Sort settings into the places you'd look for them, and say what each one does (#69) (#107)

Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/107

.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
@@ -71,9 +72,14 @@ 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/workflows/release.yaml

@@ -1,11 +1,13 @@
-name: Release — F-Droid repo + Gitea release
+name: Release — F-Droid repo + Gitea/Codeberg release
 
 # 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
+# it to the F-Droid repo, creates the vX.Y.Z tag + Gitea release, and mirrors
-# itself — the tag is an output of the pipeline, not its trigger. Ordinary
+# that release to Codeberg with the signed APK + a SHA-256 checksum as a
-# merges (no version bump) fall through `detect` and do nothing.
+# 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 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 +27,14 @@ 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 +43,22 @@ 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 }}
+          # Tags are read from Codeberg, which is canonical — deliberately NOT
-          API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
+          # 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=$(grep -oP 'versionName\s*=\s*"\K[^"]+' app/build.gradle.kts)
@@ -56,15 +76,28 @@ jobs:
           fi
           # A tag for this version already existing means the release shipped on
           # an earlier push; do nothing. Absent => this merge cuts the release.
-          STATUS=$(curl -s -o /dev/null -w '%{http_code}' \
+          #
-            -H "Authorization: token $TOKEN" "$API/git/refs/tags/v$VERSION")
+          # Anything other than a clean 200/404 is treated as fatal rather than
-          if [ "$STATUS" = "200" ]; then
+          # as "no tag". A Codeberg outage or a network blip would otherwise
-            echo "Tag v$VERSION already exists — nothing to release."
+          # read as absent and re-cut a release that has already shipped —
+          # republishing to F-Droid and Play. Failing here is recoverable; a
+          # duplicate release is not.
+          STATUS=$(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" >> "$GITHUB_OUTPUT"
-          else
+              ;;
-            echo "No tag for v$VERSION yet — cutting the release."
+            404)
+              echo "No tag for v$VERSION on Codeberg yet — cutting the release."
               echo "is_release=true" >> "$GITHUB_OUTPUT"
-          fi
+              ;;
+            *)
+              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 +115,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          submodules: recursive
 
       - name: Setup Java
         uses: actions/setup-java@v4
@@ -346,3 +381,99 @@ 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."

.gitea/workflows/renovate.yml

@@ -29,14 +29,30 @@ jobs:
       - name: Run Renovate
         run: renovate
         env:
-          # Self-hosted Gitea, not github.com.
+          # Renovate targets Codeberg (canonical) while still RUNNING on the
-          RENOVATE_PLATFORM: gitea
+          # Gitea runner. Moving the job to Codeberg would put a repo-write
-          RENOVATE_ENDPOINT: https://gitea.jeanlucmakiola.de/api/v1
+          # token on the contributor-facing runner, which is exactly what the
-          # Bot-account token (Gitea secret). Needs repo read/write + PR scope.
+          # .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"]'
+          RENOVATE_REPOSITORIES: '["jlmakiola/calendula"]'
-          # Commits/PRs authored as the bot, not a real maintainer.
+          # 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

@@ -55,3 +55,6 @@ Thumbs.db
 
 # KSP
 .ksp/
+
+# Claude Code
+/CLAUDE.md

.gitmodules

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

CHANGELOG.md

@@ -5,6 +5,381 @@ 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]
+
+### 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 → Agenda → 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]).
+
+### Changed
+- 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
@@ -808,5 +1183,43 @@ automatically, with zero telemetry and no internet permission.
 [#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

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">

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 = 21300
+        versionCode = 21600
-        versionName = "2.13.0"
+        versionName = "2.16.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -113,10 +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 {
@@ -161,6 +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

@@ -38,3 +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/main/AndroidManifest.xml

@@ -33,6 +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
@@ -63,10 +71,9 @@
             android:exported="true"
             android:launchMode="singleTop"
             android:windowSoftInputMode="adjustResize">
-            <intent-filter>
+            <!-- The MAIN/LAUNCHER entry (the launcher icon + its label) lives on
-                <action android:name="android.intent.action.MAIN" />
+                 the two <activity-alias> below, so the app name can be switched at
-                <category android:name="android.intent.category.LAUNCHER" />
+                 runtime (issue #44). MainActivity keeps every other filter. -->
-            </intent-filter>
 
             <!-- Be selectable as the system calendar app. Android has no API for
                  an app to make itself the default, so registering the filters
@@ -97,26 +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="content" />
-                <data android:scheme="file" android:mimeType="text/calendar" />
+                <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
@@ -141,17 +278,22 @@
             </intent-filter>
         </service>
 
-        <!-- The provider broadcasts EVENT_REMINDER at reminder time but posts
+        <!-- Reminder delivery is the app's own (#75): it plans the alarms from
-             no notification itself — a calendar app must (v1.4, Etar model).
+             Instances + Reminders instead of waiting for the provider's
-             Exported: the broadcast arrives from the provider's process. -->
+             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" />
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
-                <data
+                <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
-                    android:host="com.android.calendar"
+                <action android:name="android.intent.action.TIME_SET" />
-                    android:scheme="content" />
+                <action android:name="android.intent.action.TIMEZONE_CHANGED" />
             </intent-filter>
         </receiver>
 

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

@@ -4,10 +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.contacts.SpecialDatesScheduler
 import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesSyncWorker
-import de.jeanlucmakiola.calendula.data.crash.CrashReporter
+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
@@ -24,10 +28,57 @@ 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).
+        // respecting, on-device; the user submits the report by hand). The
-        CrashReporter.install(this)
+        // 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). The app plans and arms
+     * its own reminder alarms now, so launch is one of the moments that has to
+     * re-check them: a scan re-arms whatever the system dropped, posts anything
+     * a missed alarm still owes, and starts watching the provider so an edit
+     * re-plans without waiting for the next pass. The daily worker is the
+     * backstop for a device that drops the alarm with no reboot to announce it.
+     */
+    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 the app hasn't been allowed to write into
+     * the system's `Calendars.VISIBLE` yet — including the retired app-local
+     * "disabled calendars" set the upgrade inherits (#75). A no-op on a fresh
+     * install and in the steady state; a launch without the calendar permission
+     * leaves the set pending, and `RootScreen` runs it again once the app comes
+     * up holding it — whichever way it was granted.
+     */
+    private fun reconcileCalendarVisibility() {
+        val deps = EntryPointAccessors.fromApplication(
+            this, CalendarVisibilityReconciler.Deps::class.java,
+        )
+        CoroutineScope(SupervisorJob() + Dispatchers.Default).launch {
+            deps.calendarVisibilityReconciler().run()
+        }
     }
 
     /**

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

@@ -4,6 +4,7 @@ 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
@@ -22,26 +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.common.DebugRibbon
+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
@@ -60,6 +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.
@@ -81,9 +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
@@ -123,6 +141,7 @@ class MainActivity : AppCompatActivity() {
                     CompositionLocalProvider(
                         LocalUse24HourFormat provides use24Hour,
                         LocalShowHourLines provides settings.showHourLines,
+                        LocalSoftenColors provides settings.softenColors,
                     ) {
                         RootScreen(
                             modifier = Modifier.fillMaxSize(),
@@ -132,6 +151,10 @@ class MainActivity : AppCompatActivity() {
                             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
@@ -166,9 +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 }
     }
 
     /**
@@ -188,6 +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/
@@ -255,6 +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>.

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
@@ -73,19 +72,14 @@ internal fun nextYearlyOccurrence(month: Int, day: Int, today: LocalDate): Local
 
 /**
  * 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
+ * [rawMinutes] — the inverse of [toProviderAllDayMinutes], for the form and the
- * returns the right day count regardless of which [timeOfDayMinutes] wrote the
+ * detail screen. Delegates to [allDayLeadDays] so what is displayed is the day
- * row — including pre-feature rows (raw multiples of 1440, fired at UTC midnight)
+ * the reminder actually fires on; see there for how an encoded row is told from
- * and rows written under a different timezone. A negative [rawMinutes] (fire
+ * a plain one written by another calendar app.
- * after DTSTART) folds to day 0.
  */
 internal fun fromProviderAllDayMinutes(
     rawMinutes: Int,
     startDate: LocalDate,
     zone: ZoneId,
-): Int {
+    timeOfDayMinutes: Int,
-    val utcMidnight = startDate.atStartOfDay(ZoneOffset.UTC).toInstant().toEpochMilli()
+): Int = allDayLeadDays(rawMinutes, startDate, zone, timeOfDayMinutes).toInt() * MINUTES_PER_DAY
-    val fireLocalDate = Instant.ofEpochMilli(utcMidnight - rawMinutes * MILLIS_PER_MINUTE)
-        .atZone(zone).toLocalDate()
-    return ChronoUnit.DAYS.between(fireLocalDate, startDate).toInt() * MINUTES_PER_DAY
-}

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
@@ -16,10 +18,13 @@ 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
@@ -49,7 +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
@@ -61,19 +71,23 @@ interface CalendarDataSource {
 
     /**
      * The event-colour palette the calendar's account publishes
-     * (`CalendarContract.Colors`, `TYPE_EVENT`), sorted by key. Empty when the
+     * (`CalendarContract.Colors`, `TYPE_EVENT`), curated for display — deduped,
-     * account exposes no palette (most local calendars, some CalDAV) — the
+     * thinned to visually distinct swatches when oversized (CalDAV adapters
-     * signal that a custom colour can only be written as a raw `EVENT_COLOR`,
+     * publish all ~147 CSS3 names, #22) and hue-sorted; see [curatedForPicker].
-     * which a synced calendar may drop on its next sync.
+     * 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
@@ -101,6 +115,32 @@ 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). `VISIBLE` also gates the provider's own
+     * reminder scheduling, so switching a calendar off here is what actually
+     * stops its notifications; switching it on is what brings them back.
+     * Writable by a plain app (one of the three columns the platform documents
+     * as such) and device-local — no sync adapter pushes it anywhere.
+     */
+    fun setCalendarVisible(id: Long, visible: Boolean)
+
+    /**
+     * Whether one calendar is currently switched on at system level, without
+     * reading every row — for the reminder gate, which sees a calendar id and
+     * nothing else. Null when the answer can't be had: no row (the calendar was
+     * deleted) 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
@@ -172,6 +212,25 @@ 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
@@ -345,6 +404,40 @@ 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` short-circuits to a raw database
+     * update unless the selection is `_id=…`, skipping the dirty marking *and*
+     * the `checkNextAlarm()` reschedule — i.e. an `_id IN (…)` batch would write
+     * the flag but never re-arm the reminder alarms this write exists to
+     * trigger. The sync-adapter URI is avoided so the write also applies to
+     * synced calendars, which is where the bug bites.
+     */
+    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=$id")
+    }
+
+    override fun isCalendarVisible(id: Long): Boolean? {
+        if (!hasCalendarPermission()) return null
+        return resolver.query(
+            ContentUris.withAppendedId(CalendarContract.Calendars.CONTENT_URI, id),
+            arrayOf(CalendarContract.Calendars.VISIBLE),
+            null, null, null,
+        )?.use { if (it.moveToFirst()) it.getInt(0) != 0 else null }
+    }
+
+    override fun canWriteCalendars(): Boolean =
+        ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_CALENDAR) ==
+            PackageManager.PERMISSION_GRANTED
+
     override fun createManagedCalendar(displayName: String, color: Int, type: SpecialDateType): Long {
         val name = displayName.trim().ifEmpty { Fallbacks.UNNAMED_CALENDAR }
         val values = ContentValues().apply {
@@ -488,7 +581,13 @@ class AndroidCalendarDataSource @Inject constructor(
         return resolver.query(
             uri,
             InstanceProjection.COLUMNS,
-            null, null,
+            // Hide cancelled occurrences: "delete only this event" writes a
+            // cancelled exception for the one instance (#47). A NULL status is a
+            // normal, un-cancelled event, so it must survive the filter — a bare
+            // `!= CANCELED` would drop it (NULL != 2 is NULL, not true).
+            "${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()
     }
@@ -576,7 +675,7 @@ 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(
@@ -585,7 +684,9 @@ 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,
+            )
         }
     }
 
@@ -607,16 +708,23 @@ 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()
 
@@ -865,6 +973,190 @@ 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,
@@ -959,6 +1251,8 @@ 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 ->
@@ -969,6 +1263,8 @@ 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
@@ -981,6 +1277,9 @@ 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(
@@ -1171,16 +1470,49 @@ class AndroidCalendarDataSource @Inject constructor(
     }
 
     override fun deleteOccurrence(eventId: Long, beginMillis: Long) {
-        // A cancelled exception row hides exactly this occurrence; the sync
+        val row = querySeriesRow(eventId)
-        // adapter turns it into an EXDATE/cancelled VEVENT upstream.
+        if (row.syncId == null) {
-        val values = ContentValues().apply {
+            // No _sync_id — a local calendar, or a synced event not pushed yet.
-            put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, beginMillis)
+            // A cancelled exception can only attach to its parent through
-            put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
+            // 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")
     }
 

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

@@ -31,5 +31,10 @@ internal fun ColumnReader.toCalendarSource(): CalendarSource {
         isManaged = isLocal &&
             getString(CalendarProjection.IDX_MANAGED_MARKER)
                 ?.startsWith(CalendarProjection.MANAGED_MARKER_PREFIX) == true,
+        // A provider that leaves the column NULL is treated as syncing — the
+        // harmless default, since this flag only ever holds the one-shot
+        // visibility migration back from switching a calendar on.
+        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 +38,26 @@ 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 is also what
+     * turns the provider's reminder scheduling for them on or off — see
+     * [CalendarDataSource.setCalendarVisible]. Each calendar is written on its
+     * own, in order; a failure part-way leaves the earlier writes standing (the
+     * observer reports whatever actually landed).
+     *
+     * Without `WRITE_CALENDAR` the choice is kept app-side instead (see
+     * [de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs.pendingDisabledCalendarIds]),
+     * where it filters events and reminders just the same until it can be
+     * written.
+     */
+    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 +75,20 @@ 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 +53,141 @@ 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
+     * Re-query signal for everything filtered by visibility: the provider's own
-            .onStart { emit(Unit) }
+     * notifications, plus every change to the pending switch-off set (an id
-            .reQuery { dataSource.calendars() }
+     * leaves it as its `VISIBLE` write lands, which changes what is shown).
-            .flowOn(io)
+     * [calendarsSnapshot] keeps the two in step.
-
+     */
-    // Instances are filtered by the app-side hidden ∪ disabled calendar sets
+    private fun visibilityTicks(): Flow<Unit> = merge(
-    // (M3): an event is dropped whenever the user has hidden *or* disabled its
+        ticks.onStart { emit(Unit) },
-    // calendar. Re-runs when the provider ticks *or* either set changes —
+        // The current value is already covered by the tick above; only later
-    // toggling a calendar in the filter sheet or the calendar manager updates
+        // changes re-query (the set is deduped, so an unrelated DataStore write
-    // every view immediately. [calendars] stays unfiltered so those screens can
+        // doesn't).
-    // list and re-enable hidden/disabled calendars.
+        prefs.pendingDisabledCalendarIds.drop(1).map {},
-    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,
+    // A switch-off the app hasn't been allowed to write yet is folded into the
-            prefs.disabledCalendarIds,
+    // flag itself, so every consumer — the Settings switch, the filter sheet,
-        ) { instances, hidden, disabled ->
+    // the form and import pickers, the widgets — reads one visibility and can't
-            val excluded = hidden + disabled
+    // disagree with what the user just tapped. The reconciler reads the data
-            if (excluded.isEmpty()) instances
+    // source directly, because it needs the provider's own answer.
-            else instances.filterNot { it.calendarId in excluded }
+    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
+            // Collapse re-emissions that carry an identical list (see
-            // list twice — collapse the duplicate so views don't re-render for it.
+            // [instances]).
             .distinctUntilChanged()
             .flowOn(io)
 
+    // Instances are filtered by the system's per-calendar VISIBLE flag ∪ the
+    // switch-offs still waiting to be written to it ∪ the app-side hidden set:
+    // an event is dropped when the user switched its calendar off in Settings →
+    // Calendars (which also stops the provider scheduling its reminders) *or*
+    // hid it in the filter sheet. Re-runs when the provider ticks — writing
+    // VISIBLE notifies, so switching a calendar updates every view — or when
+    // either set changes. [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 it is
+            // unchanged (e.g. writing the last-used calendar), which would
+            // re-surface an identical list — 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. Every
+     * open view collects [calendars] *and* filters its instances by visibility,
+     * which used to cost one full `Calendars` query each per tick. Reusing a
+     * single read also keeps them consistent: within a tick, what a screen lists
+     * and what its events are filtered against can't come from two snapshots.
+     *
+     * An empty result is never cached — it 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. An id leaves
+     * that set the moment its `VISIBLE` write lands, while the observer that
+     * would invalidate the snapshot is only dispatched through the main looper
+     * afterwards — so a snapshot taken while the id was still pending, read
+     * against the set that no longer holds it, would report the calendar as *on*
+     * again and re-admit exactly the events being hidden.
+     */
+    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 +213,24 @@ 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 +268,17 @@ 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 +1,141 @@
+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 the app's pending "switched off" set (see
+ * [CalendarPrefs.pendingDisabledCalendarIds]) and the system's
+ * `Calendars.VISIBLE` in step — the fold-in of the retired app-local visibility
+ * model (#75), and the standing drain for switch-offs made without
+ * `WRITE_CALENDAR`.
+ *
+ * Runs on every launch, and again whenever the app comes up holding the calendar
+ * permission — a grant made on Android's own app-settings screen never reaches
+ * the permission screen's callback. It is a no-op whenever the pending set is
+ * empty and the notice has been settled, which
+ * is the steady state: each entry is written and dropped individually, so a run
+ * that dies part-way resumes exactly where it stopped and never re-applies a
+ * write the user has since undone by hand.
+ *
+ * The reconciliation only hides (see [calendarVisibilityPlan]). Calendars hidden
+ * at system level stay hidden, and on an *upgraded* install the first run that
+ * sees one arms the one-time notice explaining why Calendula no longer lists
+ * their events. A fresh install never had the old behaviour, so it retires that
+ * notice unshown — every other device ships with something hidden.
+ */
+@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) {
+        // Everything, the DataStore reads included, sits inside the guard: this
+        // runs in a bare application-scope coroutine with no exception handler,
+        // so an IOException from a damaged preferences file would otherwise take
+        // the process down on every launch.
+        try {
+            // A fresh install has no retired model behind it — nothing to
+            // migrate, and nothing to explain. Settled ahead of the permission
+            // gate so an update installed before the first grant can't make a
+            // first run look like an upgrade afterwards.
+            if (!isUpgradeInstall()) settleNoticeOnce(pending = false)
+            if (!hasPermission(Manifest.permission.READ_CALENDAR)) return@withContext
+            val pending = prefs.pendingDisabledCalendarIds.first()
+            val noticeSettled = prefs.visibilityNoticePending.first() != null
+            // The steady state, and every run after the first: nothing left to
+            // drain and nothing left to decide, so don't pay for the query.
+            if (pending.isEmpty() && noticeSettled) return@withContext
+            val calendars = dataSource.calendars()
+            // An empty read means "couldn't read", not "no calendars": the data
+            // source turns a null cursor — a provider momentarily unavailable —
+            // into an empty list. Both decisions below are one-way, so taking
+            // that reading as the truth would drop the whole pending set without
+            // ever writing VISIBLE = 0 (switching the user's calendars back on,
+            // events and reminders with them) and settle the notice as "nothing
+            // to explain". Leave both 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)
+            // Already off, or gone from the device — nothing to write, so let
+            // those ids leave the pending set with the rest.
+            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]). Dropping each id as it
+            // lands keeps a part-applied run resumable.
+            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, by whichever run can answer it first; the answer is stored
+     * either way, so the notice can't resurface later, when the same state would
+     * no longer be news to the user.
+     */
+    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 change to behaviour the user has already seen, so a first install has
+     * nothing to announce — and hidden calendars are the *norm* on a fresh
+     * device (a second account's, "Holidays in …", a subscribed calendar), which
+     * would otherwise put a changelog dialog in front of a first-run user.
+     */
+    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? {
+    // 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)
 
-    if (begin < 0L) {
-        Log.w(TAG, "Dropping event with negative dtstart=$begin")
-        return null
-    }
-
     // Recurring events store DURATION instead of DTEND, so the series row's
-    // DTEND is null. Keep the event (end == begin); callers that opened a
+    // DTEND is null — derive the length from DURATION (as SearchMapper and
-    // specific occurrence supply the real per-occurrence times from
+    // IcsExportMapper do). Callers that opened a specific occurrence overwrite
-    // CalendarContract.Instances. Only a present-but-backwards DTEND is malformed.
+    // both times with the per-occurrence values from CalendarContract.Instances;
+    // a caller that names no occurrence (a bare content://.../events/<id> VIEW
+    // intent, issue #48) keeps this row's own times, so the length has to be
+    // right here or the series renders zero-length. A present-but-backwards
+    // DTEND is malformed, but dropping the row would make the event un-openable
+    // — the same trap as the pre-1970 DTSTART bug above (issue #34): it would
+    // surface as the generic error screen with no way to open the event and fix
+    // it. Clamp to a zero-length event instead (matching SearchMapper).
     val end = if (isNull(EventDetailProjection.IDX_DTEND)) {
-        begin
+        begin + parseRfc2445DurationMillis(getString(EventDetailProjection.IDX_DURATION))
     } else {
-        val rawEnd = getLong(EventDetailProjection.IDX_DTEND)
+        getLong(EventDetailProjection.IDX_DTEND).coerceAtLeast(begin)
-        if (rawEnd < begin) {
-            Log.w(TAG, "Dropping event with dtend=$rawEnd < dtstart=$begin")
-            return null
-        }
-        rawEnd
     }
 
     // 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 +37,56 @@ internal fun EventForm.toWriteTimes(zone: ZoneId): EventWriteTimes = if (isAllDa
         timezone = "UTC",
     )
 } else {
+    val writeZone = writeZone(zone)
     EventWriteTimes(
-        dtStartMillis = start.toJavaLocalDateTime().atZone(zone).toInstant().toEpochMilli(),
+        dtStartMillis = start.toJavaLocalDateTime().atZone(writeZone).toInstant().toEpochMilli(),
-        dtEndMillis = end.toJavaLocalDateTime().atZone(zone).toInstant().toEpochMilli(),
+        dtEndMillis = end.toJavaLocalDateTime().atZone(writeZone).toInstant().toEpochMilli(),
-        timezone = zone.id,
+        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) {
+internal fun EventWriteTimes.toRfc2445Duration(isAllDay: Boolean): String =
-    "P${(dtEndMillis - dtStartMillis) / MILLIS_PER_DAY}D"
+    rfc2445Duration(dtEndMillis - dtStartMillis, isAllDay)
+
+/**
+ * RFC 2445 duration for a [spanMillis]-long event: whole days for all-day
+ * events (the provider's convention), seconds otherwise. Shared by the write
+ * paths that need a DURATION but start from a raw millisecond span (the series
+ * copy and exception replay of a calendar move) rather than [EventWriteTimes].
+ */
+internal fun rfc2445Duration(spanMillis: Long, isAllDay: Boolean): String = if (isAllDay) {
+    "P${spanMillis / MILLIS_PER_DAY}D"
 } else {
-    "P${(dtEndMillis - dtStartMillis) / 1_000L}S"
+    "P${spanMillis / 1_000L}S"
 }
 
 /**
@@ -95,10 +135,12 @@ internal fun buildEventInsertValues(
  * 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
+ * - recurring result → the *series* DTSTART moves by the same **wall-clock**
- *   applied to the displayed occurrence ([seriesDtStartMillis] is the row's
+ *   shift the user applied to the displayed occurrence and is re-resolved in the
- *   current DTSTART), DURATION replaces DTEND, RRULE is written. This keeps
+ *   event's zone ([seriesDtStartMillis] is the row's current DTSTART), DURATION
- *   past occurrences intact when someone edits a later occurrence's time.
+ *   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,
@@ -125,10 +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)
@@ -140,8 +186,23 @@ internal fun buildEventUpdateValues(
         put(CalendarContract.Events.RRULE, null)
         put(CalendarContract.Events.DURATION, null)
     } else {
-        val startDelta = newTimes.dtStartMillis - original.toWriteTimes(zone).dtStartMillis
+        // Move the series anchor by the *wall-clock* shift the user applied to the
-        put(CalendarContract.Events.DTSTART, seriesDtStartMillis + startDelta)
+        // 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))
@@ -182,6 +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/Projections.kt

@@ -19,6 +19,7 @@ internal object CalendarProjection {
         // 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
@@ -36,6 +37,7 @@ internal object CalendarProjection {
     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 {
@@ -84,6 +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
@@ -104,6 +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
 }
 
