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

@@ -72,9 +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.

.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 }}
@@ -39,8 +49,16 @@ jobs:
       - 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=$(grep -oP 'versionName\s*=\s*"\K[^"]+' app/build.gradle.kts)
@@ -58,15 +76,28 @@ jobs:
           fi
           # A tag for this version already existing means the release shipped on
           # an earlier push; do nothing. Absent => this merge cuts the release.
-          STATUS=$(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$VERSION already exists — nothing to release."
+          # read as absent and re-cut a release that has already shipped —
-            echo "is_release=false" >> "$GITHUB_OUTPUT"
+          # republishing to F-Droid and Play. Failing here is recoverable; a
-          else
+          # duplicate release is not.
-            echo "No tag for v$VERSION yet — cutting the release."
+          STATUS=$(curl -s -o /dev/null -w '%{http_code}' "$TAG_API/git/refs/tags/v$VERSION" || echo 000)
-            echo "is_release=true" >> "$GITHUB_OUTPUT"
+          case "$STATUS" in
-          fi
+            200)
+              echo "Tag v$VERSION already exists on Codeberg — nothing to release."
+              echo "is_release=false" >> "$GITHUB_OUTPUT"
+              ;;
+            404)
+              echo "No tag for v$VERSION on Codeberg yet — cutting the release."
+              echo "is_release=true" >> "$GITHUB_OUTPUT"
+              ;;
+            *)
+              echo "Codeberg tag lookup for v$VERSION returned HTTP $STATUS." >&2
+              echo "Refusing to guess: treating this as 'no tag' could re-cut a shipped release." >&2
+              exit 1
+              ;;
+          esac
 
   # Releases: build + sign + publish, then mint the tag and Gitea release.
   # Also runs on manual dispatch, where it skips the build and just re-signs and
@@ -350,3 +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

.gitmodules

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

CHANGELOG.md

@@ -5,6 +5,212 @@ 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
@@ -984,6 +1190,7 @@ automatically, with zero telemetry and no internet permission.
 [#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
@@ -996,4 +1203,23 @@ automatically, with zero telemetry and no internet permission.
 [#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 = 21500
+        versionCode = 21600
-        versionName = "2.15.0"
+        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 {

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
@@ -113,6 +120,28 @@
                 <data android:mimeType="text/x-vcalendar" />
                 <data android:mimeType="application/ics" />
             </intent-filter>
+            <!-- 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" />
@@ -124,11 +153,13 @@
 
             <!-- 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
+                 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. -->
+                 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" />
@@ -136,14 +167,31 @@
                 <data android:mimeType="vnd.android.cursor.dir/event" />
             </intent-filter>
 
-            <!-- Edit an existing event another app/assistant/widget points at:
+            <!-- Create or edit an event another app/assistant/widget points at,
-                 ACTION_EDIT on content://com.android.calendar/events/<id>, the way
+                 addressed by the provider's *item* MIME type. Three actions share
-                 AOSP fires it. Opens the occurrence in the edit form (not the
+                 this filter, told apart at runtime by the intent's data:
-                 read-only detail — that's the VIEW filter above). Matched by the
+
-                 provider's item MIME type, like the VIEW filter. The occurrence's
+                 • ACTION_INSERT — create. This is the form the Android docs'
-                 times ride as EXTRA_EVENT_BEGIN_TIME / EXTRA_EVENT_END_TIME when
+                   "insert an event" example and many apps use
-                 supplied (MainActivity.editEventKeyOrNull). -->
+                   (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" />
@@ -165,11 +213,47 @@
                 <data android:mimeType="vnd.android.cursor.item/event" />
             </intent-filter>
 
-            <!-- Launcher long-press shortcuts (e.g. "New event"). -->
+        </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
@@ -194,17 +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

@@ -4,9 +4,12 @@ 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.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
@@ -39,6 +42,43 @@ class CalendulaApp : Application() {
         )
         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

@@ -222,10 +222,12 @@ class MainActivity : AppCompatActivity() {
      * [buildInsertEventForm].
      */
     private fun Intent.insertFormOrNull(): EventForm? {
-        // ACTION_EDIT on an existing event routes to the edit form instead
+        // ACTION_EDIT / ACTION_INSERT_OR_EDIT on an existing event route to the
-        // ([editEventKeyOrNull]); only an id-less EDIT is a create.
+        // 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 && editEventKeyOrNull() == null)
+            ((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),
@@ -344,10 +346,11 @@ class MainActivity : AppCompatActivity() {
      * 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` is a create instead ([insertFormOrNull]).
+     * 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) return null
+        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

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

@@ -54,7 +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
@@ -110,6 +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
@@ -373,6 +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 {
@@ -610,7 +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(
@@ -619,7 +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,
+            )
         }
     }
 

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

@@ -38,6 +38,20 @@ 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]).

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

@@ -16,11 +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
@@ -47,52 +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.
+     */
+    private fun visibilityTicks(): Flow<Unit> = merge(
+        ticks.onStart { emit(Unit) },
+        // The current value is already covered by the tick above; only later
+        // changes re-query (the set is deduped, so an unrelated DataStore write
+        // doesn't).
+        prefs.pendingDisabledCalendarIds.drop(1).map {},
+    )
 
-    // Instances are filtered by the app-side hidden ∪ disabled calendar sets
+    // A switch-off the app hasn't been allowed to write yet is folded into the
-    // (M3): an event is dropped whenever the user has hidden *or* disabled its
+    // flag itself, so every consumer — the Settings switch, the filter sheet,
-    // calendar. Re-runs when the provider ticks *or* either set changes —
+    // the form and import pickers, the widgets — reads one visibility and can't
-    // toggling a calendar in the filter sheet or the calendar manager updates
+    // disagree with what the user just tapped. The reconciler reads the data
-    // every view immediately. [calendars] stays unfiltered so those screens can
+    // source directly, because it needs the provider's own answer.
-    // list and re-enable hidden/disabled calendars.
+    override fun calendars(): Flow<List<CalendarSource>> =
-    override fun instances(range: ClosedRange<Instant>): Flow<List<EventInstance>> =
+        visibilityTicks().reQuery {
-        combine(
+            val calendars = calendarsSnapshot()
-            ticks
+            val pendingDisabled = prefs.pendingDisabledCalendarIds.first()
-                .onStart { emit(Unit) }
+            if (pendingDisabled.isEmpty()) calendars
-                .reQuery {
+            else calendars.map {
-                    dataSource.instances(
+                if (it.id in pendingDisabled) it.copy(isVisibleInSystem = false) else it
-                        beginMillis = range.start.toEpochMillis(),
+            }
-                        endMillis = range.endInclusive.toEpochMillis(),
-                    )
-                },
-            prefs.hiddenCalendarIds,
-            prefs.disabledCalendarIds,
-        ) { instances, hidden, disabled ->
-            val excluded = hidden + disabled
-            if (excluded.isEmpty()) instances
-            else instances.filterNot { it.calendarId in excluded }
         }
-            // hidden and disabled both derive from one DataStore, so toggling
+            // Collapse re-emissions that carry an identical list (see
-            // either makes both re-emit and combine briefly surfaces the same
+            // [instances]).
-            // list twice — collapse the duplicate so views don't re-render for it.
             .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 } }
     }
@@ -118,6 +213,22 @@ class CalendarRepositoryImpl @Inject constructor(
     override suspend fun deleteCalendar(id: Long) =
         withContext(io) { dataSource.deleteCalendar(id) }
 
+    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) }
 

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

@@ -24,6 +24,7 @@ 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
@@ -89,7 +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(
@@ -31,13 +37,38 @@ 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
@@ -104,10 +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,
@@ -134,10 +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)
@@ -149,8 +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))

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 {

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 -> prefs.writeIds(HIDDEN_IDS_KEY, ids) }
+    }
+
+    /**
+     * 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 ->
-            if (ids.isEmpty()) {
+            prefs.writeIds(DISABLED_IDS_KEY, transform(prefs[DISABLED_IDS_KEY].parseIds()))
-                prefs.remove(HIDDEN_IDS_KEY)
-            } else {
-                prefs[HIDDEN_IDS_KEY] = ids.sorted().joinToString(",")
-            }
         }
     }
 
     /**
-     * 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

@@ -21,9 +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
@@ -81,6 +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
@@ -233,6 +258,33 @@ class SettingsPrefs @Inject constructor(
         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
@@ -255,6 +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.
@@ -354,6 +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
@@ -650,6 +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(',')
@@ -703,6 +799,7 @@ 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")
@@ -710,6 +807,8 @@ class SettingsPrefs @Inject constructor(
         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")
@@ -736,6 +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")

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

@@ -14,6 +14,7 @@ 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
@@ -28,17 +29,20 @@ 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. */
@@ -49,12 +53,25 @@ 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()
@@ -101,16 +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 =
@@ -123,7 +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/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/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/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

@@ -23,6 +23,7 @@ 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.floret.identity.fadeThrough
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
@@ -88,6 +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))
@@ -146,6 +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)
@@ -208,6 +216,7 @@ fun CalendarHost(
     fun dismissCoveringOverlays() {
         showSettings = false
         showCalendars = false
+        showBackup = false
         detailKey = null
         editKey = null
         importUri = null
@@ -291,8 +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)
     }
@@ -318,6 +327,7 @@ fun CalendarHost(
                     onCreateEvent = onCreateEvent,
                     quickSwitchViews = quickSwitchViews,
                     drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Day -> DayScreen(
                     selectedView = currentView,
@@ -329,16 +339,19 @@ fun CalendarHost(
                     initialDateIso = pendingDayIso,
                     quickSwitchViews = quickSwitchViews,
                     drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Month -> MonthScreen(
                     selectedView = currentView,
                     onSelectView = onSelectView,
                     onOpenDay = onOpenDay,
+                    onEventClick = onEventClick,
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
                     quickSwitchViews = quickSwitchViews,
                     drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
                 CalendarView.Agenda -> AgendaScreen(
                     selectedView = currentView,
@@ -350,6 +363,7 @@ fun CalendarHost(
                     onCreateEvent = onCreateEvent,
                     quickSwitchViews = quickSwitchViews,
                     drawerViewOrder = drawerViewOrder,
+                    todayInToolbar = todayInToolbar,
                 )
             }
         }
@@ -408,6 +422,7 @@ fun CalendarHost(
                     initialStartMinutes = createStartMinutes ?: heldCreateMinutes,
                     onClose = { createDateIso = null },
                     onSaved = { createDateIso = null },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -427,6 +442,7 @@ fun CalendarHost(
                         editKey = null
                         detailKey = null
                     },
+                    onManageCalendars = { showCalendars = true },
                 )
             }
         }
@@ -440,18 +456,7 @@ 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 },
-                onImport = { importUri = it; importForceMany = true },
             )
         }
 
@@ -462,6 +467,7 @@ fun CalendarHost(
                 uri = uri,
                 forceMany = importForceMany,
                 onClose = { importUri = null },
+                onManageCalendars = { showCalendars = true },
                 onOpenSingle = { form ->
                     importUri = null
                     importFormSource = ImportSource.File
@@ -476,6 +482,39 @@ fun CalendarHost(
                 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
@@ -48,6 +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 ->
@@ -78,6 +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(

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

@@ -1,6 +1,6 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
-import de.jeanlucmakiola.calendula.ui.common.localizedDateFormatter
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import java.time.YearMonth

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
@@ -17,13 +14,11 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 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.Menu
 import androidx.compose.material.icons.filled.Search
 import androidx.compose.material3.ButtonDefaults
-import androidx.compose.material3.Card
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -32,7 +27,6 @@ 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
@@ -46,8 +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
@@ -59,36 +51,27 @@ import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
 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.LocalSoftenColors
-import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 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.localizedDateFormatter
-import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
-import de.jeanlucmakiola.floret.components.GroupedRow
-import de.jeanlucmakiola.floret.components.Position
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.floret.components.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.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
@@ -102,6 +85,7 @@ fun AgendaScreen(
     onCreateEvent: (LocalDate, Int?) -> Unit,
     quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
     drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
+    todayInToolbar: Boolean = false,
     modifier: Modifier = Modifier,
     viewModel: AgendaViewModel = hiltViewModel(),
 ) {
@@ -109,6 +93,7 @@ fun AgendaScreen(
     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)
@@ -151,12 +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) },
@@ -212,6 +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 },
         )
@@ -328,6 +316,7 @@ private fun AgendaContent(
                 AgendaList(
                     days = days,
                     today = state.today,
+                    zone = state.zone,
                     dimPast = pastDisplay == PastEventDisplay.DIM,
                     now = now,
                     onEventClick = onEventClick,
@@ -344,6 +333,7 @@ private fun AgendaContent(
 private fun AgendaList(
     days: List<AgendaDay>,
     today: LocalDate,
+    zone: TimeZone,
     dimPast: Boolean,
     now: Instant,
     onEventClick: (EventInstance) -> Unit,
@@ -362,15 +352,23 @@ private fun AgendaList(
             if (day.events.isEmpty()) {
                 // An anchored, event-less today (#35) — "nothing left today".
                 item(key = "placeholder-${day.date}") {
-                    AgendaEmptyDayRow(onClick = { onOpenDay(day.date) })
+                    AgendaEmptyDayRow(
+                        text = stringResource(R.string.agenda_no_more_today),
+                        onClick = { onOpenDay(day.date) },
+                    )
                 }
             } else {
                 itemsIndexed(
                     items = day.events,
-                    key = { _, event -> event.instanceId },
+                    // Scope the key by day: a multi-day event appears under every
+                    // day it spans, so its instanceId alone is not unique across
+                    // the list (LazyColumn requires unique keys).
+                    key = { _, event -> "${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 = animateItemMotion(),
@@ -383,98 +381,6 @@ private fun AgendaList(
     }
 }
 
-@Composable
-private 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 under an anchored, event-less today (#35) — the same coffee-cup motif
- * as the full-screen [AgendaEmpty] state, boxed into a card so today keeps a
- * visible slot when nothing is left rather than a bare header.
- */
-@Composable
-private fun AgendaEmptyDayRow(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 = stringResource(R.string.agenda_no_more_today),
-                style = MaterialTheme.typography.bodyLarge,
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                textAlign = TextAlign.Center,
-            )
-        }
-    }
-}
-
-@Composable
-private fun AgendaEventRow(
-    event: EventInstance,
-    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),
-        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,
-    )
-}
-
 @Composable
 private fun AgendaEmpty(modifier: Modifier = Modifier) {
     Column(
@@ -504,6 +410,8 @@ private fun AgendaTopBar(
     onCycleView: () -> Unit,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
+    showTodayButton: Boolean,
+    onToday: () -> Unit,
     scrollBehavior: TopAppBarScrollBehavior,
 ) {
     TopAppBar(
@@ -522,6 +430,7 @@ private fun AgendaTopBar(
             }
         },
         actions = {
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,
@@ -541,42 +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)
-    // 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/AgendaUiState.kt

@@ -2,9 +2,43 @@ package de.jeanlucmakiola.calendula.ui.agenda
 
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import de.jeanlucmakiola.calendula.domain.spanFirstDay
+import de.jeanlucmakiola.calendula.domain.spanLastDay
+import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.toLocalDateTime
+import kotlinx.datetime.plus
+import kotlin.time.Instant
+
+/**
+ * What an agenda row's time line should convey for an event on a given day —
+ * the part of a multi-day span that [day] falls in. Pure and shared so the
+ * agenda screen and the agenda widget label multi-day events identically; each
+ * surface only formats the instants into its own locale/24h string.
+ */
+sealed interface AgendaTimeLabel {
+    /** An all-day event, or a whole in-between day of a multi-day span. */
+    data object AllDay : AgendaTimeLabel
+    /** The first day of a multi-day timed event: when it begins. */
+    data class Starts(val start: Instant) : AgendaTimeLabel
+    /** The last day of a multi-day timed event: when it ends. */
+    data class Ends(val end: Instant) : AgendaTimeLabel
+    /** A single-day timed event: its start–end range. */
+    data class Range(val start: Instant, val end: Instant) : AgendaTimeLabel
+}
+
+/** The [AgendaTimeLabel] for [event] as it appears on [day], resolved in [zone]. */
+fun agendaTimeLabel(event: EventInstance, day: LocalDate, zone: TimeZone): AgendaTimeLabel {
+    if (event.isAllDay) return AgendaTimeLabel.AllDay
+    val firstDay = event.spanFirstDay(zone)
+    val lastDay = event.spanLastDay(zone)
+    return when {
+        firstDay == lastDay -> AgendaTimeLabel.Range(event.start, event.end)
+        day <= firstDay -> AgendaTimeLabel.Starts(event.start)
+        day >= lastDay -> AgendaTimeLabel.Ends(event.end)
+        else -> AgendaTimeLabel.AllDay // a full in-between day
+    }
+}
 
 /** One calendar day with at least one event, for the agenda list. */
 data class AgendaDay(
@@ -15,31 +49,51 @@ 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)
-            AgendaDay(
+        // Skip instances that don't actually occupy any day in [[anchor], [windowEnd]].
-                date = date,
+        // The provider returns an event whenever its instant span overlaps the query
-                events = dayEvents.sortedWith(
+        // window, but all-day events live at UTC midnights with an exclusive end: east
-                    compareByDescending<EventInstance> { it.isAllDay }
+        // of UTC that end dips just past local midnight, so *yesterday's* all-day event
-                        .thenBy { it.start }
+        // overlaps today's window start and comes back even though its true last day
-                        .thenBy { it.title },
+        // (resolved in UTC) is before the anchor. Clamping it up to the anchor would
-                ),
+        // surface it under "today" (issue #65); drop it instead. The symmetric case —
-            )
+        // a next-day all-day event overlapping the window's last instant — drops too.
+        if (lastDay < firstDay) continue
+        var day = firstDay
+        while (day <= lastDay) {
+            byDay.getOrPut(day) { mutableListOf() }.add(instance)
+            day = day.plus(1, DateTimeUnit.DAY)
         }
+    }
+    return byDay.map { (date, dayEvents) ->
+        AgendaDay(
+            date = date,
+            events = dayEvents.sortedWith(
+                compareByDescending<EventInstance> { it.isAllDay }
+                    .thenBy { it.start }
+                    .thenBy { it.title },
+            ),
+        )
+    }
+}
 
 /**
  * Ensure [today] surfaces as the first agenda day even when it carries no
@@ -79,5 +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
@@ -93,7 +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,
@@ -159,11 +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,
@@ -172,6 +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

@@ -4,9 +4,6 @@ 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.background
 import androidx.compose.foundation.isSystemInDarkTheme
@@ -26,25 +23,22 @@ 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.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.FileUpload
 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
 import androidx.compose.material3.Button
-import androidx.compose.material3.Checkbox
 import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -66,83 +60,71 @@ 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.draw.alpha
-import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 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.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.accountGroupTitle
+import de.jeanlucmakiola.calendula.ui.common.groupByAccount
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
 import de.jeanlucmakiola.calendula.ui.common.SourceLogo
 import de.jeanlucmakiola.calendula.ui.common.curatedSourcePackage
 import de.jeanlucmakiola.floret.components.CollapsingScaffold
-import de.jeanlucmakiola.floret.components.DialogAmountField
-import de.jeanlucmakiola.floret.components.DialogUnitDropdown
-import de.jeanlucmakiola.floret.components.FullScreenPicker
-import de.jeanlucmakiola.floret.components.positionOf
 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.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.InlineTextField
 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
 
-// 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",
-)
-
 /**
  * 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,
-    onImport: (android.net.Uri) -> 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
@@ -158,6 +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) {
@@ -177,22 +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,
-            onImport = onImport,
-            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,
         )
     }
 }
@@ -201,28 +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, Set<Long>?) -> Unit,
-    onImport: (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)
 
@@ -233,47 +200,6 @@ private fun CalendarsList(
         }
     }
 
-    // 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 { onExportBackup(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(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,
@@ -281,12 +207,12 @@ private fun CalendarsList(
         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,
@@ -298,17 +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,
@@ -317,7 +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) },
@@ -326,82 +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 exportable: the user's
+        // pointer, so someone looking at their local calendars still finds the
-        // own local calendars (managed special-dates mirrors don't count).
+        // way to keep a copy of them.
-        val exportable = local.filter { it.canModifyContents && !it.isManaged }
+        Spacer(Modifier.height(16.dp))
-        // Restore/import can target any writable, non-managed calendar (local or
+        GroupedRow(
-        // synced), so its availability is broader than export's.
+            title = stringResource(R.string.settings_section_backup),
-        val canImport = (local + synced).any { it.canModifyContents && !it.isManaged }
+            summary = stringResource(R.string.settings_backup_subtitle),
-        if (exportable.isNotEmpty()) {
+            position = Position.Alone,
-            Spacer(Modifier.height(16.dp))
+            leading = { LeadingAvatar(Icons.Default.Backup) },
-            SectionHeader(stringResource(R.string.calendars_backup_header))
+            trailing = {
-            HintText(stringResource(R.string.calendars_backup_hint))
+                Icon(
-            // One connected card: the one-time export on top, then automatic
+                    imageVector = Icons.AutoMirrored.Filled.KeyboardArrowRight,
-            // backup (and its folder/interval rows when on).
+                    contentDescription = null,
-            GroupedRow(
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                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 = onSetAutoBackupEnabled)
-                },
-                onClick = { onSetAutoBackupEnabled(!autoBackup.enabled) },
-            )
-            if (autoBackup.enabled) {
-                GroupedRow(
-                    title = stringResource(R.string.calendars_auto_backup_folder),
-                    summary = rememberFolderName(autoBackup.folderUri)
-                        ?: stringResource(R.string.calendars_auto_backup_folder_unset),
-                    position = Position.Middle,
-                    onClick = { runCatching { pickFolder.launch(null) } },
                 )
-                GroupedRow(
+            },
-                    title = stringResource(R.string.calendars_auto_backup_interval),
+            onClick = onOpenBackup,
-                    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.
-            Spacer(Modifier.height(16.dp))
-            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) } },
-            )
-        }
 
