = rememberReduceMotion()): Modifier =
-    if (reduceMotion) {
-        Modifier
-    } else {
-        Modifier.animateItem(
-            fadeInSpec = MaterialTheme.motionScheme.fastEffectsSpec(),
-            placementSpec = MaterialTheme.motionScheme.fastSpatialSpec(),
-            fadeOutSpec = MaterialTheme.motionScheme.fastEffectsSpec(),
-        )
-    }
-
-/**
- * Standard Android predictive-back transform for a full-screen overlay: as the
- * back gesture is dragged, the surface scales toward ~90%, shifts toward the
- * swiped edge and rounds its corners, previewing what's behind. Completing the
- * gesture invokes [onBack]; cancelling springs it back.
- *
- * A drop-in replacement for a screen's own `BackHandler(onBack)` — register it
- * once and apply the returned [Modifier] to that screen's root so the preview
- * respects the same back semantics. Under reduced motion the visual preview is
- * skipped (the back still works); on API < 34 the system delivers no progress,
- * so it degrades to a plain back.
- */
-@Composable
-fun Modifier.predictiveBack(
-    onBack: () -> Unit,
-    enabled: Boolean = true,
-    reduceMotion: Boolean = rememberReduceMotion(),
-): Modifier {
-    val progress = remember { Animatable(0f) }
-    var fromLeftEdge by remember { mutableStateOf(true) }
-
-    PredictiveBackHandler(enabled = enabled) { events ->
-        try {
-            events.collect { event ->
-                fromLeftEdge = event.swipeEdge == BackEventCompat.EDGE_LEFT
-                progress.snapTo(FastOutSlowInEasing.transform(event.progress))
-            }
-            onBack()
-            progress.snapTo(0f)
-        } catch (_: CancellationException) {
-            progress.animateTo(0f)
-        }
-    }
-
-    if (reduceMotion) return this
-    return this.graphicsLayer {
-        val p = progress.value
-        val scale = 1f - 0.1f * p
-        scaleX = scale
-        scaleY = scale
-        translationX = (if (fromLeftEdge) 1f else -1f) * 24.dp.toPx() * p
-        shape = RoundedCornerShape(32.dp.toPx() * p)
-        clip = p > 0f
-    }
-}
+private const val SLIDE_TRAVEL_DIVISOR = 5

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarView.kt

@@ -45,11 +45,39 @@ val IMPLEMENTED_VIEWS: List<CalendarView> =
 
 /** Next view in [available], wrapping around. Falls back to Month if absent. */
 fun CalendarView.next(available: List<CalendarView> = IMPLEMENTED_VIEWS): CalendarView {
+    if (available.isEmpty()) return this
     val i = available.indexOf(this)
-    if (i < 0) return available.firstOrNull() ?: CalendarView.Month
+    if (i < 0) return available.first()
     return available[(i + 1) % available.size]
 }
 
+/**
+ * The user's customisation of the top-bar quick-switch button (#24): which views
+ * it cycles through ([enabled]) and in what [order]. [order] always lists every
+ * implemented view — the settings screen reorders the whole set — while [cycle]
+ * is the subset the pill actually steps through, in [order]. The navigation
+ * drawer keeps its own separate order and always lists every view, so a view
+ * disabled here stays reachable there.
+ */
+data class QuickSwitchConfig(
+    val order: List<CalendarView>,
+    val enabled: Set<CalendarView>,
+) {
+    /** Views the pill steps through, in [order]. */
+    val cycle: List<CalendarView> get() = order.filter { it in enabled }
+
+    companion object {
+        /** All views, in default order, all enabled. */
+        val Default = QuickSwitchConfig(IMPLEMENTED_VIEWS, IMPLEMENTED_VIEWS.toSet())
+
+        /**
+         * Fewest views that keep the switch meaningful — a "switch" needs at
+         * least two targets, so the settings screen blocks disabling below this.
+         */
+        const val MIN_ENABLED = 2
+    }
+}
+
 /**
  * The top-level view back stack (bottom → top): the [default] home view always
  * sits at the bottom. Pressing back pops one level until only the home view