 /**
@@ -186,6 +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/SpecialDatesSyncEngine.kt

@@ -4,7 +4,7 @@ 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.calendula.data.prefs.CalendarReminderOverride
+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
@@ -111,13 +111,13 @@ class SpecialDatesSyncEngine @Inject constructor(
      * 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: CalendarReminderOverride) {
+    suspend fun applyReminders(type: SpecialDateType, override: ReminderOverride) {
         val calendarId = prefs.specialDatesCalendars.first()[type] ?: return
         prefs.setCalendarAllDayReminderOverride(calendarId, override)
         val minutes = when (override) {
-            CalendarReminderOverride.Inherit -> prefs.defaultAllDayReminderMinutes.first()
+            ReminderOverride.Inherit -> prefs.defaultAllDayReminderMinutes.first()
-            CalendarReminderOverride.None -> emptyList()
+            ReminderOverride.None -> emptyList()
-            is CalendarReminderOverride.Minutes -> override.minutes
+            is ReminderOverride.Minutes -> override.minutes
         }
         calendars.applyManagedCalendarReminders(
             calendarId = calendarId,
@@ -169,7 +169,7 @@ class SpecialDatesSyncEngine @Inject constructor(
         if (!prefs.perCalendarAllDayReminderOverride.first().containsKey(id)) {
             prefs.setCalendarAllDayReminderOverride(
                 id,
-                CalendarReminderOverride.Minutes(DEFAULT_REMINDER_MINUTES),
+                ReminderOverride.Minutes(DEFAULT_REMINDER_MINUTES),
             )
         }
         return id

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

@@ -18,8 +18,8 @@ import de.jeanlucmakiola.calendula.data.contacts.AndroidContactSpecialDatesDataS
 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.AndroidReminderAlertStore
+import de.jeanlucmakiola.calendula.data.reminders.ProviderReminderInstanceSource
-import de.jeanlucmakiola.calendula.data.reminders.ReminderAlertStore
+import de.jeanlucmakiola.calendula.data.reminders.ReminderInstanceSource
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 import javax.inject.Singleton
@@ -46,9 +46,9 @@ abstract class DataBindModule {
 
     @Binds
     @Singleton
-    abstract fun bindReminderAlertStore(
+    abstract fun bindReminderInstanceSource(
-        impl: AndroidReminderAlertStore,
+        impl: ProviderReminderInstanceSource,
-    ): ReminderAlertStore
+    ): ReminderInstanceSource
 
     @Binds
     @Singleton

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",
+ * App-side calendar preferences. [hiddenCalendarIds] is the drawer's filter
- * separate from the system's per-calendar VISIBLE flag.
+ * 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 +29,63 @@ class CalendarPrefs @Inject constructor(
     private val store: DataStore<Preferences>,
 ) {
 
-    val hiddenCalendarIds: Flow<Set<Long>> = store.data.map { prefs ->
+    // Both id sets are deduped: the store is shared with SettingsPrefs, so every
-        prefs[HIDDEN_IDS_KEY].orEmpty()
+    // unrelated write (a settings toggle, the last-used calendar) re-emits an
-            .split(',')
+    // identical set otherwise — and a change to the pending set now costs a
-            .mapNotNull { it.trim().toLongOrNull() }
+    // fresh provider read in CalendarRepositoryImpl.
-            .toSet()
+    val hiddenCalendarIds: Flow<Set<Long>> = store.data
-    }
+        .map { prefs -> prefs[HIDDEN_IDS_KEY].parseIds() }
+        .distinctUntilChanged()
 
     suspend fun setHiddenCalendarIds(ids: Set<Long>) {
-        store.edit { prefs ->
+        store.edit { prefs -> prefs.writeIds(HIDDEN_IDS_KEY, ids) }
-            if (ids.isEmpty()) {
-                prefs.remove(HIDDEN_IDS_KEY)
-            } else {
-                prefs[HIDDEN_IDS_KEY] = ids.sorted().joinToString(",")
     }
+
+    /**
+     * Calendars switched off in Settings → Calendars that the provider does not
+     * know about yet. That switch writes the system's `Calendars.VISIBLE` (#75),
+     * which needs `WRITE_CALENDAR` — a user who granted read-only keeps their
+     * choice here instead, and so does everyone upgrading from the retired
+     * app-local model, whose set is read straight back out of the same key.
+     *
+     * Honoured as a display and reminder filter for as long as it is non-empty,
+     * so an un-flushable switch still does what the user asked. Not a second
+     * visibility model: `CalendarVisibilityReconciler` drains it into the
+     * provider entry by entry the moment the app may write, and nothing ever
+     * 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 id at a time as the reconciler
+     * flushes it, so a run that fails part-way never re-applies what already
+     * landed (and can't undo a switch the user has since flipped by hand).
+     */
+    suspend fun removePendingDisabledCalendarIds(ids: Collection<Long>) =
+        editPendingDisabled { it - ids.toSet() }
+
+    private suspend fun editPendingDisabled(transform: (Set<Long>) -> Set<Long>) {
+        store.edit { prefs ->
+            prefs.writeIds(DISABLED_IDS_KEY, transform(prefs[DISABLED_IDS_KEY].parseIds()))
         }
     }
 
     /**
-     * App-side preference for "calendars the user has disabled in this app" — a
+     * Whether the one-time "visibility follows this device" notice is still
-     * heavier level than [hiddenCalendarIds]. A disabled calendar is removed from
+     * owed. Null until the reconciler has evaluated it (which needs the calendar
-     * every surface (drawer filter, event-form picker, import picker) and its
+     * permission), false once it has been shown or was never needed.
-     * 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.
      */
-    val disabledCalendarIds: Flow<Set<Long>> = store.data.map { prefs ->
+    val visibilityNoticePending: Flow<Boolean?> = store.data.map { prefs ->
-        prefs[DISABLED_IDS_KEY].orEmpty()
+        prefs[VISIBILITY_NOTICE_KEY]
-            .split(',')
-            .mapNotNull { it.trim().toLongOrNull() }
-            .toSet()
     }
 
-    suspend fun setDisabledCalendarIds(ids: Set<Long>) {
+    suspend fun setVisibilityNoticePending(pending: Boolean) {
-        store.edit { prefs ->
+        store.edit { prefs -> prefs[VISIBILITY_NOTICE_KEY] = pending }
-            if (ids.isEmpty()) {
-                prefs.remove(DISABLED_IDS_KEY)
-            } else {
-                prefs[DISABLED_IDS_KEY] = ids.sorted().joinToString(",")
-            }
-        }
     }
 
     /**
@@ -79,6 +103,16 @@ 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 +1,42 @@
+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. One number, and it replaces everything the
+ * provider's `CalendarAlerts.STATE` used to do for us (#75).
+ *
+ * A scan posts the reminders whose moment falls after this watermark and up to
+ * now, then moves it to now. That single rule gives both halves of what the
+ * retired path got from the provider: a scan that runs twice cannot post the
+ * same reminder again, and a scan that runs *late* — after a reboot, an app
+ * update or a doze window swallowed the alarm — still posts everything the
+ * missed alarm would have.
+ *
+ * Unset means "never scanned". It is deliberately not treated as zero: the first
+ * scan after an install or an upgrade would otherwise consider every reminder
+ * since the epoch overdue and bury the user in notifications.
+ */
+@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

@@ -7,6 +7,11 @@ 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
@@ -16,9 +21,16 @@ 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
@@ -76,6 +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
@@ -109,6 +139,21 @@ 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
@@ -200,6 +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
@@ -222,6 +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.
@@ -234,6 +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
@@ -307,6 +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
@@ -436,14 +572,14 @@ class SettingsPrefs @Inject constructor(
      * (All-day events ignore this and use [defaultAllDayReminderMinutes].)
      */
     val perCalendarReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
-        parseReminderOverrides(prefs[CALENDAR_REMINDER_OVERRIDE_KEY])
+        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()
+            val current = reminderOverrideCodec.parse(prefs[CALENDAR_REMINDER_OVERRIDE_KEY]).toMutableMap()
-            current.applyOverride(calendarId, override)
+            current.applyReminderOverride(calendarId, override)
-            prefs[CALENDAR_REMINDER_OVERRIDE_KEY] = serializeReminderOverrides(current)
+            prefs[CALENDAR_REMINDER_OVERRIDE_KEY] = reminderOverrideCodec.serialize(current)
         }
     }
 
@@ -453,18 +589,18 @@ class SettingsPrefs @Inject constructor(
      * inherit the global all-day default; present null = no reminder).
      */
     val perCalendarAllDayReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
-        parseReminderOverrides(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY])
+        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()
+                reminderOverrideCodec.parse(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY]).toMutableMap()
-            current.applyOverride(calendarId, override)
+            current.applyReminderOverride(calendarId, override)
-            prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY] = serializeReminderOverrides(current)
+            prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY] = reminderOverrideCodec.serialize(current)
         }
     }
 
@@ -603,6 +739,13 @@ class SettingsPrefs @Inject constructor(
     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(',')
@@ -647,6 +790,7 @@ class SettingsPrefs @Inject constructor(
     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")
@@ -655,10 +799,16 @@ class SettingsPrefs @Inject constructor(
         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")
@@ -685,6 +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")
@@ -727,28 +881,6 @@ 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
-    /** Specific lead times in minutes before the event start (non-empty). */
-    data class Minutes(val minutes: List<Int>) : CalendarReminderOverride
-}
-
-/**
- * The stored override for [calendarId] in an override map, as a
- * [CalendarReminderOverride] (absent → [CalendarReminderOverride.Inherit],
- * empty → [CalendarReminderOverride.None]) — the inverse of how
- * [SettingsPrefs.setCalendarReminderOverride] stores a choice.
- */
-fun Map<Long, List<Int>>.choiceFor(calendarId: Long): CalendarReminderOverride = when {
-    !containsKey(calendarId) -> CalendarReminderOverride.Inherit
-    getValue(calendarId).isEmpty() -> CalendarReminderOverride.None
-    else -> CalendarReminderOverride.Minutes(getValue(calendarId))
-}
-
 /**
  * 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
@@ -773,21 +905,6 @@ fun resolveDefaultReminder(
     }
 }
 
-/**
- * Apply a [CalendarReminderOverride] to an override map ([Inherit] removes the
- * key; [None] and an empty [Minutes] both store the empty list).
- */
-private fun MutableMap<Long, List<Int>>.applyOverride(
-    calendarId: Long,
-    override: CalendarReminderOverride,
-) {
-    when (override) {
-        CalendarReminderOverride.Inherit -> remove(calendarId)
-        CalendarReminderOverride.None -> put(calendarId, emptyList())
-        is CalendarReminderOverride.Minutes -> put(calendarId, override.minutes.normalizeReminders())
-    }
-}
-
 /** Sentinel stored for [WeekStartPref.Auto]; days store their [DayOfWeek.name]. */
 private const val WEEK_START_AUTO = "AUTO"
 
@@ -812,8 +929,14 @@ private const val ENTRY_SEP = ";"
 private const val KEY_VALUE_SEP = "="
 private const val LIST_SEP = ","
 
-/** Distinct, ascending lead times — the canonical form stored and resolved. */
+/**
-private fun List<Int>.normalizeReminders(): List<Int> = distinct().sorted()
+ * 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
@@ -829,25 +952,6 @@ private fun String?.toReminderList(): List<Int> = when {
 private fun List<Int>.toStoredReminders(): String =
     if (isEmpty()) NONE else normalizeReminders().joinToString(LIST_SEP) { it.toString() }
 
-private fun parseReminderOverrides(stored: String?): Map<Long, List<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
-        // Only the deliberate "none" sentinel means an explicit no-reminder
-        // override (empty list); a non-sentinel value that parses to no valid
-        // minutes is garbage and drops the entry, so the calendar inherits the
-        // global default rather than silently reading as "no reminder".
-        when (val value = parts[1]) {
-            NONE -> id to emptyList()
-            else -> value.toReminderList().takeIf { it.isNotEmpty() }?.let { id to it }
-                ?: return@mapNotNull null
-        }
-    }.toMap()
-}
-
-private fun serializeReminderOverrides(map: Map<Long, List<Int>>): String =
-    map.entries.joinToString(ENTRY_SEP) { (id, minutes) -> "$id$KEY_VALUE_SEP${minutes.toStoredReminders()}" }
 
 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

@@ -1,92 +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.CalendarPrefs
-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
-
-/**
- * True when [this] alert belongs to a calendar the user disabled in-app, so its
- * reminder must be suppressed (mirroring the event filtering in
- * CalendarRepositoryImpl). Alerts whose calendar is unknown (id 0L — e.g. a
- * pre-upgrade snooze PendingIntent minted before EXTRA_CALENDAR_ID existed) are
- * never treated as disabled. This is the one predicate the disabled-calendar
- * gate is built from: [postableAlerts] here and the choke point in
- * [ReminderNotifier.post] both use it.
- */
-internal fun ReminderAlert.isForDisabledCalendar(disabledCalendarIds: Set<Long>): Boolean =
-    calendarId != 0L && calendarId in disabledCalendarIds
-
-/**
- * The due alerts that should actually surface as notifications: everything
- * except alerts whose calendar the user has disabled in-app. The caller still
- * marks the full due set fired, so suppressed alerts are not re-broadcast by the
- * provider.
- */
-internal fun postableAlerts(
-    due: List<ReminderAlert>,
-    disabledCalendarIds: Set<Long>,
-): List<ReminderAlert> = due.filterNot { it.isForDisabledCalendar(disabledCalendarIds) }
-
-/**
- * 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
-    @Inject lateinit var calendarPrefs: CalendarPrefs
-    @Inject lateinit var suppressedStore: SuppressedReminderStore
-
-    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)
-                    val disabled = calendarPrefs.disabledCalendarIds.first()
-                    val postable = postableAlerts(due, disabled)
-                    // Suppress reminders for disabled calendars, but still mark
-                    // every due alert fired so the provider stops re-broadcasting
-                    // the suppressed ones. Stash those suppressed alerts so
-                    // re-enabling their calendar can recover them (they would
-                    // otherwise stay STATE_FIRED forever with no re-scan).
-                    postable.forEach { notifier.post(it) }
-                    alertStore.markFired(due.map { it.alertId }, now)
-                    suppressedStore.stash(due - postable.toSet(), now)
-                    suppressedStore.purgeExpired(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
+ * - **Dismiss** just cancels the notification — the scan's watermark has moved
- *   already fired, so nothing re-posts it.
+ *   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() {
@@ -73,7 +76,14 @@ 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"
@@ -82,11 +92,20 @@ class ReminderActionReceiver : BroadcastReceiver() {
         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 names the reminder and carries no information the extras
+         * don't. It is what actually keeps two reminders' `PendingIntent`s
+         * apart: `filterEquals` compares action, component, data, type and
+         * categories — never extras — so without it a request-code collision
+         * would have them share one alarm and one payload.
+         */
         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)
@@ -97,23 +116,29 @@ class ReminderActionReceiver : BroadcastReceiver() {
             }
 
         /**
-         * A stable request code per (alert, action) so the three PendingIntents
+         * A stable request code per (alert, action) so one notification's
-         * of one notification stay distinct and don't clobber each other.
+         * PendingIntents stay distinct and don't clobber each other.
+         *
+         * The key is a hash now rather than a small row id, so the shift is what
+         * keeps the action slot intact; the top three bits it drops can make two
+         * *different* reminders share a code, which the per-reminder data URI in
+         * [intent] separates.
          */
         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),

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

@@ -0,0 +1,71 @@
+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 — the half of delivery that
+ * used to be the provider's (#75).
+ *
+ * Exactly **one** alarm exists at a time, for the earliest reminder still ahead.
+ * Every firing re-scans and re-arms, so a reminder added, moved or deleted in
+ * between is picked up on the next pass instead of needing an alarm per reminder
+ * to be kept in sync with the provider's tables.
+ *
+ * A reminder that lands late is a broken reminder, hence an *exact* alarm; the
+ * inexact allow-while-idle fallback only applies where the OS withholds the
+ * capability (API 31–32 with the user's 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 +1,37 @@
+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] that identifies it across a reboot, a re-scan and a reinstall.
+ *
+ * [key] used to be the `CalendarAlerts` row id. It is now derived from the
+ * reminder itself (see [PlannedReminder.key]) because there is no row any more —
+ * in-house delivery reads `Instances` and `Reminders` and owns the alarm (#75).
+ * Everything downstream only ever needed it to be stable and unique, which it
+ * still is: it keys the notification tag, so a reminder posted twice replaces
+ * itself instead of stacking, and it keys the snooze/dismiss `PendingIntent`s.
+ */
+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

@@ -1,115 +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 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,
-)
-
-/**
- * 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),
-                        calendarId = c.getLong(2),
-                        beginMillis = c.getLong(3),
-                        endMillis = c.getLong(4),
-                        title = c.getString(5).orEmpty(),
-                        location = c.getString(6)?.takeIf { it.isNotBlank() },
-                        isAllDay = c.getInt(7) == 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.CALENDAR_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 +1,128 @@
+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 the reminder
+ * offsets hanging off them, straight out of the provider's own tables.
+ *
+ * Deliberately *not* `CalendarAlerts`. That table is the provider's own working
+ * copy of this same information, and the whole point of #75's second round is
+ * that we can no longer assume it gets written. `Instances` and `Reminders` are
+ * plain data the app already reads everywhere else.
+ *
+ * An interface so [ReminderScanner] can be exercised on the JVM without a
+ * ContentResolver, in the shape the rest of `data/calendar` uses.
+ */
+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 calendar's system flag, which the app's one visibility
+        // model writes (#75) — a switched-off calendar must not plan reminders.
+        // The status clause mirrors CalendarDataSource.instances: a cancelled
+        // single occurrence of a series is a real row, and 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} != ${CalendarContract.Events.STATUS_CANCELED})"
+        return context.contentResolver.query(
+            uri, OCCURRENCE_PROJECTION, selection, null, null,
+        )?.use { c ->
+            buildList {
+                while (c.moveToNext()) {
+                    add(
+                        ReminderEventInstance(
+                            eventId = c.getLong(0),
+                            calendarId = c.getLong(1),
+                            beginMillis = c.getLong(2),
+                            endMillis = if (c.isNull(3)) 0L else c.getLong(3),
+                            title = c.getString(4).orEmpty(),
+                            location = c.getString(5)?.takeIf { it.isNotBlank() },
+                            isAllDay = c.getInt(6) == 1,
+                        ),
+                    )
+                }
+            }
+        } ?: emptyList()
+    }
+
+    override fun reminderMinutes(eventIds: Collection<Long>): Map<Long, List<Int>> {
+        if (eventIds.isEmpty()) return emptyMap()
+        val out = mutableMapOf<Long, MutableList<Int>>()
+        // Batched because the ids go into the selection literally; an unbounded
+        // `IN (...)` on a busy calendar would grow the SQL past what SQLite takes.
+        eventIds.distinct().chunked(EVENT_ID_BATCH).forEach { batch ->
+            context.contentResolver.query(
+                CalendarContract.Reminders.CONTENT_URI,
+                REMINDER_PROJECTION,
+                "${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 +1,67 @@
+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.
+ *
+ * The scan alarm re-arms itself at most a day out, so in the steady state this
+ * finds nothing to do. It exists for the case the whole feature is about — a
+ * device that quietly drops the alarm without a reboot to announce it. The
+ * scheduling half of reminder delivery must not have a single point of failure,
+ * which is exactly what the provider's broadcast turned out to be.
+ */
+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; anything reaching here is the
+        // entry point itself, which a retry will not mend. Never fail the chain.
+        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

@@ -14,27 +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.
+ * Posts one notification per due reminder on a dedicated channel. Tapping opens
- * Tapping opens the event's detail screen; the tag is the alert id, so a
+ * the event's detail screen.
- * re-broadcast of an alert we couldn't mark fired replaces its notification
+ *
- * silently ([NotificationCompat.Builder.setOnlyAlertOnce]) instead of
+ * The tag is the reminder's stable key, so a scan that posts the same reminder
- * duplicating it.
+ * 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. */
@@ -45,23 +53,45 @@ class ReminderNotifier @Inject constructor(
         return granted && NotificationManagerCompat.from(context).areNotificationsEnabled()
     }
 
-    suspend fun post(alert: ReminderAlert) {
+    /**
-        // The single choke point for the disabled-calendar gate: it covers both
+     * The single choke point for "this calendar is switched off". The scan
-        // the provider broadcast (EventReminderReceiver) and a snoozed re-show
+     * already filters on `Calendars.VISIBLE`, but two paths reach [post] around
-        // (ReminderActionReceiver), so a calendar disabled after a snooze no
+     * it: a snooze re-shown from its own alarm, armed before the calendar was
-        // longer notifies — without either receiver duplicating the check.
+     * switched off, and a read-only install whose switch lives app-side
-        if (alert.isForDisabledCalendar(calendarPrefs.disabledCalendarIds.first())) return
+     * ([CalendarPrefs]) because it may not write the flag. Both are covered here
+     * rather than in either receiver.
+     */
+    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(),
+            zone = zone,
-            locale = Locale.getDefault(),
+            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)
@@ -88,16 +118,18 @@ 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: re-running it would hit 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 =
@@ -110,7 +142,11 @@ 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, so
+        // the key's wider value range can't collide one notification's intents.
+        /* 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 +1,170 @@
+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.
+ *
+ * This is the whole loop. Every trigger — the alarm firing, boot, a clock or
+ * timezone change, an edit landing in the provider, the app starting, the daily
+ * safety net — runs the same [scan], so there is a single path to reason about
+ * and no ordering between triggers to get wrong. Re-running it 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) {
+                // The calendar permission was revoked mid-flight. Nothing to
+                // re-arm and nothing to recover from — 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 everything missed meanwhile.
+            alarms.cancelScan()
+            state.setLastScanMillis(now)
+            return
+        }
+
+        val lookahead = reminderQueryHorizon(LOOKAHEAD_MILLIS, source.longestReminderMinutes())
+        // Reach a little into the past as well: an event already under way can
+        // still owe a reminder (an all-day "at time of event" encodes to a
+        // negative offset, which fires after begin), and a catch-up pass needs
+        // to see the occurrences whose moment 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 regardless of whether anything could be posted: a user who
+        // muted notifications is not owed a backlog when they unmute.
+        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 an event saved or deleted in the app
+     * re-arms the alarm immediately rather than waiting for the next pass.
+     *
+     * Debounced: a single save writes the event, its reminders and its
+     * attendees, and each lands as its own notification. Only useful while the
+     * process is alive — every other trigger covers the rest, which is why
+     * nothing here needs to survive it.
+     */
+    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, even with nothing
+         * pending: 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 +1,63 @@
+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 reason to re-run a reminder scan that arrives from outside the process.
+ *
+ * All of them do the same thing, because [ReminderScanner.scan] is idempotent
+ * and works out what is owed from its watermark rather than from why it was
+ * called:
+ *
+ * - **our own alarm** ([ACTION_SCAN]) — the ordinary case, a reminder is due;
+ * - **boot** and **package replaced** — both wipe pending alarms, so the app has
+ *   to re-arm or reminders stop silently, which is the failure #75 is about;
+ * - **time and timezone changes** — they move every reminder relative to the
+ *   armed alarm, and an all-day reminder's fire hour is recomposed in the
+ *   current zone, so both need a fresh plan.
+ *
+ * Exported because the system broadcasts arrive from outside. [ACTION_SCAN] is
+ * ours and always sent as an explicit intent; another app triggering a scan
+ * early would only make it re-read the provider and re-arm, which is harmless.
+ */
+@AndroidEntryPoint
+class ReminderScheduleReceiver : BroadcastReceiver() {
+
+    @Inject lateinit var scanner: ReminderScanner
+
+    override fun onReceive(context: Context, intent: Intent) {
+        // Every action here does the same thing, but the filter still has to be
+        // checked: the receiver is exported, and the system broadcasts it takes
+        // are protected, so an intent arriving with 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

@@ -12,9 +12,12 @@ import javax.inject.Singleton
 /**
  * Schedules a one-off exact alarm that re-shows a snoozed reminder.
  *
- * The app otherwise relies entirely on the calendar provider's `EVENT_REMINDER`
+ * Separate from [ReminderAlarmScheduler]'s scan alarm, and deliberately so: a
- * broadcast (the Etar model), but a snoozed reminder has no provider backing —
+ * snooze is pinned to one reminder at a time the user chose, while the scan
- * its `CalendarAlerts` row is already fired — so we must re-fire it ourselves.
+ * alarm is a single moving wake-up for whatever comes next. A re-show also has
+ * to outlive the scan's watermark moving past that reminder, so it carries the
+ * reminder in its own intent rather than re-deriving it.
+ *
  * 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).