         Spacer(Modifier.height(16.dp))
 
@@ -411,14 +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,
@@ -430,29 +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,
+                                    EnableSwitch(
-                                    enabled = !disabled,
+                                        calendarName = calendar.displayName,
-                                    onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
+                                        enabled = calendar.isVisibleInSystem,
-                                )
+                                        onToggle = { enabled ->
+                                            onSetVisible(calendar.id, enabled)
+                                        },
+                                    )
+                                }
+                            } else {
+                                null
                             },
                         )
                     }
@@ -460,93 +345,6 @@ private fun CalendarsList(
             }
     }
 
-    if (showInterval) {
-        BackupIntervalDialog(
-            currentMinutes = autoBackup.intervalMinutes,
-            onConfirm = onSetAutoBackupInterval,
-            onDismiss = { showInterval = false },
-        )
-    }
-
-    if (showExportPicker) {
-        ExportCalendarPicker(
-            calendars = local.filter { it.canModifyContents && !it.isManaged },
-            onExport = onExportBackup,
-            onDismiss = { showExportPicker = 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: (android.net.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))
-        }
-    }
 }
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -560,6 +358,7 @@ 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) }
@@ -593,11 +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
+                                },
                             )
                         }
                     }
@@ -626,6 +437,19 @@ private fun CalendarEditor(
                 .padding(horizontal = 16.dp, vertical = 8.dp),
             verticalArrangement = Arrangement.spacedBy(12.dp),
         ) {
+            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,
@@ -698,10 +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(
@@ -709,7 +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,
@@ -883,113 +730,31 @@ private fun CalendarGroupMenu(
 
 
 @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

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()
 
@@ -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/CalendarPickerGroups.kt

@@ -11,9 +11,10 @@ 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.filled.Check
+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
@@ -33,6 +34,7 @@ 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
@@ -42,18 +44,23 @@ import de.jeanlucmakiola.floret.components.Position
  * 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 }
+        calendars.filterNot { it.isLocal }.groupByAccount()
-            .groupBy { it.accountName.ifBlank { it.accountType }.ifBlank { it.displayName } }
-            .toList()
     }
 
     if (local.isNotEmpty()) {
@@ -65,16 +72,33 @@ fun ColumnScope.CalendarPickerGroups(
             onSelect = onSelect,
         )
     }
-    syncedGroups.forEachIndexed { index, (account, cals) ->
+    syncedGroups.forEachIndexed { index, group ->
         if (local.isNotEmpty() || index > 0) Spacer(Modifier.height(16.dp))
         CalendarPickerGroup(
-            title = account,
+            title = accountGroupTitle(group),
-            leading = { SourceLogo(cals.first().accountType) },
+            leading = { SourceLogo(group.accountType) },
-            calendars = cals,
+            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. */
@@ -99,13 +123,7 @@ private fun CalendarPickerGroup(
             selected = isSelected,
             leading = { CalendarColorChip(calendar.color) },
             trailing = if (isSelected) {
-                {
+                { SelectedCheck() }
-                    Icon(
-                        imageVector = Icons.Default.Check,
-                        contentDescription = null,
-                        tint = MaterialTheme.colorScheme.primary,
-                    )
-                }
             } else {
                 null
             },
@@ -161,20 +179,22 @@ fun LeadingAvatar(icon: ImageVector) {
 /** 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 {
+    for (pkg in sourceAppPackages(context, accountType)) {
-        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
 }
 
+/** 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"

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

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.common
 
 import androidx.compose.animation.ContentTransform
+import androidx.compose.animation.SizeTransform
 import androidx.compose.animation.core.FiniteAnimationSpec
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
@@ -23,9 +24,13 @@ import androidx.compose.ui.unit.IntOffset
  */
 
 /**
- * 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.
@@ -33,27 +38,34 @@ import androidx.compose.ui.unit.IntOffset
 @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,
@@ -65,6 +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),
+        // AnimatedContent clips to the animating container by default, which
+        // shears the pages against the viewport edge as they pass. There is no
+        // size change here to contain — both pages are the same grid.
+        sizeTransform = SizeTransform(clip = false),
+    )
 }
+
+/**
+ * How far a page travels, as a fraction of the container width.
+ *
+ * A full width was the obvious reading of "paging", but the two pages are
+ * stacked and both opaque, so a full-width slide showed one grid racing across
+ * another — the movement carried the whole transition and had a long way to go.
+ * Under M3's shared-axis pattern the offset only has to *hint* the direction
+ * while the cross-fade does the swapping, so a fifth of the width is plenty and
+ * leaves nothing skating past.
+ */
+private const val SLIDE_TRAVEL_DIVISOR = 5

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/LocaleSupport.kt

@@ -1,33 +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.time.format.DateTimeFormatter
-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()
-    }
-}
-
-/**
- * A [DateTimeFormatter] for [skeleton]'s fields laid out in [locale]'s own order
- * (via Android's best-pattern matching), so dates read naturally per locale
- * instead of a hardcoded day-month-year order. [skeleton] lists the wanted
- * fields, e.g. "dMMMy" (day, abbreviated month, year) or "EEEdMMM" (weekday too).
- */
-fun localizedDateFormatter(locale: Locale, skeleton: String): DateTimeFormatter =
-    DateTimeFormatter.ofPattern(
-        android.text.format.DateFormat.getBestDateTimePattern(locale, skeleton),
-        locale,
-    )

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

@@ -5,7 +5,6 @@ import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Check
 import androidx.compose.material3.Checkbox
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -24,15 +23,26 @@ import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 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
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.plus
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
 
 /**
  * Reminder-default picker, full-screen and **multi-select**: each [presets]
@@ -48,6 +58,11 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
  * 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(
@@ -57,6 +72,7 @@ fun ReminderDefaultPicker(
     allowInherit: Boolean,
     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
@@ -132,6 +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) }) },
@@ -196,37 +213,37 @@ private fun CustomReminderEditor(
     )
 }
 
-/** 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,
 ) {
@@ -240,10 +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) {
@@ -278,6 +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) {

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/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/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
@@ -77,13 +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.rememberCalendarPageSwipe
 import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 import de.jeanlucmakiola.calendula.ui.common.next
 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
@@ -93,7 +94,9 @@ 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
 
@@ -125,6 +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(),
@@ -157,6 +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() }
@@ -205,16 +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) },
@@ -251,8 +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()
@@ -281,20 +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,
@@ -360,16 +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,
             )
         },
@@ -382,6 +385,7 @@ private fun DayTopBar(
             }
         },
         actions = {
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,
@@ -669,10 +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

@@ -93,22 +93,26 @@ 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.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.icuTimeZoneRegion
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.floret.components.OptionCard
-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.timeOfDayFormatter
 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
@@ -453,14 +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,
+                )
             }
         }
 
@@ -752,21 +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/edit/EventEditScreen.kt

@@ -89,6 +89,8 @@ import androidx.compose.ui.graphics.isSpecified
 import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalFocusManager
+import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.AnnotatedString
@@ -98,7 +100,6 @@ import androidx.compose.ui.text.style.TextOverflow
 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
 import androidx.compose.ui.unit.dp
 import androidx.core.content.ContextCompat
 import androidx.hilt.navigation.compose.hiltViewModel
@@ -111,6 +112,9 @@ import de.jeanlucmakiola.calendula.domain.EventAttendee
 import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.domain.zoneDescriptor
+import de.jeanlucmakiola.calendula.domain.timeZoneOptionOf
+import de.jeanlucmakiola.calendula.domain.timesIn
 import de.jeanlucmakiola.calendula.domain.EventFormProblem
 import de.jeanlucmakiola.calendula.domain.RecurrenceEnd
 import de.jeanlucmakiola.calendula.domain.RecurrenceFreq
@@ -126,6 +130,8 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.ui.common.CalendarPickerGroups
 import de.jeanlucmakiola.calendula.ui.common.CalendarDatePickerDialog
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
+import de.jeanlucmakiola.calendula.ui.common.TimeZonePickerDialog
+import de.jeanlucmakiola.calendula.ui.common.icuTimeZoneRegion
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.floret.components.DialogAmountField
@@ -134,20 +140,24 @@ import de.jeanlucmakiola.calendula.ui.common.eventFormFieldIcon
 import de.jeanlucmakiola.calendula.ui.common.eventFormFieldLabel
 import de.jeanlucmakiola.floret.components.FullScreenPicker
 import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.GroupedSurface
 import de.jeanlucmakiola.calendula.ui.common.MILLIS_PER_DAY
 import de.jeanlucmakiola.floret.components.InlineTextField
 import de.jeanlucmakiola.floret.components.OptionCard
 import de.jeanlucmakiola.floret.components.OptionPicker
 import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.groupedShape as floretGroupedShape
 import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.calendula.ui.common.REMINDER_PRESETS
 import de.jeanlucmakiola.calendula.ui.common.TimePickerAlert
 import de.jeanlucmakiola.floret.reminders.ReminderUnit
-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.timeOfDayFormatter
 import de.jeanlucmakiola.calendula.ui.common.reminderLeadTimeLabel
 import de.jeanlucmakiola.calendula.ui.common.reminderUnitLabel
+import de.jeanlucmakiola.calendula.ui.common.nextOccurrencesText
 import de.jeanlucmakiola.calendula.ui.common.recurrenceText
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
@@ -157,13 +167,14 @@ import kotlinx.datetime.TimeZone
 import kotlinx.datetime.isoDayNumber
 import kotlinx.datetime.toJavaDayOfWeek
 import kotlinx.datetime.toJavaLocalDate
-import kotlinx.datetime.toKotlinDayOfWeek
+import kotlinx.datetime.toInstant
 import kotlinx.datetime.toJavaLocalTime
 import kotlinx.datetime.toLocalDateTime
+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.time.temporal.WeekFields
 import java.util.Locale
 import kotlin.time.Clock
 
@@ -185,6 +196,7 @@ fun EventEditScreen(
     initialStartMinutes: Int? = null,
     initialForm: EventForm? = null,
     initialFormSource: ImportSource = ImportSource.File,
+    onManageCalendars: (() -> Unit)? = null,
     viewModel: EventEditViewModel = hiltViewModel(),
 ) {
     LaunchedEffect(initialDateIso, editKey, initialForm) {
@@ -301,6 +313,7 @@ fun EventEditScreen(
                 modifier = Modifier
                     .fillMaxSize()
                     .padding(innerPadding),
+                onManageCalendars = onManageCalendars,
             )
         }
     }
@@ -492,20 +505,27 @@ private fun EventEditContent(
     state: EventEditUiState,
     viewModel: EventEditViewModel,
     modifier: Modifier = Modifier,
+    onManageCalendars: (() -> Unit)? = null,
 ) {
     val form = state.form
     val locale = currentLocale()
+    val firstDayOfWeek by viewModel.firstDayOfWeek.collectAsStateWithLifecycle()
     val dark = isSystemInDarkTheme()
     // The title, date and recurrence are managed by the special-dates sync, so
     // they're locked here; everything else (reminders, location, notes) is the
     // user's to edit.
     val locked = state.isManaged
+    // Read in the form's own window, not the picker's: the field holding focus
+    // lives here, so this is the controller that can put its keyboard away.
+    val focusManager = LocalFocusManager.current
+    val keyboardController = LocalSoftwareKeyboardController.current
     var picker by remember { mutableStateOf<PickerTarget?>(null) }
     var showCalendarPicker by rememberSaveable { mutableStateOf(false) }
     var showReminderPicker by rememberSaveable { mutableStateOf(false) }
     var showRecurrencePicker by rememberSaveable { mutableStateOf(false) }
     var showVisibilityPicker by rememberSaveable { mutableStateOf(false) }
     var showColorPicker by rememberSaveable { mutableStateOf(false) }
+    var showTimezonePicker by rememberSaveable { mutableStateOf(false) }
     var showFieldPicker by rememberSaveable { mutableStateOf(false) }
 
     // Pick a guest from contacts: a one-shot system picker returning the chosen
@@ -670,6 +690,28 @@ private fun EventEditContent(
                     color = MaterialTheme.colorScheme.error,
                 )
             }
+            // The rows above edit a pinned event in *its own* zone, which is the
+            // time it was set at — but that says nothing about when it lands for
+            // whoever is reading it. Spell the local equivalent out rather than
+            // leaving the user to do the offset arithmetic. Absent (null) unless
+            // the event is pinned somewhere other than here.
+            // Keyed rather than recomputed: this sits in the same Column as the
+            // title field, so it would otherwise re-parse the zone on every
+            // keystroke.
+            val localTimes = remember(form.timezone, form.start, form.end, form.isAllDay) {
+                form.timesIn(TimeZone.currentSystemDefault())
+            }
+            localTimes?.let { (localStart, localEnd) ->
+                Spacer(Modifier.height(2.dp))
+                Text(
+                    text = stringResource(
+                        R.string.event_edit_timezone_local_time,
+                        formatTimeRange(localStart, localEnd, locale),
+                    ),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
         }
 
         Spacer(Modifier.height(gap))
@@ -706,6 +748,54 @@ private fun EventEditContent(
 
         // Optional sections: which ones render by default is a setting; the
         // rest unfold behind the "more fields" button below.
+        OptionalFormSection(visible = EventFormField.Timezone in state.visibleFields) {
+            Spacer(Modifier.height(gap))
+            EditCard(
+                icon = Icons.Default.Public,
+                iconContentDescription = null,
+                onClick = { showTimezonePicker = true },
+            ) {
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    // Resolved at the event's own start, not at "now": the
+                    // abbreviation and offset shown ("CEST · GMT+02:00") must be
+                    // the ones that apply when the event actually happens.
+                    val pinned = remember(form.timezone, form.start, locale) {
+                        form.timezone
+                            ?.let { id -> runCatching { id to TimeZone.of(id) }.getOrNull() }
+                            ?.let { (id, zone) ->
+                                timeZoneOptionOf(
+                                    id,
+                                    locale,
+                                    at = form.start.toInstant(zone).toJavaInstant(),
+                                    regionOf = ::icuTimeZoneRegion,
+                                )
+                            }
+                    }
+                    Column(modifier = Modifier.weight(1f)) {
+                        Text(
+                            text = pinned?.label
+                                ?: stringResource(R.string.event_edit_timezone_device),
+                            style = MaterialTheme.typography.titleMedium,
+                        )
+                        Text(
+                            text = pinned?.let { zoneDescriptor(it) }
+                                ?: stringResource(R.string.event_edit_timezone_device_summary),
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                    Icon(
+                        imageVector = Icons.Default.ArrowDropDown,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+        }
+
         OptionalFormSection(visible = EventFormField.Location in state.visibleFields) {
             Spacer(Modifier.height(gap))
             EditCard(
@@ -1034,6 +1124,17 @@ private fun EventEditContent(
         null -> Unit
     }
 
+    // A full-screen picker over the form is a change of place, so the form's
+    // keyboard has no business following it there — least of all onto the
+    // calendar manager, which the picker can hand off to. The form's own field
+    // keeps its text; only focus and the IME go.
+    LaunchedEffect(showCalendarPicker) {
+        if (showCalendarPicker) {
+            focusManager.clearFocus(force = true)
+            keyboardController?.hide()
+        }
+    }
+
     if (showCalendarPicker) {
         CalendarPicker(
             calendars = state.calendars,
@@ -1042,6 +1143,17 @@ private fun EventEditContent(
                 viewModel.setCalendar(it)
                 showCalendarPicker = false
             },
+            // Close the picker on the way out. It is a Compose Dialog — its own
+            // window, always above the activity's content — so the manager would
+            // otherwise open behind it and the tap would look dead. The form
+            // stays standing underneath, its calendar row one tap from a picker
+            // that re-queries on open.
+            onManageCalendars = onManageCalendars?.let { openManager ->
+                {
+                    showCalendarPicker = false
+                    openManager()
+                }
+            },
             onDismiss = { showCalendarPicker = false },
         )
     }
@@ -1061,7 +1173,8 @@ private fun EventEditContent(
     if (showRecurrencePicker) {
         RecurrencePickerDialog(
             current = form.rrule,
-            startDay = form.start.date.dayOfWeek,
+            startDate = form.start.date,
+            firstDayOfWeek = firstDayOfWeek,
             onSelect = { rrule ->
                 viewModel.setRecurrence(rrule)
                 showRecurrencePicker = false
@@ -1081,6 +1194,16 @@ private fun EventEditContent(
         )
     }
 
+    if (showTimezonePicker) {
+        TimeZonePickerDialog(
+            selected = form.timezone,
+            deviceZoneId = ZoneId.systemDefault().id,
+            recents = state.recentTimeZones,
+            onSelect = viewModel::setTimezone,
+            onDismiss = { showTimezonePicker = false },
+        )
+    }
+
     if (showColorPicker) {
         ColorPickerDialog(
             palette = state.colorPalette,
@@ -1218,14 +1341,23 @@ private enum class RecurrenceEndMode { Never, Until, Count }
  * and an end condition — only that step needs an OK button. A rule the
  * simple shape can't express (ordinal BYDAY etc.) stays untouched unless the
  * user picks something here.
+ *
+ * Both steps show the rule as *dates* as well as words: every preset row
+ * carries the next few occurrences it would produce from [startDate], and the
+ * custom step repeats that under its live read-out. It is where a rule most
+ * easily means something other than it sounds like — "monthly" on the 31st
+ * skips February, an every-other-week rule lands a fortnight from the start's
+ * own week — and only the dates say so.
  */
 @Composable
 private fun RecurrencePickerDialog(
     current: String?,
-    startDay: DayOfWeek,
+    startDate: LocalDate,
+    firstDayOfWeek: DayOfWeek,
     onSelect: (String?) -> Unit,
     onDismiss: () -> Unit,
 ) {
+    val startDay = startDate.dayOfWeek
     val parsed = remember(current) { current?.let(::parseSimpleRecurrence) }
     val isPlainPreset = parsed != null && parsed.interval == 1 &&
         parsed.end == RecurrenceEnd.Never && parsed.byDays.isEmpty()
@@ -1257,23 +1389,40 @@ private fun RecurrencePickerDialog(
 
     val locale = currentLocale()
     val untilDate = untilIso?.let { runCatching { LocalDate.parse(it) }.getOrNull() }
-    val interval = intervalText.toIntOrNull()?.takeIf { it in 1..999 }
+    // remember() must not sit behind the ?. — a slot that appears and disappears
-    val count = countText.toIntOrNull()?.takeIf { it in 1..999 }
+    // as a date is picked breaks Compose's positional memoisation. Format
+    // unconditionally and let the null fall through to a null summary.
+    val untilSummary = remember(untilDate, locale) {
+        untilDate?.let {
+            DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM)
+                .withLocale(locale).format(it.toJavaLocalDate())
+        }
+    }
+    // A blank amount field shows its placeholder ("1" / "10") greyed out, so read
+    // blank as that default rather than as an error — otherwise simply clearing
+    // the field silently greys out OK. Only a real out-of-range value (0) is
+    // invalid, and that's the one case the read-out below reports.
+    val interval = if (intervalText.isBlank()) 1 else intervalText.toIntOrNull()?.takeIf { it in 1..999 }
+    val count = if (countText.isBlank()) 10 else countText.toIntOrNull()?.takeIf { it in 1..999 }
     val customEnd: RecurrenceEnd? = when (endMode) {
         RecurrenceEndMode.Never -> RecurrenceEnd.Never
         RecurrenceEndMode.Until -> untilDate?.let { RecurrenceEnd.Until(it) }
         RecurrenceEndMode.Count -> count?.let { RecurrenceEnd.Count(it) }
     }
-    val customResult: String? = if (interval != null && customEnd != null) {
+    // Kept as the rule object, not just its RRULE text: the read-out renders the
+    // string, the date list expands the rule, and both must describe the one
+    // thing OK would save.
+    val customRule: SimpleRecurrence? = if (interval != null && customEnd != null) {
         SimpleRecurrence(
             freq = freq,
             interval = interval,
             end = customEnd,
             byDays = if (freq == RecurrenceFreq.Weekly) daysMask.toDaySet() else emptySet(),
-        ).toRRule()
+        )
     } else {
         null
     }
+    val customResult: String? = customRule?.toRRule()
 