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 events that fall on a day other than [today] are prefixed with that
- * - timed, crossing days: "11 Jun, 23:30 – 12 Jun, 00:30" (medium date + short time)
+ * 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, $range"
     } else {
         // Cross-day: medium date + the chosen short time, joined per side. Built
         // from the two formatters (not ofLocalizedDateTime) so the 12/24h choice
-        // applies to the time portion too.
+        // applies to the time portion too. The explicit dates already say which
-        val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
+        // day, so no relative prefix is layered on top.
         val dateTime = { z: java.time.ZonedDateTime -> "${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/data/reminders/SuppressedReminderStore.kt

@@ -1,130 +0,0 @@
-package de.jeanlucmakiola.calendula.data.reminders
-
-import androidx.datastore.core.DataStore
-import androidx.datastore.preferences.core.MutablePreferences
-import androidx.datastore.preferences.core.Preferences
-import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.core.stringSetPreferencesKey
-import java.util.Base64
-import javax.inject.Inject
-import javax.inject.Singleton
-
-/**
- * Still relevant while the event has not ended: a reminder for an event that is
- * already over is pointless to re-surface. Falls back to the begin time when the
- * end is unknown (0L). Used both to decide what to re-post and to purge the stash.
- */
-internal fun ReminderAlert.isRelevantAt(nowMillis: Long): Boolean =
-    (endMillis.takeIf { it > 0L } ?: beginMillis) >= nowMillis
-
-/**
- * Local stash of reminder alerts that fired while their calendar was disabled
- * in-app. [EventReminderReceiver] marks every due alert `STATE_FIRED` regardless
- * (so the provider stops re-broadcasting the suppressed ones), which would
- * otherwise lose those reminders forever — there is no re-scan. Stashing lets
- * [de.jeanlucmakiola.calendula.ui.calendars.CalendarsViewModel] re-post them if
- * the user re-enables the calendar before the event is over.
- *
- * Persisted in the shared preferences DataStore as a set of self-describing
- * strings (one per alert); the stash never reaches a screen, so there is no
- * domain model. Entries whose event has already ended are dropped on the next
- * stash/recover/purge, so the stash only ever holds a handful of pending alerts.
- */
-@Singleton
-class SuppressedReminderStore @Inject constructor(
-    private val store: DataStore<Preferences>,
-) {
-
-    /** Add [alerts] to the stash, replacing any existing entry with the same id. */
-    suspend fun stash(alerts: List<ReminderAlert>, nowMillis: Long) {
-        if (alerts.isEmpty()) return
-        store.edit { prefs ->
-            val byId = decodeAll(prefs).associateByTo(mutableMapOf()) { it.alertId }
-            alerts.forEach { byId[it.alertId] = it }
-            prefs.putStash(byId.values.filter { it.isRelevantAt(nowMillis) })
-        }
-    }
-
-    /**
-     * Remove and return the still-relevant stashed alerts belonging to any of
-     * [calendarIds]; drops expired entries for every calendar in passing.
-     */
-    suspend fun recoverFor(calendarIds: Set<Long>, nowMillis: Long): List<ReminderAlert> {
-        val recovered = mutableListOf<ReminderAlert>()
-        store.edit { prefs ->
-            val kept = decodeAll(prefs).filter { alert ->
-                when {
-                    !alert.isRelevantAt(nowMillis) -> false // expired: drop
-                    alert.calendarId in calendarIds -> { recovered += alert; false }
-                    else -> true
-                }
-            }
-            prefs.putStash(kept)
-        }
-        return recovered
-    }
-
-    /** Drop entries whose event has already ended — cheap opportunistic cleanup. */
-    suspend fun purgeExpired(nowMillis: Long) {
-        store.edit { prefs ->
-            prefs.putStash(decodeAll(prefs).filter { it.isRelevantAt(nowMillis) })
-        }
-    }
-
-    private fun decodeAll(prefs: Preferences): List<ReminderAlert> =
-        prefs[KEY].orEmpty().mapNotNull { decodeStashEntry(it) }
-
-    private fun MutablePreferences.putStash(alerts: List<ReminderAlert>) {
-        val encoded = alerts.map { encodeStashEntry(it) }.toSet()
-        if (encoded.isEmpty()) remove(KEY) else set(KEY, encoded)
-    }
-
-    private companion object {
-        val KEY = stringSetPreferencesKey("suppressed_reminders")
-    }
-}
-
-// One stash entry as a delimited string. The '|' separator is safe because every
-// free-text field is Base64-encoded first (that alphabet never contains '|'), and
-// a null location is stored as a distinct sentinel that Base64 also never yields.
-private const val FIELD_SEP = "|"
-private const val NULL_LOCATION = "-"
-
-internal fun encodeStashEntry(alert: ReminderAlert): String = listOf(
-    alert.alertId.toString(),
-    alert.eventId.toString(),
-    alert.calendarId.toString(),
-    alert.beginMillis.toString(),
-    alert.endMillis.toString(),
-    if (alert.isAllDay) "1" else "0",
-    alert.title.toBase64(),
-    alert.location?.toBase64() ?: NULL_LOCATION,
-).joinToString(FIELD_SEP)
-
-/** Reverse of [encodeStashEntry]; returns null for a malformed entry (dropped). */
-internal fun decodeStashEntry(raw: String): ReminderAlert? {
-    val parts = raw.split(FIELD_SEP)
-    if (parts.size != 8) return null
-    return try {
-        ReminderAlert(
-            alertId = parts[0].toLong(),
-            eventId = parts[1].toLong(),
-            calendarId = parts[2].toLong(),
-            beginMillis = parts[3].toLong(),
-            endMillis = parts[4].toLong(),
-            title = parts[6].fromBase64(),
-            location = parts[7].takeIf { it != NULL_LOCATION }?.fromBase64(),
-            isAllDay = parts[5] == "1",
-        )
-    } catch (e: NumberFormatException) {
-        null
-    } catch (e: IllegalArgumentException) { // bad Base64
-        null
-    }
-}
-
-private fun String.toBase64(): String =
-    Base64.getEncoder().encodeToString(toByteArray(Charsets.UTF_8))
-
-private fun String.fromBase64(): String =
-    String(Base64.getDecoder().decode(this), Charsets.UTF_8)

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

@@ -0,0 +1,76 @@
+package de.jeanlucmakiola.calendula.domain
+
+/**
+ * The ways a calendar can behave unlike a plain, writable one — each of them a
+ * reason it is missing from the event and import pickers, and each of them
+ * something the app knows and used to keep to itself (#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,
+     * which is why it is the one exclusion with nothing else to give it away.
+     */
+    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 this calendar belongs to keeps its events off the device
+ * (`Calendars.SYNC_EVENTS = 0`) — an "empty by construction" calendar: the rows
+ * simply aren't here, so nothing can display them and no reminder can fire.
+ *
+ * Device-local calendars are excluded deliberately. Nothing syncs them by
+ * definition, so the flag says nothing about them, and a local calendar from
+ * another app can hold real events at `sync_events = 0` — the same unsoundness
+ * that made the #75 migration guard wrong.
+ */
+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: there are no events on the device
+ * to reveal, so the switch would be a control that does nothing.
+ */
+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):
+ *
+ * - read-only has nowhere to write;
+ * - switched off would hide the event the moment it was saved;
+ * - a managed mirror has the next contact sync delete it;
+ * - a non-syncing one never carries the event up to the account, and
+ *   `CalendarProvider2` wipes the calendar's rows outright when the
+ *   subscription is switched back on — a saved event is a dead end either way.
+ *
+ * This is the test for *targets*. 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 +1,58 @@
+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] — calendars switched off in Settings →
+ * Calendars while the app could not write `Calendars.VISIBLE`, plus whatever
+ * the retired app-local visibility model left behind (#75) — against the
+ * calendars actually on the device.
+ *
+ * The plan only ever *hides*. Switching a calendar off is intent the user
+ * expressed in Calendula, so carrying it into the provider is fair. The other
+ * direction is deliberately absent: a calendar hidden at system level was hidden
+ * somewhere else (another calendar app, the account's own settings), and
+ * switching it back on would un-hide it there too *and* start firing reminders
+ * nobody asked for. Calendula follows that flag instead and explains itself once
+ * (see [hasSystemHiddenCalendars]).
+ *
+ * [CalendarVisibilityPlan.settled] carries the ids that need no write — already
+ * hidden, or gone from the device. They leave the pending set exactly as a
+ * successful write would.
+ */
+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]
+        // No row means the calendar is gone; already invisible means someone
+        // (us, on an earlier run) got there first. Either way: 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. Those calendars showed their events before the app adopted
+ * `Calendars.VISIBLE` as its one visibility model and no longer do, which is
+ * what the one-time notice explains — the alternative, switching them on, would
+ * reach into every other calendar app on the device.
+ */
+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
+ * wall-clock values in [timezone]; the data layer translates them to provider
- * provider millis (all-day events normalise to UTC midnights there).
+ * 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(beginMillis).toLocalDateTime(formZone) to
-            Instant.fromEpochMilliseconds(endMillis).toLocalDateTime(zone)
+            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/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 +12,13 @@ data class CalendarSource(
     val accountName: String,
     val accountType: String,
     val color: Int,
+    /**
+     * The system's per-calendar `Calendars.VISIBLE` flag — the single visibility
+     * model: it decides both what Calendula shows and whether the provider
+     * schedules this calendar's reminder alarms at all (#75). Settings →
+     * Calendars writes it; the drawer's filter sheet is a separate, purely
+     * in-app declutter that leaves reminders alone.
+     */
     val isVisibleInSystem: Boolean,
     /**
      * Whether events in this calendar can be created/edited/deleted
@@ -34,6 +45,15 @@ data class CalendarSource(
      * 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]. For a
+     * synced account it means the events aren't stored locally at all, so the
+     * calendar reads as permanently empty; a device-local calendar another app
+     * created can hold events with the flag off, so it says nothing there.
+     * Read for the "not synced" row label (#76).
+     */
+    val syncsEvents: Boolean = true,
 )
 
 data class EventInstance(
@@ -56,6 +76,35 @@ data class EventInstance(
  */
 fun EventInstance.hasEnded(now: Instant): Boolean = end <= now
 
+/**
+ * The zone this event's calendar dates live in. Timed events are resolved in the
+ * device [zone]; all-day events live at UTC midnights with an exclusive end, so
+ * resolving them anywhere else shifts the day boundaries — east of UTC the end
+ * leaks onto the following day (#65), west of UTC the start pulls back onto the
+ * previous one (#82). Every surface that has to name an all-day event's date
+ * goes through here, so grid, agenda, detail and search cannot disagree.
+ */
+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 actually occupies. An event ending exactly at
+ * midnight (all-day events end at the exclusive next-midnight) does not reach
+ * into that boundary day, so resolve the instant 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 +1,122 @@
+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]
+ * (the event's own start date, i.e. DTSTART), for showing a rule as dates
+ * instead of as words.
+ *
+ * A recurrence rule is the one place in the editor where a correct-sounding
+ * phrase can still mean something the user didn't intend — "every 2 weeks on
+ * Mon, Fri", "monthly" on the 31st — and the only honest answer is the dates
+ * themselves. This is a *preview*, deliberately kept to the shapes the picker
+ * can build; the provider remains the authority on what actually gets stored
+ * and expanded.
+ *
+ * The rules it mirrors, all from RFC 5545 (the spec the platform's recurrence
+ * engine implements):
+ * - a monthly or yearly rule **skips** a period the start day doesn't exist in,
+ *   rather than sliding to the month's last day: the 31st recurring monthly
+ *   lands only in 31-day months, 29 February yearly only in leap years.
+ * - a weekly rule with weekday picks repeats in blocks of `interval` weeks,
+ *   with the week beginning on **Monday** — the RFC's default WKST, and the one
+ *   that applies here because [toRRule] never writes a WKST part. The
+ *   display-only "first day of week" preference deliberately doesn't enter into
+ *   it, or the preview would disagree with the stored rule.
+ * - [RecurrenceEnd.Count] counts real occurrences (skipped periods don't
+ *   consume one), [RecurrenceEnd.Until] is inclusive of its date.
+ *
+ * Returns fewer than [limit] dates when the series ends first, and an empty
+ * list when the rule yields nothing at all (an UNTIL before the 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()
+
+    val result = mutableListOf<LocalDate>()
+    var period = 0
+    // Periods that produce nothing (a skipped 31st, a weekday block whose picks
+    // all fall before the start) must not stall the walk, so the cap is on
+    // periods examined rather than on 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 the day into the shorter month; the rule instead
+            // 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.
+ *
+ * Day and month alone are enough for a rule that stays inside one year, and
+ * dropping the year keeps the line short. They are actively misleading
+ * otherwise: a yearly rule reads as the same date three times over, and a
+ * monthly one rolling past December gives no hint that it has.
+ */
+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 (29 February yearly with a 999-year
+ * interval is nonsense; 31st monthly needs at most a handful), and 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/reminders/ReminderPlan.kt

@@ -0,0 +1,258 @@
+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
+
+/**
+ * Works out *when* each reminder has to fire and *which* ones are due, with no
+ * provider and no clock of its own — the whole decision layer of in-house
+ * reminder delivery (#75).
+ *
+ * Calendula used to leave both halves to the calendar provider: it scheduled the
+ * alarms, wrote the `CalendarAlerts` rows, and broadcast `EVENT_REMINDER` at the
+ * right moment. That chain is intact on stock Android but demonstrably not on
+ * every device — AOSP's own unbundled calendar carries three separate
+ * workarounds for OEMs that retarget the broadcast, or that only write the alert
+ * row at alert time. An app that can only *react* to that broadcast has no way
+ * to notice it never came.
+ *
+ * So the offsets in `CalendarContract.Reminders` are now read as data and turned
+ * into alarms we own. Everything here is pure: instances and reminder offsets in,
+ * fire instants out.
+ */
+
+/** 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 of this reminder, derived from what defines it rather
+     * than from a provider row id (there is none any more). It keys the
+     * notification tag and the snooze/dismiss `PendingIntent`s, so it has to
+     * survive a reboot, a re-scan and a reinstall — the same reminder must land
+     * on the same notification instead of stacking a second one.
+     */
+    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.
+ *
+ * A **timed** occurrence is trivial: `begin` is an absolute instant, so
+ * `begin − minutes` is exact by construction, in any timezone, across any DST
+ * boundary.
+ *
+ * An **all-day** occurrence is not, and taking the offset at face value is what
+ * makes reminders land at the wrong hour. Its `begin` is UTC midnight, and the
+ * stored offset is not a plain lead time — `AllDayReminderEncoding` folds the
+ * wanted wall-clock hour into it, sampled against *one* date's UTC offset. Fire
+ * at `begin − minutes` and every occurrence in a different DST phase than the one
+ * that was sampled drifts by the offset delta, an hour early in one direction and
+ * an hour late in the other. Rows written by other apps carry no wall-clock at
+ * all — a conventional `1440` fires at UTC midnight, which is 01:00 or 02:00
+ * local in Berlin and the wrong day west of UTC.
+ *
+ * So the offset is only read for *which day* it means, via [allDayLeadDays], and
+ * the hour comes from [allDayTimeMinutes] — the one global "show all-day
+ * reminders at" setting — recomposed against each occurrence's own date in
+ * [zone]. 09:00 Berlin is then 09:00 Berlin on every occurrence, whatever the
+ * offset was when the row was written.
+ *
+ * [minutesByEvent] may hold duplicate offsets (two identical reminder rows on one
+ * event); they collapse, because they would otherwise fight over one notification.
+ */
+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.
+ *
+ * Normally the local date of the encoded fire instant answers it: our own rows
+ * fold the wanted hour into the offset, so that date *is* the day the reminder
+ * belongs to, whatever the offset was when it was written.
+ *
+ * A plain multiple of 1440 is the exception. Those come from calendar apps that
+ * store a bare lead time against UTC midnight, and east of UTC both readings
+ * agree anyway — but west of UTC the instant falls on the previous local date,
+ * so the day count has to be taken at face value or it comes out one too many.
+ *
+ * Except when the row is one of ours after all: our offset lands on a multiple
+ * whenever the all-day hour equals the zone's UTC offset (20:00 in New York,
+ * 19:00 an hour further west, and so on), and reading those at face value fired
+ * them a day late — a "1 day before" arriving on the morning of the event. So
+ * the hour decides, not the shape of the number: an instant landing on the hour
+ * the setting names is ours. Within an hour or so of it counts, because a fixed
+ * offset written in one DST phase drifts by the offset delta in the other.
+ *
+ * The two are genuinely indistinguishable in that band — the encodings collide
+ * exactly there — so the tie goes to the reading that honours the lead time the
+ * user chose in this app.
+ *
+ * [de.jeanlucmakiola.calendula.data.calendar.fromProviderAllDayMinutes] calls
+ * this for display, so the notification arrives on the day the event screen says
+ * it will.
+ */
+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]` — a
+ * half-open watermark, so a scan triggered twice cannot post the same reminder
+ * twice, while a scan that runs late still catches everything the missed alarm
+ * would have posted. That catch-up is the point: an alarm dropped by a reboot,
+ * an app update or a doze window is recovered by the next scan rather than lost.
+ *
+ * A reminder whose event has already ended is dropped rather than posted late —
+ * see [isStillRelevant].
+ *
+ * [nextAlarmMillis] is capped at [horizonMillis] even when nothing is pending, so
+ * the scan re-runs at least that often and the lookahead window rolls 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, given what the
+ * last one recorded.
+ *
+ * A first-ever scan ([lastScanMillis] `null`) claims the present, so an install
+ * or an upgrade onto in-house delivery does not treat every reminder since the
+ * epoch as overdue and bury the user in notifications. A watermark in the
+ * *future* — the clock was moved back, or the user travelled across the date
+ * line — is clamped for the mirror-image reason: left alone it would silence
+ * every reminder until real time caught up with it.
+ */
+fun reminderWatermark(lastScanMillis: Long?, nowMillis: Long): Long =
+    lastScanMillis?.coerceAtMost(nowMillis) ?: nowMillis
+
+/**
+ * How far ahead instances must be queried for [scheduleReminders] to see every
+ * reminder in time: the plain lookahead plus the longest offset any reminder row
+ * carries, so a "two weeks before" reminder is planned before it comes due
+ * instead of firing late (the limitation Etar's equivalent documents).
+ *
+ * The stretch is capped at [MAX_REMINDER_LEAD_MILLIS]. `maxReminderMinutes` is
+ * whatever the largest row in the whole provider says, across every calendar and
+ * whoever wrote it — an imported `TRIGGER:-P100W`, or a sync adapter writing
+ * nonsense, would otherwise make every scan (launch, every provider change, every
+ * alarm) expand every recurring series over years. A lead beyond the cap is not
+ * delivered; a year is far past anything the picker composes.
+ */
+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
@@ -83,6 +89,8 @@ fun CalendarHost(
     // 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))
@@ -141,6 +149,11 @@ fun CalendarHost(
     // over Settings and survives view switches.
     var showCalendars by rememberSaveable { mutableStateOf(false) }
 
+    // Backup & restore (#69) — like the manager, driven by the calendar list
+    // rather than by preferences, so it is hoisted here instead of living as a
+    // Settings sub-section. Reached from Settings and from the manager.
+    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)
@@ -170,12 +183,32 @@ 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
@@ -183,12 +216,27 @@ 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
@@ -252,8 +300,8 @@ 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 ||
+        editKey != null || showSettings || showCalendars || showBackup ||
-        importForm != null
+        importUri != null || importForm != null
     BackHandler(enabled = !anyOverlayVisible && viewStack.size > 1) {
         viewStack = viewStack.dropLast(1)
     }
@@ -262,7 +310,7 @@ 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 },
@@ -272,12 +320,14 @@ 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,
@@ -289,26 +339,31 @@ fun CalendarHost(
                     initialDateIso = pendingDayIso,
                     quickSwitchViews = quickSwitchViews,
                     drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Month -> MonthScreen(
                     selectedView = currentView,
                     onSelectView = onSelectView,
                     onOpenDay = onOpenDay,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
-                    onCreateEvent = onCreateEvent,
-                    quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                )
-                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,
                 )
             }
         }
@@ -343,6 +398,14 @@ 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
+                    },
                 )
             }
         }
@@ -359,6 +422,7 @@ fun CalendarHost(
                     initialStartMinutes = createStartMinutes ?: heldCreateMinutes,
                     onClose = { createDateIso = null },
                     onSaved = { createDateIso = null },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -378,6 +442,7 @@ fun CalendarHost(
                         editKey = null
                         detailKey = null
                     },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -391,26 +456,21 @@ 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
                 },
             )
@@ -419,8 +479,42 @@ fun CalendarHost(
             EventEditScreen(
                 initialDateIso = null,
                 initialForm = form,
+                initialFormSource = importFormSource,
                 onClose = { importForm = null },
                 onSaved = { importForm = null },
+                onManageCalendars = { showCalendars = true },
+            )
+        }
+
+        // Calendar manager — declared last so it covers every overlay that can
+        // open it: Settings, both event forms, and the .ics import picker (#76).
+        // Coming back from it leaves the caller exactly as it was, with the
+        // calendar list already refreshed by the provider's notification.
+        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 },
+                // Restoring runs the normal .ics import, and that way round this
+                // screen has to step aside: declared above the import overlays,
+                // it would otherwise cover the screen it just asked for. Closing
+                // it hands the user back to whatever opened Backup once the
+                // import is done.
+                onImport = { importUri = it; importForceMany = true; showBackup = false },
             )
         }
     }

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

@@ -45,4 +45,12 @@ class CalendarHostViewModel @Inject constructor(
             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
@@ -21,6 +22,8 @@ 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
@@ -35,6 +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 {
@@ -44,6 +51,10 @@ fun RootScreen(
         )
     }
 
+    // Whether the app came up already holding it — a launch scan has covered
+    // that case, 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 ->
@@ -74,6 +85,20 @@ 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, shown over the app.
+            val visibilityNotice: CalendarVisibilityNoticeViewModel = hiltViewModel()
+            val noticePending by visibilityNotice.pending.collectAsStateWithLifecycle()
+            // Runs on entry however the permission was granted — including from
+            // Android's app-settings screen, which only comes back through the
+            // ON_RESUME check above. Cheap once there is nothing left to do.
+            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(
@@ -84,6 +109,10 @@ 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/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
 
 /**
@@ -87,10 +86,12 @@ 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:
+ * (inclusive), for a human-readable header. Both ends use the same day-month
- * - [AgendaRange.Day] → a single medium date ("27 Jun 2026")
+ * 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.
  */
 fun agendaRangeWindowSummary(
     range: AgendaRange,
@@ -100,11 +101,15 @@ fun agendaRangeWindowSummary(
 ): 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)
+    val dayMonth = localizedDateFormatter(locale, "dMMM")
+    val dayMonthYear = localizedDateFormatter(locale, "dMMMy")
     return when (range) {
-        AgendaRange.Day -> medium.format(javaStart)
+        AgendaRange.Day -> dayMonthYear.format(javaStart)
-        AgendaRange.ThisMonth -> DateTimeFormatter.ofPattern("LLLL yyyy", locale).format(javaStart)
+        AgendaRange.ThisMonth -> localizedDateFormatter(locale, "LLLLy").format(javaStart)
-        else -> "${DateTimeFormatter.ofPattern("d MMM", locale).format(javaStart)} – ${medium.format(javaEnd)}"
+        else -> {
+            val startFmt = if (start.year == end.year) dayMonth else dayMonthYear
+            "${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
@@ -59,52 +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.IMPLEMENTED_VIEWS
-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.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.next
-import de.jeanlucmakiola.calendula.ui.common.pastelize
+import de.jeanlucmakiola.floret.components.positionOf
-import de.jeanlucmakiola.calendula.ui.common.positionOf
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
-import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.floret.locale.currentLocale
-import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
-import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
 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)
@@ -147,12 +136,14 @@ fun AgendaScreen(
                     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) },
@@ -169,9 +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,
@@ -189,8 +182,10 @@ fun AgendaScreen(
                 AgendaContent(
                     state = state,
                     pastDisplay = pastDisplay,
+                    showToday = showToday,
                     onRetry = viewModel::goToToday,
                     onEventClick = onEventClick,
+                    onOpenDay = onOpenDay,
                     modifier = Modifier
                         .weight(1f)
                         .fillMaxWidth(),
@@ -204,6 +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 },
         )
@@ -211,9 +207,11 @@ fun AgendaScreen(
 }
 
 /**
- * A compact tonal pill showing the agenda's current range. Tapping it opens the
+ * The agenda's current range, tapped to open the range picker as a session-only
- * range picker as a session-only override. Filled with the primary container
+ * override. Shares the top-bar view switcher's button shape so the two read as a
- * while an override is active, so the temporary state is obvious.
+ * 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(
@@ -222,43 +220,34 @@ private fun AgendaRangePill(
     onClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
-    val container = if (isOverride) {
+    FilledTonalButton(
+        onClick = onClick,
+        shape = MaterialTheme.shapes.large,
+        colors = ButtonDefaults.filledTonalButtonColors(
+            containerColor = if (isOverride) {
                 MaterialTheme.colorScheme.primaryContainer
             } else {
                 MaterialTheme.colorScheme.surfaceContainerHigh
-    }
+            },
-    val content = if (isOverride) {
+            contentColor = if (isOverride) {
                 MaterialTheme.colorScheme.onPrimaryContainer
             } else {
                 MaterialTheme.colorScheme.onSurfaceVariant
-    }
+            },
-    Surface(
+        ),
-        color = container,
+        modifier = modifier,
-        contentColor = content,
-        shape = RoundedCornerShape(50),
-        modifier = modifier.clickable(onClick = onClick),
     ) {
-        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,
         )
     }
-    }
 }
 
 /**
- * A header naming the concrete window currently shown, e.g. "Showing all events
+ * A header naming the concrete window currently shown under a "showing …" label,
- * for · Today, 27 Jun 2026" / "This week, 27 Jun – 3 Jul" / "This month, June 2026".
+ * 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(
@@ -275,8 +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,
         )
@@ -287,8 +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) {
@@ -301,7 +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)
@@ -309,15 +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,
                 )
             }
@@ -330,9 +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(
@@ -342,72 +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)
             }
+            if (day.events.isEmpty()) {
+                // An anchored, event-less today (#35) — "nothing left today".
+                item(key = "placeholder-${day.date}") {
+                    AgendaEmptyDayRow(
+                        text = stringResource(R.string.agenda_no_more_today),
+                        onClick = { onOpenDay(day.date) },
+                    )
+                }
+            } else {
                 itemsIndexed(
                     items = day.events,
-                key = { _, event -> event.instanceId },
+                    // Scope the key by day: a multi-day event appears under every
+                    // day it spans, so its instanceId alone is not unique across
+                    // the list (LazyColumn requires unique keys).
+                    key = { _, event -> "${day.date}-${event.instanceId}" },
                 ) { index, event ->
                     AgendaEventRow(
                         event = event,
+                        day = day.date,
+                        zone = zone,
                         position = positionOf(index, day.events.size),
                         dimmed = dimPast && event.hasEnded(now),
-                    modifier = calendarAnimateItem(),
+                        modifier = animateItemMotion(),
                         onClick = { onEventClick(event) },
                     )
                 }
+            }
             item(key = "gap-${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(
@@ -437,6 +410,8 @@ private fun AgendaTopBar(
     onCycleView: () -> Unit,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
+    showTodayButton: Boolean,
+    onToday: () -> Unit,
     scrollBehavior: TopAppBarScrollBehavior,
 ) {
     TopAppBar(
@@ -455,6 +430,7 @@ private fun AgendaTopBar(
             }
         },
         actions = {
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,
@@ -474,42 +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(
@@ -15,22 +49,41 @@ 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
+ * actually carry events). A multi-day event surfaces on *every* day it spans,
- * multi-day) is clamped to the anchor day so it still surfaces on top. Within a
+ * not just its first — clamped to [[anchor], [windowEnd]] so an event that began
- * day, all-day events sort first, then ascending by start time, then title.
+ * 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> =
+): List<AgendaDay> {
-    instances
+    val byDay = sortedMapOf<LocalDate, MutableList<EventInstance>>()
-        .groupBy { it.start.toLocalDateTime(zone).date.coerceAtLeast(anchor) }
+    for (instance in instances) {
-        .toSortedMap()
+        val firstDay = instance.spanFirstDay(zone).coerceAtLeast(anchor)
-        .map { (date, dayEvents) ->
+        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(
@@ -40,6 +93,25 @@ fun groupAgendaDays(
             ),
         )
     }
+}
+
+/**
+ * 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
+     * First day of the week, for the calendar-aligned "this week" range. Public
-        .map { it.resolveFirstDay(Locale.getDefault()) }
+     * 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 +1,390 @@
+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. `.ics` files reach us under several
+// mimes depending on the source app (our own export uses text/calendar; others
+// hand them out as octet-stream or text/plain), so accept the common set rather
+// than hide valid backups behind an over-tight filter.
+private val RESTORE_MIME_TYPES = arrayOf(
+    "text/calendar",
+    "application/octet-stream",
+    "text/plain",
+)
+
+/**
+ * Backup & restore (#69). Local calendars aren't synced anywhere, so a `.ics`
+ * export is their only safety net — that made it a data-safety feature hiding in
+ * the calendar manager, where nobody went looking. It now has its own Settings
+ * entry, sharing [CalendarsViewModel] with the manager (both are driven by the
+ * same calendar list).
+ *
+ * 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 the user's own local calendars (managed special-dates
+    // mirrors don't count — they are rebuilt from contacts). Restore can target
+    // any calendar the import picker would offer, so its availability is broader.
+    val exportable = calendars.filter { it.isLocal && it.canModifyContents && !it.isManaged }
+    val canImport = calendars.any { it.isEventTarget }
+
+    // SAF "create document" target for the backup file. The picked Uri is handed
+    // to the VM to stream the .ics into. This launcher 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) }
+
+    // SAF "open document" picker for restoring events from a .ics file. The
+    // picked Uri is handed up to the host, which runs it through the same import
+    // flow as an externally opened .ics (parse, dedup by UID, target picker).
+    val openBackup = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocument(),
+    ) { uri -> uri?.let(onImport) }
+
+    // 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(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()) {
+            // One connected card: the one-time export on top, restore under it,
+            // 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 = {
+                    // With more than one exportable calendar, let the user choose
+                    // which to include; a single one exports straight away.
+                    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 (no writable local calendar), but events can
+            // still be restored into a writable calendar — offer restore on its
+            // own so it isn't hidden 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,
+) {
+    // Seed once with everything selected and hold it across recomposition and
+    // rotation. NOT keyed on [calendars]: the list is observer-driven, so keying
+    // it would silently reset the user's de-selections whenever the provider
+    // re-emits (a background sync, a recolor). Ids that later vanish are harmless
+    // — the data layer intersects the chosen set with the eligible calendars.
+    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,
+) {
+    // 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

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

@@ -0,0 +1,76 @@
+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` on the first launch
+ * that finds a calendar switched off outside the app — those used to show their
+ * events here and no longer do, and the app deliberately does not switch them
+ * back on, because that would un-hide them in every other calendar app 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.
+     * The launch itself is covered by `CalendulaApp`, but a permission granted
+     * on Android's app-settings screen comes back through `RootScreen`'s
+     * ON_RESUME and never touches the permission screen's callback — so the
+     * trigger hangs off "we are showing the app", not off one grant route.
+     * Settled runs cost two DataStore reads and stop there.
+     */
+    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
@@ -71,43 +65,42 @@ 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.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.accountGroupTitle
-import de.jeanlucmakiola.calendula.ui.common.DialogUnitDropdown
+import de.jeanlucmakiola.calendula.ui.common.groupByAccount
-import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
-import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
+import de.jeanlucmakiola.calendula.ui.common.eventFill
-import de.jeanlucmakiola.calendula.ui.common.predictiveBack
+import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
-import de.jeanlucmakiola.calendula.ui.common.CollapsingScaffold
+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.floret.components.GroupedListInset
-import de.jeanlucmakiola.calendula.ui.common.InlineTextField
+import de.jeanlucmakiola.floret.components.GroupedRow
-import de.jeanlucmakiola.calendula.ui.common.Position
+import de.jeanlucmakiola.floret.components.InlineTextField
-import de.jeanlucmakiola.calendula.ui.common.pastelize
+import de.jeanlucmakiola.floret.components.Position
-import java.time.LocalDate
 
 /** Sentinel [editorId] meaning "the editor is composing a new calendar". */
 private const val NEW_CALENDAR_ID = Long.MIN_VALUE
@@ -116,19 +109,22 @@ 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
+ * app" deep-link — the app never touches a synced calendar's server.
- * full-screen destination; [onBack] pops it.
+ *
+ * Export/import lives in its own Settings entry ([BackupScreen], #69); this
+ * screen only points at it, because the two are looked for separately: "which
+ * calendars do I have" versus "keep a copy of them". A full-screen destination;
+ * [onBack] pops it.
  */
 @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
@@ -144,6 +140,7 @@ fun CalendarsScreen(
             initialName = editing?.displayName.orEmpty(),
             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 +160,14 @@ fun CalendarsScreen(
         CalendarsList(
             local = calendars.filter { it.isLocal },
             synced = calendars.filterNot { it.isLocal },
-            disabledIds = disabledIds,
             error = error,
             onConsumeError = viewModel::consumeError,
-            backupResult = backupResult,
+            onOpenBackup = onOpenBackup,
-            onExportBackup = viewModel::exportBackup,
-            onConsumeBackupResult = viewModel::consumeBackupResult,
-            autoBackup = autoBackup,
-            onSetAutoBackupEnabled = viewModel::setAutoBackupEnabled,
-            onSetAutoBackupInterval = viewModel::setAutoBackupIntervalMinutes,
-            onSetAutoBackupFolder = viewModel::setAutoBackupFolder,
             onBack = onBack,
             onAdd = { editorSession++; editorId = NEW_CALENDAR_ID },
             onEdit = { calendar -> editorSession++; editorId = calendar.id },
-            onSetDisabled = viewModel::setDisabled,
+            onSetVisible = viewModel::setCalendarVisible,
-            onSetAccountDisabled = viewModel::setAccountDisabled,
+            onSetAccountVisible = viewModel::setAccountVisible,
         )
     }
 }
@@ -186,27 +176,20 @@ fun CalendarsScreen(
 private fun CalendarsList(
     local: List<CalendarSource>,
     synced: List<CalendarSource>,
-    disabledIds: Set<Long>,
     error: Boolean,
     onConsumeError: () -> Unit,
-    backupResult: BackupResult?,
+    onOpenBackup: () -> Unit,
-    onExportBackup: (android.net.Uri) -> Unit,
-    onConsumeBackupResult: () -> Unit,
-    autoBackup: AutoBackupUiState,
-    onSetAutoBackupEnabled: (Boolean) -> Unit,
-    onSetAutoBackupInterval: (Long) -> Unit,
-    onSetAutoBackupFolder: (android.net.Uri) -> Unit,
     onBack: () -> Unit,
     onAdd: () -> Unit,
     onEdit: (CalendarSource) -> Unit,
-    onSetDisabled: (Long, Boolean) -> Unit,
+    onSetVisible: (Long, Boolean) -> Unit,
-    onSetAccountDisabled: (Collection<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 +200,19 @@ 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 +224,17 @@ private fun CalendarsList(
             onManage = onAdd,
             onToggleExpand = { localExpanded = !localExpanded },
             showToggleAll = local.isNotEmpty(),
-            allEnabled = local.none { it.id in disabledIds },
+            allEnabled = local.all { it.isVisibleInSystem },
-            onToggleAll = { enabled -> onSetAccountDisabled(local.map { it.id }, !enabled) },
+            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 +243,7 @@ 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 +252,24 @@ private fun CalendarsList(
             }
         }
 
-        // Backup — local calendars have no sync, so a .ics export is their only
+        // Backup lives in its own Settings entry now (#69) — this row is the
-        // safety net. Offered only when there is something to back up.
+        // pointer, so someone looking at their local calendars still finds the
-        if (local.isNotEmpty()) {
+        // way to keep a copy of them.
         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),
+            title = stringResource(R.string.settings_section_backup),
-                position = Position.Top,
+            summary = stringResource(R.string.settings_backup_subtitle),
-                leading = { LeadingAvatar(Icons.Default.FileDownload) },
+            position = Position.Alone,
-                onClick = {
+            leading = { LeadingAvatar(Icons.Default.Backup) },
-                    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)
+                Icon(
+                    imageVector = Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
             },
-                onClick = { onSetAutoBackupEnabled(!autoBackup.enabled) },
+            onClick = onOpenBackup,
         )
-            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))
-            }
-        }
 
         Spacer(Modifier.height(16.dp))
 
@@ -352,14 +279,19 @@ private fun CalendarsList(
         SectionHeader(stringResource(R.string.calendars_synced_header))
         HintText(stringResource(R.string.calendars_synced_hint))
         synced
-            .groupBy { it.accountName.ifBlank { it.accountType } }
+            .groupByAccount()
-            .forEach { (account, cals) ->
+            .forEach { group ->
-                val expanded = account !in collapsedAccounts
+                val cals = group.calendars
-                val accountType = cals.first().accountType
+                val expanded = group.key !in collapsedAccounts
-                val accountDisabled = cals.all { it.id in disabledIds }
+                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 +303,41 @@ private fun CalendarsList(
                     },
                     onToggleExpand = {
                         collapsedAccounts = if (expanded) {
-                            collapsedAccounts + account
+                            collapsedAccounts + group.key
                         } else {
-                            collapsedAccounts - account
+                            collapsedAccounts - group.key
                         }
                     },
-                    showToggleAll = true,
+                    showToggleAll = switchable.isNotEmpty(),
-                    allEnabled = cals.none { it.id in disabledIds },
+                    allEnabled = switchable.all { it.isVisibleInSystem },
-                    onToggleAll = { enabled -> onSetAccountDisabled(cals.map { it.id }, !enabled) },
+                    onToggleAll = { enabled ->
+                        onSetAccountVisible(switchable.map { it.id }, enabled)
+                    },
                 ) {
-                    cals.forEachIndexed { index, calendar ->
+                    // Calendars you can act on first; the ones this device isn't
-                        val disabled = calendar.id in disabledIds
+                    // syncing sit 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 = {
+                            trailing = if (calendar.hasVisibilitySwitch) {
+                                {
                                     EnableSwitch(
                                         calendarName = calendar.displayName,
-                                    enabled = !disabled,
+                                        enabled = calendar.isVisibleInSystem,
-                                    onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
+                                        onToggle = { enabled ->
+                                            onSetVisible(calendar.id, enabled)
+                                        },
                                     )
+                                }
+                            } else {
+                                null
                             },
                         )
                     }
@@ -401,13 +345,6 @@ private fun CalendarsList(
             }
     }
 
-    if (showInterval) {
-        BackupIntervalDialog(
-            currentMinutes = autoBackup.intervalMinutes,
-            onConfirm = onSetAutoBackupInterval,
-            onDismiss = { showInterval = false },
-        )
-    }
 }
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -421,12 +358,14 @@ 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 +392,23 @@ private fun CalendarEditor(
                 },
                 actions = {
                     if (!isNew) {
-                        IconButton(onClick = { confirmDelete = true }) {
+                        // Kept in place while the special-dates sync owns this
+                        // calendar, rather than hidden: the button is where you
+                        // expect it, disabled, with the card below saying why —
+                        // and it comes back to life the moment the feature is
+                        // off, when the delete would actually stick.
+                        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 +437,20 @@ 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 },
@@ -558,10 +522,33 @@ private fun CalendarEditor(
 }
 
 /**
- * The per-row enable/disable control. Checked = the calendar is shown in the
+ * The row's supporting line: the states that make this calendar behave unlike a
- * app; unchecking disables it (events, filters and pickers all drop it) without
+ * plain writable one (#76), then its own description. Text rather than badges —
- * touching any provider data. Carries its own content description so the toggle
+ * a row can carry several of these at once next to a switch, which is exactly
- * is self-describing to screen readers even on a dimmed row.
+ * what M3 supporting text composes and a row of static chips doesn't.
+ */
+@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 `Calendars.VISIBLE`: checked
+ * = the calendar is shown, unchecked = it drops out of every surface (events,
+ * filters, pickers) and the provider stops scheduling its reminders. The flag is
+ * device-local — nothing is deleted and nothing is synced anywhere. Carries its
+ * own content description so the toggle is self-describing to screen readers
+ * even on a dimmed row.
  */
 @Composable
 private fun EnableSwitch(
@@ -569,7 +556,7 @@ 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 +651,8 @@ private fun CalendarGroup(
     )
     AnimatedVisibility(
         visible = expanded,
-        enter = calendarExpandEnter(),
+        enter = expandEnter(),
-        exit = calendarCollapseExit(),
+        exit = collapseExit(),
     ) {
         Column(content = body)
     }
@@ -741,175 +728,33 @@ 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 +780,3 @@ 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

@@ -12,10 +12,7 @@ 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.data.reminders.ReminderNotifier
-import de.jeanlucmakiola.calendula.data.reminders.SuppressedReminderStore
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
 import kotlinx.coroutines.CoroutineDispatcher
@@ -45,10 +42,7 @@ 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,
-    private val suppressedStore: SuppressedReminderStore,
-    private val notifier: ReminderNotifier,
     @IoDispatcher private val io: CoroutineDispatcher,
 ) : ViewModel() {
 
@@ -62,20 +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,
@@ -92,6 +72,33 @@ class CalendarsViewModel @Inject constructor(
             initialValue = AutoBackupUiState(),
         )
 
+    /**
+     * Managed special-dates calendars whose deletion would not stick. While the
+     * feature is on, the sync owns every mirror: it recreates a missing one for
+     * an enabled type on the next pass and deletes the leftover of a disabled
+     * one (`SpecialDatesSyncEngine.reconcileCalendars`), so either way the
+     * delete would appear to work and then undo itself. Turning special dates
+     * off empties this set, and deleting a leftover mirror is a real delete from
+     * then on.
+     *
+     * Read off each calendar's own durable marker ([CalendarSource.isManaged],
+     * the `CAL_SYNC2` one the editor lock already trusts) rather than the stored
+     * ids, which are only rewritten on the next sync pass — a preferences loss
+     * would otherwise unlock a live mirror until then.
+     */
+    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()
 
@@ -107,11 +114,11 @@ 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()),
@@ -140,54 +147,30 @@ class CalendarsViewModel @Inject constructor(
     }
 
     /**
-     * Enable or disable a calendar app-side. Disabling removes it from every
+     * Switch a calendar on or off. This is the app's one visibility model: it
-     * surface but Settings → Calendars (and hides its events) without touching
+     * writes the system's `Calendars.VISIBLE`, so the calendar disappears from
-     * provider data — purely a reversible Calendula-local view choice.
+     * every surface *and* the provider stops (or resumes) scheduling its
+     * reminders. Nothing is patched by hand — the provider notifies and the
+     * observer re-queries.
+     *
+     * A reminder that came due while the calendar was off stays gone when it is
+     * switched back on. Delivery plans from `Instances` and `Reminders` on every
+     * scan (#75), but the watermark has already moved past that moment, so no
+     * scan returns it again — and on a read-only install the switch never
+     * reaches the provider at all, so nothing even triggers one. Deliberate: the
+     * reminder was silenced on purpose, and the event itself is back in view.
      */
-    fun setDisabled(id: Long, disabled: Boolean) {
+    fun setCalendarVisible(id: Long, visible: Boolean) = write {
-        viewModelScope.launch {
+        repository.setCalendarsVisible(listOf(id), visible)
-            val current = prefs.disabledCalendarIds.first()
-            val next = if (disabled) current + id else current - id
-            if (next != current) {
-                prefs.setDisabledCalendarIds(next)
-                if (!disabled) recoverReminders(setOf(id))
-            }
-        }
     }
 
     /**
-     * Enable or disable every calendar of one account in a single write — the
+     * Switch every calendar of one account on or off — the "toggle all"
-     * "toggle all" affordance on an account header. Done as one set update so the
+     * affordance on an account header. Each row is written on its own, in one
-     * per-calendar [setDisabled] calls can't race each other.
+     * coroutine so the writes can't race each other.
      */
-    fun setAccountDisabled(ids: Collection<Long>, disabled: Boolean) {
+    fun setAccountVisible(ids: Collection<Long>, visible: Boolean) = write {
-        viewModelScope.launch {
+        repository.setCalendarsVisible(ids, visible)
-            val current = prefs.disabledCalendarIds.first()
-            val next = if (disabled) current + ids else current - ids.toSet()
-            if (next != current) {
-                prefs.setDisabledCalendarIds(next)
-                if (!disabled) recoverReminders(current intersect ids.toSet())
-            }
-        }
-    }
-
-    /**
-     * Re-post the reminders that fired while [reEnabledIds] were disabled and are
-     * still relevant (event not yet over), then drop them from the stash. Runs
-     * after the disabled set is written, so the notifier's own disabled gate lets
-     * them through. Best-effort at re-enable time: it mirrors the receiver gates
-     * (reminders on + postable), and there is no later re-scan, so alerts left
-     * unposted because those gates are closed are simply released.
-     */
-    private suspend fun recoverReminders(reEnabledIds: Set<Long>) {
-        if (reEnabledIds.isEmpty()) return
-        val recovered = suppressedStore.recoverFor(reEnabledIds, System.currentTimeMillis())
-        if (recovered.isNotEmpty() &&
-            settingsPrefs.remindersEnabled.first() &&
-            notifier.canPost()
-        ) {
-            recovered.forEach { notifier.post(it) }
-        }
     }
 
     // --- Automatic backup (issue #8) ------------------------------------

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

@@ -0,0 +1,86 @@
+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 account and a
+ * DAVx5 account can carry the same address and still be two separate accounts,
+ * from separate apps: merging them mixed their calendars into one group whose
+ * header — source logo, "manage in app", toggle-all, collapsed state — was
+ * derived from whichever calendar happened to sort first.
+ */
+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] — the same app whose icon
+ * [SourceLogo] draws. Falls back to the raw account type, which is at least
+ * unique, 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
+ * in the calendar's colour — softened to a pastel, or raw when the softener is
- * visibility filter so they read identically.
+ * 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
 
 /**

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

@@ -0,0 +1,202 @@
+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 calendar that is switched off,
+ * read-only or managed is silently absent — which reads as a missing calendar
+ * rather than an excluded one (#76). [onManageCalendars], when given, adds the
+ * footer row that names the possible reasons and opens the calendar manager,
+ * where each row then says which one applies.
+ */
+@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.SizeTransform
-import androidx.compose.animation.ExitTransition
-import androidx.compose.animation.core.Animatable
-import androidx.compose.animation.core.FastOutSlowInEasing
 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 →
+ * Calendar-specific motion. The family's generic content transitions — section
- * Accessibility → "Remove animations", which sets the global animator duration
+ * expand/collapse, item reveal, list relayout, cross-fade, predictive-back, and
- * scale to 0). Compose animations do *not* honour this platform flag on their
+ * the reduce-motion check — now live in floret-kit's identity module
- * own, so the shared motion helpers in this file check it and fall back to a
+ * (`expandEnter`, `collapseExit`, `itemEnter`, `animateItemMotion`,
- * quick cross-fade — opacity only, no spatial movement — to respect the
+ * `fadeThrough`, `Modifier.predictiveBack`, `rememberReduceMotion`). What stays
- * vestibular intent of the setting while keeping state changes legible.
+ * here is only what's specific to paging the calendar grid: the directional
- *
+ * month/week/day slide and the specs that feed it.
- * Read once at composition; the scale changes rarely and only takes full effect
- * after a process restart anyway.
  */
-@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*
+ * The M3 Expressive spatial spring used for the month/week/day slide: the
- * spring-physics spec from the active motion scheme — snappy with a subtle
+ * *default* spring-physics spec from the active motion scheme, rather than a
- * springy settle, rather than a fixed easing curve.
+ * 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)
+ * The effects spec from the active motion scheme, for the opacity half of the
- * transitions. Captured in composable scope alongside [rememberCalendarSlideSpec]
+ * transition. Captured in composable scope alongside [rememberCalendarSlideSpec]
- * for use in non-composable transition lambdas and as the reduced-motion fallback.
+ * 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 }
+    return ContentTransform(
-        .togetherWith(slideOutHorizontally(spec) { w -> -dir * w })
+        targetContentEnter =
-}
+            slideInHorizontally(spec) { w -> dir * w / SLIDE_TRAVEL_DIVISOR } + fadeIn(fadeSpec),
-
+        initialContentExit =
-/**
+            slideOutHorizontally(spec) { w -> -dir * w / SLIDE_TRAVEL_DIVISOR } + fadeOut(fadeSpec),
- * Cross-fade [ContentTransform] for swapping whole screens or content blocks
+        // AnimatedContent clips to the animating container by default, which
- * where there is no meaningful spatial direction (e.g. onboarding gates). Pure
+        // shears the pages against the viewport edge as they pass. There is no
- * opacity, so it doubles as its own reduced-motion form.
+        // size change here to contain — both pages are the same grid.
- */
+        sizeTransform = SizeTransform(clip = false),
-@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.
- *
- * 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.
- */
-@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
+ * How far a page travels, as a fraction of the container width.
- * 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
+ * A full width was the obvious reading of "paging", but the two pages are
- * once and apply the returned [Modifier] to that screen's root so the preview
+ * stacked and both opaque, so a full-width slide showed one grid racing across
- * respects the same back semantics. Under reduced motion the visual preview is
+ * another — the movement carried the whole transition and had a long way to go.
- * skipped (the back still works); on API < 34 the system delivers no progress,
+ * Under M3's shared-axis pattern the offset only has to *hint* the direction
- * so it degrades to a plain back.
+ * while the cross-fade does the swapping, so a fifth of the width is plenty and
+ * leaves nothing skating past.
  */
-@Composable
+private const val SLIDE_TRAVEL_DIVISOR = 5
-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
-    }
-}