     FullScreenPicker(
         title = stringResource(R.string.event_detail_recurrence),
@@ -1294,13 +1443,24 @@ private fun RecurrencePickerDialog(
                 title = stringResource(R.string.event_edit_recurrence_none),
                 position = positionOf(0, rowCount),
                 selected = current == null,
+                trailing = if (current == null) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
                 onClick = { onSelect(null) },
             )
             RecurrenceFreq.entries.forEachIndexed { index, entry ->
                 GroupedRow(
                     title = stringResource(recurrencePresetLabel(entry)),
+                    summary = nextOccurrencesText(SimpleRecurrence(entry), startDate, locale),
                     position = positionOf(index + 1, rowCount),
                     selected = isPlainPreset && parsed?.freq == entry,
+                    trailing = if (isPlainPreset && parsed?.freq == entry) {
+                        { SelectedCheck() }
+                    } else {
+                        null
+                    },
                     onClick = { onSelect(SimpleRecurrence(entry).toRRule()) },
                 )
             }
@@ -1308,88 +1468,207 @@ private fun RecurrencePickerDialog(
                 title = stringResource(R.string.event_edit_recurrence_custom),
                 position = positionOf(rowCount - 1, rowCount),
                 selected = current != null && !isPlainPreset,
+                trailing = if (current != null && !isPlainPreset) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
                 onClick = { customMode = true },
             )
         } else {
-            Column(
+            // Section gaps live on each block (not a parent spacedBy) so the
-                verticalArrangement = Arrangement.spacedBy(8.dp),
+            // weekday card's gap collapses *with* it under AnimatedVisibility —
-                modifier = Modifier.padding(horizontal = 24.dp),
+            // a parent arrangement would leave a residual gap that snaps shut.
-            ) {
+            Column(modifier = Modifier.fillMaxWidth()) {
-                Row(verticalAlignment = Alignment.CenterVertically) {
+                // A live, human-readable read-out of the rule being built, so the
-                    Text(
+                // effect of the controls below is never a guess. It renders
-                        text = stringResource(R.string.event_edit_recurrence_every),
+                // *[customResult] itself* — the exact string OK would save — so it
-                        style = MaterialTheme.typography.titleMedium,
+                // can never describe a different rule than the one that lands. When
-                    )
+                // the form can't produce a rule, it says why instead of falling
-                    Spacer(Modifier.width(12.dp))
+                // back to defaults and quietly disagreeing with the controls.
-                    DialogAmountField(
+                // minLines reserves the second line up front: without it the whole
-                        value = intervalText,
+                // stack below shifts a line as the phrase grows with each weekday.
-                        onValueChange = { intervalText = it },
-                        placeholder = "1",
-                    )
-                    Spacer(Modifier.width(12.dp))
-                    DialogUnitDropdown(
-                        label = stringResource(recurrenceUnitLabel(freq)),
-                        entries = RecurrenceFreq.entries.map {
-                            stringResource(recurrenceUnitLabel(it))
-                        },
-                        onPick = { freq = RecurrenceFreq.entries[it] },
-                    )
-                }
-                if (freq == RecurrenceFreq.Weekly) {
-                    WeekdayToggleRow(
-                        selected = daysMask.toDaySet(),
-                        onToggle = { day -> daysMask = daysMask xor day.toMaskBit() },
-                        locale = locale,
-                    )
-                }
                 Text(
-                    text = stringResource(R.string.event_edit_recurrence_ends),
+                    text = customResult?.let { recurrenceText(it, locale) }
+                        ?: AnnotatedString(
+                            stringResource(R.string.event_edit_recurrence_incomplete),
+                        ),
+                    style = MaterialTheme.typography.titleMedium,
+                    color = if (customResult != null) {
+                        MaterialTheme.colorScheme.onSurface
+                    } else {
+                        MaterialTheme.colorScheme.error
+                    },
+                    minLines = 2,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 16.dp),
+                )
+
+                // The same rule as dates. Rendered even while the form is
+                // incomplete (as an empty line) so the controls below don't
+                // shift as it comes and goes.
+                Text(
+                    text = customRule?.let { nextOccurrencesText(it, startDate, locale) }.orEmpty(),
                     style = MaterialTheme.typography.bodyMedium,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 16.dp, vertical = 4.dp),
                 )
-            }
+
-            GroupedRow(
+                // How often: an interval amount plus a frequency segmented row —
-                title = stringResource(R.string.event_edit_recurrence_end_never),
+                // all four units on show, no unit hidden behind a dropdown.
-                position = positionOf(0, 3),
+                GroupedSurface(
-                selected = endMode == RecurrenceEndMode.Never,
+                    position = Position.Alone,
-                onClick = { endMode = RecurrenceEndMode.Never },
+                    modifier = Modifier
-            )
+                        .padding(top = 16.dp)
-            GroupedRow(
+                        .padding(horizontal = 16.dp),
-                title = stringResource(R.string.event_edit_recurrence_end_until),
-                summary = untilDate?.let {
-                    remember(it, locale) {
-                        DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM)
-                            .withLocale(locale).format(it.toJavaLocalDate())
-                    }
-                },
-                position = positionOf(1, 3),
-                selected = endMode == RecurrenceEndMode.Until,
-                onClick = {
-                    endMode = RecurrenceEndMode.Until
-                    showUntilPicker = true
-                },
-            )
-            GroupedRow(
-                title = stringResource(R.string.event_edit_recurrence_end_count),
-                position = positionOf(2, 3),
-                selected = endMode == RecurrenceEndMode.Count,
-                onClick = { endMode = RecurrenceEndMode.Count },
-            )
-            if (endMode == RecurrenceEndMode.Count) {
-                Row(
-                    verticalAlignment = Alignment.CenterVertically,
-                    modifier = Modifier.padding(horizontal = 24.dp, vertical = 4.dp),
                 ) {
-                    DialogAmountField(
+                    Column(
-                        value = countText,
+                        modifier = Modifier.padding(16.dp),
-                        onValueChange = { countText = it },
+                        verticalArrangement = Arrangement.spacedBy(16.dp),
-                        placeholder = "10",
+                    ) {
-                    )
+                        Row(verticalAlignment = Alignment.CenterVertically) {
-                    Spacer(Modifier.width(12.dp))
+                            Text(
+                                text = stringResource(R.string.event_edit_recurrence_every),
+                                style = MaterialTheme.typography.titleMedium,
+                            )
+                            Spacer(Modifier.width(12.dp))
+                            DialogAmountField(
+                                value = intervalText,
+                                onValueChange = { intervalText = it },
+                                placeholder = "1",
+                            )
+                        }
+                        SingleChoiceSegmentedButtonRow(modifier = Modifier.fillMaxWidth()) {
+                            RecurrenceFreq.entries.forEachIndexed { index, entry ->
+                                SegmentedButton(
+                                    selected = freq == entry,
+                                    onClick = { freq = entry },
+                                    shape = SegmentedButtonDefaults.itemShape(
+                                        index, RecurrenceFreq.entries.size,
+                                    ),
+                                    // Drop the default check-icon slot: four segments
+                                    // share one row, and its reserved width is what
+                                    // pushes longer labels ("Monate", "Wochen") into
+                                    // an ellipsis on a compact screen. Selection is
+                                    // already carried by the segment's fill.
+                                    icon = {},
+                                    label = {
+                                        Text(
+                                            text = stringResource(recurrenceUnitLabel(entry)),
+                                            maxLines = 1,
+                                        )
+                                    },
+                                )
+                            }
+                        }
+                    }
+                }
+
+                // Weekday picks — only meaningful on a weekly rule. The 16dp gap
+                // sits inside the animated block so it grows/shrinks with the card.
+                AnimatedVisibility(
+                    visible = freq == RecurrenceFreq.Weekly,
+                    enter = expandEnter(),
+                    exit = collapseExit(),
+                ) {
+                    GroupedSurface(
+                        position = Position.Alone,
+                        modifier = Modifier
+                            .padding(top = 16.dp)
+                            .padding(horizontal = 16.dp),
+                    ) {
+                        WeekdayToggleRow(
+                            selected = daysMask.toDaySet(),
+                            onToggle = { day -> daysMask = daysMask xor day.toMaskBit() },
+                            locale = locale,
+                            firstDay = firstDayOfWeek,
+                            modifier = Modifier.padding(16.dp),
+                        )
+                    }
+                }
+
+                // Ends: a connected never / on-a-date / after-N group, the count
+                // field folding into the bottom of the run when chosen.
+                Column(modifier = Modifier.padding(top = 16.dp)) {
                     Text(
-                        text = stringResource(R.string.event_edit_recurrence_times),
+                        text = stringResource(R.string.event_edit_recurrence_ends),
-                        style = MaterialTheme.typography.titleMedium,
+                        style = MaterialTheme.typography.labelLarge,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.padding(start = 16.dp, bottom = 8.dp),
                     )
+                    GroupedRow(
+                        title = stringResource(R.string.event_edit_recurrence_end_never),
+                        position = Position.Top,
+                        selected = endMode == RecurrenceEndMode.Never,
+                        trailing = if (endMode == RecurrenceEndMode.Never) {
+                            { SelectedCheck() }
+                        } else {
+                            null
+                        },
+                        onClick = { endMode = RecurrenceEndMode.Never },
+                    )
+                    GroupedRow(
+                        title = stringResource(R.string.event_edit_recurrence_end_until),
+                        summary = untilSummary,
+                        position = Position.Middle,
+                        selected = endMode == RecurrenceEndMode.Until,
+                        trailing = if (endMode == RecurrenceEndMode.Until) {
+                            { SelectedCheck() }
+                        } else {
+                            null
+                        },
+                        onClick = {
+                            endMode = RecurrenceEndMode.Until
+                            showUntilPicker = true
+                        },
+                    )
+                    GroupedRow(
+                        title = stringResource(R.string.event_edit_recurrence_end_count),
+                        position = if (endMode == RecurrenceEndMode.Count) {
+                            Position.Middle
+                        } else {
+                            Position.Bottom
+                        },
+                        selected = endMode == RecurrenceEndMode.Count,
+                        trailing = if (endMode == RecurrenceEndMode.Count) {
+                            { SelectedCheck() }
+                        } else {
+                            null
+                        },
+                        onClick = { endMode = RecurrenceEndMode.Count },
+                    )
+                    // Animated for the same reason the weekday card is: this is the
+                    // picker's other collapsible block, and a bare `if` here made
+                    // the ends group snap while the card above it glided.
+                    AnimatedVisibility(
+                        visible = endMode == RecurrenceEndMode.Count,
+                        enter = expandEnter(),
+                        exit = collapseExit(),
+                    ) {
+                        GroupedSurface(
+                            position = Position.Bottom,
+                            modifier = Modifier.padding(horizontal = 16.dp),
+                        ) {
+                            Row(
+                                verticalAlignment = Alignment.CenterVertically,
+                                modifier = Modifier.padding(16.dp),
+                            ) {
+                                DialogAmountField(
+                                    value = countText,
+                                    onValueChange = { countText = it },
+                                    placeholder = "10",
+                                )
+                                Spacer(Modifier.width(12.dp))
+                                Text(
+                                    text = stringResource(R.string.event_edit_recurrence_times),
+                                    style = MaterialTheme.typography.titleMedium,
+                                )
+                            }
+                        }
+                    }
                 }
             }
         }
@@ -1404,7 +1683,13 @@ private fun RecurrencePickerDialog(
                 untilIso = it.toString()
                 showUntilPicker = false
             },
-            onDismiss = { showUntilPicker = false },
+            onDismiss = {
+                showUntilPicker = false
+                // Backing out of the date picker with nothing chosen would leave
+                // "on date" selected but dateless — a state that can't be saved and
+                // greys out OK with no visible cause. Fall back to "never".
+                if (untilIso == null) endMode = RecurrenceEndMode.Never
+            },
         )
     }
 }
@@ -1419,14 +1704,15 @@ private fun WeekdayToggleRow(
     selected: Set<DayOfWeek>,
     onToggle: (DayOfWeek) -> Unit,
     locale: Locale,
+    firstDay: DayOfWeek,
+    modifier: Modifier = Modifier,
 ) {
-    val days = remember(locale) {
+    val days = remember(firstDay) {
-        val first = WeekFields.of(locale).firstDayOfWeek.toKotlinDayOfWeek()
+        (0 until 7).map { DayOfWeek(((firstDay.isoDayNumber - 1 + it) % 7) + 1) }
-        (0 until 7).map { DayOfWeek(((first.isoDayNumber - 1 + it) % 7) + 1) }
     }
     Row(
         horizontalArrangement = Arrangement.SpaceBetween,
-        modifier = Modifier.fillMaxWidth(),
+        modifier = modifier.fillMaxWidth(),
     ) {
         days.forEach { day ->
             val isSelected = day in selected
@@ -1479,18 +1765,14 @@ private fun recurrenceUnitLabel(freq: RecurrenceFreq): Int = when (freq) {
     RecurrenceFreq.Yearly -> R.string.recurrence_unit_years
 }
 
-/** Corner shape for a card at [position] in a grouped run (mirrors GroupedRow). */
+/**
-private fun groupedShape(position: Position, full: Dp = 20.dp, small: Dp = 6.dp): Shape =
+ * Corner shape for a card at [position] in a grouped run. Delegates to the
-    when (position) {
+ * family primitive with the same radii [GroupedSurface] draws at rest — a local
-        Position.Alone -> RoundedCornerShape(full)
+ * copy had drifted to 20dp, so a card sharing a run with GroupedRows had
-        Position.Top -> RoundedCornerShape(
+ * visibly tighter outer corners than the rows above it.
-            topStart = full, topEnd = full, bottomStart = small, bottomEnd = small,
+ */
-        )
+private fun groupedShape(position: Position): Shape =
-        Position.Middle -> RoundedCornerShape(small)
+    floretGroupedShape(position, full = 22.dp, small = 6.dp)
-        Position.Bottom -> RoundedCornerShape(
-            topStart = small, topEnd = small, bottomStart = full, bottomEnd = full,
-        )
-    }
 
 /** The 2dp gap that visually separates grouped cards (none after the last). */
 private fun groupedGap(position: Position): Modifier = when (position) {
@@ -1751,6 +2033,11 @@ private fun readContactAddress(context: Context, uri: Uri): String? =
 /**
  * Visibility selector: one card per level, each with its own icon; the
  * current level is highlighted. Tap picks and closes.
+ *
+ * Every level carries a line saying who this affects, because the four words
+ * alone don't: visibility is about what *other people on a shared calendar*
+ * see, which is exactly the part the label leaves out — and "Confidential" has
+ * no meaning at all until you know the server decides what it does with it.
  */
 @Composable
 private fun VisibilityPickerDialog(
@@ -1763,6 +2050,7 @@ private fun VisibilityPickerDialog(
         options = AccessLevel.entries.toList(),
         selected = selected,
         label = { stringResource(accessLevelLabel(it)) },
+        summary = { stringResource(accessLevelSummary(it)) },
         onSelect = onSelect,
         onDismiss = onDismiss,
         leading = { Icon(imageVector = accessLevelIcon(it), contentDescription = null) },
@@ -1855,6 +2143,14 @@ private fun accessLevelLabel(level: AccessLevel): Int = when (level) {
     AccessLevel.Confidential -> R.string.event_access_confidential
 }
 
+/** What each level means for people the calendar is shared with. */
+private fun accessLevelSummary(level: AccessLevel): Int = when (level) {
+    AccessLevel.Default -> R.string.event_access_default_summary
+    AccessLevel.Public -> R.string.event_access_public_summary
+    AccessLevel.Private -> R.string.event_access_private_summary
+    AccessLevel.Confidential -> R.string.event_access_confidential_summary
+}
+
 /** Humanise a reminder lead time, mirroring the detail screen's rendering. */
 @Composable
 private fun reminderLabel(minutes: Int): String = reminderLeadTimeLabel(minutes)
@@ -1933,6 +2229,21 @@ private fun EditCard(
     }
 }
 
+/**
+ * "2:00 PM – 3:00 PM", honouring the user's 12/24-hour setting. Collapses to one
+ * time when both land on the same minute (an instant event shouldn't read as a
+ * range against itself). Dates are deliberately absent — the rows above carry
+ * them.
+ */
+@Composable
+private fun formatTimeRange(start: LocalDateTime, end: LocalDateTime, locale: Locale): String {
+    val use24Hour = LocalUse24HourFormat.current
+    val timeFormat = remember(locale, use24Hour) { timeOfDayFormatter(use24Hour, locale) }
+    val from = timeFormat.format(start.time.toJavaLocalTime())
+    val to = timeFormat.format(end.time.toJavaLocalTime())
+    return if (from == to) from else "$from – $to"
+}
+
 /**
  * Borderless text input used inside the cards (and as the headline title).
  * Thin wrapper over the shared [InlineTextField] so the form and the rest of
@@ -2037,6 +2348,7 @@ private fun CalendarPicker(
     selectedId: Long?,
     onSelect: (Long) -> Unit,
     onDismiss: () -> Unit,
+    onManageCalendars: (() -> Unit)? = null,
 ) {
     FullScreenPicker(
         title = stringResource(R.string.event_detail_calendar),
@@ -2046,6 +2358,7 @@ private fun CalendarPicker(
             calendars = calendars,
             selectedId = selectedId,
             onSelect = onSelect,
+            onManageCalendars = onManageCalendars,
         )
     }
 }

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,
     /**

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

@@ -8,6 +8,7 @@ import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.data.prefs.firstDayOfWeek
 import de.jeanlucmakiola.calendula.data.prefs.resolveDefaultReminder
 import de.jeanlucmakiola.calendula.domain.AccessLevel
 import de.jeanlucmakiola.calendula.domain.Availability
@@ -18,6 +19,7 @@ import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventFormField
 import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
+import de.jeanlucmakiola.calendula.domain.isEventTarget
 import de.jeanlucmakiola.calendula.domain.populatedFields
 import de.jeanlucmakiola.calendula.domain.problems
 import de.jeanlucmakiola.calendula.domain.toEditSnapshot
@@ -39,6 +41,8 @@ import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.LocalDateTime
 import kotlinx.datetime.LocalTime
@@ -174,18 +178,16 @@ class EventEditViewModel @Inject constructor(
         repository.calendars().catch { emit(emptyList()) }
 
     /**
-     * Writable calendars — the only valid event targets. Disabled calendars are
+     * The calendars a new event can be saved to ([isEventTarget]): writable,
-     * excluded, so you can't create into a calendar you've removed from the app;
+     * switched on, not a contact-filled mirror, not a non-syncing subscription.
-     * a last-used preselect landing on a now-disabled calendar falls back to the
+     * A last-used preselect landing on an excluded calendar falls back to the
-     * first remaining writable one (handled by [resolvedCalendarId] and [state]).
+     * first remaining one (handled by [resolvedCalendarId] and [state]).
-     * Managed special-dates calendars are excluded too: their events are owned by
+     *
-     * the contact sync, which would delete any user event created there.
+     * This is the list of *targets*. An event already living in an excluded
+     * calendar keeps it — [state] adds it back to the picker.
      */
-    private val writableCalendars: Flow<List<CalendarSource>> = combine(
+    private val writableCalendars: Flow<List<CalendarSource>> = allCalendars.map { calendars ->
-        allCalendars,
+        calendars.filter { it.isEventTarget }
-        prefs.disabledCalendarIds,
-    ) { calendars, disabled ->
-        calendars.filter { it.canModifyContents && it.id !in disabled && !it.isManaged }
     }
 
     /** The target calendar id, resolved exactly as the form shows it. */
@@ -219,7 +221,8 @@ class EventEditViewModel @Inject constructor(
         ).flowOn(io),
         colorPalette,
         allCalendars,
-    ) { local, external, palette, allCalendars ->
+        settingsPrefs.recentTimeZones.flowOn(io),
+    ) { local, external, palette, allCalendars, recentTimeZones ->
         val form = local.form ?: return@combine null
         val resolvedId = form.calendarId
             ?: external.lastUsed?.takeIf { id -> external.writable.any { it.id == id } }
@@ -230,19 +233,29 @@ class EventEditViewModel @Inject constructor(
         // off the calendar's durable marker, not a stored id, so it holds after a
         // backup restore too.
         val isManaged = local.editTarget != null && resolvedCalendar?.isManaged == true
-        // The picker offers writable calendars only; when editing a managed event
+        // The picker offers writable calendars only; the event's own calendar is
-        // its own (excluded) calendar is added back so the row still names it.
+        // added back whenever it isn't among them — a managed special-dates one,
+        // or one switched off on this device — so the row keeps naming it instead
+        // of reading as the "no calendar" error, and saving can leave the event
+        // where it is. A calendar the app may not write to is still no target.
+        val ownCalendar = resolvedCalendar?.takeIf { own ->
+            own.canModifyContents && external.writable.none { it.id == own.id }
+        }
         val pickerCalendars =
-            if (isManaged && resolvedCalendar != null) external.writable + resolvedCalendar
+            if (ownCalendar != null) external.writable + ownCalendar else external.writable
-            else external.writable
+        // An all-day event is date-anchored, so a zone is meaningless on it —
-        val visibleFields = external.defaultFields + local.revealed
+        // the field is withheld from both lists rather than shown as a no-op.
+        val offerableFields = EventFormField.entries.toSet() -
+            if (resolved.isAllDay) setOf(EventFormField.Timezone) else emptySet()
+        val visibleFields = (external.defaultFields + local.revealed) intersect offerableFields
         EventEditUiState(
             form = resolved,
             calendars = pickerCalendars,
             problems = if (local.showProblems) resolved.problems() else emptySet(),
             saveState = local.saveState,
             visibleFields = visibleFields,
-            hiddenFields = (EventFormField.entries.toSet() - visibleFields).sorted(),
+            hiddenFields = (offerableFields - visibleFields).sorted(),
+            recentTimeZones = recentTimeZones,
             isEditing = local.editTarget != null,
             isManaged = isManaged,
             autofocusTitle = external.autofocusTitle,
@@ -260,6 +273,13 @@ class EventEditViewModel @Inject constructor(
             initialValue = null,
         )
 
+    /**
+     * First day of the week for ordering the recurrence weekday toggles — the
+     * app's "week starts on" preference, matching the calendar views (Auto
+     * falls back to the locale convention).
+     */
+    val firstDayOfWeek: StateFlow<DayOfWeek> = settingsPrefs.firstDayOfWeek(viewModelScope)
+
     /**
      * Initialise a fresh form for a new event on [date]. [startMinutes] (minutes
      * from midnight) anchors the start when the form is opened by tapping a slot
@@ -453,12 +473,28 @@ class EventEditViewModel @Inject constructor(
     fun setLocation(value: String) = update { it.copy(location = value) }
     fun setDescription(value: String) = update { it.copy(description = value) }
     fun setAllDay(value: Boolean) {
-        update { it.copy(isAllDay = value) }
+        // Going all-day drops any pinned zone: the times become bare dates that
+        // the provider stores UTC-anchored, so a zone could only misrepresent
+        // them. Coming back out of all-day leaves the event on the device zone,
+        // which is the same thing a fresh event gets.
+        update { it.copy(isAllDay = value, timezone = if (value) null else it.timezone) }
         // The default reminder differs for all-day vs timed; re-apply the
         // type-appropriate default unless the user has hand-edited it (guarded).
         applyDefaultReminder()
     }
 
+    /**
+     * Pin the event to [zoneId], or pass null to follow the device. The zone
+     * rides along as a recent so the picker can offer it without a search next
+     * time — only real picks are remembered, not the device fallback.
+     */
+    fun setTimezone(zoneId: String?) {
+        update { it.copy(timezone = zoneId) }
+        if (zoneId != null) {
+            viewModelScope.launch { withContext(io) { settingsPrefs.addRecentTimeZone(zoneId) } }
+        }
+    }
+
     /**
      * Switching calendars drops any chosen colour: a palette key is
      * account-scoped, and a raw colour may be invalid on the new calendar.