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

@@ -18,14 +18,14 @@ 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
 
 /**
  * A wrapping row of round colour swatches; the one matching [selected] is
  * ringed and checked. Shared by the calendar editor and the event-colour
  * picker so both pick a colour the same way. Swatches render through
- * [pastelize] — the softened colour the app actually paints, not the raw hue.
+ * [eventFill] — the colour the app actually paints (softened, or raw when the
+ * softener is off, issue #36), not necessarily the stored hue.
  */
 @OptIn(ExperimentalLayoutApi::class)
 @Composable
@@ -36,16 +36,18 @@ fun ColorSwatchRow(
     dark: Boolean,
     modifier: Modifier = Modifier,
 ) {
+    val soften = LocalSoftenColors.current
     FlowRow(modifier = modifier, horizontalArrangement = Arrangement.spacedBy(12.dp)) {
         colors.forEach { argb ->
             val isSelected = argb == selected
+            val fill = eventFill(argb, dark, soften)
             Box(
                 contentAlignment = Alignment.Center,
                 modifier = Modifier
                     .padding(vertical = 4.dp)
                     .size(40.dp)
                     .clip(CircleShape)
-                    .background(pastelize(argb, dark))
+                    .background(fill)
                     .then(
                         if (isSelected) {
                             Modifier.border(2.dp, MaterialTheme.colorScheme.onSurface, CircleShape)
@@ -59,7 +61,7 @@ fun ColorSwatchRow(
                     Icon(
                         Icons.Default.Check,
                         contentDescription = null,
-                        tint = Color.Black.copy(alpha = 0.7f),
+                        tint = eventInk(fill, alpha = 0.7f),
                         modifier = Modifier.size(20.dp),
                     )
                 }

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

@@ -1,50 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.BoxScope
-import androidx.compose.foundation.layout.offset
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.width
-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.rotate
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import androidx.compose.ui.zIndex
-
-/**
- * A Flutter-style "DEBUG" corner ribbon, drawn across the top-right corner of
- * the app. Deliberately a stark, un-themed marker (not a product component) so a
- * debug build is unmistakable at a glance — gate it on `BuildConfig.DEBUG` at the
- * call site so it never reaches a release build. Non-interactive: it's a plain
- * label with no pointer handler, so taps fall through to whatever is beneath it.
- *
- * Drop it in as the last child of a full-screen [androidx.compose.foundation.layout.Box]
- * so it overlays the UI.
- */
-@Composable
-fun BoxScope.DebugRibbon() {
-    Text(
-        text = "DEBUG",
-        color = Color.White,
-        fontSize = 10.sp,
-        fontWeight = FontWeight.Bold,
-        letterSpacing = 1.sp,
-        textAlign = TextAlign.Center,
-        modifier = Modifier
-            .align(Alignment.TopEnd)
-            .zIndex(1f)
-            // Push the band out so its midline crosses the very corner, then
-            // rotate it to the classic 45° ribbon.
-            .offset(x = 36.dp, y = 24.dp)
-            .rotate(45f)
-            .background(Color(0xFFB23B00))
-            .width(140.dp)
-            .padding(vertical = 2.dp),
-    )
-}

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

@@ -1,94 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ArrowDropDown
-import androidx.compose.material3.DropdownMenu
-import androidx.compose.material3.DropdownMenuItem
-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.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.text.input.KeyboardType
-import androidx.compose.ui.unit.dp
-
-/**
- * Tonal 3-digit number input shared by the custom reminder/recurrence steps and
- * the reminder pickers — the app's [InlineTextField] over a tonal surface, so it
- * matches the card/grouped-row design language (not Material's outlined field).
- */
-@Composable
-fun DialogAmountField(
-    value: String,
-    onValueChange: (String) -> Unit,
-    placeholder: String,
-) {
-    // surfaceContainerHighest — the picker/dialog sits on surfaceContainerHigh,
-    // so anything lower vanishes.
-    Surface(
-        color = MaterialTheme.colorScheme.surfaceContainerHighest,
-        shape = RoundedCornerShape(12.dp),
-    ) {
-        InlineTextField(
-            value = value,
-            onValueChange = { text ->
-                if (text.length <= 3 && text.all(Char::isDigit)) onValueChange(text)
-            },
-            placeholder = placeholder,
-            textStyle = MaterialTheme.typography.titleMedium,
-            keyboardType = KeyboardType.Number,
-            modifier = Modifier
-                .width(72.dp)
-                .padding(horizontal = 14.dp, vertical = 12.dp),
-        )
-    }
-}
-
-/** Tonal dropdown trigger + menu shared by the custom reminder/recurrence steps and pickers. */
-@Composable
-fun DialogUnitDropdown(
-    label: String,
-    entries: List<String>,
-    onPick: (Int) -> Unit,
-) {
-    var open by remember { mutableStateOf(false) }
-    Box {
-        Surface(
-            color = MaterialTheme.colorScheme.surfaceContainerHighest,
-            shape = RoundedCornerShape(12.dp),
-            onClick = { open = true },
-        ) {
-            Row(
-                verticalAlignment = Alignment.CenterVertically,
-                modifier = Modifier.padding(start = 14.dp, end = 8.dp, top = 12.dp, bottom = 12.dp),
-            ) {
-                Text(text = label, style = MaterialTheme.typography.titleMedium)
-                Spacer(Modifier.width(4.dp))
-                Icon(imageVector = Icons.Default.ArrowDropDown, contentDescription = null)
-            }
-        }
-        DropdownMenu(expanded = open, onDismissRequest = { open = false }) {
-            entries.forEachIndexed { index, entry ->
-                DropdownMenuItem(
-                    text = { Text(entry) },
-                    onClick = {
-                        onPick(index)
-                        open = false
-                    },
-                )
-            }
-        }
-    }
-}

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

@@ -0,0 +1,46 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.luminance
+import de.jeanlucmakiola.floret.components.pastelize
+
+/**
+ * Whether calendar/event colours are softened toward theme-fitting pastels
+ * before display (issue #36). Provided app-wide from the "soften colours"
+ * setting; the default `true` keeps the historical look. When off, the raw
+ * provider colour is painted verbatim — matching the sync source (DAVx5/CalDAV)
+ * and other calendar apps. Widgets live outside this composition and read the
+ * preference directly, then pass the flag to [eventFill] / [eventInk].
+ */
+val LocalSoftenColors = staticCompositionLocalOf { true }
+
+/**
+ * Display fill for an event chip/bar or a calendar tint: the [pastelize]d colour
+ * when [soften] is on, else the raw provider ARGB verbatim (forced opaque, since
+ * pastelize also returns an opaque colour).
+ */
+fun eventFill(rawArgb: Int, dark: Boolean, soften: Boolean): Color =
+    if (soften) pastelize(rawArgb, dark) else Color(rawArgb or 0xFF000000.toInt())
+
+/**
+ * Contrast ink (title text / glyph) for a filled chip painted with [eventFill]:
+ * white on a dark fill, near-black on a light one (issue #21). Applies to both
+ * softened and raw fills — a saturated hue (deep blue, purple, red) is
+ * perceptually dark even after softening pins its HSV value, so black text on it
+ * reads poorly. The choice is objective, not a tuned threshold: white wins only
+ * when it out-contrasts black against the fill, which (by the WCAG contrast
+ * ratio) is at relative luminance ≈ 0.18 — so mid and light colours keep
+ * near-black text. [alpha] carries the caller's soft emphasis.
+ */
+fun eventInk(fill: Color, alpha: Float = 0.8f): Color {
+    val useWhite = fill.luminance() < INK_LUMINANCE_CROSSOVER
+    return (if (useWhite) Color.White else Color.Black).copy(alpha = alpha)
+}
+
+/**
+ * Relative-luminance crossover where white text starts to out-contrast black.
+ * Solving `contrast(white, L) = contrast(black, L)` on the WCAG ratio gives
+ * `L = sqrt(1.05 * 0.05) - 0.05 ≈ 0.179`.
+ */
+private const val INK_LUMINANCE_CROSSOVER = 0.179f

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

@@ -9,6 +9,7 @@ import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.Palette
 import androidx.compose.material.icons.filled.People
 import androidx.compose.material.icons.filled.Place
+import androidx.compose.material.icons.filled.Public
 import androidx.compose.material.icons.filled.Repeat
 import androidx.compose.ui.graphics.vector.ImageVector
 import de.jeanlucmakiola.calendula.R
@@ -24,6 +25,7 @@ import de.jeanlucmakiola.calendula.domain.EventFormField
 fun eventFormFieldLabel(field: EventFormField): Int = when (field) {
     EventFormField.Location -> R.string.event_detail_location
     EventFormField.Description -> R.string.event_detail_description
+    EventFormField.Timezone -> R.string.event_detail_timezone
     EventFormField.Reminders -> R.string.event_detail_reminders
     EventFormField.Recurrence -> R.string.event_detail_recurrence
     EventFormField.Availability -> R.string.event_edit_availability
@@ -35,6 +37,7 @@ fun eventFormFieldLabel(field: EventFormField): Int = when (field) {
 fun eventFormFieldIcon(field: EventFormField): ImageVector = when (field) {
     EventFormField.Location -> Icons.Default.Place
     EventFormField.Description -> Icons.AutoMirrored.Filled.Notes
+    EventFormField.Timezone -> Icons.Default.Public
     EventFormField.Reminders -> Icons.Default.Notifications
     EventFormField.Recurrence -> Icons.Default.Repeat
     EventFormField.Availability -> Icons.Default.EventAvailable

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

@@ -1,245 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.animation.core.animateDpAsState
-import androidx.compose.foundation.background
-import androidx.compose.foundation.interaction.MutableInteractionSource
-import androidx.compose.foundation.interaction.collectIsPressedAsState
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ColumnScope
-import androidx.compose.foundation.layout.RowScope
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.consumeWindowInsets
-import androidx.compose.foundation.layout.heightIn
-import androidx.compose.foundation.layout.imePadding
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.rememberScrollState
-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.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.material3.LargeTopAppBar
-import androidx.compose.material3.ListItem
-import androidx.compose.material3.ListItemDefaults
-import androidx.compose.material3.MaterialTheme
-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
-import androidx.compose.material3.rememberTopAppBarState
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.remember
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.input.nestedscroll.nestedScroll
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
-import de.jeanlucmakiola.calendula.R
-
-/**
- * Position of a row within a grouped list, after the Android-15 settings
- * pattern: a run of rows shares one rounded container, with full corners at the
- * group's outer edges and small corners between, separated by small gaps.
- */
-enum class Position { Top, Middle, Bottom, Alone }
-
-/** Maps an index within a group of [count] rows to its [Position]. */
-fun positionOf(index: Int, count: Int): Position = when {
-    count <= 1 -> Position.Alone
-    index == 0 -> Position.Top
-    index == count - 1 -> Position.Bottom
-    else -> Position.Middle
-}
-
-/**
- * The app's standard full-screen list scaffold. By default a collapsing
- * [LargeTopAppBar] whose title shrinks into the bar (next to the back button) as
- * the content scrolls — used by Settings and the calendar manager, where the
- * large header sets the page. Content is a scrollable column that feeds the
- * toolbar via nested scroll.
- *
- * Set [largeTopBar] to false for a pinned, single-line [TopAppBar] instead: the
- * title sits in the bar from the start, with no expanded header to scroll past.
- * Preferred for selection pickers, where the tall header is just wasted space
- * above the options.
- */
-@OptIn(ExperimentalMaterial3Api::class)
-@Composable
-fun CollapsingScaffold(
-    title: String,
-    onBack: () -> Unit,
-    modifier: Modifier = Modifier,
-    largeTopBar: Boolean = true,
-    snackbarHost: @Composable () -> Unit = {},
-    actions: @Composable RowScope.() -> Unit = {},
-    content: @Composable ColumnScope.() -> Unit,
-) {
-    val scrollBehavior = if (largeTopBar) {
-        TopAppBarDefaults.exitUntilCollapsedScrollBehavior(rememberTopAppBarState())
-    } else {
-        TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState())
-    }
-    Scaffold(
-        modifier = modifier
-            .predictiveBack(onBack = onBack)
-            .fillMaxSize()
-            .background(MaterialTheme.colorScheme.surface)
-            .nestedScroll(scrollBehavior.nestedScrollConnection),
-        topBar = {
-            val navigationIcon = @Composable {
-                IconButton(onClick = onBack) {
-                    Icon(
-                        Icons.AutoMirrored.Filled.ArrowBack,
-                        contentDescription = stringResource(R.string.settings_back),
-                    )
-                }
-            }
-            val colors = TopAppBarDefaults.topAppBarColors(
-                scrolledContainerColor = MaterialTheme.colorScheme.surface,
-            )
-            if (largeTopBar) {
-                LargeTopAppBar(
-                    title = { Text(title) },
-                    navigationIcon = navigationIcon,
-                    actions = actions,
-                    scrollBehavior = scrollBehavior,
-                    colors = colors,
-                )
-            } else {
-                TopAppBar(
-                    title = { Text(title) },
-                    navigationIcon = navigationIcon,
-                    actions = actions,
-                    scrollBehavior = scrollBehavior,
-                    colors = colors,
-                )
-            }
-        },
-        snackbarHost = snackbarHost,
-    ) { innerPadding ->
-        Column(
-            modifier = Modifier
-                .padding(innerPadding)
-                // Mark the scaffold's system-bar insets as consumed so the
-                // imePadding below adds only the keyboard height beyond them
-                // (max, not sum) — otherwise the nav-bar inset double-counts and
-                // leaves an empty strip above the keyboard.
-                .consumeWindowInsets(innerPadding)
-                .fillMaxSize()
-                // Paint the surface across the full area before imePadding carves
-                // into it, so any sliver above the keyboard reads as surface — not
-                // the dialog window's black — during the IME animation.
-                .background(MaterialTheme.colorScheme.surface)
-                // Shrink the scroll viewport by the keyboard inset so a focused
-                // field (e.g. the custom-reminder amount) can scroll into view.
-                .imePadding()
-                .verticalScroll(rememberScrollState())
-                .padding(top = 8.dp, bottom = 24.dp),
-            content = content,
-        )
-    }
-}
-
-/**
- * One row in a grouped list: an M3 [ListItem] over a tonal [Surface] whose
- * corner radii come from its [position] (so a run of rows reads as a single
- * rounded card). Corners round further on press. A null [onClick] makes the
- * row non-interactive (e.g. read-only entries). [dimmed] fades the headline and
- * summary to the M3 disabled emphasis while leaving the [trailing] control at
- * full opacity — for rows that are present but switched off.
- */
-@OptIn(ExperimentalMaterial3Api::class)
-@Composable
-fun GroupedRow(
-    title: String,
-    position: Position,
-    modifier: Modifier = Modifier,
-    summary: String? = null,
-    selected: Boolean = false,
-    dimmed: Boolean = false,
-    container: Color? = null,
-    minHeight: Dp = 72.dp,
-    // The 2.dp separation between rows in a run. Suppressed by the reorderable
-    // list, which owns uniform spacing itself so every slot has the same pitch.
-    gapBelow: Boolean = true,
-    leading: @Composable (() -> Unit)? = null,
-    trailing: @Composable (() -> Unit)? = null,
-    onClick: (() -> Unit)? = null,
-) {
-    val interaction = remember { MutableInteractionSource() }
-    val pressed by interaction.collectIsPressedAsState()
-    val full by animateDpAsState(if (pressed) 36.dp else 22.dp, label = "fullCorner")
-    val small by animateDpAsState(if (pressed) 36.dp else 6.dp, label = "smallCorner")
-    val shape = when (position) {
-        Position.Alone -> RoundedCornerShape(full)
-        Position.Top -> RoundedCornerShape(
-            topStart = full, topEnd = full, bottomStart = small, bottomEnd = small,
-        )
-        Position.Middle -> RoundedCornerShape(small)
-        Position.Bottom -> RoundedCornerShape(
-            topStart = small, topEnd = small, bottomStart = full, bottomEnd = full,
-        )
-    }
-    val gap = when {
-        !gapBelow -> Modifier
-        position == Position.Top || position == Position.Middle -> Modifier.padding(bottom = 2.dp)
-        else -> Modifier
-    }
-    val itemColors = if (selected) {
-        ListItemDefaults.colors(
-            containerColor = Color.Transparent,
-            headlineColor = MaterialTheme.colorScheme.onSecondaryContainer,
-            leadingIconColor = MaterialTheme.colorScheme.onSecondaryContainer,
-            supportingColor = MaterialTheme.colorScheme.onSecondaryContainer,
-            trailingIconColor = MaterialTheme.colorScheme.onSecondaryContainer,
-        )
-    } else if (dimmed) {
-        // M3 disabled emphasis (0.38α) on the text/leading; the trailing control
-        // stays full-opacity so the toggle reads as live even on a faded row.
-        val muted = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.38f)
-        ListItemDefaults.colors(
-            containerColor = Color.Transparent,
-            headlineColor = muted,
-            leadingIconColor = muted,
-            supportingColor = muted,
-        )
-    } else {
-        ListItemDefaults.colors(containerColor = Color.Transparent)
-    }
-    val item: @Composable () -> Unit = {
-        ListItem(
-            headlineContent = { Text(title) },
-            supportingContent = summary?.let { text -> { Text(text) } },
-            leadingContent = leading,
-            trailingContent = trailing,
-            colors = itemColors,
-            modifier = Modifier.heightIn(min = minHeight),
-        )
-    }
-    val base = modifier
-        .fillMaxWidth()
-        .padding(horizontal = 16.dp)
-        .then(gap)
-    val containerColor = when {
-        selected -> MaterialTheme.colorScheme.secondaryContainer
-        container != null -> container
-        else -> MaterialTheme.colorScheme.surfaceContainerHigh
-    }
-    if (onClick != null) {
-        Surface(
-            onClick = onClick,
-            color = containerColor,
-            shape = shape,
-            interactionSource = interaction,
-            modifier = base,
-        ) { item() }
-    } else {
-        Surface(color = containerColor, shape = shape, modifier = base) { item() }
-    }
-}

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

@@ -1,86 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.text.BasicTextField
-import androidx.compose.foundation.text.KeyboardActions
-import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.SolidColor
-import androidx.compose.ui.graphics.isSpecified
-import androidx.compose.ui.text.TextStyle
-import androidx.compose.ui.text.input.ImeAction
-import androidx.compose.ui.text.input.KeyboardCapitalization
-import androidx.compose.ui.text.input.KeyboardType
-import androidx.compose.ui.unit.dp
-
-/**
- * The app's borderless text input: no underline, no outline, just the tonal
- * card behind it. This is the standard input across the app — we deliberately
- * don't use Material's outlined/filled text fields, so anything that takes text
- * (the event form, the calendar manager, dialogs) uses this inside a tonal
- * [androidx.compose.material3.Surface].
- */
-@Composable
-fun InlineTextField(
-    value: String,
-    onValueChange: (String) -> Unit,
-    placeholder: String,
-    modifier: Modifier = Modifier
-        .fillMaxWidth()
-        .padding(vertical = 4.dp),
-    textStyle: TextStyle = MaterialTheme.typography.titleMedium,
-    singleLine: Boolean = true,
-    minLines: Int = 1,
-    enabled: Boolean = true,
-    keyboardType: KeyboardType = KeyboardType.Text,
-    capitalization: KeyboardCapitalization = KeyboardCapitalization.None,
-    imeAction: ImeAction = ImeAction.Default,
-    /** Invoked when the IME action key (e.g. Done) is pressed. */
-    onImeAction: (() -> Unit)? = null,
-) {
-    val resolvedStyle = textStyle.copy(
-        color = when {
-            // A disabled field reads as dimmed, like a locked value.
-            !enabled -> MaterialTheme.colorScheme.onSurfaceVariant
-            textStyle.color.isSpecified -> textStyle.color
-            else -> MaterialTheme.colorScheme.onSurface
-        },
-    )
-    BasicTextField(
-        value = value,
-        onValueChange = onValueChange,
-        enabled = enabled,
-        textStyle = resolvedStyle,
-        singleLine = singleLine,
-        minLines = minLines,
-        keyboardOptions = KeyboardOptions(
-            keyboardType = keyboardType,
-            capitalization = capitalization,
-            imeAction = imeAction,
-        ),
-        keyboardActions = onImeAction?.let { action ->
-            KeyboardActions(onAny = { action() })
-        } ?: KeyboardActions.Default,
-        cursorBrush = SolidColor(MaterialTheme.colorScheme.primary),
-        decorationBox = { innerTextField ->
-            Box {
-                if (value.isEmpty()) {
-                    // Clearly fainter than typed text, so a hint never reads as
-                    // prefilled content.
-                    Text(
-                        text = placeholder,
-                        style = resolvedStyle,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f),
-                    )
-                }
-                innerTextField()
-            }
-        },
-        modifier = modifier,
-    )
-}

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

@@ -1,20 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.remember
-import androidx.compose.ui.platform.LocalConfiguration
-import androidx.core.os.ConfigurationCompat
-import java.util.Locale
-
-/**
- * Current display [Locale], read observably from [LocalConfiguration] so the UI
- * recomposes after a locale change (lint: NonObservableLocale). Used for
- * weekday/month name formatting.
- */
-@Composable
-fun currentLocale(): Locale {
-    val configuration = LocalConfiguration.current
-    return remember(configuration) {
-        ConfigurationCompat.getLocales(configuration).get(0) ?: Locale.getDefault()
-    }
-}

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

@@ -1,94 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-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.padding
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.shape.RoundedCornerShape
-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.graphics.Color
-import androidx.compose.ui.graphics.isSpecified
-import androidx.compose.ui.graphics.vector.ImageVector
-import androidx.compose.ui.unit.dp
-
-/**
- * The app's standard pick in a selection dialog: a full-width tonal card,
- * optionally with a leading icon and a supporting line; the selected option
- * is highlighted. Stack with 8dp gaps inside an AlertDialog — this is the
- * only sanctioned selection-modal style (no radio rows, no bare text lists).
- */
-@Composable
-fun OptionCard(
-    label: String,
-    onClick: () -> Unit,
-    modifier: Modifier = Modifier,
-    icon: ImageVector? = null,
-    /** Icon tint override, e.g. a calendar colour; unspecified follows selection. */
-    iconTint: Color = Color.Unspecified,
-    supportingText: String? = null,
-    selected: Boolean = false,
-    /** Label colour override, e.g. primary for an emphasised "Custom" entry. */
-    labelColor: Color = Color.Unspecified,
-) {
-    val contentColor = if (selected) {
-        MaterialTheme.colorScheme.onSecondaryContainer
-    } else {
-        MaterialTheme.colorScheme.onSurface
-    }
-    Surface(
-        onClick = onClick,
-        color = if (selected) {
-            MaterialTheme.colorScheme.secondaryContainer
-        } else {
-            MaterialTheme.colorScheme.surfaceContainerHighest
-        },
-        shape = RoundedCornerShape(12.dp),
-        modifier = modifier.fillMaxWidth(),
-    ) {
-        Row(
-            verticalAlignment = Alignment.CenterVertically,
-            modifier = Modifier.padding(horizontal = 16.dp, vertical = 14.dp),
-        ) {
-            if (icon != null) {
-                Icon(
-                    imageVector = icon,
-                    contentDescription = null,
-                    tint = when {
-                        iconTint.isSpecified -> iconTint
-                        selected -> MaterialTheme.colorScheme.onSecondaryContainer
-                        else -> MaterialTheme.colorScheme.onSurfaceVariant
-                    },
-                    modifier = Modifier.size(20.dp),
-                )
-                Spacer(Modifier.width(12.dp))
-            }
-            Column {
-                Text(
-                    text = label,
-                    style = MaterialTheme.typography.titleMedium,
-                    color = if (labelColor.isSpecified) labelColor else contentColor,
-                )
-                if (supportingText != null) {
-                    Text(
-                        text = supportingText,
-                        style = MaterialTheme.typography.bodySmall,
-                        color = if (selected) {
-                            MaterialTheme.colorScheme.onSecondaryContainer.copy(alpha = 0.8f)
-                        } else {
-                            MaterialTheme.colorScheme.onSurfaceVariant
-                        },
-                    )
-                }
-            }
-        }
-    }
-}

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

@@ -1,123 +1,48 @@
 package de.jeanlucmakiola.calendula.ui.common
 
 import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ColumnScope
-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.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Check
 import androidx.compose.material3.Checkbox
-import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.SegmentedButton
-import androidx.compose.material3.SegmentedButtonDefaults
-import androidx.compose.material3.SingleChoiceSegmentedButtonRow
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
-import android.view.WindowManager
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 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.LocalView
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.window.Dialog
-import androidx.compose.ui.window.DialogProperties
-import androidx.compose.ui.window.DialogWindowProvider
 import de.jeanlucmakiola.calendula.R
-import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
+import de.jeanlucmakiola.floret.components.CustomAmountEditor
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.identity.collapseExit
+import de.jeanlucmakiola.floret.identity.expandEnter
+import de.jeanlucmakiola.floret.locale.currentLocale
+import de.jeanlucmakiola.floret.reminders.ReminderOverride
+import de.jeanlucmakiola.floret.reminders.ReminderUnit
+import de.jeanlucmakiola.floret.reminders.reminderOverrideForMinutes
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
-
+import de.jeanlucmakiola.calendula.ui.agenda.agendaRangeWindowSummary
-/**
+import de.jeanlucmakiola.calendula.ui.agenda.dayCount
- * Shared full-screen scaffold for selection pickers: a full-bleed [Dialog] that
+import kotlinx.datetime.DateTimeUnit
- * reuses the app's [CollapsingScaffold] (back button + full width), but with a
+import kotlinx.datetime.DayOfWeek
- * pinned single-line title rather than the large collapsing header — a picker is
+import kotlinx.datetime.TimeZone
- * a short list, so the tall header would only be empty space to scroll past.
+import kotlinx.datetime.plus
- * [content] places the connected grouped rows; selecting one calls [onDismiss].
+import kotlinx.datetime.toLocalDateTime
- */
+import kotlin.time.Clock
-@Composable
-fun FullScreenPicker(
-    title: String,
-    onDismiss: () -> Unit,
-    content: @Composable ColumnScope.() -> Unit,
-) {
-    Dialog(
-        onDismissRequest = onDismiss,
-        properties = DialogProperties(
-            usePlatformDefaultWidth = false,
-            decorFitsSystemWindows = false,
-        ),
-    ) {
-        // The dialog window pans by default when the keyboard opens, which —
-        // combined with the content's own imePadding — leaves a fixed black gap
-        // above the keyboard. Switch it to ADJUST_NOTHING so the window stays
-        // full-screen and imePadding alone lifts the focused field.
-        val view = LocalView.current
-        SideEffect {
-            (view.parent as? DialogWindowProvider)?.window
-                ?.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_NOTHING)
-        }
-        CollapsingScaffold(
-            title = title,
-            onBack = onDismiss,
-            largeTopBar = false,
-            content = content,
-        )
-    }
-}
-
-/**
- * General single-select picker, full-screen: each option is a connected grouped
- * row and the current one carries a check. Drop-in for the former dialog
- * (theme, week start, language, …).
- */
-@Composable
-fun <T> OptionPicker(
-    title: String,
-    options: List<T>,
-    selected: T,
-    label: @Composable (T) -> String,
-    onSelect: (T) -> Unit,
-    onDismiss: () -> Unit,
-    header: (@Composable ColumnScope.() -> Unit)? = null,
-) {
-    FullScreenPicker(title = title, onDismiss = onDismiss) {
-        header?.invoke(this)
-        options.forEachIndexed { index, option ->
-            val isSelected = option == selected
-            GroupedRow(
-                title = label(option),
-                position = positionOf(index, options.size),
-                selected = isSelected,
-                trailing = if (isSelected) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
-                onClick = {
-                    onSelect(option)
-                    onDismiss()
-                },
-            )
-        }
-    }
-}
 
 /**
  * Reminder-default picker, full-screen and **multi-select**: each [presets]
@@ -128,20 +53,26 @@ fun <T> OptionPicker(
  * and, for a per-calendar picker ([allowInherit]), "Use default reminder", which
  * defers to the global default. Clearing the last checked time reverts to "Use
  * default" on a per-calendar picker (so an accidental toggle-undo can't silently
- * wipe the calendar's default) and to explicit [CalendarReminderOverride.None]
+ * wipe the calendar's default) and to explicit [ReminderOverride.None]
  * on the global default (where empty legitimately means no reminder). A "Custom"
  * row expands an inline number field plus a unit selector to add an arbitrary
  * lead time to the set. Changes apply live via [onSelect]; the user leaves via
  * back.
+ *
+ * [leadTimeSummary] adds a second line to each lead-time row. It exists for the
+ * all-day pickers, where the lead time alone doesn't say when anything happens:
+ * the hour comes from the separate "show all-day reminders at" setting, so
+ * "1 day before" is only half the answer until the row spells out the time.
  */
 @Composable
 fun ReminderDefaultPicker(
     title: String,
     presets: List<Int>,
-    selected: CalendarReminderOverride,
+    selected: ReminderOverride,
     allowInherit: Boolean,
-    onSelect: (CalendarReminderOverride) -> Unit,
+    onSelect: (ReminderOverride) -> Unit,
     onDismiss: () -> Unit,
+    leadTimeSummary: (@Composable (Int) -> String?)? = null,
 ) {
     // Optimistic local state: once the user edits, the chosen override is
     // authoritative while the picker is open, so quick successive toggles compose
@@ -158,9 +89,9 @@ fun ReminderDefaultPicker(
     LaunchedEffect(selected) {
         if (!userEdited) current = selected
     }
-    val inherits = current is CalendarReminderOverride.Inherit
+    val inherits = current is ReminderOverride.Inherit
-    val isNone = current is CalendarReminderOverride.None
+    val isNone = current is ReminderOverride.None
-    val selectedMinutes = (current as? CalendarReminderOverride.Minutes)?.minutes.orEmpty()
+    val selectedMinutes = (current as? ReminderOverride.Minutes)?.minutes.orEmpty()
     // Custom (non-preset) lead times seen this session, so unchecking one keeps
     // its row (unchecked) until the picker closes instead of vanishing mid-tap,
     // which would strand a hand-entered value with no way to re-check it.
@@ -173,7 +104,7 @@ fun ReminderDefaultPicker(
     var amountText by rememberSaveable { mutableStateOf("") }
     var unit by rememberSaveable { mutableStateOf(ReminderUnit.Minutes) }
 
-    fun apply(override: CalendarReminderOverride) {
+    fun apply(override: ReminderOverride) {
         userEdited = true
         current = override
         onSelect(override)
@@ -197,7 +128,7 @@ fun ReminderDefaultPicker(
                 } else {
                     null
                 },
-                onClick = { apply(CalendarReminderOverride.Inherit) },
+                onClick = { apply(ReminderOverride.Inherit) },
             )
         }
         GroupedRow(
@@ -209,7 +140,7 @@ fun ReminderDefaultPicker(
             } else {
                 null
             },
-            onClick = { apply(CalendarReminderOverride.None) },
+            onClick = { apply(ReminderOverride.None) },
         )
         Spacer(Modifier.height(24.dp))
         val rowCount = rows.size + 1 // + the custom row
@@ -217,6 +148,7 @@ fun ReminderDefaultPicker(
             val checked = minute in selectedMinutes
             GroupedRow(
                 title = reminderLeadTimeLabel(minute),
+                summary = leadTimeSummary?.invoke(minute),
                 position = positionOf(index, rowCount),
                 selected = checked,
                 trailing = { Checkbox(checked = checked, onCheckedChange = { toggle(minute) }) },
@@ -232,8 +164,8 @@ fun ReminderDefaultPicker(
         )
         AnimatedVisibility(
             visible = customExpanded,
-            enter = calendarExpandEnter(),
+            enter = expandEnter(),
-            exit = calendarCollapseExit(),
+            exit = collapseExit(),
         ) {
             CustomReminderEditor(
                 amountText = amountText,
@@ -250,26 +182,6 @@ fun ReminderDefaultPicker(
     }
 }
 
-/**
- * The override a lead-time set maps to when emitted from [ReminderDefaultPicker].
- * A non-empty set is [CalendarReminderOverride.Minutes]; an empty set (the last
- * time was unchecked) reverts to [CalendarReminderOverride.Inherit] on a
- * per-calendar picker ([allowInherit]) so an accidental toggle-undo can't
- * silently wipe the calendar's default, and to explicit
- * [CalendarReminderOverride.None] on the global default (where empty legitimately
- * means no reminder). Pure so it can be unit-tested.
- */
-internal fun reminderOverrideForMinutes(
-    minutes: List<Int>,
-    allowInherit: Boolean,
-): CalendarReminderOverride {
-    val norm = minutes.distinct().sorted()
-    return when {
-        norm.isNotEmpty() -> CalendarReminderOverride.Minutes(norm)
-        allowInherit -> CalendarReminderOverride.Inherit
-        else -> CalendarReminderOverride.None
-    }
-}
 
 /**
  * The expanded "Custom" lead-time editor: a tonal card connected to the Custom
@@ -287,89 +199,51 @@ private fun CustomReminderEditor(
     onConfirm: (Int) -> Unit,
 ) {
     val amount = amountText.toIntOrNull()?.takeIf { it in 1..999 }
-    Surface(
+    CustomAmountEditor(
-        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        amountText = amountText,
-        // A Position.Bottom shape: tight top corners meeting the row, full bottom.
+        onAmountChange = onAmountChange,
-        shape = RoundedCornerShape(topStart = 6.dp, topEnd = 6.dp, bottomStart = 22.dp, bottomEnd = 22.dp),
+        unitLabels = ReminderUnit.entries.map { stringResource(reminderUnitLabel(it)) },
-        modifier = Modifier
+        selectedUnit = unit.ordinal,
-            .fillMaxWidth()
+        onUnitChange = { onUnitChange(ReminderUnit.entries[it]) },
-            .padding(horizontal = 16.dp),
+        preview = amount?.let { reminderLeadTimeLabel(it * unit.minutesFactor) }
-    ) {
-        Column(
-            modifier = Modifier.padding(16.dp),
-            verticalArrangement = Arrangement.spacedBy(16.dp),
-        ) {
-            // Unit toggle first so it stays visible above the keyboard once the
-            // amount field (the bottom row) is focused and scrolled into view.
-            SingleChoiceSegmentedButtonRow(modifier = Modifier.fillMaxWidth()) {
-                ReminderUnit.entries.forEachIndexed { index, entry ->
-                    SegmentedButton(
-                        selected = unit == entry,
-                        onClick = { onUnitChange(entry) },
-                        shape = SegmentedButtonDefaults.itemShape(index, ReminderUnit.entries.size),
-                        label = { Text(stringResource(reminderUnitLabel(entry))) },
-                    )
-                }
-            }
-            // Amount, a live preview of the lead time it resolves to, and Set —
-            // all on one row, sitting just above the keyboard.
-            Row(verticalAlignment = Alignment.CenterVertically) {
-                DialogAmountField(
-                    value = amountText,
-                    onValueChange = onAmountChange,
-                    placeholder = "10",
-                )
-                Spacer(Modifier.width(16.dp))
-                Text(
-                    text = amount?.let { reminderLeadTimeLabel(it * unit.minutesFactor) }
             ?: stringResource(R.string.reminder_custom_amount),
-                    style = MaterialTheme.typography.bodyLarge,
+        setLabel = stringResource(R.string.reminder_custom_set),
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+        confirmEnabled = amount != null,
-                    modifier = Modifier.weight(1f),
+        onConfirm = { amount?.let { onConfirm(it * unit.minutesFactor) } },
     )
-                Spacer(Modifier.width(16.dp))
-                FilledTonalButton(
-                    onClick = { amount?.let { onConfirm(it * unit.minutesFactor) } },
-                    enabled = amount != null,
-                ) {
-                    Text(stringResource(R.string.reminder_custom_set))
-                }
-            }
-        }
-    }
 }
 
-/** A short explanatory paragraph shown under a picker's title, above the rows. */
+/** A short explanatory paragraph shown under a picker's title, above the rows,
+ *  on the same left margin as the rows themselves. */
 @Composable
-private fun PickerDescription(text: String) {
+internal fun PickerDescription(text: String) {
     Text(
         text = text,
         style = MaterialTheme.typography.bodyMedium,
         color = MaterialTheme.colorScheme.onSurfaceVariant,
-        modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+        modifier = Modifier.padding(horizontal = GroupedListInset, vertical = 8.dp),
     )
 }
 
-@Composable
-private fun SelectedCheck() {
-    Icon(
-        imageVector = Icons.Default.Check,
-        contentDescription = null,
-        tint = MaterialTheme.colorScheme.primary,
-    )
-}
 
 /**
  * Agenda-range picker, full-screen. Two grouped lists — the calendar-aligned
  * options (today / this week / this month) and the rolling windows (next 7 / 30
  * days), with a "Custom" row that expands an inline day-count editor (1–365).
  * Mirrors [ReminderDefaultPicker]'s custom-expand pattern.
+ *
+ * Every option carries the dates it resolves to today as its summary, computed
+ * through the same [dayCount] the agenda windows by (hence [weekStart], which
+ * "This week" depends on). Without it the two groups are near-indistinguishable
+ * — "This week" and "Next 7 days" name different windows in the same words, and
+ * only the concrete span tells them apart.
  */
 @Composable
 fun AgendaRangePicker(
     title: String,
     description: String,
     selected: AgendaRange,
+    weekStart: DayOfWeek,
     onSelect: (AgendaRange) -> Unit,
     onDismiss: () -> Unit,
 ) {
@@ -383,10 +257,21 @@ fun AgendaRangePicker(
         mutableStateOf((selected as? AgendaRange.Custom)?.days?.toString() ?: "")
     }
 
+    val locale = currentLocale()
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    // The window each option would open right now — the agenda's own end-day
+    // arithmetic (anchor + dayCount - 1), so the dates match what it will show.
+    val windowSummary: (AgendaRange) -> String = { range ->
+        val end = today.plus(range.dayCount(today, weekStart) - 1, DateTimeUnit.DAY)
+        agendaRangeWindowSummary(range, today, end, locale)
+    }
+
     val rangeRow: @Composable (AgendaRange, Position) -> Unit = { option, position ->
         val isSelected = option == selected
         GroupedRow(
             title = agendaRangeLabel(option),
+            summary = windowSummary(option),
             position = position,
             selected = isSelected,
             trailing = if (isSelected) {
@@ -421,6 +306,9 @@ fun AgendaRangePicker(
             } else {
                 stringResource(R.string.agenda_range_custom)
             },
+            // Only a chosen custom window has dates to show; an unset one has no
+            // day count yet, so the row stays single-line until it does.
+            summary = if (customSelected) windowSummary(selected) else null,
             position = if (customExpanded) Position.Top else positionOf(rolling.size, rollingRowCount),
             selected = customSelected,
             trailing = if (customSelected) {
@@ -432,8 +320,8 @@ fun AgendaRangePicker(
         )
         AnimatedVisibility(
             visible = customExpanded,
-            enter = calendarExpandEnter(),
+            enter = expandEnter(),
-            exit = calendarCollapseExit(),
+            exit = collapseExit(),
         ) {
             CustomDaysEditor(
                 amountText = amountText,
@@ -456,41 +344,136 @@ private fun CustomDaysEditor(
 ) {
     val days = amountText.toIntOrNull()
         ?.takeIf { it in AgendaRange.MIN_CUSTOM_DAYS..AgendaRange.MAX_CUSTOM_DAYS }
-    Surface(
+    CustomAmountEditor(
-        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        amountText = amountText,
-        shape = RoundedCornerShape(topStart = 6.dp, topEnd = 6.dp, bottomStart = 22.dp, bottomEnd = 22.dp),
+        onAmountChange = onAmountChange,
-        modifier = Modifier
-            .fillMaxWidth()
-            .padding(horizontal = 16.dp),
-    ) {
-        Row(
-            modifier = Modifier.padding(16.dp),
-            verticalAlignment = Alignment.CenterVertically,
-        ) {
-            DialogAmountField(
-                value = amountText,
-                onValueChange = onAmountChange,
         placeholder = "30",
-            )
+        preview = days?.let { pluralStringResource(R.plurals.agenda_range_days, it, it) }
-            Spacer(Modifier.width(16.dp))
-            Text(
-                text = days?.let { pluralStringResource(R.plurals.agenda_range_days, it, it) }
             ?: stringResource(R.string.agenda_range_custom_hint),
-                style = MaterialTheme.typography.bodyLarge,
+        setLabel = stringResource(R.string.reminder_custom_set),
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
+        confirmEnabled = days != null,
-                modifier = Modifier.weight(1f),
+        onConfirm = { days?.let(onConfirm) },
     )
-            Spacer(Modifier.width(16.dp))
+}
-            FilledTonalButton(
+
-                onClick = { days?.let(onConfirm) },
+/**
-                enabled = days != null,
+ * Snooze-duration picker, full-screen and **single-select**: the [presets]
+ * (whole-minute delays) each sit as a checkmark row, with a "Custom" row that
+ * expands an inline amount field plus a Minutes/Hours unit toggle to enter an
+ * arbitrary delay. Mirrors [AgendaRangePicker]'s custom-expand pattern; picking
+ * a preset or confirming a custom value applies via [onSelect] and closes.
+ * [label] renders a delay in minutes as a duration ("10 minutes", "1 hour") and
+ * is reused for both the rows and the custom preview.
+ */
+@Composable
+fun SnoozeDurationPicker(
+    title: String,
+    presets: List<Int>,
+    selected: Int,
+    label: @Composable (Int) -> String,
+    onSelect: (Int) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val customSelected = selected !in presets
+    val rowCount = presets.size + 1 // + the custom row
+
+    var customExpanded by rememberSaveable { mutableStateOf(false) }
+    var amountText by rememberSaveable {
+        mutableStateOf(if (customSelected) snoozeCustomAmount(selected).toString() else "")
+    }
+    var unit by rememberSaveable {
+        mutableStateOf(if (customSelected) snoozeCustomUnit(selected) else ReminderUnit.Minutes)
+    }
+
+    FullScreenPicker(title = title, onDismiss = onDismiss, predictiveBack = true) {
+        presets.forEachIndexed { index, minute ->
+            val isSelected = minute == selected
+            GroupedRow(
+                title = label(minute),
+                position = positionOf(index, rowCount),
+                selected = isSelected,
+                trailing = if (isSelected) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
+                onClick = {
+                    onSelect(minute)
+                    onDismiss()
+                },
+            )
+        }
+        // The Custom row connects downward into the editor card when expanded, so
+        // the two read as one grouped container (the shared custom-expand pattern).
+        GroupedRow(
+            title = if (customSelected) label(selected) else stringResource(R.string.event_edit_reminder_custom),
+            position = if (customExpanded) Position.Top else positionOf(presets.size, rowCount),
+            selected = customSelected,
+            trailing = if (customSelected) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
+            onClick = { customExpanded = !customExpanded },
+        )
+        AnimatedVisibility(
+            visible = customExpanded,
+            enter = expandEnter(),
+            exit = collapseExit(),
         ) {
-                Text(stringResource(R.string.reminder_custom_set))
+            CustomSnoozeEditor(
-            }
+                amountText = amountText,
+                onAmountChange = { amountText = it },
+                unit = unit,
+                onUnitChange = { unit = it },
+                label = label,
+                onConfirm = { minutes ->
+                    onSelect(minutes)
+                    onDismiss()
+                },
+            )
         }
     }
 }
 
+/** Whole hours if the delay divides evenly, else minutes. */
+private fun snoozeCustomUnit(minutes: Int): ReminderUnit =
+    if (minutes % ReminderUnit.Hours.minutesFactor == 0) ReminderUnit.Hours else ReminderUnit.Minutes
+
+private fun snoozeCustomAmount(minutes: Int): Int =
+    if (minutes % ReminderUnit.Hours.minutesFactor == 0) minutes / ReminderUnit.Hours.minutesFactor else minutes
+
+/**
+ * The expanded "Custom" snooze editor: a tonal card connected to the Custom row
+ * above it. A Minutes/Hours unit toggle, an amount field with a live preview of
+ * the delay it resolves to, and a tonal confirm enabled only for a valid 1–999
+ * amount. [onConfirm] receives the final delay in minutes.
+ */
+@Composable
+private fun CustomSnoozeEditor(
+    amountText: String,
+    onAmountChange: (String) -> Unit,
+    unit: ReminderUnit,
+    onUnitChange: (ReminderUnit) -> Unit,
+    label: @Composable (Int) -> String,
+    onConfirm: (Int) -> Unit,
+) {
+    val units = remember { listOf(ReminderUnit.Minutes, ReminderUnit.Hours) }
+    val amount = amountText.toIntOrNull()?.takeIf { it in 1..999 }
+    CustomAmountEditor(
+        amountText = amountText,
+        onAmountChange = onAmountChange,
+        unitLabels = units.map { stringResource(reminderUnitLabel(it)) },
+        selectedUnit = units.indexOf(unit).coerceAtLeast(0),
+        onUnitChange = { onUnitChange(units[it]) },
+        preview = amount?.let { label(it * unit.minutesFactor) }
+            ?: stringResource(R.string.reminder_custom_amount),
+        setLabel = stringResource(R.string.reminder_custom_set),
+        confirmEnabled = amount != null,
+        onConfirm = { amount?.let { onConfirm(it * unit.minutesFactor) } },
+    )
+}
+
 /** Human label for an [AgendaRange] (used by the picker rows and settings summary). */
 @Composable
 fun agendaRangeLabel(range: AgendaRange): String = when (range) {

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

@@ -8,7 +8,16 @@ import androidx.compose.ui.text.SpanStyle
 import androidx.compose.ui.text.buildAnnotatedString
 import androidx.compose.ui.text.font.FontStyle
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.SimpleRecurrence
+import de.jeanlucmakiola.calendula.domain.occurrencesSpanYears
+import de.jeanlucmakiola.calendula.domain.upcomingOccurrences
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
+import kotlinx.datetime.toJavaLocalDate
 import java.time.DayOfWeek
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.ZoneId
+import java.time.ZoneOffset
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
 import java.time.format.TextStyle as JavaTextStyle
@@ -94,6 +103,43 @@ fun recurrenceText(rrule: String, locale: Locale): AnnotatedString {
     }
 }
 
+/**
+ * The rule's first few dates as one line — "Next: 30 Jul, 6 Aug, 13 Aug" — for
+ * the recurrence picker.
+ *
+ * The phrase [recurrenceText] renders says what the rule *is*; this says what
+ * it *does*, which is the part a monthly rule on the 31st or an every-other-week
+ * rule with weekday picks gets wrong in people's heads. It expands the rule
+ * with [upcomingOccurrences], so it inherits that function's RFC reading — and
+ * its limits: only the shapes the picker itself can build.
+ *
+ * A rule that yields nothing at all (an end date before the start) says so
+ * rather than showing an empty list, since that is a mistake worth catching
+ * before saving.
+ */
+@Composable
+fun nextOccurrencesText(
+    rule: SimpleRecurrence,
+    // Spelled out: in this file, the bare LocalDate is java.time's.
+    start: kotlinx.datetime.LocalDate,
+    locale: Locale,
+): String {
+    val dates = rule.upcomingOccurrences(start, limit = NEXT_OCCURRENCE_COUNT)
+    if (dates.isEmpty()) return stringResource(R.string.event_edit_recurrence_next_none)
+    // Years only once they carry information — a yearly rule is otherwise the
+    // same date repeated, and a monthly one crossing New Year hides that it did.
+    val pattern = if (occurrencesSpanYears(dates, start)) "dMMMy" else "dMMM"
+    val formatter = localizedDateFormatter(locale, pattern)
+    val formatted = dates.map { formatter.format(it.toJavaLocalDate()) }
+    return stringResource(
+        R.string.event_edit_recurrence_next,
+        ListFormatter.getInstance(locale).format(formatted),
+    )
+}
+
+/** Enough dates to show a rhythm (and a skipped month), few enough for one line. */
+private const val NEXT_OCCURRENCE_COUNT = 3
+
 /** Map an RRULE BYDAY token (e.g. "TU" or "2TH") to a localized short weekday name. */
 private fun rruleDayName(token: String, locale: Locale): String? {
     val dow = when (token.takeLast(2).uppercase()) {
@@ -111,16 +157,36 @@ private fun rruleDayName(token: String, locale: Locale): String? {
 