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/CalendarFilterList.kt

@@ -21,6 +21,7 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.sourceAppName
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.positionOf
 
@@ -61,7 +62,15 @@ private fun FilterList(
     Column(modifier = modifier.fillMaxWidth()) {
         groups.forEach { group ->
             Text(
-                text = group.account,
+                text = if (group.ambiguous) {
+                    stringResource(
+                        R.string.calendars_account_from_source,
+                        group.account,
+                        sourceAppName(group.accountType),
+                    )
+                } else {
+                    group.account
+                },
                 style = MaterialTheme.typography.labelMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
                 modifier = Modifier.padding(start = 28.dp, end = 28.dp, top = 12.dp, bottom = 4.dp),

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/FilterUiState.kt

@@ -13,9 +13,17 @@ sealed interface FilterUiState {
     data class Success(val groups: List<AccountGroup>) : FilterUiState
 }
 
-/** Calendars grouped under the account that owns them (Nextcloud / Local / …). */
+/**
+ * Calendars grouped under the account that owns them (Nextcloud / Local / …).
+ *
+ * [accountType] and [ambiguous] carry what the header needs to tell two
+ * same-named accounts from different apps apart (#77); the label itself is
+ * built in the UI layer, which is where the source app's name can be looked up.
+ */
 data class AccountGroup(
     val account: String,
+    val accountType: String,
+    val ambiguous: Boolean,
     val calendars: List<CalendarRow>,
 )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/FilterViewModel.kt

@@ -8,6 +8,7 @@ import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import de.jeanlucmakiola.calendula.ui.common.groupByAccount
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -30,16 +31,15 @@ class FilterViewModel @Inject constructor(
         combine(
             repository.calendars(),
             prefs.hiddenCalendarIds,
-            prefs.disabledCalendarIds,
+        ) { calendars, hidden ->
-        ) { calendars, hidden, disabled ->
+            // Calendars switched off in Settings → Calendars are off device-wide
-            // Disabled calendars are gone from the app entirely — they don't
+            // and don't belong in the drawer's hide/show list (you can't hide
-            // belong in the drawer's hide/show list (you can't hide what's
+            // what is already off). They live only in Settings → Calendars.
-            // already disabled). They live only in Settings → Calendars.
+            val enabled = calendars.filter { it.isVisibleInSystem }
-            val enabled = calendars.filterNot { it.id in disabled }
             if (enabled.isEmpty()) {
                 FilterUiState.Failure(FailureReason.NoCalendarsConfigured)
             } else {
-                FilterUiState.Success(groupByAccount(enabled, hidden))
+                FilterUiState.Success(groupCalendarsForFilter(enabled, hidden))
             }
         }
             .catch { emit(FilterUiState.Failure(FailureReason.ProviderUnavailable)) }
@@ -61,30 +61,27 @@ class FilterViewModel @Inject constructor(
 }
 
 /**
- * Group calendars under their owning account, preserving the provider's order
+ * Group calendars under their owning account — by name *and* type, so two
- * within each group and ordering groups by first appearance. A calendar is
+ * accounts that merely share a name stay apart (#77) — preserving the
- * "visible" when its id is *not* in [hidden].
+ * provider's order within each group and ordering groups by first appearance.
+ * A calendar is "visible" when its id is *not* in [hidden].
  */
-internal fun groupByAccount(
+internal fun groupCalendarsForFilter(
     calendars: List<CalendarSource>,
     hidden: Set<Long>,
 ): List<AccountGroup> =
-    calendars
+    calendars.groupByAccount().map { group ->
-        .groupBy { it.accountLabel() }
+        AccountGroup(
-        .map { (account, cals) ->
+            account = group.label,
-            AccountGroup(
+            accountType = group.accountType,
-                account = account,
+            ambiguous = group.ambiguous,
-                calendars = cals.map { c ->
+            calendars = group.calendars.map { c ->
-                    CalendarRow(
+                CalendarRow(
-                        id = c.id,
+                    id = c.id,
-                        displayName = c.displayName,
+                    displayName = c.displayName,
-                        color = c.color,
+                    color = c.color,
-                        visible = c.id !in hidden,
+                    visible = c.id !in hidden,
-                    )
+                )
-                },
+            },
-            )
+        )
-        }
+    }
-
-/** Account header text: the account name, falling back to its type. */
-private fun CalendarSource.accountLabel(): String =
-    accountName.takeIf { it.isNotBlank() } ?: accountType.takeIf { it.isNotBlank() } ?: displayName

app/src/main/java/de/jeanlucmakiola/calendula/ui/imports/ImportScreen.kt

@@ -75,6 +75,7 @@ fun ImportScreen(
     onClose: () -> Unit,
     onOpenSingle: (EventForm) -> Unit,
     forceMany: Boolean = false,
+    onManageCalendars: (() -> Unit)? = null,
     // Key the VM by the file uri. This screen has no nav backstack, so an
     // unkeyed hiltViewModel() resolves to the Activity's store and is retained
     // across imports — its one-shot `load` guard would then show the *previous*
@@ -155,7 +156,12 @@ fun ImportScreen(
 
                 ImportUiState.Empty -> CenteredMessage(stringResource(R.string.import_empty), onClose)
                 ImportUiState.Failed -> CenteredMessage(stringResource(R.string.import_failed), onClose)
-                is ImportUiState.Many -> ManyContent(s, selected, onSelect = { selected = it })
+                is ImportUiState.Many -> ManyContent(
+                    state = s,
+                    selected = selected,
+                    onSelect = { selected = it },
+                    onManageCalendars = onManageCalendars,
+                )
                 is ImportUiState.Done -> DoneContent(s, onClose)
             }
         }
@@ -163,10 +169,24 @@ fun ImportScreen(
 }
 
 @Composable
-private fun ManyContent(state: ImportUiState.Many, selected: Long?, onSelect: (Long) -> Unit) {
+private fun ManyContent(
-    // No writable calendar to import into — tell the user honestly.
+    state: ImportUiState.Many,
+    selected: Long?,
+    onSelect: (Long) -> Unit,
+    onManageCalendars: (() -> Unit)? = null,
+) {
+    // No calendar to import into — tell the user honestly, and carry the same
+    // way out the picker's footer offers below. This is the state that footer
+    // exists for: every writable calendar being switched off, read-only or
+    // contact-filled is exactly what empties this list (#76).
     if (state.calendars.isEmpty()) {
-        CenteredMessage(stringResource(R.string.import_no_calendar), onClose = null)
+        CenteredMessage(
+            message = stringResource(R.string.import_no_calendar),
+            onClose = null,
+            actionLabel = stringResource(R.string.settings_manage_calendars)
+                .takeIf { onManageCalendars != null },
+            onAction = onManageCalendars,
+        )
         return
     }
 
@@ -178,6 +198,7 @@ private fun ManyContent(state: ImportUiState.Many, selected: Long?, onSelect: (L
             calendars = state.calendars,
             selectedId = selected,
             onSelect = onSelect,
+            onManageCalendars = onManageCalendars,
         )
         if (state.warnings.isNotEmpty()) {
             Column(
@@ -333,7 +354,12 @@ private fun WarningText(warning: IcsParseWarning) {
 }
 
 @Composable
-private fun CenteredMessage(message: String, onClose: (() -> Unit)?) {
+private fun CenteredMessage(
+    message: String,
+    onClose: (() -> Unit)?,
+    actionLabel: String? = null,
+    onAction: (() -> Unit)? = null,
+) {
     Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
         Column(
             Modifier.padding(24.dp),
@@ -344,6 +370,9 @@ private fun CenteredMessage(message: String, onClose: (() -> Unit)?) {
             if (onClose != null) {
                 Button(onClick = onClose) { Text(stringResource(R.string.import_close)) }
             }
+            if (actionLabel != null && onAction != null) {
+                Button(onClick = onAction) { Text(actionLabel) }
+            }
         }
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/imports/ImportViewModel.kt

@@ -7,7 +7,6 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsImporter
-import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.ics.IcsImportSummary
@@ -15,6 +14,7 @@ import de.jeanlucmakiola.calendula.domain.ics.IcsParseWarning
 import de.jeanlucmakiola.calendula.domain.ics.IcsParser
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.toEventForm
+import de.jeanlucmakiola.calendula.domain.isEventTarget
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -57,7 +57,6 @@ sealed interface ImportUiState {
 class ImportViewModel @Inject constructor(
     private val repository: CalendarRepository,
     private val importer: IcsImporter,
-    private val prefs: CalendarPrefs,
     @IoDispatcher private val io: CoroutineDispatcher,
 ) : ViewModel() {
 
@@ -87,16 +86,14 @@ class ImportViewModel @Inject constructor(
                     warnings = parsed.warnings,
                 )
                 else -> {
-                    // A disabled calendar is removed from the app, so it can't be
+                    // The same targets the event form offers ([isEventTarget]):
-                    // an import target — exclude it alongside the read-only ones.
+                    // an import is a bulk create, so a calendar that can't hold
-                    // Managed special-dates calendars are contact-derived and
+                    // one event can't hold thirty.
-                    // editor-locked, so they're not a valid destination either.
-                    val disabled = prefs.disabledCalendarIds.first()
                     ImportUiState.Many(
                         events = parsed.events,
                         warnings = parsed.warnings,
                         calendars = repository.calendars().first()
-                            .filter { it.canModifyContents && !it.isManaged && it.id !in disabled },
+                            .filter { it.isEventTarget },
                     )
                 }
             }

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthMorph.kt

@@ -0,0 +1,154 @@
+package de.jeanlucmakiola.calendula.ui.month
+
+import androidx.compose.animation.AnimatedVisibilityScope
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionScope
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.ui.Modifier
+import kotlinx.datetime.LocalDate
+
+/**
+ * What lets the split style's compact grid *become* the full month rather than be
+ * swapped for it (#53).
+ *
+ * The two grids are separate composables — the compact one draws dots, the
+ * expanded one draws the paged style's bars and pills — so nothing about them is
+ * shared by construction. Tagging the pieces that mean the same thing on both
+ * sides with the same [MonthMorphKey] hands Compose enough to animate one into
+ * the other: a day's cell grows, its number rides along, and each dot travels out
+ * to the bar it stood for.
+ *
+ * It travels as a composition local rather than as parameters because the pieces
+ * sit five levels below where the scopes exist, and because a null default is
+ * exactly the right meaning for everyone else: the paged, continuous, and dense
+ * styles share the same row and cell composables, provide nothing, and pay
+ * nothing. Reduced motion provides nothing either, which leaves the plain
+ * cross-fade underneath.
+ */
+internal sealed interface MonthMorphKey {
+    /** A day's background pill — the structural anchor the rest rides on. */
+    data class Cell(val date: LocalDate) : MonthMorphKey
+
+    data class DayNumber(val date: LocalDate) : MonthMorphKey
+
+    /**
+     * One event *on one day*. Keyed by date as well as instance because a
+     * multi-day event has a dot on every day it covers but only one bar, drawn
+     * from where it starts: the start day's dot is the one that becomes the bar,
+     * and the rest are left unmatched on purpose. They fade where they stand
+     * while the bar sweeps out over them, which is the honest reading — one of
+     * them could not become the bar without the others teleporting into it.
+     */
+    data class Event(val date: LocalDate, val instanceId: Long) : MonthMorphKey
+
+    /**
+     * A day's "+N" marker. The compact grid writes it as a count beside the dots
+     * and the expanded one as a row of small dots under the bars, but they stand
+     * for the same events and appear on exactly the same days — both sides seat
+     * three and overflow the rest — so they are a matched pair, not two unrelated
+     * bits of text. Tagged, the marker travels with its day like everything else
+     * in the cell.
+     */
+    data class Overflow(val date: LocalDate) : MonthMorphKey
+
+    /**
+     * The selected day's outline. The expanded grid draws no outline — once the
+     * cells carry real event bars it is one mark too many — so this pairs the
+     * compact grid's outline with an *invisible* stand-in over the same cell
+     * there. Without one it had nowhere to travel and could only fade in place
+     * while everything around it moved.
+     */
+    data class Selection(val date: LocalDate) : MonthMorphKey
+
+    /** The grab handle, which slides from the pane's seam to the foot of the grid. */
+    data object Handle : MonthMorphKey
+}
+
+@OptIn(ExperimentalSharedTransitionApi::class)
+internal class MonthMorphScope(
+    val shared: SharedTransitionScope,
+    val visibility: AnimatedVisibilityScope,
+)
+
+internal val LocalMonthMorph = compositionLocalOf<MonthMorphScope?> { null }
+
+/**
+ * True while the grid is mid-morph, for content that has to stop clipping to let
+ * the travelling pieces through.
+ *
+ * A mark's two homes are in *different rows*: the dot for the 20th sits a third
+ * of the way down the compact grid, its bar most of the way down the expanded
+ * one. Clipped to the row it is arriving at, a mark spends the first half of its
+ * journey outside those bounds and is simply not drawn — so it appears from
+ * nowhere, part-way through, already near its destination. Rendering in place
+ * rather than in an overlay is what subjects them to that clip, and is worth
+ * keeping; the clip is what has to yield, and only while pieces are in flight.
+ */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+internal fun morphInFlight(): Boolean {
+    val morph = LocalMonthMorph.current ?: return false
+    return morph.shared.isTransitionActive
+}
+
+/**
+ * Tag content that is *the same thing* on both sides — a background pill, a day
+ * number — so it animates between its two positions and sizes.
+ *
+ * ### Why nothing renders in the overlay
+ *
+ * By default a travelling piece is painted into an overlay above the *entire*
+ * regular tree, so it can fly over anything in its way. That is right for a
+ * thumbnail crossing a screen, and wrong here: everything is moving inside one
+ * grid, and the overlay meant every untagged neighbour — the selection outline,
+ * the "+N" markers — spent the transition buried under pieces that had left the
+ * tree's z-order behind. Lifting each of them out in turn fixed the burying and
+ * bought a worse problem: they then floated over the grid on their own layer,
+ * out of step with it.
+ *
+ * Rendering in place puts everything back in one z-order and one clip, which is
+ * what makes the grid read as a single surface changing shape rather than a
+ * stack of pieces sliding past each other. Nothing here needs to escape its
+ * ancestors: the cells, marks and markers all travel within the grid.
+ */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+internal fun Modifier.morphElement(key: MonthMorphKey): Modifier {
+    val morph = LocalMonthMorph.current ?: return this
+    return with(morph.shared) {
+        this@morphElement.sharedElement(
+            sharedContentState = rememberSharedContentState(key),
+            animatedVisibilityScope = morph.visibility,
+            renderInOverlayDuringTransition = false,
+        )
+    }
+}
+
+/**
+ * Tag content that means the same thing but *is drawn differently* on each side —
+ * a 5dp dot and a titled bar — so only the bounds are shared and the contents
+ * cross-fade inside them.
+ *
+ * [ResizeMode.RemeasureToBounds][SharedTransitionScope.ResizeMode] rather than
+ * scaling: a bar's title laid out at the dot's 5dp and then scaled up would
+ * arrive as a smear. Remeasuring keeps the text at its real size throughout and
+ * simply clips it while there is no room, so what grows is the pill, not the type.
+ */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+internal fun Modifier.morphBounds(key: MonthMorphKey): Modifier {
+    val morph = LocalMonthMorph.current ?: return this
+    return with(morph.shared) {
+        this@morphBounds.sharedBounds(
+            sharedContentState = rememberSharedContentState(key),
+            animatedVisibilityScope = morph.visibility,
+            enter = fadeIn(),
+            exit = fadeOut(),
+            resizeMode = SharedTransitionScope.ResizeMode.RemeasureToBounds,
+            renderInOverlayDuringTransition = false,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthStylePreview.kt