 /** Parse an RRULE UNTIL value ("20261231" or "20261231T235959Z") to a localized date. */
 private fun parseUntilDate(raw: String, locale: Locale): String? {
-    val digits = raw.takeWhile { it.isDigit() }
+    val date = untilLocalDate(raw) ?: return null
-    if (digits.length < 8) return null
+    return DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale).format(date)
-    return try {
+}
-        val date = java.time.LocalDate.of(
+
+private val UNTIL_UTC_FORMAT: DateTimeFormatter =
+    DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss'Z'", Locale.ROOT)
+
+/**
+ * The calendar day an RRULE UNTIL value denotes, *in the device's zone*.
+ *
+ * The UTC form ("20261231T225959Z") must be converted back before its date is
+ * read: `SimpleRecurrence.toRRule` writes the end of the chosen **local** day
+ * expressed in UTC, so for zones behind UTC that instant already falls on the
+ * following UTC date. Taking the leading digits straight off would then show
+ * the day after the one the user picked. Date-only and floating forms are
+ * already local and pass through unchanged.
+ */
+internal fun untilLocalDate(raw: String, zone: ZoneId = ZoneId.systemDefault()): LocalDate? {
+    val value = raw.trim()
+    return runCatching {
+        LocalDateTime.parse(value, UNTIL_UTC_FORMAT)
+            .atOffset(ZoneOffset.UTC)
+            .atZoneSameInstant(zone)
+            .toLocalDate()
+    }.recoverCatching {
+        val digits = value.takeWhile { it.isDigit() }
+        LocalDate.of(
             digits.substring(0, 4).toInt(),
             digits.substring(4, 6).toInt(),
             digits.substring(6, 8).toInt(),
         )
-        DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale).format(date)
+    }.getOrNull()
-    } catch (e: Exception) {
-        null
-    }
 }

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

@@ -5,18 +5,11 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.reminders.ReminderUnit
 
 /** Common reminder lead times offered as quick picks in the form and settings. */
 val REMINDER_PRESETS = listOf(0, 10, 30, 60, 1_440)
 
-/** The unit of a custom reminder lead time; [minutesFactor] converts to minutes. */
-enum class ReminderUnit(val minutesFactor: Int) {
-    Minutes(1),
-    Hours(60),
-    Days(1_440),
-    Weeks(10_080),
-}
-
 @StringRes
 fun reminderUnitLabel(unit: ReminderUnit): Int = when (unit) {
     ReminderUnit.Minutes -> R.string.reminder_unit_minutes

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

@@ -1,183 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.animation.core.Animatable
-import androidx.compose.animation.core.Spring
-import androidx.compose.animation.core.animateFloatAsState
-import androidx.compose.animation.core.snap
-import androidx.compose.animation.core.spring
-import androidx.compose.animation.core.tween
-import androidx.compose.foundation.gestures.detectDragGestures
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.derivedStateOf
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableFloatStateOf
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.graphicsLayer
-import androidx.compose.ui.input.pointer.pointerInput
-import androidx.compose.ui.platform.LocalDensity
-import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.zIndex
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.launch
-import kotlin.math.roundToInt
-
-/** Uniform row height for [ReorderableColumn]; a fixed pitch keeps drag maths exact. */
-val ReorderableRowHeight: Dp = 64.dp
-private val RowGap: Dp = 2.dp
-
-/**
- * A vertical list whose rows can be dragged into a new order by their handle.
- *
- * Built for the short, fixed grouped-card lists in Settings (#24) — no external
- * dependency and no [androidx.compose.foundation.lazy.LazyColumn] (the settings
- * screens are a single [androidx.compose.foundation.verticalScroll] column, which
- * can't nest a scrolling list). Rows are a fixed [ReorderableRowHeight] with a
- * uniform gap, so a row's target slot is simply how many whole pitches it has
- * been dragged. The held row follows the finger while the others slide out of
- * its way (animated); on release the order is committed immediately with a
- * single [onReorder] call, then the held row eases into its new slot as a
- * purely visual settle — safe to interrupt with another drag, since the
- * commit itself never waits on it.
- *
- * [rowContent] receives the [Position] for the row's place in the order (to reuse
- * [GroupedRow]'s card shaping — pass `gapBelow = false` there, this owns spacing)
- * and a `dragHandle` [Modifier] to attach to the element that starts a drag.
- */
-@Composable
-fun <T> ReorderableColumn(
-    items: List<T>,
-    keyOf: (T) -> Any,
-    onReorder: (List<T>) -> Unit,
-    modifier: Modifier = Modifier,
-    rowContent: @Composable (item: T, position: Position, dragHandle: Modifier, isDragging: Boolean) -> Unit,
-) {
-    val pitchPx = with(LocalDensity.current) { (ReorderableRowHeight + RowGap).toPx() }
-    val scope = rememberCoroutineScope()
-
-    // Local working copy; re-seeded when the incoming list changes (including the
-    // echo of our own committed order).
-    var order by remember(items) { mutableStateOf(items) }
-    var draggedKey by remember { mutableStateOf<Any?>(null) }
-    // Live translation of the held row from its slot (px); also drives the
-    // release settle — re-based onto the row's new slot once the order commits
-    // (see onDragEnd), then eased down to zero.
-    var dragOffset by remember { mutableFloatStateOf(0f) }
-    // The running release/cancel settle, cancelled if a new drag pre-empts it.
-    // Purely visual — the order commit (see onDragEnd) never depends on it.
-    var settleJob by remember { mutableStateOf<Job?>(null) }
-
-    val draggedIndex = draggedKey?.let { key -> order.indexOfFirst { keyOf(it) == key }.takeIf { it >= 0 } }
-    // Whole slots dragged → the slot the held row currently hovers over. Derived
-    // so recomposition only fires when the *target slot* actually changes, not on
-    // every dragged pixel: dragOffset moves every frame during a drag, but the
-    // held row's own translation is already applied in the draw phase via
-    // graphicsLayer below, so only the neighbours' shift (which depends on this)
-    // needs to recompose, and only when a slot boundary is actually crossed.
-    // (Read as a plain val, not `by`, below: a delegated property has a custom
-    // getter and Kotlin won't smart-cast it in the `when` over `targetIndex` in
-    // the loop, so the derived value is captured into a real local instead.)
-    val targetIndex = remember(items, pitchPx) {
-        derivedStateOf {
-            val idx = draggedKey?.let { key -> order.indexOfFirst { keyOf(it) == key }.takeIf { it >= 0 } }
-            idx?.let { (it + (dragOffset / pitchPx).roundToInt()).coerceIn(0, order.lastIndex) }
-        }
-    }.value
-
-    Column(modifier, verticalArrangement = Arrangement.spacedBy(RowGap)) {
-        order.forEachIndexed { index, item ->
-            val key = keyOf(item)
-            val isDragged = key == draggedKey
-
-            // Slide neighbours by one pitch to open the gap the held row will drop
-            // into. Snap (not animate) once idle, so committing the new order — which
-            // moves each row's slot — doesn't visibly fight a lingering animation.
-            val shift = when {
-                draggedIndex == null || targetIndex == null || isDragged -> 0f
-                index in (draggedIndex + 1)..targetIndex -> -pitchPx
-                index in targetIndex until draggedIndex -> pitchPx
-                else -> 0f
-            }
-            val animatedShift by animateFloatAsState(
-                targetValue = shift,
-                animationSpec = if (draggedKey != null) spring(stiffness = Spring.StiffnessMediumLow) else snap(),
-                label = "reorderShift",
-            )
-
-            val dragHandle = Modifier.pointerInput(key) {
-                detectDragGestures(
-                    onDragStart = {
-                        settleJob?.cancel()
-                        draggedKey = key
-                        dragOffset = 0f
-                    },
-                    onDrag = { change, amount ->
-                        change.consume()
-                        dragOffset += amount.y
-                    },
-                    onDragEnd = {
-                        val from = order.indexOfFirst { keyOf(it) == key }
-                        if (from < 0) return@detectDragGestures
-                        val to = (from + (dragOffset / pitchPx).roundToInt()).coerceIn(0, order.lastIndex)
-                        if (to != from) {
-                            // Commit synchronously and unconditionally, before the settle
-                            // animation below runs — the commit must not depend on that
-                            // coroutine reaching its end, or a new drag starting within the
-                            // ~160ms settle window would cancel it and silently revert an
-                            // already-finished reorder.
-                            order = order.toMutableList().apply { add(to, removeAt(from)) }
-                            onReorder(order)
-                            // The row now lays out at slot `to` instead of `from`; re-base
-                            // the live offset onto that new slot (same visual position,
-                            // expressed relative to the new one) so the settle below eases
-                            // it the rest of the way instead of jumping.
-                            dragOffset -= (to - from) * pitchPx
-                        }
-                        settleJob = scope.launch {
-                            // Purely visual from here: ease the held row onto its slot, then
-                            // release the drag state. Safe to cancel — the order was already
-                            // committed above.
-                            Animatable(dragOffset).animateTo(0f, tween(160)) { dragOffset = value }
-                            draggedKey = null
-                            dragOffset = 0f
-                        }
-                    },
-                    onDragCancel = {
-                        settleJob = scope.launch {
-                            Animatable(dragOffset).animateTo(0f, tween(160)) { dragOffset = value }
-                            draggedKey = null
-                            dragOffset = 0f
-                        }
-                    },
-                )
-            }
-
-            Box(
-                Modifier
-                    .height(ReorderableRowHeight)
-                    .zIndex(if (isDragged) 1f else 0f)
-                    .graphicsLayer {
-                        translationY = if (isDragged) dragOffset else animatedShift
-                        if (isDragged) {
-                            scaleX = 1.02f
-                            scaleY = 1.02f
-                            shadowElevation = 8.dp.toPx()
-                            shape = RoundedCornerShape(20.dp)
-                            clip = false
-                        }
-                    },
-            ) {
-                rowContent(item, positionOf(index, order.size), dragHandle, isDragged)
-            }
-        }
-    }
-}

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

@@ -4,14 +4,9 @@ import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
-import android.content.Context
-import android.content.res.Resources
-import android.provider.Settings
-import android.text.format.DateFormat
 import androidx.compose.material3.TimePicker
 import androidx.compose.material3.rememberTimePickerState
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import de.jeanlucmakiola.calendula.R
 import kotlinx.datetime.LocalTime
@@ -27,10 +22,13 @@ fun TimePickerAlert(
     onConfirm: (LocalTime) -> Unit,
     onDismiss: () -> Unit,
 ) {
+    // Honour the app's own time-format preference (the value every time label
+    // reads), not the system/locale clock — otherwise an explicit 24h setting
+    // still showed an AM/PM dial (issue #27).
     val state = rememberTimePickerState(
         initialHour = initial.hour,
         initialMinute = initial.minute,
-        is24Hour = deviceUses24HourClock(LocalContext.current),
+        is24Hour = LocalUse24HourFormat.current,
     )
     AlertDialog(
         onDismissRequest = onDismiss,
@@ -45,24 +43,3 @@ fun TimePickerAlert(
         text = { TimePicker(state = state) },
     )
 }
-
-/**
- * Whether the clock should read 24-hour, matching the rest of the device.
- *
- * [DateFormat.is24HourFormat] resolves a "locale default" system setting against
- * the *app's* context locale — and this app applies a per-app language
- * (AppCompatDelegate), so an English UI on a German-region phone would wrongly
- * read 12-hour while the system clock shows 24-hour. So we honour an explicit
- * system 12/24 override, and otherwise fall back to the **device** locale
- * (Resources.getSystem), not the app's.
- */
-private fun deviceUses24HourClock(context: Context): Boolean =
-    when (Settings.System.getString(context.contentResolver, Settings.System.TIME_12_24)) {
-        "24" -> true
-        "12" -> false
-        // 'a' is the AM/PM marker; a best-fit pattern without it is 24-hour.
-        else -> {
-            val deviceLocale = Resources.getSystem().configuration.locales[0]
-            !DateFormat.getBestDateTimePattern(deviceLocale, "jm").contains('a')
-        }
-    }

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

@@ -0,0 +1,273 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+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.Close
+import androidx.compose.material.icons.filled.Public
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.remember
+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.LocalSoftwareKeyboardController
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardCapitalization
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.TimeZoneOption
+import de.jeanlucmakiola.calendula.domain.filterTimeZones
+import de.jeanlucmakiola.calendula.domain.timeZoneOptionOf
+import de.jeanlucmakiola.calendula.domain.timeZoneOptions
+import de.jeanlucmakiola.calendula.domain.zoneDescriptor
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.InlineTextField
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.locale.currentLocale
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+/**
+ * Full-screen zone picker: a query field over every zone the JVM knows, with the
+ * device zone and recently-picked ones pinned on top so the common case needs no
+ * typing. [selected] is the pinned zone id, or null when the event follows the
+ * device — picking the device row reports null back, which is what keeps an
+ * unpinned event unpinned rather than freezing it to today's zone.
+ *
+ * Unlike the kit's [de.jeanlucmakiola.floret.components.OptionPicker], this
+ * drives its own [LazyColumn] (hence `scrollable = false`): ~600 options is far
+ * past what an eagerly composed column can carry.
+ */
+@Composable
+fun TimeZonePickerDialog(
+    selected: String?,
+    deviceZoneId: String,
+    recents: List<String>,
+    onSelect: (String?) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var query by rememberSaveable { mutableStateOf("") }
+    val locale = currentLocale()
+    // ~600 zones, each resolving a localized name and up to two ICU short names:
+    // far too much to run inside composition, so build it on a worker and let the
+    // list fill in a frame later. Filtering the built catalogue is cheap (its
+    // search keys are pre-normalized), so that stays here.
+    val allZones by produceState(initialValue = emptyList<TimeZoneOption>(), locale) {
+        value = withContext(Dispatchers.Default) {
+            timeZoneOptions(locale, regionOf = ::icuTimeZoneRegion)
+        }
+    }
+    val matches = remember(allZones, query) { filterTimeZones(allZones, query) }
+    val recentZones = remember(allZones, recents) {
+        recents.mapNotNull { id -> allZones.firstOrNull { it.id == id } }
+    }
+    // Resolved on its own rather than looked up in the catalogue: it's one zone,
+    // so it costs nothing, and the device row can then render complete on the
+    // first frame instead of showing a bare id until the catalogue lands.
+    val deviceSummary = remember(deviceZoneId, locale) {
+        timeZoneOptionOf(deviceZoneId, locale, regionOf = ::icuTimeZoneRegion)
+            ?.let { zoneDescriptor(it) }
+            ?: deviceZoneId
+    }
+    val searching = query.isNotBlank()
+
+    fun choose(zoneId: String?) {
+        onSelect(zoneId)
+        onDismiss()
+    }
+
+    FullScreenPicker(
+        title = stringResource(R.string.event_detail_timezone),
+        onDismiss = onDismiss,
+        scrollable = false,
+    ) {
+        SearchField(
+            query = query,
+            onQueryChange = { query = it },
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+        )
+        LazyColumn(contentPadding = PaddingValues(top = 8.dp, bottom = 24.dp)) {
+            if (!searching) {
+                // The device row is the "unpinned" choice, so it reads as a mode
+                // rather than as a zone among zones — it stays out of the big
+                // list and never carries an offset.
+                item(key = "device") {
+                    GroupedRow(
+                        title = stringResource(R.string.event_edit_timezone_device),
+                        summary = deviceSummary,
+                        position = Position.Alone,
+                        selected = selected == null,
+                        leading = { Icon(Icons.Default.Public, contentDescription = null) },
+                        trailing = if (selected == null) {
+                            { SelectedCheck() }
+                        } else {
+                            null
+                        },
+                        onClick = { choose(null) },
+                    )
+                }
+                if (recentZones.isNotEmpty()) {
+                    item(key = "recent_header") {
+                        SectionHeader(stringResource(R.string.event_edit_timezone_recent))
+                    }
+                    itemsIndexed(
+                        items = recentZones,
+                        key = { _, zone -> "recent_${zone.id}" },
+                    ) { index, zone ->
+                        ZoneRow(
+                            zone = zone,
+                            position = positionOf(index, recentZones.size),
+                            selected = zone.id == selected,
+                            onClick = { choose(zone.id) },
+                        )
+                    }
+                }
+                item(key = "all_header") {
+                    SectionHeader(stringResource(R.string.event_edit_timezone_all))
+                }
+            }
+
+            // allZones.isNotEmpty() gates this: until the catalogue lands there is
+            // simply nothing to match yet, and claiming "no time zone matches"
+            // for that frame would be wrong.
+            if (searching && matches.isEmpty() && allZones.isNotEmpty()) {
+                item(key = "empty") {
+                    Text(
+                        text = stringResource(R.string.event_edit_timezone_none, query),
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        textAlign = TextAlign.Center,
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 32.dp, vertical = 48.dp),
+                    )
+                }
+            }
+
+            itemsIndexed(
+                items = matches,
+                key = { _, zone -> "zone_${zone.id}" },
+            ) { index, zone ->
+                ZoneRow(
+                    zone = zone,
+                    position = positionOf(index, matches.size),
+                    selected = zone.id == selected,
+                    onClick = { choose(zone.id) },
+                )
+            }
+        }
+    }
+}
+
+/**
+ * The query box: the family's borderless [InlineTextField] over a tonal surface,
+ * so it reads like the rest of the app's inputs rather than a boxed Material
+ * field. The clear button rides inside the surface (unlike the search screen,
+ * which has a top bar to put it in) because the picker's bar is the title.
+ */
+@Composable
+private fun SearchField(
+    query: String,
+    onQueryChange: (String) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val keyboard = LocalSoftwareKeyboardController.current
+    // surfaceContainerHighest — the picker sits on surfaceContainerHigh, so
+    // anything lower vanishes into it.
+    Surface(
+        color = MaterialTheme.colorScheme.surfaceContainerHighest,
+        shape = RoundedCornerShape(28.dp),
+        modifier = modifier.fillMaxWidth(),
+    ) {
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier.padding(horizontal = 16.dp),
+        ) {
+            Icon(
+                imageVector = Icons.Default.Search,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            InlineTextField(
+                value = query,
+                onValueChange = onQueryChange,
+                placeholder = stringResource(R.string.event_edit_timezone_search),
+                capitalization = KeyboardCapitalization.None,
+                imeAction = ImeAction.Search,
+                onImeAction = { keyboard?.hide() },
+                modifier = Modifier
+                    .weight(1f)
+                    .padding(horizontal = 12.dp, vertical = 14.dp),
+            )
+            if (query.isNotEmpty()) {
+                IconButton(onClick = { onQueryChange("") }) {
+                    Icon(
+                        imageVector = Icons.Default.Close,
+                        contentDescription = stringResource(R.string.search_clear),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+        }
+    }
+}
+
+/** A small primary-coloured group label, matching the settings screens. */
+@Composable
+private fun SectionHeader(text: String) {
+    Text(
+        text = text,
+        style = MaterialTheme.typography.labelLarge,
+        color = MaterialTheme.colorScheme.primary,
+        modifier = Modifier.padding(
+            start = GroupedListInset,
+            end = GroupedListInset,
+            top = 16.dp,
+            bottom = 4.dp,
+        ),
+    )
+}
+
+
+@Composable
+private fun ZoneRow(
+    zone: TimeZoneOption,
+    position: Position,
+    selected: Boolean,
+    onClick: () -> Unit,
+) {
+    GroupedRow(
+        title = zone.label,
+        summary = zoneDescriptor(zone),
+        position = position,
+        selected = selected,
+        trailing = if (selected) {
+            { SelectedCheck() }
+        } else {
+            null
+        },
+        onClick = onClick,
+    )
+}

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

@@ -0,0 +1,16 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import android.icu.util.TimeZone as IcuTimeZone
+
+/**
+ * The ISO 3166 region an IANA zone belongs to ("America/New_York" -> "US"), or
+ * null when ICU has none or maps it to the multi-country "001" ("Etc/UTC").
+ *
+ * This is the `android.icu`-backed bridge the pure-JVM
+ * [de.jeanlucmakiola.calendula.domain.timeZoneOptions] takes as `regionOf`, so
+ * it can ask ICU for a zone's abbreviation in that zone's own region — the only
+ * region for which ICU will surface it (see `resolveAbbreviation`). Lives here,
+ * not in `domain/`, precisely because it needs an Android import.
+ */
+fun icuTimeZoneRegion(id: String): String? =
+    runCatching { IcuTimeZone.getRegion(id) }.getOrNull()?.takeIf { it.length == 2 }

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

@@ -0,0 +1,26 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Today
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import de.jeanlucmakiola.calendula.R
+
+/**
+ * The top-bar "jump to today" icon button, shared by every calendar view's app
+ * bar (#60). Shown in place of the fade-in FAB pill when the user moves the
+ * today control into the toolbar; renders nothing when [show] is false, so it
+ * drops straight into an app bar's `actions` slot without a wrapping condition.
+ */
+@Composable
+fun TodayAction(show: Boolean, onToday: () -> Unit) {
+    if (!show) return
+    IconButton(onClick = onToday) {
+        Icon(
+            imageVector = Icons.Default.Today,
+            contentDescription = stringResource(R.string.today_jump_action),
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/crash/CrashReportActivity.kt

@@ -8,8 +8,10 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.ui.Modifier
-import de.jeanlucmakiola.calendula.data.crash.CrashReporter
 import de.jeanlucmakiola.calendula.ui.theme.CalendulaTheme
+import de.jeanlucmakiola.floret.crash.CrashReportDialog
+import de.jeanlucmakiola.floret.crash.CrashReporter
+import de.jeanlucmakiola.floret.crash.submitCrashReport
 
 /**
  * A deliberately minimal, standalone surface for a captured crash report.

app/src/main/java/de/jeanlucmakiola/calendula/ui/crash/CrashReportDialog.kt

@@ -1,75 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.crash
-
-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.heightIn
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.verticalScroll
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.BugReport
-import androidx.compose.material3.AlertDialog
-import androidx.compose.material3.Icon
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
-import androidx.compose.material3.Text
-import androidx.compose.material3.TextButton
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.font.FontFamily
-import androidx.compose.ui.unit.dp
-import de.jeanlucmakiola.calendula.R
-
-/**
- * Asks the user to send a captured crash report as an issue. The full report is
- * shown verbatim in a scrollable panel — the user sees exactly what will leave
- * the device before choosing to share it (the privacy backstop). [onSend] hands
- * off to [submitCrashReport]; [onDismiss] declines.
- */
-@Composable
-fun CrashReportDialog(
-    report: String,
-    onSend: () -> Unit,
-    onDismiss: () -> Unit,
-) {
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        icon = { Icon(Icons.Default.BugReport, contentDescription = null) },
-        title = { Text(stringResource(R.string.crash_dialog_title)) },
-        text = {
-            Column {
-                Text(
-                    text = stringResource(R.string.crash_dialog_message),
-                    style = MaterialTheme.typography.bodyMedium,
-                )
-                Spacer(Modifier.height(12.dp))
-                Surface(
-                    color = MaterialTheme.colorScheme.surfaceContainerHighest,
-                    shape = RoundedCornerShape(12.dp),
-                    modifier = Modifier.fillMaxWidth(),
-                ) {
-                    Text(
-                        text = report,
-                        style = MaterialTheme.typography.bodySmall,
-                        fontFamily = FontFamily.Monospace,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
-                        modifier = Modifier
-                            .heightIn(max = 220.dp)
-                            .verticalScroll(rememberScrollState())
-                            .padding(12.dp),
-                    )
-                }
-            }
-        },
-        confirmButton = {
-            TextButton(onClick = onSend) { Text(stringResource(R.string.crash_dialog_report)) }
-        },
-        dismissButton = {
-            TextButton(onClick = onDismiss) { Text(stringResource(R.string.crash_dialog_dismiss)) }
-        },
-    )
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/crash/CrashReportSubmit.kt