@@ -0,0 +1,284 @@
+package de.jeanlucmakiola.calendula.ui.month
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clipToBounds
+import androidx.compose.ui.layout.layout
+import androidx.compose.ui.unit.Constraints
+import androidx.compose.ui.graphics.TransformOrigin
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.YearMonth
+import kotlinx.datetime.atTime
+import kotlinx.datetime.plus
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+import kotlin.math.roundToInt
+
+/**
+ * A live, scaled-down Month view in a given [MonthViewStyle], for the settings
+ * chooser.
+ *
+ * It renders the *real* grid composables rather than a drawing of them, so the
+ * preview cannot drift from the thing it depicts: change a cell's shape or an
+ * event bar's colour and every preview follows automatically. The trick is
+ * [requiredSize] — it ignores the incoming constraints, so the grid lays itself
+ * out at a full phone width and a plausible viewport height, and a
+ * [graphicsLayer] scale shrinks the finished layout into the card.
+ *
+ * The month, today's position and the week start are all real; only the events
+ * are stand-ins, since the settings screen has no business querying the
+ * provider for a thumbnail.
+ */
+@Composable
+internal fun MonthStylePreview(
+    style: MonthViewStyle,
+    weekStart: DayOfWeek,
+    height: Dp,
+    modifier: Modifier = Modifier,
+) {
+    val screenWidth = LocalConfiguration.current.screenWidthDp.dp
+    val scale = height.value / VIRTUAL_HEIGHT.value
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    val sample = remember(today, weekStart, zone) { sampleMonthState(today, weekStart, zone) }
+
+    Box(
+        modifier = modifier
+            .clipToBounds()
+            .background(MaterialTheme.colorScheme.surface)
+            // A preview is a picture, not a control: swallow touches before the
+            // grid's own clickables see them, and give screen readers one label
+            // instead of six weeks of day cells.
+            .pointerInput(Unit) {
+                awaitPointerEventScope {
+                    while (true) {
+                        awaitPointerEvent(PointerEventPass.Initial).changes
+                            .forEach { it.consume() }
+                    }
+                }
+            }
+            .clearAndSetSemantics { }
+            // Measure the grid at a full phone viewport but report the scaled
+            // size, so the node occupies exactly what it draws.
+            //
+            // Modifier.requiredSize would be the obvious way to force the larger
+            // measurement, but it *centres* content that overflows the incoming
+            // constraints — which pushed the grid to a negative offset and left
+            // only its bottom-right corner inside the clip.
+            .layout { measurable, _ ->
+                val fullWidth = screenWidth.roundToPx()
+                val fullHeight = VIRTUAL_HEIGHT.roundToPx()
+                val placeable = measurable.measure(Constraints.fixed(fullWidth, fullHeight))
+                layout((fullWidth * scale).roundToInt(), (fullHeight * scale).roundToInt()) {
+                    placeable.place(0, 0)
+                }
+            }
+            .graphicsLayer {
+                scaleX = scale
+                scaleY = scale
+                transformOrigin = TransformOrigin(0f, 0f)
+            },
+    ) {
+        Column(Modifier.fillMaxSize()) {
+            WeekdayHeader(weekStart = weekStart, showWeekNumbers = false)
+                when (style) {
+                    MonthViewStyle.Paged -> MonthGrid(
+                        state = sample.month,
+                        showWeekNumbers = false,
+                        onOpenDay = {},
+                    )
+                    MonthViewStyle.Continuous -> ContinuousMonthGrid(
+                        state = sample.continuous,
+                        listState = rememberLazyListState(
+                            initialFirstVisibleItemIndex = itemIndexForMonth(
+                                monthIndexOf(YearMonth(today.year, today.month)),
+                            ),
+                        ),
+                        showWeekNumbers = false,
+                        onOpenDay = {},
+                    )
+                    MonthViewStyle.Dense -> DenseMonthGrid(
+                        state = sample.continuous,
+                        listState = rememberLazyListState(
+                            // Start a week above today's, so the preview shows a
+                            // stream running past the viewport rather than one
+                            // beginning at its top edge.
+                            initialFirstVisibleItemIndex =
+                                weekIndexOf(today, weekStart) - 1,
+                        ),
+                        showWeekNumbers = false,
+                        onOpenDay = {},
+                    )
+                    MonthViewStyle.Split -> {
+                        SplitMonthGrid(
+                            state = sample.month,
+                            selected = today,
+                            showWeekNumbers = false,
+                            onSelectDay = {},
+                        )
+                        SplitDayPane(
+                            date = today,
+                            today = today,
+                            events = sample.month.instancesByDay[today].orEmpty(),
+                            zone = zone,
+                            onOpenDay = {},
+                            onEventClick = {},
+                            onCreateEvent = {},
+                            modifier = Modifier.fillMaxWidth().height(SPLIT_PANE_HEIGHT),
+                        )
+                    }
+                }
+            }
+    }
+}
+
+/**
+ * The viewport the preview pretends to be: a phone's width by the height a
+ * calendar view gets under the top bar. Scaling from a fixed height keeps the
+ * three styles comparable — each shows the same slice of screen.
+ */
+private val VIRTUAL_HEIGHT = 440.dp
+private val SPLIT_PANE_HEIGHT = 170.dp
+
+private class SampleMonth(
+    val month: MonthUiState.Success,
+    val continuous: ContinuousMonthUiState.Success,
+)
+
+/**
+ * A month's worth of stand-in events, laid out through the same
+ * [layoutMonthWeeks] / [clipWeekToMonth] the live views use — so the preview
+ * exercises the real span, lane and overflow logic rather than approximating it.
+ *
+ * Colours are raw ARGB on purpose: that is what the provider hands out for an
+ * event, so a token here would misrepresent what the grid actually renders.
+ */
+private fun sampleMonthState(
+    today: LocalDate,
+    weekStart: DayOfWeek,
+    zone: TimeZone,
+): SampleMonth {
+    val ym = YearMonth(today.year, today.month)
+    val first = LocalDate(ym.year, ym.month, 1)
+    val events = sampleEvents(first, today, zone)
+
+    val weeks = layoutMonthWeeks(ym, weekStart, events, zone)
+    val month = MonthUiState.Success(
+        month = ym,
+        today = today,
+        weeks = weeks,
+        instancesByDay = instancesByDay(weeks.flatMap { it.days }, events, zone),
+        zone = zone,
+    )
+
+    // The month either side of this one: enough for Continuous to show a block,
+    // the whitespace under it and the next month's header coming up, and for
+    // Dense to have somewhere to scroll in both directions.
+    val centre = monthIndexOf(ym)
+    val window = (centre - 1)..(centre + 1)
+    val continuous = ContinuousMonthUiState.Success(
+        today = today,
+        monthsByIndex = window.associateWith { index ->
+            val m = yearMonthForIndex(index)
+            layoutMonthWeeks(m, weekStart, events, zone).map { clipWeekToMonth(it, m) }
+        },
+        weeksByIndex = weekWindowFor(window, weekStart).associateWith { index ->
+            val days = (0 until 7).map {
+                weekStartForIndex(index, weekStart).plus(it, DateTimeUnit.DAY)
+            }
+            layoutCalendarWeek(days, events, zone)
+        },
+        weekStart = weekStart,
+    )
+    return SampleMonth(month, continuous)
+}
+
+private val SAMPLE_COLORS = listOf(
+    0xFF3F7BD4.toInt(),
+    0xFFCE5B4C.toInt(),
+    0xFF4E9A6A.toInt(),
+    0xFF8A63C7.toInt(),
+)
+
+private fun sampleEvents(
+    firstOfMonth: LocalDate,
+    today: LocalDate,
+    zone: TimeZone,
+): List<EventInstance> {
+    var id = 0L
+    fun next() = ++id
+
+    fun timed(day: LocalDate, hour: Int, length: Int, colorIndex: Int) = EventInstance(
+        instanceId = next(),
+        eventId = id,
+        calendarId = 1L,
+        title = SAMPLE_TITLES[(id.toInt() - 1) % SAMPLE_TITLES.size],
+        start = day.atTime(hour, 0).toInstant(zone),
+        end = day.atTime(hour + length, 0).toInstant(zone),
+        isAllDay = false,
+        color = SAMPLE_COLORS[colorIndex % SAMPLE_COLORS.size],
+        location = null,
+    )
+
+    fun allDay(from: LocalDate, days: Int, colorIndex: Int) = EventInstance(
+        instanceId = next(),
+        eventId = id,
+        calendarId = 1L,
+        title = SAMPLE_TITLES[(id.toInt() - 1) % SAMPLE_TITLES.size],
+        // All-day events sit at UTC midnights with an exclusive end.
+        start = from.atTime(0, 0).toInstant(TimeZone.UTC),
+        end = from.plus(days, DateTimeUnit.DAY).atTime(0, 0).toInstant(TimeZone.UTC),
+        isAllDay = true,
+        color = SAMPLE_COLORS[colorIndex % SAMPLE_COLORS.size],
+        location = null,
+    )
+
+    // Spread across the month so most weeks carry something, with one multi-day
+    // bar to show a span bridging cells and a busy today for the split pane.
+    return buildList {
+        add(allDay(firstOfMonth.plus(9, DateTimeUnit.DAY), days = 3, colorIndex = 2))
+        add(timed(firstOfMonth.plus(1, DateTimeUnit.DAY), 9, 1, 0))
+        add(timed(firstOfMonth.plus(4, DateTimeUnit.DAY), 14, 2, 1))
+        add(timed(firstOfMonth.plus(7, DateTimeUnit.DAY), 11, 1, 3))
+        add(timed(firstOfMonth.plus(15, DateTimeUnit.DAY), 10, 1, 0))
+        add(timed(firstOfMonth.plus(18, DateTimeUnit.DAY), 16, 1, 2))
+        add(timed(firstOfMonth.plus(22, DateTimeUnit.DAY), 8, 2, 1))
+        add(timed(firstOfMonth.plus(25, DateTimeUnit.DAY), 13, 1, 3))
+        // Today, so the split pane's list and the grid's dots both have content.
+        add(timed(today, 9, 1, 0))
+        add(timed(today, 12, 1, 1))
+        add(timed(today, 15, 2, 3))
+    }
+}
+
+private val SAMPLE_TITLES = listOf(
+    "Standup",
+    "Lunch",
+    "Review",
+    "Gym",
+    "Call",
+    "Workshop",
+    "Dentist",
+    "Trip",
+)

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthUiState.kt

@@ -2,7 +2,9 @@ package de.jeanlucmakiola.calendula.ui.month
 
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
 import kotlinx.datetime.YearMonth
 
 /**
@@ -37,12 +39,103 @@ data class MonthWeek(
     val countByDay: Map<LocalDate, Int>,
 )
 
+/**
+ * The events occupying each lane of [day] — column [col] of this week — in lane
+ * order, capped at [laneCap] lanes.
+ *
+ * This is the same seating [spans]/[timedByDay] get when the paged grid draws a
+ * week: bars keep the lane the row layout gave them, and the day's timed events
+ * fill whatever slots are left, top-most first. Reading it here means the split
+ * style's dots and the paged style's bars describe a day in the *same order*, so
+ * dot _i_ and lane _i_ are the same event and one can morph into the other (#53).
+ *
+ * Deriving the dots independently — by distinct colour, as they first were —
+ * left dot _i_ standing for no particular event, and quietly merged two events
+ * that shared a calendar into a single dot.
+ */
+fun MonthWeek.laneEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInstance> {
+    val byLane = arrayOfNulls<EventInstance>(laneCap)
+    spans.forEach { span ->
+        if (span.lane < laneCap && col in span.startCol..span.endCol) {
+            byLane[span.lane] = span.event
+        }
+    }
+    val free = (0 until laneCap).filter { byLane[it] == null }
+    timedByDay[day].orEmpty().take(free.size).forEachIndexed { i, event ->
+        byLane[free[i]] = event
+    }
+    return byLane.filterNotNull()
+}
+
+/**
+ * The events on [day] that [laneEvents] had no lane left for — the exact
+ * complement of what it seats, in the same bars-then-pills order. Together the
+ * two partition the day, so their sizes add up to [countByDay].
+ *
+ * The "+N" marker needs the events themselves, not just how many there are:
+ * dimming a completed event is a per-event question (#79).
+ */
+fun MonthWeek.overflowEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInstance> {
+    val seatedLanes = spans.count { it.lane < laneCap && col in it.startCol..it.endCol }
+    return buildList {
+        spans.forEach { span ->
+            if (span.lane >= laneCap && col in span.startCol..span.endCol) add(span.event)
+        }
+        addAll(timedByDay[day].orEmpty().drop(laneCap - seatedLanes))
+    }
+}
+
+/**
+ * State for the continuous style (#38): a vertical stream of *self-contained*
+ * months rather than one undifferentiated run of weeks. Each month is keyed by
+ * absolute month index and carries only its own days — the boundary week keeps
+ * its seven columns so the grid geometry never shifts, but the neighbour month's
+ * dates are clipped out of it (see `clipWeekToMonth`) and render as blanks.
+ *
+ * The same loaded window is served two ways, because the Dense style is the same
+ * scroll with the seams taken out and it would be wasteful to query the provider
+ * twice for one range:
+ *
+ *  - [monthsByIndex] — the block layout, keyed by absolute month index, each week
+ *    clipped to its own month.
+ *  - [weeksByIndex] — the flowing layout, keyed by absolute week index, boundary
+ *    weeks left carrying both months.
+ *
+ * Both hold only the loaded window; indices outside it render as placeholders
+ * until the window catches up.
+ */
+sealed interface ContinuousMonthUiState {
+    data object Loading : ContinuousMonthUiState
+    data class Failure(val reason: FailureReason) : ContinuousMonthUiState
+    data class Success(
+        val today: LocalDate,
+        val monthsByIndex: Map<Int, List<MonthWeek>>,
+        val weeksByIndex: Map<Int, MonthWeek>,
+        val weekStart: DayOfWeek,
+    ) : ContinuousMonthUiState
+}
+
 sealed interface MonthUiState {
     data object Loading : MonthUiState
     data class Failure(val reason: FailureReason) : MonthUiState
+
+    /**
+     * [weeks] is what the grid draws; [instancesByDay] is the same events keyed by
+     * date and *uncapped*, so the split style's day pane can list everything on a
+     * date without a second provider query — the month grid range already covers
+     * it. All-day events sort first, then by start.
+     */
     data class Success(
         val month: YearMonth,
         val today: LocalDate,
         val weeks: List<MonthWeek>,
+        val instancesByDay: Map<LocalDate, List<EventInstance>> = emptyMap(),
+        /**
+         * Travels on the state rather than being read at the call site, for the
+         * same reason the agenda does it: a file-level constant would be fixed
+         * for the process lifetime and drift from the zone the events were laid
+         * out in after a device time-zone change.
+         */
+        val zone: TimeZone = TimeZone.currentSystemDefault(),
     ) : MonthUiState
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthViewModel.kt

@@ -6,7 +6,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 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
@@ -20,21 +20,23 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
+import kotlinx.datetime.Month
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.YearMonth
 import kotlinx.datetime.atStartOfDayIn
 import kotlinx.datetime.atTime
+import kotlinx.datetime.daysUntil
 import kotlinx.datetime.minus
 import kotlinx.datetime.plus
 import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
-import java.util.Locale
 import kotlin.time.Clock
 import kotlin.time.Instant
 import javax.inject.Inject
@@ -48,16 +50,9 @@ class MonthViewModel @Inject constructor(
 ) : ViewModel() {
 
     private val zone = TimeZone.currentSystemDefault()
-    private val locale: Locale = Locale.getDefault()
 
     /** First day of the week, from the Settings preference (AUTO → locale). */
-    val weekStart: StateFlow<DayOfWeek> = settingsPrefs.weekStart
+    val weekStart: StateFlow<DayOfWeek> = settingsPrefs.firstDayOfWeek(viewModelScope)
-        .map { it.resolveFirstDay(locale) }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = DayOfWeek.MONDAY,
-        )
 
     /** Whether to fade events that have already finished (display concern only). */
     val dimCompletedEvents: StateFlow<Boolean> = settingsPrefs.dimCompletedEvents
@@ -75,6 +70,14 @@ class MonthViewModel @Inject constructor(
             initialValue = false,
         )
 
+    /** How the grid is laid out and navigated (#38, #53). */
+    val viewStyle: StateFlow<MonthViewStyle> = settingsPrefs.monthViewStyle
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = MonthViewStyle.Paged,
+        )
+
     private val todayDate: LocalDate
         get() = Clock.System.now().toLocalDateTime(zone).date
 
@@ -82,8 +85,12 @@ class MonthViewModel @Inject constructor(
     val month: StateFlow<YearMonth> = _month
 
     val state: StateFlow<MonthUiState> =
-        combine(_month, weekStart) { ym, ws -> ym to ws }
+        combine(_month, weekStart, viewStyle) { ym, ws, style -> Triple(ym, ws, style) }
-            .flatMapLatest { (ym, ws) ->
+            .flatMapLatest { (ym, ws, style) ->
+                // The mirror of the gate below: the paged grid is what Paged and
+                // Split draw, so under a scrolling style this query is a month
+                // of provider work for a view that isn't on screen.
+                if (style.isScrolling) return@flatMapLatest flowOf(MonthUiState.Loading)
                 val range = monthGridRange(ym, ws, zone)
                 combine(
                     repository.calendars(),
@@ -100,21 +107,202 @@ class MonthViewModel @Inject constructor(
                 initialValue = MonthUiState.Loading,
             )
 
+    // --- Continuous + Dense styles (#38) ----------------------------------
+    //
+    // These scroll through every month there is, so they can't load "a month" —
+    // they load a sliding window of month indices around whatever is on screen.
+    // The window only moves when the visible range comes within WINDOW_EDGE
+    // months of a loaded edge, so a scroll re-queries occasionally rather than
+    // on every frame.
+    //
+    // The window also *starts small and grows*. A provider Instances query
+    // expands recurrences across its whole range, so opening straight onto a
+    // year of months made the first frame wait for eleven months of expansion
+    // when only one was about to be looked at. It now opens on INITIAL_PAD
+    // months, and each completed load widens by GROWTH_STEP in both directions
+    // until MAX_PAD — the months you can reach by scrolling arrive while you're
+    // still looking at the first one.
+
+    /** How far around the visible range we currently load; grows as loads land. */
+    @Volatile
+    private var loadPad = INITIAL_PAD
+
+    /** Last reported visible range, so a widening step can re-centre on it. */
+    @Volatile
+    private var visibleMonths = monthIndexOf(YearMonth(todayDate.year, todayDate.month))
+        .let { it..it }
+
+    private val _loadedMonths = MutableStateFlow(
+        monthIndexOf(YearMonth(todayDate.year, todayDate.month))
+            .let { clampMonthWindow(it - INITIAL_PAD..it + INITIAL_PAD) },
+    )
+
+    val continuousState: StateFlow<ContinuousMonthUiState> =
+        combine(_loadedMonths, weekStart, viewStyle) { window, ws, style ->
+            Triple(window, ws, style)
+        }
+            .flatMapLatest { (window, ws, style) ->
+                // Nothing to load for the paged and split styles — they have
+                // their own single-month flow, and querying a year of months
+                // behind them is pure waste.
+                if (!style.isScrolling) return@flatMapLatest flowOf(ContinuousMonthUiState.Loading)
+                // Widened to whole grid weeks at both ends: a month block still
+                // has to know about an event that starts in the boundary week's
+                // clipped-off days, or a bar running into the block would vanish.
+                val first = firstOfMonth(yearMonthForIndex(window.first)).startOfGridWeek(ws)
+                val last = firstOfMonth(yearMonthForIndex(window.last))
+                    .plus(1, DateTimeUnit.MONTH)
+                    .minus(1, DateTimeUnit.DAY)
+                    .startOfGridWeek(ws)
+                    .plus(6, DateTimeUnit.DAY)
+                val range = first.atStartOfDayIn(zone)..last.atTime(23, 59, 59).toInstant(zone)
+                combine(
+                    repository.calendars(),
+                    repository.instances(range),
+                ) { calendars, instances ->
+                    buildContinuousState(window, ws, style, calendars, instances)
+                }
+            }
+            // A load landing is the cue to reach further out. Widening from here
+            // rather than on a timer means each step waits for the previous one,
+            // so the ladder can never outrun the provider.
+            .onEach { if (it is ContinuousMonthUiState.Success) widenLoadedWindow() }
+            .catch { emit(ContinuousMonthUiState.Failure(FailureReason.ProviderUnavailable)) }
+            .flowOn(io)
+            .stateIn(
+                scope = viewModelScope,
+                started = SharingStarted.WhileSubscribed(5_000L),
+                initialValue = ContinuousMonthUiState.Loading,
+            )
+
+    /**
+     * Report which absolute month indices are on screen. Cheap to call on every
+     * scroll frame: it returns immediately unless the visible range has drifted
+     * close enough to a loaded edge to warrant a wider query.
+     */
+    fun onVisibleMonthsChanged(firstIndex: Int, lastIndex: Int) {
+        visibleMonths = firstIndex..lastIndex
+        nextLoadWindow(_loadedMonths.value, firstIndex, lastIndex, loadPad)
+            ?.let { _loadedMonths.value = clampMonthWindow(it) }
+    }
+
+    /**
+     * One rung up the ladder: reach [GROWTH_STEP] further in each direction,
+     * stopping at [MAX_PAD]. A no-op once there, so the provider notifications
+     * that re-emit the same window don't restart it.
+     */
+    private fun widenLoadedWindow() {
+        if (loadPad >= MAX_PAD) return
+        loadPad = (loadPad + GROWTH_STEP).coerceAtMost(MAX_PAD)
+        _loadedMonths.value = clampMonthWindow(
+            visibleMonths.first - loadPad..visibleMonths.last + loadPad,
+        )
+    }
+
+    private fun buildContinuousState(
+        window: IntRange,
+        weekStart: DayOfWeek,
+        style: MonthViewStyle,
+        calendars: List<CalendarSource>,
+        instances: List<EventInstance>,
+    ): ContinuousMonthUiState {
+        if (calendars.isEmpty()) {
+            return ContinuousMonthUiState.Failure(FailureReason.NoCalendarsConfigured)
+        }
+        // Bucketed once for the whole window: a row then takes the handful of
+        // events on its seven days instead of re-scanning a year of them.
+        val byDay = DayIndex(instances, zone)
+        // Only the style on screen is laid out. Building both doubled the work
+        // for a layout nothing was going to draw.
+        val months = if (style == MonthViewStyle.Continuous) {
+            window.associateWith { index ->
+                val ym = yearMonthForIndex(index)
+                layoutMonthWeeks(ym, weekStart, byDay, zone).map { clipWeekToMonth(it, ym) }
+            }
+        } else {
+            emptyMap()
+        }
+        val weeks = if (style == MonthViewStyle.Dense) {
+            weekWindowFor(window, weekStart).associateWith { index ->
+                val days = (0 until 7).map {
+                    weekStartForIndex(index, weekStart).plus(it, DateTimeUnit.DAY)
+                }
+                layoutCalendarWeek(days, byDay.eventsOn(days), zone)
+            }
+        } else {
+            emptyMap()
+        }
+        return ContinuousMonthUiState.Success(
+            today = todayDate,
+            monthsByIndex = months,
+            weeksByIndex = weeks,
+            weekStart = weekStart,
+        )
+    }
+
+    // --- Split style (#53) ------------------------------------------------
+    //
+    // The first selected-day concept in the app: the other views drill straight
+    // into a date, while the split style keeps one selected and lists it below
+    // the grid.
+
+    private val _selectedDate = MutableStateFlow(todayDate)
+    val selectedDate: StateFlow<LocalDate> = _selectedDate
+
+    /**
+     * Select [date], following it to its month if it sits in the grid's leading
+     * or trailing days — tapping a greyed-out day should show that day, not
+     * silently list a date the grid isn't pointing at.
+     */
+    fun selectDate(date: LocalDate) {
+        _selectedDate.value = date
+        val target = YearMonth(date.year, date.month)
+        if (target != _month.value) _month.value = target
+    }
+
+    /**
+     * Move the selection with the month: today if the new month holds it, else
+     * its 1st. Leaving the old date selected would list a day the grid no longer
+     * shows.
+     */
+    private fun realignSelection() {
+        _selectedDate.value = selectionForMonth(_month.value, todayDate)
+    }
+
     fun goToPrev() {
         _month.value = _month.value.minus(1, DateTimeUnit.MONTH)
+        realignSelection()
     }
 
     fun goToNext() {
         _month.value = _month.value.plus(1, DateTimeUnit.MONTH)
+        realignSelection()
     }
 
     fun goToToday() {
         _month.value = YearMonth(todayDate.year, todayDate.month)
+        _selectedDate.value = todayDate
+    }
+
+    /**
+     * Track [_month] to the month a scrolling style is showing. Those styles
+     * navigate by scroll position and never set [_month] themselves, so it would
+     * otherwise sit wherever paged navigation last left it (today's month, on a
+     * fresh open) — and a switch to a paged style, or a reseed of the other
+     * scrolling style's list, would jump there instead of holding position. The
+     * selection is realigned alongside it so that landing on the Split style
+     * shows a live day in the month on screen rather than a stale, off-month one.
+     */
+    fun syncScrollMonth(ym: YearMonth) {
+        if (_month.value == ym) return
+        _month.value = ym
+        _selectedDate.value = selectionForMonth(ym, todayDate)
     }
 