@@ -1,61 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.crash
-
-import android.content.ClipData
-import android.content.ClipboardManager
-import android.content.Context
-import android.content.Intent
-import android.widget.Toast
-import androidx.core.net.toUri
-import de.jeanlucmakiola.calendula.R
-
-/**
- * Hand the captured crash report off to the user's chosen channel: the report
- * is copied to the clipboard (the reliable path for a full stack trace) and the
- * project's Gitea "new issue" page is opened with the body prefilled. Nothing is
- * sent automatically — the app has no network access; the user reviews and
- * submits the issue themselves.
- */
-fun submitCrashReport(context: Context, report: String) {
-    copyReportToClipboard(context, report)
-    val opened = runCatching {
-        context.startActivity(Intent(Intent.ACTION_VIEW, buildIssueUri(context, report)))
-    }.isSuccess
-    val message = if (opened) R.string.crash_report_copied else R.string.crash_report_open_failed
-    Toast.makeText(context, message, Toast.LENGTH_LONG).show()
-}
-
-/** Open the issue tracker's template chooser for a manual (non-crash) report. */
-fun openIssueTracker(context: Context) {
-    val uri = context.getString(R.string.report_issue_choose_url).toUri()
-    runCatching { context.startActivity(Intent(Intent.ACTION_VIEW, uri)) }
-}
-
-private fun copyReportToClipboard(context: Context, report: String) {
-    val clipboard = context.getSystemService(Context.CLIPBOARD_SERVICE) as? ClipboardManager ?: return
-    val label = context.getString(R.string.crash_report_clip_label)
-    clipboard.setPrimaryClip(ClipData.newPlainText(label, report))
-}
-
-/**
- * The Gitea `issues/new` URL with `title` and `body` prefilled. A full report
- * can blow past URL-length limits, so an over-long one is left out of the link
- * (with a "paste from clipboard" placeholder) — the clipboard copy is the
- * source of truth in that case.
- */
-private fun buildIssueUri(context: Context, report: String) =
-    context.getString(R.string.report_issue_url).toUri().buildUpon()
-        .appendQueryParameter("title", context.getString(R.string.crash_report_issue_title))
-        .appendQueryParameter("body", buildIssueBody(context, report))
-        .build()
-
-private fun buildIssueBody(context: Context, report: String): String {
-    val block = if (report.length > MAX_URL_REPORT_CHARS) {
-        context.getString(R.string.crash_report_body_paste)
-    } else {
-        "```\n$report\n```"
-    }
-    return context.getString(R.string.crash_report_body_template, block)
-}
-
-/** Keep the prefilled body comfortably under common URL-length ceilings. */
-private const val MAX_URL_REPORT_CHARS = 6_000

app/src/main/java/de/jeanlucmakiola/calendula/ui/day/DayScreen.kt

@@ -5,7 +5,6 @@ import androidx.compose.animation.animateColorAsState
 import androidx.compose.animation.core.animateDpAsState
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
-import androidx.compose.foundation.gestures.detectHorizontalDragGestures
 import androidx.compose.foundation.gestures.detectTapGestures
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Box
@@ -43,7 +42,6 @@ import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -68,8 +66,10 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.common.formatCalendarTitle
 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.IMPLEMENTED_VIEWS
@@ -77,11 +77,14 @@ import de.jeanlucmakiola.calendula.ui.common.NowLine
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.calendarSlideTransition
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
-import de.jeanlucmakiola.calendula.ui.common.rememberReduceMotion
+import de.jeanlucmakiola.calendula.ui.common.rememberCalendarPageSwipe
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 import de.jeanlucmakiola.calendula.ui.common.next
-import de.jeanlucmakiola.calendula.ui.common.pastelize
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
+import de.jeanlucmakiola.calendula.ui.common.eventFill
+import de.jeanlucmakiola.calendula.ui.common.eventInk
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
-import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.LocalShowHourLines
 import de.jeanlucmakiola.calendula.ui.common.formatHourLabel
@@ -91,12 +94,18 @@ import de.jeanlucmakiola.calendula.ui.week.TimedBlock
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import kotlinx.datetime.LocalDate
-import java.time.format.TextStyle as JavaTextStyle
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
 import java.util.Locale
 import kotlin.math.roundToInt
 
 private val HOUR_HEIGHT = 56.dp
 private val GUTTER_WIDTH = 48.dp
+/** Start inset for the gutter's hour labels so they centre on the top bar's
+ *  hamburger: with a 48dp gutter, 8dp lands the centre at 28dp (the app bar's
+ *  4dp inset + 24dp half icon button), matching the week view. */
+private val GUTTER_CONTENT_START_INSET = 8.dp
 private val MIN_EVENT_HEIGHT = 24.dp
 private val ALL_DAY_ROW_HEIGHT = 24.dp
 private val ALL_DAY_VERTICAL_PADDING = 6.dp
@@ -119,6 +128,7 @@ fun DayScreen(
     onCreateEvent: (LocalDate, Int?) -> Unit,
     quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
     drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
+    todayInToolbar: Boolean = false,
     modifier: Modifier = Modifier,
     initialDateIso: String? = null,
     viewModel: DayViewModel = hiltViewModel(),
@@ -151,6 +161,13 @@ fun DayScreen(
         else -> true
     }
 
+    // Drives whether the title carries the year. Falls back to the clock only
+    // while the first load is in flight, when there is no state to read today from.
+    val currentYear = when (val s = state) {
+        is DayUiState.Success -> s.today.year
+        else -> Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault()).date.year
+    }
+
     // Slide direction for the day transition: +1 = next, -1 = prev, 0 = jump.
     var slideDir by remember { mutableIntStateOf(0) }
     val goNext = { slideDir = 1; viewModel.goToNext() }
@@ -199,16 +216,19 @@ fun DayScreen(
             topBar = {
                 DayTopBar(
                     date = date,
+                    currentYear = currentYear,
                     selectedView = selectedView,
                     onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
+                    showTodayButton = todayInToolbar,
+                    onToday = jumpToToday,
                     scrollBehavior = scrollBehavior,
                 )
             },
             floatingActionButton = {
                 CalendarFabColumn(
-                    todayVisible = !isOnToday,
+                    todayVisible = !isOnToday && !todayInToolbar,
                     todayText = stringResource(R.string.day_today_action),
                     onToday = jumpToToday,
                     onCreate = { onCreateEvent(date, null) },
@@ -245,8 +265,6 @@ private fun DayContent(
     modifier: Modifier = Modifier,
 ) {
     val density = LocalDensity.current
-    val threshold = with(density) { 24.dp.toPx() }
-    var dragAccum by remember { mutableFloatStateOf(0f) }
     val slideSpec = rememberCalendarSlideSpec()
     val fadeSpec = rememberCalendarFadeSpec()
     val reduceMotion = rememberReduceMotion()
@@ -275,20 +293,7 @@ private fun DayContent(
     // Whole-page horizontal swipe, one level above the timeline's vertical
     // scroll: a horizontal drag crosses this detector's slop, while a vertical
     // drag is consumed by the inner scroll first — the two gestures coexist.
-    val swipeModifier = Modifier.pointerInput(Unit) {
+    val swipeModifier = rememberCalendarPageSwipe(onSwipeNext, onSwipePrev)
-        detectHorizontalDragGestures(
-            onDragStart = { dragAccum = 0f },
-            onDragEnd = {
-                when {
-                    dragAccum < -threshold -> onSwipeNext()
-                    dragAccum > threshold -> onSwipePrev()
-                }
-                dragAccum = 0f
-            },
-            onDragCancel = { dragAccum = 0f },
-            onHorizontalDrag = { _, drag -> dragAccum += drag },
-        )
-    }
 
     AnimatedContent(
         targetState = state,
@@ -354,16 +359,20 @@ private fun DaySuccess(
 @Composable
 private fun DayTopBar(
     date: LocalDate,
+    currentYear: Int,
     selectedView: CalendarView,
     onCycleView: () -> Unit,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
+    showTodayButton: Boolean,
+    onToday: () -> Unit,
     scrollBehavior: androidx.compose.material3.TopAppBarScrollBehavior,
 ) {
+    val locale = currentLocale()
     TopAppBar(
         title = {
             Text(
-                text = formatDayTitle(date),
+                text = formatDayTitle(date, locale, currentYear),
                 style = MaterialTheme.typography.titleLarge,
             )
         },
@@ -376,6 +385,7 @@ private fun DayTopBar(
             }
         },
         actions = {
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,
@@ -448,9 +458,11 @@ private fun AllDayBar(
     modifier: Modifier = Modifier,
 ) {
     val title = event.title.ifBlank { stringResource(R.string.event_untitled) }
+    val soften = LocalSoftenColors.current
+    val fill = eventFill(event.color, dark, soften)
     Box(
         modifier = modifier
-            .background(pastelize(event.color, dark), RoundedCornerShape(4.dp))
+            .background(fill, RoundedCornerShape(4.dp))
             .clickable(onClick = onClick)
             .padding(horizontal = 6.dp, vertical = 2.dp)
             .semantics { contentDescription = title },
@@ -461,7 +473,7 @@ private fun AllDayBar(
             style = MaterialTheme.typography.labelSmall,
             maxLines = 1,
             overflow = TextOverflow.Ellipsis,
-            color = Color.Black.copy(alpha = 0.8f),
+            color = eventInk(fill),
         )
     }
 }
@@ -484,10 +496,12 @@ private fun Timeline(
         // static, rounded-clipped window — the content scrolls inside it, so the
         // soft corners are permanent at any scroll position.
         Row(modifier = Modifier.fillMaxSize()) {
-            // Hour gutter (scrolls in sync with the day column)
+            // Hour gutter (scrolls in sync with the day column). Start inset so the
+            // labels centre on the top bar hamburger, matching the week view.
             Column(
                 modifier = Modifier
                     .width(GUTTER_WIDTH)
+                    .padding(start = GUTTER_CONTENT_START_INSET)
                     .fillMaxHeight()
                     .verticalScroll(scrollState),
             ) {
@@ -610,9 +624,11 @@ private fun EventBlock(
     val timeLabel = "${minToHm(block.startMin, use24Hour, locale)}–" +
         minToHm(block.endMin, use24Hour, locale)
     val showTime = block.endMin - block.startMin >= 45
+    val soften = LocalSoftenColors.current
+    val fill = eventFill(block.event.color, dark, soften)
     Box(
         modifier = modifier
-            .background(pastelize(block.event.color, dark), RoundedCornerShape(4.dp))
+            .background(fill, RoundedCornerShape(4.dp))
             .clickable(onClick = onClick)
             .padding(horizontal = 4.dp, vertical = 2.dp)
             .semantics { contentDescription = "$title, $timeLabel" },
@@ -623,7 +639,7 @@ private fun EventBlock(
                 style = MaterialTheme.typography.labelMedium,
                 maxLines = if (showTime) 1 else 2,
                 overflow = TextOverflow.Ellipsis,
-                color = Color.Black.copy(alpha = 0.85f),
+                color = eventInk(fill, alpha = 0.85f),
             )
             if (showTime) {
                 Text(
@@ -631,7 +647,7 @@ private fun EventBlock(
                     style = MaterialTheme.typography.labelSmall,
                     maxLines = 1,
                     overflow = TextOverflow.Ellipsis,
-                    color = Color.Black.copy(alpha = 0.6f),
+                    color = eventInk(fill, alpha = 0.6f),
                 )
             }
         }
@@ -657,10 +673,10 @@ private fun DayLoading() {
 private fun minToHm(min: Int, is24Hour: Boolean, locale: Locale): String =
     formatMinuteOfDay(min, is24Hour, locale)
 
-private fun formatDayTitle(date: LocalDate): String {
+private fun formatDayTitle(date: LocalDate, locale: Locale, currentYear: Int): String =
-    val locale = Locale.getDefault()
+    formatCalendarTitle(
-    val java = java.time.LocalDate.of(date.year, date.month.ordinal + 1, date.day)
+        date = java.time.LocalDate.of(date.year, date.month.ordinal + 1, date.day),
-    val weekday = java.dayOfWeek.getDisplayName(JavaTextStyle.SHORT, locale)
+        locale = locale,
-    val monthName = java.month.getDisplayName(JavaTextStyle.SHORT, locale)
+        currentYear = currentYear,
-    return "$weekday, ${date.day}. $monthName ${date.year}"
+        skeleton = "EEEdMMM",
-}
+    )

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailScreen.kt

@@ -32,6 +32,7 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.automirrored.filled.Notes
 import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.ContentCopy
 import androidx.compose.material.icons.filled.Delete
 import androidx.compose.material.icons.filled.Edit
 import androidx.compose.material.icons.filled.Notifications
@@ -87,25 +88,31 @@ import de.jeanlucmakiola.calendula.domain.AttendeeRelationship
 import de.jeanlucmakiola.calendula.domain.AttendeeStatus
 import de.jeanlucmakiola.calendula.domain.AttendeeType
 import de.jeanlucmakiola.calendula.domain.Availability
+import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.Reminder
-import de.jeanlucmakiola.calendula.ui.common.predictiveBack
+import de.jeanlucmakiola.calendula.domain.TimeZoneOption
+import de.jeanlucmakiola.calendula.domain.timeZoneOptionOf
+import de.jeanlucmakiola.calendula.domain.zoneDescriptor
+import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
-import de.jeanlucmakiola.calendula.ui.common.OptionCard
+import de.jeanlucmakiola.calendula.ui.common.icuTimeZoneRegion
-import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
+import de.jeanlucmakiola.calendula.ui.common.eventFill
+import de.jeanlucmakiola.floret.components.OptionCard
+import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
-import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.ui.common.recurrenceText
 import de.jeanlucmakiola.calendula.ui.common.reminderLeadTimeLabel
 import kotlinx.coroutines.launch
 import kotlinx.datetime.TimeZone
+import kotlin.time.toJavaInstant
 import java.time.ZoneId
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
-import java.time.format.TextStyle as JavaTextStyle
 import java.util.Locale
 import kotlin.time.Duration.Companion.seconds
 import kotlin.time.Instant
@@ -116,7 +123,10 @@ import kotlin.time.Instant
  * top-bar arrow both return to the calendar. Events in writable calendars can
  * be deleted (v1.1) and edited (v1.3) from here; [onEdit] opens the shared
  * event form for this occurrence — for recurring events the form asks how
- * far the change reaches when saving.
+ * far the change reaches when saving. [onDuplicate] opens the same form
+ * seeded with a copy of this event as a new, unsaved event (#52) — offered
+ * for any event, including read-only ones, since the copy lands in an
+ * editable calendar.
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -126,6 +136,7 @@ fun EventDetailScreen(
     endMillis: Long,
     onBack: () -> Unit,
     onEdit: () -> Unit,
+    onDuplicate: (EventForm) -> Unit,
     viewModel: EventDetailViewModel = hiltViewModel(),
 ) {
     LaunchedEffect(eventId, beginMillis, endMillis) {
@@ -160,15 +171,14 @@ fun EventDetailScreen(
     }
 
     // v1.0 installs only hold READ_CALENDAR; the first write asks for the
-    // upgrade in place. Granting continues straight into the tapped action.
+    // upgrade in place. Granting continues straight into the tapped action —
-    var pendingEdit by remember { mutableStateOf(false) }
+    // edit, delete, or duplicate — held here until the result comes back.
+    var pendingWrite by remember { mutableStateOf<(() -> Unit)?>(null) }
     val writePermissionLauncher = rememberLauncherForActivityResult(
         contract = ActivityResultContracts.RequestPermission(),
     ) { granted ->
-        if (granted) {
+        if (granted) pendingWrite?.invoke()
-            if (pendingEdit) onEdit() else showDeleteDialog = true
+        pendingWrite = null
-        }
-        pendingEdit = false
     }
     val hasWritePermission = {
         ContextCompat.checkSelfPermission(
@@ -176,21 +186,20 @@ fun EventDetailScreen(
             Manifest.permission.WRITE_CALENDAR,
         ) == PackageManager.PERMISSION_GRANTED
     }
-    val onDeleteClick = {
+    val requireWrite: (() -> Unit) -> Unit = { action ->
         if (hasWritePermission()) {
-            showDeleteDialog = true
+            action()
         } else {
-            pendingEdit = false
+            pendingWrite = action
             writePermissionLauncher.launch(Manifest.permission.WRITE_CALENDAR)
         }
     }
-    val onEditClick = {
+    val onDeleteClick = { requireWrite { showDeleteDialog = true } }
-        if (hasWritePermission()) {
+    val onEditClick = { requireWrite(onEdit) }
-            onEdit()
+    // Duplicate reads the loaded detail into a create form and hands it up; the
-        } else {
+    // create still needs WRITE_CALENDAR even when the source is read-only.
-            pendingEdit = true
+    val onDuplicateClick = {
-            writePermissionLauncher.launch(Manifest.permission.WRITE_CALENDAR)
+        requireWrite { viewModel.duplicateForm()?.let(onDuplicate) }
-        }
     }
 
     val deleteFailedMessage = stringResource(R.string.event_delete_failed)
@@ -229,7 +238,8 @@ fun EventDetailScreen(
                 },
                 actions = {
                     val s = state
-                    // Share works for any loaded event — it only reads the event.
+                    // Share and duplicate work for any loaded event — both only
+                    // read it; the duplicate is created into a writable calendar.
                     if (s is EventDetailUiState.Success) {
                         IconButton(onClick = onShareClick) {
                             Icon(
@@ -237,6 +247,15 @@ fun EventDetailScreen(
                                 contentDescription = stringResource(R.string.event_detail_share),
                             )
                         }
+                        IconButton(
+                            onClick = onDuplicateClick,
+                            enabled = deleteState != DeleteUiState.Deleting,
+                        ) {
+                            Icon(
+                                imageVector = Icons.Default.ContentCopy,
+                                contentDescription = stringResource(R.string.event_detail_duplicate),
+                            )
+                        }
                     }
                     // Edit/delete need a writable calendar — WebCal subscriptions,
                     // birthday calendars etc. are read-only at the provider level.
@@ -367,7 +386,7 @@ private fun EventDetailContent(state: EventDetailUiState.Success, modifier: Modi
     val instance = detail.instance
     val dark = isSystemInDarkTheme()
     val locale = currentDetailLocale()
-    val accent = pastelize(instance.color, dark)
+    val accent = eventFill(instance.color, dark, LocalSoftenColors.current)
 
     Column(
         modifier = modifier
@@ -438,14 +457,44 @@ private fun EventDetailContent(state: EventDetailUiState.Success, modifier: Modi
         }
 
         // Time zone — only when the event is timed and pinned to a zone other
-        // than the device's, so cross-zone events read unambiguously.
+        // than the device's, so cross-zone events read unambiguously. It answers
-        foreignTimeZoneLabel(detail.eventTimezone, instance.isAllDay, locale)?.let { tzLabel ->
+        // "when was it set", which the zone's name alone never did: an 8 AM New
+        // York call showing as 2 PM here should still say 8 AM somewhere.
+        //
+        // Same hierarchy as the When card above — the label carries the card,
+        // the time sits small beneath it. The local time is the one the reader
+        // acts on, so the original must stay quieter than it, not compete.
+        val foreignZone = remember(detail.eventTimezone, instance.isAllDay, instance.start, locale) {
+            foreignTimeZone(detail.eventTimezone, instance.isAllDay, locale, instance.start)
+        }
+        foreignZone?.let { zoneOption ->
             Spacer(Modifier.height(gap))
             DetailCard(
                 icon = Icons.Default.Public,
                 iconContentDescription = stringResource(R.string.event_detail_timezone),
             ) {
-                Text(text = tzLabel, style = MaterialTheme.typography.titleMedium)
+                // The id is the primary label ("Europe/Berlin"); the long
+                // localized name spelled next to it made the field too wide.
+                Text(text = zoneOption.label, style = MaterialTheme.typography.titleMedium)
+                // Beneath, small: the abbreviation plus the event's own-zone time,
+                // e.g. "CET · 8:00 AM – 9:00 AM". formatWhen puts the range in the
+                // secondary half only for a same-day event; one spanning midnight
+                // — which a cross-zone event easily does — carries the whole span
+                // in the primary instead, so fall back to it. If the zone can't be
+                // read back at all, drop to just the abbreviation + offset.
+                val originalTime = runCatching { TimeZone.of(zoneOption.id) }.getOrNull()
+                    ?.let { formatWhen(instance, it, locale) }
+                    ?.let { (primary, secondary) -> secondary ?: primary }
+                Spacer(Modifier.height(2.dp))
+                Text(
+                    text = if (originalTime != null) {
+                        "${zoneOption.shortName} · $originalTime"
+                    } else {
+                        zoneDescriptor(zoneOption)
+                    },
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
             }
         }
 
@@ -737,21 +786,30 @@ private fun attendeeRoleLabel(attendee: Attendee): Int? = when {
 private fun reminderLeadText(reminder: Reminder): String = reminderLeadTimeLabel(reminder.minutes)
 
 /**
- * A localized label for [tz] (e.g. "Central European Time (Europe/Berlin)"),
+ * [tz] resolved as a [TimeZoneOption], but only when the event is timed and
- * but only when the event is timed and pinned to a zone different from the
+ * pinned to a zone different from the device's — the cases where showing it
- * device's. Returns null when there's nothing worth showing.
+ * removes ambiguity. Null otherwise (all-day, device-zone, blank, or an id the
+ * tz database doesn't know).
+ *
+ * Resolved *at [at]*, the event's own start, not at "now": the abbreviation and
+ * offset both move with DST, and the card prints them next to the event's time.
+ * Resolving at now would label a July event "CET · 10:00 AM" when read in
+ * January — an abbreviation that contradicts the time beside it.
  */
-private fun foreignTimeZoneLabel(tz: String?, isAllDay: Boolean, locale: Locale): String? {
+private fun foreignTimeZone(
+    tz: String?,
+    isAllDay: Boolean,
+    locale: Locale,
+    at: Instant,
+): TimeZoneOption? {
     if (isAllDay || tz.isNullOrBlank()) return null
-    val deviceZone = ZoneId.systemDefault().id
+    if (tz == ZoneId.systemDefault().id) return null
-    if (tz == deviceZone) return null
+    return timeZoneOptionOf(
-    return try {
+        tz,
-        val zone = ZoneId.of(tz)
+        locale,
-        val name = zone.getDisplayName(JavaTextStyle.FULL, locale)
+        at = at.toJavaInstant(),
-        if (name == tz) tz else "$name ($tz)"
+        regionOf = ::icuTimeZoneRegion,
-    } catch (e: Exception) {
+    )
-        tz
-    }
 }
 
 /** Wrap http(s) URLs in [text] as tappable links tinted [linkColor]. */

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailViewModel.kt

@@ -8,10 +8,12 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
+import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
 import de.jeanlucmakiola.calendula.domain.ics.toShareIcsEvent
+import de.jeanlucmakiola.calendula.domain.toEditForm
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
 import kotlin.time.Clock
@@ -28,6 +30,7 @@ import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import kotlinx.datetime.TimeZone
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.time.Instant
 import javax.inject.Inject
@@ -138,16 +141,48 @@ class EventDetailViewModel @Inject constructor(
         }.getOrNull()
     }
 
+    /**
+     * Build a create form seeded from the open event so the user can save a
+     * copy as a new, independent event (#52). Returns null when nothing is
+     * loaded.
+     *
+     * The recurrence is dropped — a duplicate is a single event; anyone who
+     * wants a series can re-add one in the edit form that opens. The source
+     * calendar is kept only when it's writable, otherwise the id is cleared so
+     * the create resolves to the last-used/first-writable calendar — which lets
+     * a read-only event (a WebCal subscription, a birthday) be copied into an
+     * editable calendar. The occurrence's own times carry over unchanged.
+     */
+    fun duplicateForm(): EventForm? {
+        val loaded = state.value as? EventDetailUiState.Success ?: return null
+        val detail = loaded.detail
+        return detail.toEditForm(
+            beginMillis = detail.instance.start.toEpochMilliseconds(),
+            endMillis = detail.instance.end.toEpochMilliseconds(),
+            zone = TimeZone.currentSystemDefault(),
+        ).copy(
+            rrule = null,
+            calendarId = detail.instance.calendarId.takeIf { loaded.canModify },
+        )
+    }
+
     private suspend fun loadDetail(target: Target): EventDetailUiState = try {
         val detail = repository.eventDetail(target.eventId)
         // The Events row holds the series start; replace it with this
-        // occurrence's time so recurring events render correctly.
+        // occurrence's time so recurring events render correctly. An external
-        val corrected = detail.copy(
+        // "open event" that names no occurrence ([NO_OCCURRENCE_TIME] — e.g. a
+        // bare content://.../events/<id> VIEW intent, issue #48) keeps the row's
+        // own DTSTART/DTEND instead of overriding it to the epoch.
+        val corrected = if (target.beginMillis == NO_OCCURRENCE_TIME) {
+            detail
+        } else {
+            detail.copy(
                 instance = detail.instance.copy(
                     start = Instant.fromEpochMilliseconds(target.beginMillis),
                     end = Instant.fromEpochMilliseconds(target.endMillis),
                 ),
             )
+        }
         val calendar = repository.calendars().first()
             .firstOrNull { it.id == corrected.instance.calendarId }
         EventDetailUiState.Success(
@@ -168,6 +203,16 @@ class EventDetailViewModel @Inject constructor(
 
     /** A tapped occurrence: the series [eventId] plus this occurrence's own times. */
     private data class Target(val eventId: Long, val beginMillis: Long, val endMillis: Long)
+
+    companion object {
+        /**
+         * Sentinel begin/end for an "open this event" that names no occurrence —
+         * a bare `content://com.android.calendar/events/<id>` VIEW intent with no
+         * `EXTRA_EVENT_BEGIN_TIME` (issue #48). [loadDetail] then keeps the event
+         * row's own DTSTART/DTEND instead of overriding it to the epoch.
+         */
+        const val NO_OCCURRENCE_TIME: Long = Long.MIN_VALUE
+    }
 }
 
 /** A filesystem-safe `.ics` file name from an event title (or a fallback). */

app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditUiState.kt

@@ -27,6 +27,8 @@ data class EventEditUiState(
      * neither list.
      */
     val hiddenFields: List<EventFormField> = emptyList(),
+    /** Recently picked zones, most recent first — the zone picker's shortlist. */
+    val recentTimeZones: List<String> = emptyList(),
     /** True while editing an existing event (the calendar is then fixed). */
     val isEditing: Boolean = false,
     /**