     /** Jump to the month containing [date] (drawer jump-to-date). */
     fun goToDate(date: LocalDate) {
         _month.value = YearMonth(date.year, date.month)
+        _selectedDate.value = date
     }
 
     private fun buildState(
@@ -126,10 +314,13 @@ class MonthViewModel @Inject constructor(
         if (calendars.isEmpty()) {
             return MonthUiState.Failure(FailureReason.NoCalendarsConfigured)
         }
+        val weeks = layoutMonthWeeks(ym, weekStart, instances, zone)
         return MonthUiState.Success(
             month = ym,
             today = todayDate,
-            weeks = layoutMonthWeeks(ym, weekStart, instances, zone),
+            weeks = weeks,
+            instancesByDay = instancesByDay(weeks.flatMap { it.days }, instances, zone),
+            zone = zone,
         )
     }
 }
@@ -148,41 +339,124 @@ internal fun layoutMonthWeeks(
     weekStart: DayOfWeek,
     instances: List<EventInstance>,
     zone: TimeZone,
+): List<MonthWeek> = layoutMonthWeeks(ym, weekStart, DayIndex(instances, zone), zone)
+
+/**
+ * As above, but reusing a [DayIndex] already built for a wider range — what the
+ * scrolling styles need, since they lay out many months from one query and
+ * rebuilding the index per month would put the cost straight back.
+ */
+internal fun layoutMonthWeeks(
+    ym: YearMonth,
+    weekStart: DayOfWeek,
+    byDay: DayIndex,
+    zone: TimeZone,
 ): List<MonthWeek> {
-    val firstOfMonth = LocalDate(ym.year, ym.month, 1)
+    val gridStart = firstOfMonth(ym).startOfGridWeek(weekStart)
-    val gridStart = firstOfMonth.startOfGridWeek(weekStart)
+    val weekCount = weekRowsInMonth(ym, weekStart)
-    val leadOffset = ((firstOfMonth.dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7
-    val daysInMonth =
-        java.time.YearMonth.of(ym.year, ym.month.ordinal + 1).lengthOfMonth()
-    val weekCount = (leadOffset + daysInMonth + 6) / 7
 
     return (0 until weekCount).map { row ->
         val days = (0 until 7).map { gridStart.plus(row * 7 + it, DateTimeUnit.DAY) }
-        val weekEvents = instances.filter { ev -> days.any { ev.coversDay(it, zone) } }
+        layoutCalendarWeek(days, byDay.eventsOn(days), zone)
-        val (bars, singles) = weekEvents.partition { ev ->
-            ev.isAllDay || days.count { ev.coversDay(it, zone) } > 1
-        }
-        val spans = layoutAllDay(bars, days, zone).map { s ->
-            MonthSpan(
-                event = s.event,
-                startCol = s.startCol,
-                endCol = s.endCol,
-                lane = s.lane,
-                continuesLeft = s.event.coversDay(days.first().minus(1, DateTimeUnit.DAY), zone),
-                continuesRight = s.event.coversDay(days.last().plus(1, DateTimeUnit.DAY), zone),
-            )
-        }
-        MonthWeek(
-            days = days,
-            spans = spans,
-            timedByDay = days.associateWith { d ->
-                singles.filter { it.coversDay(d, zone) }.sortedBy { it.start }
-            },
-            countByDay = days.associateWith { d -> weekEvents.count { it.coversDay(d, zone) } },
-        )
     }
 }
 
+/**
+ * Events bucketed by the dates they cover, built once per load.
+ *
+ * [layoutCalendarWeek] opens by filtering the instances it was handed down to
+ * the ones touching its seven days. That is fine for a single month's grid, but
+ * the scrolling styles lay out a hundred-odd rows from one query, and scanning
+ * *every* instance in an eleven-month window for each of them made the work grow
+ * with the number of enabled calendars until opening the view stalled.
+ *
+ * Membership is decided by [coversDay] itself rather than by re-deriving the
+ * rule from the timestamps: the all-day and timed cases have enough edge cases
+ * between them (UTC anchoring, exclusive ends, zero-length events at midnight)
+ * that a second implementation would drift. The walk only visits an event's own
+ * candidate days, so the check runs a couple of times per event rather than once
+ * per event per row.
+ */
+internal class DayIndex(instances: List<EventInstance>, private val zone: TimeZone) {
+
+    private val byDay: Map<LocalDate, List<EventInstance>> = buildMap<LocalDate, MutableList<EventInstance>> {
+        instances.forEach { event ->
+            // All-day events are anchored to UTC midnights; timed ones to the
+            // device zone. Either way the candidate span is the event's own
+            // dates, which is one or two days for almost everything.
+            val anchor = if (event.isAllDay) TimeZone.UTC else zone
+            var day = event.start.toLocalDateTime(anchor).date
+            val lastCandidate = event.end.toLocalDateTime(anchor).date
+            while (day <= lastCandidate) {
+                if (event.coversDay(day, zone)) getOrPut(day) { mutableListOf() }.add(event)
+                day = day.plus(1, DateTimeUnit.DAY)
+            }
+        }
+    }
+
+    /** Every event touching any of [days], each listed once, in input order. */
+    fun eventsOn(days: List<LocalDate>): List<EventInstance> {
+        if (days.isEmpty()) return emptyList()
+        val hits = days.flatMap { byDay[it].orEmpty() }
+        // A multi-day event is bucketed on each date it covers, so a row that
+        // holds several of its days would otherwise list it several times.
+        return if (hits.size < 2) hits else hits.distinctBy { it.instanceId }
+    }
+}
+
+/**
+ * Resolve one week row's events for rendering. Split out of [layoutMonthWeeks] so
+ * the continuous style — which streams weeks rather than months and so has no
+ * enclosing [YearMonth] to slice by — lays each row out identically.
+ *
+ * [days] must be the row's seven consecutive dates, in display order.
+ */
+internal fun layoutCalendarWeek(
+    days: List<LocalDate>,
+    instances: List<EventInstance>,
+    zone: TimeZone,
+): MonthWeek {
+    val weekEvents = instances.filter { ev -> days.any { ev.coversDay(it, zone) } }
+    val (bars, singles) = weekEvents.partition { ev ->
+        ev.isAllDay || days.count { ev.coversDay(it, zone) } > 1
+    }
+    val spans = layoutAllDay(bars, days, zone).map { s ->
+        MonthSpan(
+            event = s.event,
+            startCol = s.startCol,
+            endCol = s.endCol,
+            lane = s.lane,
+            continuesLeft = s.event.coversDay(days.first().minus(1, DateTimeUnit.DAY), zone),
+            continuesRight = s.event.coversDay(days.last().plus(1, DateTimeUnit.DAY), zone),
+        )
+    }
+    return MonthWeek(
+        days = days,
+        spans = spans,
+        timedByDay = days.associateWith { d ->
+            singles.filter { it.coversDay(d, zone) }.sortedBy { it.start }
+        },
+        countByDay = days.associateWith { d -> weekEvents.count { it.coversDay(d, zone) } },
+    )
+}
+
+/**
+ * Every event touching each of [days], all-day first then by start time. Unlike
+ * [MonthWeek.timedByDay] this keeps multi-day and all-day events on every date
+ * they cover and applies no display cap, so the split style's day pane can list a
+ * date in full without querying the provider again.
+ */
+internal fun instancesByDay(
+    days: List<LocalDate>,
+    instances: List<EventInstance>,
+    zone: TimeZone,
+): Map<LocalDate, List<EventInstance>> =
+    days.associateWith { day ->
+        instances
+            .filter { it.coversDay(day, zone) }
+            .sortedWith(compareByDescending<EventInstance> { it.isAllDay }.thenBy { it.start })
+    }
+
 /**
  * The on-screen grid spans 6 weeks anchored on [weekStart]. Includes the
  * trailing days of the previous month and the leading days of the next month.
@@ -200,6 +474,198 @@ internal fun monthGridRange(
     return start..end
 }
 
+/**
+ * The sliding window's shape.
+ *
+ * [INITIAL_PAD] is what the first frame waits for — one month either side of the
+ * visible one, so opening the view costs about what the paged style costs. Each
+ * completed load then reaches [GROWTH_STEP] further out until [MAX_PAD], filling
+ * in the months a scroll could reach while the first ones are already on screen.
+ *
+ * [WINDOW_EDGE] is how close the visible range may drift to a loaded edge before
+ * it reloads. It is always kept below the current pad — a trigger at or beyond
+ * the pad would re-fire the moment its own reload landed.
+ */
+private const val INITIAL_PAD = 1
+private const val GROWTH_STEP = 2
+private const val MAX_PAD = 5
+private const val WINDOW_EDGE = 2
+
+/** The reload trigger for a given pad, held strictly inside it. */
+internal fun edgeForPad(pad: Int): Int = minOf(WINDOW_EDGE, pad - 1).coerceAtLeast(0)
+
+/**
+ * Which day the split style should select when the grid lands on [month]:
+ * [today] when the month holds it, otherwise the 1st. Pure so the rule can be
+ * tested without standing up a view model and a provider behind it.
+ */
+internal fun selectionForMonth(month: YearMonth, today: LocalDate): LocalDate =
+    if (YearMonth(today.year, today.month) == month) {
+        today
+    } else {
+        LocalDate(month.year, month.month, 1)
+    }
+
+/**
+ * The window to load for a visible range, or null to keep the current one.
+ *
+ * Kept pure and separate from the view model so the hysteresis — the reason a
+ * scroll doesn't re-query the provider on every frame — is testable on its own.
+ */
+internal fun nextLoadWindow(
+    loaded: IntRange,
+    firstVisible: Int,
+    lastVisible: Int,
+    pad: Int = MAX_PAD,
+): IntRange? {
+    val edge = edgeForPad(pad)
+    val comfortablyInside =
+        firstVisible - edge >= loaded.first && lastVisible + edge <= loaded.last
+    if (comfortablyInside) return null
+    return (firstVisible - pad)..(lastVisible + pad)
+}
+
+/**
+ * The continuous grid addresses months by an absolute index, so the list has one
+ * stable, gap-free coordinate space to scroll through and key its items by.
+ * Index 0 is January 1900; the list runs to [continuousMonthCount].
+ *
+ * Unlike the week indexing this replaced, the coordinate space doesn't depend on
+ * the week-start preference — changing it reflows the rows *inside* a month
+ * block but never moves the block, so a scroll position stays put.
+ */
+private const val MONTH_INDEX_EPOCH_YEAR = 1900
+private const val MONTH_INDEX_END_YEAR = 2100
+
+internal fun monthIndexOf(ym: YearMonth): Int =
+    (ym.year - MONTH_INDEX_EPOCH_YEAR) * 12 + ym.month.ordinal
+
+internal fun yearMonthForIndex(index: Int): YearMonth = YearMonth(
+    MONTH_INDEX_EPOCH_YEAR + index / 12,
+    Month.entries[index % 12],
+)
+
+/** Total months the continuous grid scrolls through (1900 → 2100). */
+internal fun continuousMonthCount(): Int =
+    (MONTH_INDEX_END_YEAR - MONTH_INDEX_EPOCH_YEAR + 1) * 12
+
+/**
+ * Each month occupies two LazyColumn items — its sticky header and the block of
+ * week rows under it — so the two coordinate spaces differ by a factor of two.
+ * Scrolling to a month means scrolling to its header.
+ */
+internal fun itemIndexForMonth(monthIndex: Int): Int = monthIndex * 2
+
+internal fun monthIndexForItem(itemIndex: Int): Int = itemIndex / 2
+
+/**
+ * Hold a load window inside the months that actually exist. The pad
+ * [nextLoadWindow] adds can otherwise push an index past either end of the
+ * 1900–2100 span, and [yearMonthForIndex] has no month to hand back for one.
+ */
+internal fun clampMonthWindow(window: IntRange): IntRange {
+    val last = continuousMonthCount() - 1
+    return window.first.coerceIn(0, last)..window.last.coerceIn(0, last)
+}
+
+internal fun firstOfMonth(ym: YearMonth): LocalDate = LocalDate(ym.year, ym.month, 1)
+
+/**
+ * The Dense style addresses *weeks* by absolute index instead: it has no month
+ * blocks to key by, and a row's identity has to survive the months around it
+ * scrolling past. Index 0 is the first week of 1900 under the active week-start,
+ * so — like the month space — every index is non-negative and the LazyColumn's
+ * item indices and week indices are the same number.
+ *
+ * Unlike month indices these *do* shift with the week-start preference, which is
+ * why the list state is keyed on it.
+ */
+private val WEEK_INDEX_EPOCH = LocalDate(1900, 1, 1)
+private val WEEK_INDEX_END = LocalDate(2100, 12, 31)
+
+internal fun weekIndexOf(date: LocalDate, weekStart: DayOfWeek): Int {
+    val base = WEEK_INDEX_EPOCH.startOfGridWeek(weekStart)
+    return base.daysUntil(date.startOfGridWeek(weekStart)) / 7
+}
+
+internal fun weekStartForIndex(index: Int, weekStart: DayOfWeek): LocalDate =
+    WEEK_INDEX_EPOCH.startOfGridWeek(weekStart).plus(index * 7, DateTimeUnit.DAY)
+
+/** Total weeks the Dense grid scrolls through (1900 → 2100). */
+internal fun continuousWeekCount(weekStart: DayOfWeek): Int =
+    weekIndexOf(WEEK_INDEX_END, weekStart) + 1
+
+/** Which month a Dense row belongs to, for reporting the visible range. */
+internal fun monthIndexForWeek(weekIndex: Int, weekStart: DayOfWeek): Int {
+    // The row's midweek day: a boundary week is reported as whichever month owns
+    // most of it, the same rule the title uses.
+    val midweek = weekStartForIndex(weekIndex, weekStart).plus(3, DateTimeUnit.DAY)
+    return monthIndexOf(YearMonth(midweek.year, midweek.month))
+}
+
+/**
+ * Every week index the months in [window] touch — the Dense rows one month-window
+ * load covers. Widened by a week at each end so the boundary rows either side are
+ * laid out too, rather than flickering as placeholders.
+ */
+internal fun weekWindowFor(window: IntRange, weekStart: DayOfWeek): IntRange {
+    val first = weekIndexOf(firstOfMonth(yearMonthForIndex(window.first)), weekStart) - 1
+    val lastMonthEnd = firstOfMonth(yearMonthForIndex(window.last))
+        .plus(1, DateTimeUnit.MONTH)
+        .minus(1, DateTimeUnit.DAY)
+    return first..(weekIndexOf(lastMonthEnd, weekStart) + 1)
+}
+
+/** How many week rows [ym] needs under [weekStart] — 4 (a non-leap February), 5 or 6. */
+internal fun weekRowsInMonth(ym: YearMonth, weekStart: DayOfWeek): Int {
+    val first = firstOfMonth(ym)
+    val leadOffset = ((first.dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7
+    val daysInMonth = java.time.YearMonth.of(ym.year, ym.month.ordinal + 1).lengthOfMonth()
+    return (leadOffset + daysInMonth + 6) / 7
+}
+
+/**
+ * Strip everything outside [month] from a boundary week row, for the continuous
+ * style's self-contained month blocks.
+ *
+ * The seven [MonthWeek.days] stay put — the row keeps its column geometry, and
+ * the grid decides which cells to draw blank — but the neighbour month's events
+ * are removed: its pills and counts go, and a bar reaching in from (or out into)
+ * it is cut back to the month's own columns. A bar cut this way keeps a flat
+ * cap, which is what says "this continues past the block" rather than "it ends
+ * here".
+ */
+internal fun clipWeekToMonth(week: MonthWeek, month: YearMonth): MonthWeek {
+    val inMonth = week.days.map { it.year == month.year && it.month == month.month }
+    val firstCol = inMonth.indexOfFirst { it }
+    val lastCol = inMonth.indexOfLast { it }
+    // Can't happen for a row of the month's own grid, but a caller-proof no-op
+    // beats an out-of-range crash.
+    if (firstCol == -1) {
+        return week.copy(spans = emptyList(), timedByDay = emptyMap(), countByDay = emptyMap())
+    }
+    val spans = week.spans.mapNotNull { span ->
+        val start = maxOf(span.startCol, firstCol)
+        val end = minOf(span.endCol, lastCol)
+        if (start > end) {
+            null
+        } else {
+            span.copy(
+                startCol = start,
+                endCol = end,
+                continuesLeft = span.continuesLeft || start > span.startCol,
+                continuesRight = span.continuesRight || end < span.endCol,
+            )
+        }
+    }
+    val own = week.days.filterIndexed { col, _ -> inMonth[col] }
+    return week.copy(
+        spans = spans,
+        timedByDay = week.timedByDay.filterKeys { it in own },
+        countByDay = week.countByDay.filterKeys { it in own },
+    )
+}
+
 internal fun LocalDate.startOfGridWeek(weekStart: DayOfWeek): LocalDate {
     // DayOfWeek.ordinal: MONDAY=0..SUNDAY=6 → identical to ISO ordering.
     val offset = ((dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthViewStyle.kt

@@ -0,0 +1,60 @@
+package de.jeanlucmakiola.calendula.ui.month
+
+import androidx.annotation.StringRes
+import de.jeanlucmakiola.calendula.R
+
+/**
+ * How the Month view lays itself out (#38, #53).
+ *
+ * One setting rather than two independent toggles: "vertical scrolling" and
+ * "month plus agenda" would otherwise multiply into four combinations to build
+ * and test, most of which nobody asked for.
+ *
+ * [Split] does **not** replace or disable the Agenda view — that stays a forward
+ * multi-day window with its own range model, while the split pane lists a single
+ * selected day.
+ */
+enum class MonthViewStyle {
+    /** Month pages, swiped left/right. Full event bars and pills per day. */
+    Paged,
+
+    /**
+     * Months stacked into one vertical scroll, each a self-contained block under
+     * its own sticky header: a block shows only its own days, and whitespace
+     * separates it from the next (#38).
+     */
+    Continuous,
+
+    /**
+     * [Continuous] with the seams taken out: one uninterrupted stream of weeks
+     * where months flow into each other. Each date appears exactly once — paging
+     * repeats a boundary week at both ends — and the 1st names its month, the
+     * only marker of where one ends.
+     */
+    Dense,
+
+    /** Compact dots-only grid over a list of the selected day's events (#53). */
+    Split,
+}
+
+/** Both vertically scrolling styles, which share a data window and a list state. */
+val MonthViewStyle.isScrolling: Boolean
+    get() = this == MonthViewStyle.Continuous || this == MonthViewStyle.Dense
+
+@get:StringRes
+val MonthViewStyle.labelRes: Int
+    get() = when (this) {
+        MonthViewStyle.Paged -> R.string.month_style_paged
+        MonthViewStyle.Continuous -> R.string.month_style_continuous
+        MonthViewStyle.Dense -> R.string.month_style_dense
+        MonthViewStyle.Split -> R.string.month_style_split
+    }
+
+@get:StringRes
+val MonthViewStyle.descriptionRes: Int
+    get() = when (this) {
+        MonthViewStyle.Paged -> R.string.month_style_paged_summary
+        MonthViewStyle.Continuous -> R.string.month_style_continuous_summary
+        MonthViewStyle.Dense -> R.string.month_style_dense_summary
+        MonthViewStyle.Split -> R.string.month_style_split_summary
+    }

app/src/main/java/de/jeanlucmakiola/calendula/ui/permission/PermissionViewModel.kt

@@ -13,6 +13,8 @@ class PermissionViewModel @Inject constructor() : ViewModel() {
     private val _state = MutableStateFlow<PermissionUiState>(PermissionUiState.Rationale)
     val state: StateFlow<PermissionUiState> = _state.asStateFlow()
 
+    // The visibility reconcile a grant owes (#75) hangs off RootScreen showing
+    // the app instead: it has to cover the grants made outside it too.
     fun onGranted() {
         _state.value = PermissionUiState.Granted
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/permission/ReminderOnboardingViewModel.kt

@@ -4,6 +4,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.data.reminders.ReminderScanner
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
@@ -19,6 +20,7 @@ import javax.inject.Inject
 @HiltViewModel
 class ReminderOnboardingViewModel @Inject constructor(
     private val prefs: SettingsPrefs,
+    private val scanner: ReminderScanner,
 ) : ViewModel() {
 
     val onboardingDone: StateFlow<Boolean?> = prefs.reminderOnboardingDone
@@ -34,6 +36,19 @@ class ReminderOnboardingViewModel @Inject constructor(
         viewModelScope.launch {
             prefs.setRemindersEnabled(remindersEnabled)
             prefs.setReminderOnboardingDone()
+            // Nothing else re-arms the scan: turning reminders off cancels the
+            // alarm, so a later "on" would sit without one until a provider
+            // change or the daily worker happened to run (#75).
+            scanner.scan()
         }
     }
+
+    /**
+     * Re-scan after the calendar permission is granted. The launch scan runs
+     * before the grant and bails out without arming anything, so without this
+     * the first alarm waits on the daily worker.
+     */
+    fun rearmAfterGrant() {
+        scanner.scanInBackground()
+    }
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/search/SearchScreen.kt

@@ -54,12 +54,15 @@ import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.InlineTextField
 import de.jeanlucmakiola.floret.components.Position
-import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventFill
+import de.jeanlucmakiola.calendula.domain.spanFirstDay
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
 import de.jeanlucmakiola.floret.components.positionOf
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toJavaLocalDate
 import java.time.Instant as JavaInstant
 import java.time.ZoneId
 import java.time.format.DateTimeFormatter
@@ -220,9 +223,14 @@ private fun searchSummary(event: EventInstance): String {
     val start = remember(event.start, zone) {
         JavaInstant.ofEpochMilli(event.start.toEpochMilliseconds()).atZone(zone)
     }
-    val dateText = remember(locale) {
+    // The date comes from the shared span rule, not from [start]: an all-day
+    // event sits at UTC midnight, so reading its date in the device zone names
+    // the day before west of UTC (#82). The clock time below stays in the device
+    // zone — it is only ever rendered for timed events.
+    val dateText = remember(event.start, event.end, event.isAllDay, locale) {
         DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
-    }.format(start)
+            .format(event.spanFirstDay(TimeZone.currentSystemDefault()).toJavaLocalDate())
+    }
     val use24Hour = LocalUse24HourFormat.current
     val timeText = if (event.isAllDay) {
         stringResource(R.string.event_detail_all_day)

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/AppearanceSettings.kt

@@ -0,0 +1,543 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import android.net.Uri
+import android.widget.Toast
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+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
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+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.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Check
+import androidx.compose.material.icons.filled.UploadFile
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+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.setValue
+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.graphics.vector.ImageVector
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.colorResource
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.appname.LauncherName
+import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
+import de.jeanlucmakiola.calendula.domain.FontRole
+import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.theme.BundledFont
+import de.jeanlucmakiola.calendula.ui.theme.FONT_CUSTOM_TOKEN
+import de.jeanlucmakiola.calendula.ui.theme.FONT_SYSTEM_TOKEN
+import de.jeanlucmakiola.calendula.ui.theme.resolveFontFamily
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.OptionPicker
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+
+/**
+ * Appearance: how the app itself looks — theme and colour, the two typeface
+ * roles, and the launcher name. Anything that only changes how a *calendar view*
+ * reads (week start, time format, grid options) lives in [ViewsScreen] instead,
+ * and the widget-only settings in [WidgetsScreen] (#69).
+ */
+@Composable
+internal fun AppearanceScreen(
+    state: SettingsUiState,
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+) {
+    var showTheme by remember { mutableStateOf(false) }
+    var showBrandFont by remember { mutableStateOf(false) }
+    var showPlainFont by remember { mutableStateOf(false) }
+    var showAppName by remember { mutableStateOf(false) }
+
+    val fonts by viewModel.fontState.collectAsStateWithLifecycle()
+    val launcherName by viewModel.launcherName.collectAsStateWithLifecycle()
+    // A picked file that didn't parse as a font: tell the user and keep the old choice.
+    val context = LocalContext.current
+    val importFailedMessage = stringResource(R.string.settings_font_import_failed)
+    LaunchedEffect(Unit) {
+        viewModel.fontImportFailed.collect {
+            Toast.makeText(context, importFailedMessage, Toast.LENGTH_LONG).show()
+        }
+    }
+
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_appearance),
+        onBack = onBack,
+        predictiveBack = true,
+    ) {
+        // Theme & colour
+        GroupedRow(
+            title = stringResource(R.string.settings_theme),
+            summary = themeLabel(state.themeMode),
+            position = Position.Top,
+            onClick = { showTheme = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_dynamic_color),
+            // Says what it does when on; below Android 12 that is replaced by
+            // the reason the switch is dead.
+            summary = if (state.dynamicColorAvailable) {
+                stringResource(R.string.settings_dynamic_color_summary)
+            } else {
+                stringResource(R.string.settings_dynamic_color_unavailable)
+            },
+            position = Position.Middle,
+            trailing = {
+                Switch(
+                    checked = state.dynamicColor,
+                    onCheckedChange = viewModel::setDynamicColor,
+                    enabled = state.dynamicColorAvailable,
+                )
+            },
+            onClick = if (state.dynamicColorAvailable) {
+                { viewModel.setDynamicColor(!state.dynamicColor) }
+            } else {
+                null
+            },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_soften_colors),
+            summary = stringResource(R.string.settings_soften_colors_summary),
+            position = Position.Bottom,
+            trailing = {
+                Switch(
+                    checked = state.softenColors,
+                    onCheckedChange = viewModel::setSoftenColors,
+                )
+            },
+            onClick = { viewModel.setSoftenColors(!state.softenColors) },
+        )
+
+        Spacer(Modifier.height(16.dp))
+
+        // Fonts — the two Material typeface roles, each independently choosable
+        // (issue #19). Headings = brand (display/headline); body = plain
+        // (title/body/label). Both default to the system typeface.
+        GroupedRow(
+            title = stringResource(R.string.settings_font_headings),
+            summary = fontLabel(fonts.brand),
+            position = Position.Top,
+            onClick = { showBrandFont = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_font_body),
+            summary = fontLabel(fonts.plain),
+            position = Position.Bottom,
+            onClick = { showPlainFont = true },
+        )
+
+        Spacer(Modifier.height(16.dp))
+
+        // App name — chooses the launcher label between "Calendula" and "Calendar"
+        // (issue #44). Own group: it's a launcher/system concern, not app styling.
+        // A sub-page chooser (not a switch), matching the app's other "choose one"
+        // settings and leaving room for more names later.
+        GroupedRow(
+            title = stringResource(R.string.settings_app_name),
+            summary = launcherNameLabel(launcherName),
+            position = Position.Alone,
+            onClick = { showAppName = true },
+        )
+    }
+
+    if (showAppName) {
+        FullScreenPicker(
+            title = stringResource(R.string.settings_app_name),
+            onDismiss = { showAppName = false },
+            predictiveBack = true,
+        ) {
+            // Show both names as launcher-mark previews so the user sees what
+            // they'd switch to, not just the current state. Tapping applies
+            // immediately and highlights — the picker stays open so the change is
+            // visible; back exits.
+            Text(
+                text = stringResource(R.string.settings_app_name_summary),
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                textAlign = TextAlign.Center,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 24.dp),
+            )
+            Spacer(Modifier.height(24.dp))
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp),
+                horizontalArrangement = Arrangement.spacedBy(16.dp),
+            ) {
+                LauncherName.entries.forEach { option ->
+                    AppNameOptionCard(
+                        name = option,
+                        selected = launcherName == option,
+                        onClick = { viewModel.setLauncherName(option) },
+                        modifier = Modifier.weight(1f),
+                    )
+                }
+            }
+        }
+    }
+    if (showTheme) {
+        // No preview here on purpose: picking a theme repaints the app itself,
+        // which is a better demonstration than any thumbnail. What the list
+        // *can't* show is which way "Follow the system" currently falls, so that
+        // one option says so.
+        val systemDark = isSystemInDarkTheme()
+        OptionPicker(
+            title = stringResource(R.string.settings_theme),
+            header = { PickerDescription(stringResource(R.string.settings_theme_hint)) },
+            predictiveBack = true,
+            options = ThemeMode.entries,
+            selected = state.themeMode,
+            label = { themeLabel(it) },
+            summary = { mode ->
+                if (mode == ThemeMode.SYSTEM) {
+                    stringResource(
+                        R.string.settings_theme_system_summary,
+                        themeLabel(if (systemDark) ThemeMode.DARK else ThemeMode.LIGHT),
+                    )
+                } else {
+                    null
+                }
+            },
+            onSelect = viewModel::setThemeMode,
+            onDismiss = { showTheme = false },
+        )
+    }
+    if (showBrandFont) {
+        FontPicker(
+            title = stringResource(R.string.settings_font_headings),
+            role = FontRole.BRAND,
+            selected = fonts.brand,
+            stamp = fonts.brandStamp,
+            onSelect = { viewModel.setFont(FontRole.BRAND, it) },
+            onImport = { viewModel.importCustomFont(FontRole.BRAND, it) },
+            onDismiss = { showBrandFont = false },
+        )
+    }
+    if (showPlainFont) {
+        FontPicker(
+            title = stringResource(R.string.settings_font_body),
+            role = FontRole.PLAIN,
+            selected = fonts.plain,
+            stamp = fonts.plainStamp,
+            onSelect = { viewModel.setFont(FontRole.PLAIN, it) },
+            onImport = { viewModel.importCustomFont(FontRole.PLAIN, it) },
+            onDismiss = { showPlainFont = false },
+        )
+    }
+}
+
+@Composable
+private fun themeLabel(mode: ThemeMode): String = stringResource(
+    when (mode) {
+        ThemeMode.SYSTEM -> R.string.settings_theme_system
+        ThemeMode.LIGHT -> R.string.settings_theme_light
+        ThemeMode.DARK -> R.string.settings_theme_dark
+    },
+)
+
+/** The summary label for a stored font token (issue #19). */
+@Composable
+private fun fontLabel(token: String): String = when (token) {
+    FONT_SYSTEM_TOKEN -> stringResource(R.string.settings_font_system)
+    FONT_CUSTOM_TOKEN -> stringResource(R.string.settings_font_custom_selected)
+    else -> BundledFont.fromToken(token)?.let { stringResource(it.labelRes) }
+        ?: stringResource(R.string.settings_font_system)
+}
+
+/** The display name for a launcher-label choice (issue #44). */
+@Composable
+private fun launcherNameLabel(name: LauncherName): String = stringResource(
+    when (name) {
+        LauncherName.CALENDULA -> R.string.app_name
+        LauncherName.CALENDAR -> R.string.app_name_calendar_alias
+    },
+)
+
+/**
+ * MIME types offered to the document picker so it lists only font files. Covers
+ * the modern `font/` types plus the legacy `application/` font aliases some
+ * providers still report. Anything that slips through is still validated by
+ * [de.jeanlucmakiola.calendula.data.fonts.CustomFontStore] before use.
+ */
+private val FONT_PICKER_MIME_TYPES = arrayOf(
+    "font/ttf",
+    "font/otf",
+    "font/sfnt",
+    "font/collection",
+    "application/x-font-ttf",
+    "application/x-font-otf",
+    "application/font-sfnt",
+    "application/vnd.ms-opentype",
+)
+
+/**
+ * Full-screen font chooser for one [FontRole]: the system default, each bundled
+ * font (previewed in its own face), and "Choose file…" which opens the system
+ * picker to load a .ttf/.otf. Selecting a system/bundled option applies at once;
+ * a file is validated and imported by the caller, switching to the custom font
+ * on success.
+ *
+ * Above the rows sits a specimen of the *current* choice, set in the type role
+ * this picker governs — headline for [FontRole.BRAND], body for
+ * [FontRole.PLAIN]. The per-row "Ag" says what a face looks like; only a full
+ * line at the real size says whether it works for the role, and it is the one
+ * thing that makes the two font settings distinguishable from each other.
+ *
+ * Being a preview picker, it stays open on selection (see `FullScreenPicker`):
+ * the specimen re-renders instead, which is the whole point of the screen.
+ */
+@Composable
+private fun FontPicker(
+    title: String,
+    role: FontRole,
+    selected: String,
+    stamp: Int,
+    onSelect: (String) -> Unit,
+    onImport: (Uri) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val context = LocalContext.current
+    val launcher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocument(),
+    ) { uri ->
+        // Stay open on a successful import too: the specimen switches to the
+        // imported face, which is the only look the user gets before committing.
+        if (uri != null) onImport(uri)
+    }
+
+    // System default + the bundled fonts + the "Choose file…" row.
+    val rowCount = BundledFont.entries.size + 2
+    val isCustom = selected == FONT_CUSTOM_TOKEN
+    // Resolving the custom face stats the disk and builds a fresh FontFamily, so
+    // memoise it; re-keyed on [stamp] (bumped on re-import) so a replaced file
+    // refreshes the preview while plain recompositions reuse the cached family.
+    val customPreview = remember(role, isCustom, stamp) {
+        if (isCustom) resolveFontFamily(FONT_CUSTOM_TOKEN, role, context) else null
+    }
+    // The face the specimen is set in: the same resolution the theme performs,
+    // so what is shown here is what the app will use.
+    val selectedFamily = remember(role, selected, stamp) {
+        resolveFontFamily(selected, role, context)
+    }
+
+    FullScreenPicker(title = title, onDismiss = onDismiss, predictiveBack = true) {
+        FontSpecimen(role = role, family = selectedFamily)
+        FontOptionRow(
+            label = stringResource(R.string.settings_font_system),
+            preview = FontFamily.Default,
+            selected = selected == FONT_SYSTEM_TOKEN,
+            position = positionOf(0, rowCount),
+            // Applies straight away and stays open — the specimen above is the
+            // answer to "what does this one look like".
+            onClick = { onSelect(FONT_SYSTEM_TOKEN) },
+        )
+        BundledFont.entries.forEachIndexed { index, font ->
+            FontOptionRow(
+                label = stringResource(font.labelRes),
+                preview = font.family,
+                selected = selected == font.token,
+                position = positionOf(index + 1, rowCount),
+                onClick = { onSelect(font.token) },
+            )
+        }
+        FontOptionRow(
+            label = if (isCustom) {
+                stringResource(R.string.settings_font_custom_selected)
+            } else {
+                stringResource(R.string.settings_font_choose_file)
+            },
+            // A loaded font previews in its own face; otherwise show an upload cue.
+            preview = customPreview,
+            leadingIcon = if (isCustom) null else Icons.Default.UploadFile,
+            selected = isCustom,
+            position = positionOf(rowCount - 1, rowCount),
+            onClick = { launcher.launch(FONT_PICKER_MIME_TYPES) },
+        )
+    }
+}
+
+/**
+ * A specimen of [family] set in the type role [role] governs: a headline for
+ * the brand role, a paragraph for the plain one — the same styles the app draws
+ * with, only the family swapped, so nothing here can flatter a face the app
+ * won't reproduce. A null [family] is the system typeface, i.e. the Material
+ * default the styles already carry.
+ */
+@Composable
+private fun FontSpecimen(role: FontRole, family: FontFamily?) {
+    val isBrand = role == FontRole.BRAND
+    val style = if (isBrand) {
+        MaterialTheme.typography.headlineMedium
+    } else {
+        MaterialTheme.typography.bodyLarge
+    }
+    Text(
+        text = stringResource(
+            if (isBrand) R.string.settings_font_specimen_heading else R.string.settings_font_specimen_body,
+        ),
+        style = style.copy(fontFamily = family ?: style.fontFamily),
+        color = MaterialTheme.colorScheme.onSurface,
+        // Two lines up front so switching between a wide and a narrow face
+        // doesn't shuffle the option list up and down under it.
+        minLines = 2,
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = GroupedListInset, vertical = 8.dp),
+    )
+}
+
+/**
+ * One row in the [FontPicker]: the font's name, a leading "Ag" sample rendered in
+ * the option's own [preview] face (or an [leadingIcon] cue when there's nothing
+ * to preview), and a check when it's the current selection.
+ */
+@Composable
+private fun FontOptionRow(
+    label: String,
+    preview: FontFamily?,
+    selected: Boolean,
+    position: Position,
+    onClick: () -> Unit,
+    leadingIcon: ImageVector? = null,
+) {
+    GroupedRow(
+        title = label,
+        position = position,
+        selected = selected,
+        leading = {
+            if (preview != null) {
+                Text(
+                    text = "Ag",
+                    fontFamily = preview,
+                    style = MaterialTheme.typography.titleLarge,
+                )
+            } else if (leadingIcon != null) {
+                Icon(imageVector = leadingIcon, contentDescription = null)
+            }
+        },
+        trailing = if (selected) {
+            { SelectedCheck() }
+        } else {
+            null
+        },
+        onClick = onClick,
+    )
+}
+
+/**
+ * One selectable launcher-name preview in the App name picker (issue #44): the
+ * app's launcher mark over the name, framed as a card. The active one carries a
+ * primary border, a tinted container and a check; tapping selects it. The mark
+ * is the same for both — only the label changes — so the card previews exactly
+ * what the home screen will read.
+ */
+@Composable
+private fun AppNameOptionCard(
+    name: LauncherName,
+    selected: Boolean,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val shape = RoundedCornerShape(24.dp)
+    val borderColor = if (selected) {
+        MaterialTheme.colorScheme.primary
+    } else {
+        MaterialTheme.colorScheme.outlineVariant
+    }
+    val containerColor = if (selected) {
+        MaterialTheme.colorScheme.primaryContainer.copy(alpha = 0.4f)
+    } else {
+        MaterialTheme.colorScheme.surfaceContainerHigh
+    }
+    Column(
+        modifier = modifier
+            .clip(shape)
+            .background(containerColor)
+            .border(width = if (selected) 2.dp else 1.dp, color = borderColor, shape = shape)
+            .clickable(onClick = onClick)
+            .padding(vertical = 20.dp, horizontal = 16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        // The adaptive launcher mark, reconstructed as a squircle (as in the
+        // onboarding BrandHero) so it renders identically everywhere.
+        Box(
+            modifier = Modifier
+                .size(64.dp)
+                .clip(RoundedCornerShape(18.dp))
+                .background(colorResource(R.color.ic_launcher_background)),
+        ) {
+            Image(
+                painter = painterResource(R.drawable.ic_launcher_foreground),
+                contentDescription = null,
+                modifier = Modifier.fillMaxSize(),
+            )
+        }
+        Text(
+            text = launcherNameLabel(name),
+            style = MaterialTheme.typography.titleMedium,
+            color = MaterialTheme.colorScheme.onSurface,
+            textAlign = TextAlign.Center,
+            maxLines = 1,
+        )
+        // Selection indicator: a filled check when active, an empty ring otherwise.
+        Box(
+            modifier = Modifier
+                .size(24.dp)
+                .clip(CircleShape)
+                .background(if (selected) MaterialTheme.colorScheme.primary else Color.Transparent)
+                .then(
+                    if (selected) {
+                        Modifier
+                    } else {
+                        Modifier.border(1.dp, MaterialTheme.colorScheme.outlineVariant, CircleShape)
+                    },
+                ),
+            contentAlignment = Alignment.Center,
+        ) {
+            if (selected) {
+                Icon(
+                    imageVector = Icons.Filled.Check,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onPrimary,
+                    modifier = Modifier.size(16.dp),
+                )
+            }
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/EventFormSettings.kt

@@ -0,0 +1,107 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Keyboard
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldIcon
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldLabel
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.positionOf
+
+/** New event form: which fields it opens with, and how it behaves. */
+@Composable
+internal fun EventFormScreen(
+    state: SettingsUiState,
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+) {
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_event_form),
+        onBack = onBack,
+        predictiveBack = true,
+    ) {
+        SettingsHint(stringResource(R.string.settings_form_fields_hint))
+        Spacer(Modifier.height(8.dp))
+        val fields = EventFormField.entries
+        fields.forEachIndexed { index, field ->
+            val checked = field in state.defaultFormFields
+            GroupedRow(
+                title = stringResource(eventFormFieldLabel(field)),
+                position = positionOf(index, fields.size),
+                // Same icon the field carries in the new-event form, so a toggle
+                // is easy to match to the field it controls.
+                leading = {
+                    Icon(
+                        imageVector = eventFormFieldIcon(field),
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                },
+                trailing = {
+                    Switch(
+                        checked = checked,
+                        onCheckedChange = { viewModel.setFormFieldDefault(field, it) },
+                    )
+                },
+                onClick = { viewModel.setFormFieldDefault(field, !checked) },
+            )
+        }
+
+        // Auto-focus the title on a new event (issue #10) — on by default, since
+        // most events get a title; raising the keyboard saves a tap. Off lets you
+        // set the time/calendar first without the keyboard in the way.
+        Spacer(Modifier.height(24.dp))
+        GroupedRow(
+            title = stringResource(R.string.settings_autofocus_title),
+            summary = stringResource(R.string.settings_autofocus_title_hint),
+            position = Position.Alone,
+            leading = {
+                Icon(
+                    imageVector = Icons.Default.Keyboard,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            },
+            trailing = {
+                Switch(
+                    checked = state.autofocusEventTitle,
+                    onCheckedChange = { viewModel.setAutofocusEventTitle(it) },
+                )
+            },
+            onClick = { viewModel.setAutofocusEventTitle(!state.autofocusEventTitle) },
+        )
+
+        // Per-event colour on calendars that publish no colour set (some
+        // CalDAV) — off by default, with the honest caveat that the colour may
+        // not survive their next sync. Local and palette calendars ignore it.
+        Spacer(Modifier.height(24.dp))
+        GroupedRow(
+            title = stringResource(R.string.settings_color_unsupported),
+            summary = stringResource(R.string.settings_color_unsupported_hint),
+            position = Position.Alone,
+            trailing = {
+                Switch(
+                    checked = state.allowColorOnUnsupportedCalendars,
+                    onCheckedChange = { viewModel.setAllowColorOnUnsupportedCalendars(it) },
+                )
+            },
+            onClick = {
+                viewModel.setAllowColorOnUnsupportedCalendars(
+                    !state.allowColorOnUnsupportedCalendars,
+                )
+            },
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/MonthViewStylePicker.kt

@@ -0,0 +1,112 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import androidx.compose.animation.Crossfade
+import androidx.compose.animation.core.snap
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+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.draw.clipToBounds
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.month.MonthStylePreview
+import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
+import de.jeanlucmakiola.calendula.ui.month.descriptionRes
+import de.jeanlucmakiola.calendula.ui.month.labelRes
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import kotlinx.datetime.DayOfWeek
+
+/**
+ * The Month view style chooser (#38, #53).
+ *
+ * A live, scaled-down Month view sits above the options and changes as you pick
+ * one, so the choice is made by looking rather than by reading "Continuous" and
+ * guessing. Selecting therefore applies immediately and leaves the picker open —
+ * closing on tap would hide the very thing the screen is for. Back exits, the
+ * same as the App name picker, which stays open for the same reason.
+ *
+ * Under the preview sits the selected style's own one-line blurb, then the
+ * family's standard picker shape: connected single-line grouped rows with a
+ * tonal highlight and [SelectedCheck] on the current one.
+ */
+@Composable
+internal fun MonthViewStylePicker(
+    selected: MonthViewStyle,
+    weekStart: DayOfWeek,
+    onSelect: (MonthViewStyle) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val options = MonthViewStyle.entries
+    val reduceMotion = rememberReduceMotion()
+    FullScreenPicker(
+        title = stringResource(R.string.settings_month_view_style),
+        onDismiss = onDismiss,
+        predictiveBack = true,
+    ) {
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp, vertical = 8.dp)
+                .height(PREVIEW_HEIGHT),
+            contentAlignment = Alignment.Center,
+        ) {
+            Crossfade(
+                targetState = selected,
+                animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
+                label = "month-style-preview",
+            ) { shown ->
+                // The preview renders the real grid at phone size and scales it
+                // down, so its own corners are square — the frame rounds it.
+                Box(
+                    modifier = Modifier
+                        .clip(PREVIEW_SHAPE)
+                        .background(MaterialTheme.colorScheme.surface)
+                        .clipToBounds(),
+                ) {
+                    MonthStylePreview(
+                        style = shown,
+                        weekStart = weekStart,
+                        height = PREVIEW_HEIGHT,
+                    )
+                }
+            }
+        }
+        // The selected style's own blurb lives here, under its preview, rather
+        // than on every row — the rows stay single-line and dense, and the words
+        // describe exactly what is being shown above.
+        PickerDescription(stringResource(selected.descriptionRes))
+        options.forEachIndexed { index, style ->
+            val isSelected = style == selected
+            GroupedRow(
+                title = stringResource(style.labelRes),
+                position = positionOf(index, options.size),
+                selected = isSelected,
+                trailing = if (isSelected) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
+                // Applies straight away; the preview above is the confirmation,
+                // so there is nothing to dismiss for.
+                onClick = { onSelect(style) },
+            )
+        }
+    }
+}
+
+private val PREVIEW_HEIGHT = 280.dp
+private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/NotificationSettings.kt

@@ -0,0 +1,410 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import android.Manifest
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Build
+import android.os.PowerManager
+import android.provider.Settings
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
+import androidx.compose.material.icons.filled.ExpandLess
+import androidx.compose.material.icons.filled.ExpandMore
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+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.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.core.content.ContextCompat
+import androidx.core.net.toUri
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.REMINDER_PRESETS
+import de.jeanlucmakiola.calendula.ui.common.ReminderDefaultPicker
+import de.jeanlucmakiola.calendula.ui.common.SnoozeDurationPicker
+import de.jeanlucmakiola.calendula.ui.common.TimePickerAlert
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.identity.collapseExit
+import de.jeanlucmakiola.floret.identity.expandEnter
+import de.jeanlucmakiola.floret.reminders.ReminderOverride
+import de.jeanlucmakiola.floret.reminders.reminderOverrideFor
+import kotlinx.datetime.LocalTime
+
+/**
+ * Reminder-notifications toggle (v1.4), mirroring the onboarding step.
+ * Turning it on re-requests `POST_NOTIFICATIONS` when missing (API 33+) —
+ * the pref is set either way; the OS permission is the real gate.
+ */
+@Composable
+internal fun NotificationsScreen(
+    state: SettingsUiState,
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+    onOpenSpecialDates: () -> Unit,
+) {
+    val context = LocalContext.current
+    val launcher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+    ) { /* The pref is already on; a denial just leaves the OS gate shut. */ }
+    val toggleReminders: (Boolean) -> Unit = { enabled ->
+        viewModel.setRemindersEnabled(enabled)
+        val needsPermission = enabled &&
+            Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU &&
+            ContextCompat.checkSelfPermission(
+                context, Manifest.permission.POST_NOTIFICATIONS,
+            ) != PackageManager.PERMISSION_GRANTED
+        if (needsPermission) {
+            launcher.launch(Manifest.permission.POST_NOTIFICATIONS)
+        }
+    }
+
+    var showDefaultReminder by remember { mutableStateOf(false) }
+    var showAllDayReminder by remember { mutableStateOf(false) }
+    var showAllDayReminderTime by remember { mutableStateOf(false) }
+    var showSnooze by remember { mutableStateOf(false) }
+    var overrideDialog by remember { mutableStateOf<OverrideTarget?>(null) }
+    var calendarSectionExpanded by remember { mutableStateOf(false) }
+    var expandedCalendars by remember { mutableStateOf(emptySet<Long>()) }
+
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_notifications),
+        onBack = onBack,
+        predictiveBack = true,
+    ) {
+        GroupedRow(
+            title = stringResource(R.string.settings_reminders),
+            summary = stringResource(R.string.settings_reminders_hint),
+            position = Position.Top,
+            trailing = {
+                Switch(checked = state.remindersEnabled, onCheckedChange = toggleReminders)
+            },
+            onClick = { toggleReminders(!state.remindersEnabled) },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_default_reminder),
+            summary = reminderChoiceLabel(state.defaultReminderMinutes),
+            position = Position.Middle,
+            onClick = { showDefaultReminder = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_default_reminder_allday),
+            summary = reminderChoiceLabel(state.defaultAllDayReminderMinutes),
+            position = Position.Middle,
+            onClick = { showAllDayReminder = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_allday_reminder_time),
+            summary = stringResource(
+                R.string.settings_allday_reminder_time_hint,
+                settingsTimeOfDay(state.allDayReminderTimeMinutes),
+            ),
+            position = Position.Bottom,
+            onClick = { showAllDayReminderTime = true },
+        )
+
+        // Delivery reliability + snooze: both are global reminder-delivery
+        // settings, so they sit with the defaults above rather than below the
+        // long per-calendar list. Reliability is a soft, optional battery-
+        // optimisation exemption (system-settings deep-link, no special
+        // permission); shown as live status, reversible at any time.
+        Spacer(Modifier.height(24.dp))
+        val batteryExempt = rememberBatteryOptimizationExempt()
+        GroupedRow(
+            title = stringResource(R.string.settings_reliable_delivery),
+            summary = if (batteryExempt) {
+                stringResource(R.string.settings_reliable_delivery_exempt)
+            } else {
+                stringResource(R.string.settings_reliable_delivery_hint)
+            },
+            position = Position.Top,
+            trailing = if (batteryExempt) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
+            onClick = { openBatteryOptimizationSettings(context) },
+        )
+
+        // Snooze: how long the notification's "Snooze" action defers a reminder.
+        GroupedRow(
+            title = stringResource(R.string.settings_snooze_duration),
+            summary = snoozeDurationLabel(state.snoozeMinutes),
+            position = Position.Bottom,
+            onClick = { showSnooze = true },
+        )
+
+        // Per-calendar overrides: the whole section folds behind one header to
+        // keep the screen tidy. Expanded, each writable calendar gets its own
+        // expandable card that may keep, drop, or replace the global default —
+        // separately for timed and all-day events.
+        if (state.writableCalendars.isNotEmpty()) {
+            Spacer(Modifier.height(24.dp))
+            GroupedRow(
+                title = stringResource(R.string.settings_calendar_reminders_title),
+                summary = stringResource(R.string.settings_calendar_reminders_hint),
+                position = Position.Alone,
+                trailing = {
+                    Icon(
+                        imageVector = if (calendarSectionExpanded) Icons.Default.ExpandLess else Icons.Default.ExpandMore,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                },
+                onClick = { calendarSectionExpanded = !calendarSectionExpanded },
+            )
+            AnimatedVisibility(
+                visible = calendarSectionExpanded,
+                enter = expandEnter(),
+                exit = collapseExit(),
+            ) {
+                Column {
+                    state.writableCalendars.forEach { calendar ->
+                        Spacer(Modifier.height(16.dp))
+                        // A contact special-dates calendar owns its reminders in
+                        // its own section — link there instead of an override.
+                        if (calendar.id in state.managedCalendarIds) {
+                            GroupedRow(
+                                title = calendar.displayName,
+                                summary = stringResource(R.string.settings_calendar_reminders_managed_hint),
+                                position = Position.Alone,
+                                leading = { CalendarColorChip(calendar.color) },
+                                trailing = {
+                                    Icon(
+                                        imageVector = Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                                        contentDescription = null,
+                                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                                    )
+                                },
+                                onClick = onOpenSpecialDates,
+                            )
+                            return@forEach
+                        }
+                        val expanded = calendar.id in expandedCalendars
+                        // Calendar card; tapping expands it into a grouped list
+                        // of three (the card + the timed and all-day rows).
+                        GroupedRow(
+                            title = calendar.displayName,
+                            position = if (expanded) Position.Top else Position.Alone,
+                            leading = { CalendarColorChip(calendar.color) },
+                            trailing = {
+                                Icon(
+                                    imageVector = if (expanded) Icons.Default.ExpandLess else Icons.Default.ExpandMore,
+                                    contentDescription = null,
+                                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                                )
+                            },
+                            onClick = {
+                                expandedCalendars = if (expanded) {
+                                    expandedCalendars - calendar.id
+                                } else {
+                                    expandedCalendars + calendar.id
+                                }
+                            },
+                        )
+                        AnimatedVisibility(
+                            visible = expanded,
+                            enter = expandEnter(),
+                            exit = collapseExit(),
+                        ) {
+                            Column {
+                                val timed = state.perCalendarReminderOverride.reminderOverrideFor(calendar.id)
+                                GroupedRow(
+                                    title = stringResource(R.string.settings_default_reminder),
+                                    summary = calendarOverrideSummary(timed, state.defaultReminderMinutes),
+                                    position = Position.Middle,
+                                    onClick = { overrideDialog = OverrideTarget(calendar.id, isAllDay = false) },
+                                )
+                                val allDay = state.perCalendarAllDayReminderOverride.reminderOverrideFor(calendar.id)
+                                GroupedRow(
+                                    title = stringResource(R.string.settings_default_reminder_allday),
+                                    summary = calendarOverrideSummary(allDay, state.defaultAllDayReminderMinutes),
+                                    position = Position.Bottom,
+                                    onClick = { overrideDialog = OverrideTarget(calendar.id, isAllDay = true) },
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    if (showSnooze) {
+        SnoozeDurationPicker(
+            title = stringResource(R.string.settings_snooze_duration),
+            presets = SNOOZE_PRESETS,
+            selected = state.snoozeMinutes,
+            label = { snoozeDurationLabel(it) },
+            onSelect = { viewModel.setSnoozeMinutes(it) },
+            onDismiss = { showSnooze = false },
+        )
+    }
+    if (showDefaultReminder) {
+        ReminderDefaultPicker(
+            title = stringResource(R.string.settings_default_reminder),
+            presets = REMINDER_PRESETS,
+            selected = state.defaultReminderMinutes.toReminderChoice(),
+            allowInherit = false,
+            onSelect = { viewModel.setDefaultReminderMinutes(it.toMinutesList()) },
+            onDismiss = { showDefaultReminder = false },
+        )
+    }
+    if (showAllDayReminder) {
+        ReminderDefaultPicker(
+            title = stringResource(R.string.settings_default_reminder_allday),
+            presets = ALLDAY_REMINDER_PRESETS,
+            selected = state.defaultAllDayReminderMinutes.toReminderChoice(),
+            allowInherit = false,
+            onSelect = { viewModel.setDefaultAllDayReminderMinutes(it.toMinutesList()) },
+            onDismiss = { showAllDayReminder = false },
+            leadTimeSummary = allDayFiringTimeSummary(state.allDayReminderTimeMinutes),
+        )
+    }
+    if (showAllDayReminderTime) {
+        TimePickerAlert(
+            initial = LocalTime(
+                state.allDayReminderTimeMinutes / 60,
+                state.allDayReminderTimeMinutes % 60,
+            ),
+            onConfirm = {
+                viewModel.setAllDayReminderTimeMinutes(it.hour * 60 + it.minute)
+                showAllDayReminderTime = false
+            },
+            onDismiss = { showAllDayReminderTime = false },
+        )
+    }
+    overrideDialog?.let { target ->
+        val map = if (target.isAllDay) {
+            state.perCalendarAllDayReminderOverride
+        } else {
+            state.perCalendarReminderOverride
+        }
+        ReminderDefaultPicker(
+            title = stringResource(
+                if (target.isAllDay) {
+                    R.string.settings_default_reminder_allday
+                } else {
+                    R.string.settings_default_reminder
+                },
+            ),
+            presets = if (target.isAllDay) ALLDAY_REMINDER_PRESETS else REMINDER_PRESETS,
+            selected = map.reminderOverrideFor(target.calendarId),
+            allowInherit = true,
+            onSelect = {
+                if (target.isAllDay) {
+                    viewModel.setCalendarAllDayReminderOverride(target.calendarId, it)
+                } else {
+                    viewModel.setCalendarReminderOverride(target.calendarId, it)
+                }
+            },
+            onDismiss = { overrideDialog = null },
+            leadTimeSummary = if (target.isAllDay) {
+                allDayFiringTimeSummary(state.allDayReminderTimeMinutes)
+            } else {
+                null
+            },
+        )
+    }
+}
+
+/** Which calendar + event kind a per-calendar reminder-override dialog targets. */
+private data class OverrideTarget(val calendarId: Long, val isAllDay: Boolean)
+
+/** A global default (empty = none) as a picker choice for selection highlighting. */
+private fun List<Int>.toReminderChoice(): ReminderOverride =
+    if (isEmpty()) ReminderOverride.None else ReminderOverride.Minutes(this)
+
+/** A picked choice as global-default minutes (Inherit isn't offered for globals). */
+private fun ReminderOverride.toMinutesList(): List<Int> =
+    (this as? ReminderOverride.Minutes)?.minutes ?: emptyList()
+
+/** Row summary for a calendar: its override, or the inherited global default. */
+@Composable
+private fun calendarOverrideSummary(
+    choice: ReminderOverride,
+    globalDefault: List<Int>,
+): String = when (choice) {
+    ReminderOverride.Inherit ->
+        stringResource(R.string.settings_calendar_reminder_inherits, reminderChoiceLabel(globalDefault))
+    ReminderOverride.None -> stringResource(R.string.reminder_none)
+    is ReminderOverride.Minutes -> reminderChoiceLabel(choice.minutes)
+}
+
+/** Snooze delays offered for the notification "Snooze" action, in minutes. */
+private val SNOOZE_PRESETS = listOf(5, 10, 15, 30, 60)
+
+/** A snooze delay as a plain duration ("10 minutes", "1 hour") — no "before". */
+@Composable
+private fun snoozeDurationLabel(minutes: Int): String =
+    if (minutes % 60 == 0) {
+        pluralStringResource(R.plurals.duration_hours, minutes / 60, minutes / 60)
+    } else {
+        pluralStringResource(R.plurals.duration_minutes, minutes, minutes)
+    }
+
+/**
+ * Whether Calendula is exempt from battery optimisation, re-read on every
+ * `ON_RESUME` so the row reflects a change the user just made in system
+ * settings without needing to leave and re-enter the screen.
+ */
+@Composable
+private fun rememberBatteryOptimizationExempt(): Boolean {
+    val context = LocalContext.current
+    var exempt by remember { mutableStateOf(isIgnoringBatteryOptimizations(context)) }
+    val lifecycleOwner = LocalLifecycleOwner.current
+    DisposableEffect(lifecycleOwner) {
+        val observer = LifecycleEventObserver { _, event ->
+            if (event == Lifecycle.Event.ON_RESUME) {
+                exempt = isIgnoringBatteryOptimizations(context)
+            }
+        }
+        lifecycleOwner.lifecycle.addObserver(observer)
+        onDispose { lifecycleOwner.lifecycle.removeObserver(observer) }
+    }
+    return exempt
+}
+
+private fun isIgnoringBatteryOptimizations(context: Context): Boolean {
+    val power = context.getSystemService(Context.POWER_SERVICE) as PowerManager
+    return power.isIgnoringBatteryOptimizations(context.packageName)
+}
+
+/**
+ * Take the user straight to Calendula's exemption: the direct
+ * `REQUEST_IGNORE_BATTERY_OPTIMIZATIONS` dialog ("Allow Calendula to ignore
+ * battery optimisation?") rather than the full app list they'd have to scroll.
+ * Falls back to the optimisation list if the OS refuses the direct intent.
+ */
+private fun openBatteryOptimizationSettings(context: Context) {
+    val direct = Intent(
+        Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS,
+        "package:${context.packageName}".toUri(),
+    )
+    if (runCatching { context.startActivity(direct) }.isFailure) {
+        runCatching {
+            context.startActivity(Intent(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS))
+        }
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/PastEventsPicker.kt

@@ -0,0 +1,206 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import androidx.compose.animation.Crossfade
+import androidx.compose.animation.core.snap
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+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.draw.clipToBounds
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaDayHeader
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaEventRow
+import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atTime
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+
+/**
+ * The "past events" chooser for the Agenda (#69 follow-up).
+ *
+ * "Show / dim / hide" is the case where the word cannot carry the choice —
+ * *how far* does dimmed fade, and what is left behind when finished events are
+ * hidden? So a stand-in agenda day sits above the options and re-renders as you
+ * pick one, using the very rows the Agenda draws: dimming is
+ * [AgendaEventRow]'s own `dimmed` flag, and hiding drops the row exactly as
+ * [de.jeanlucmakiola.calendula.ui.agenda.AgendaScreen] filters it — so the
+ * preview cannot claim an effect the screen doesn't have.
+ *
+ * Like the Month style and App name pickers, selecting applies immediately and
+ * leaves the picker open: closing would hide the thing the screen is for. Back
+ * exits.
+ */
+@Composable
+internal fun PastEventsPicker(
+    selected: PastEventDisplay,
+    onSelect: (PastEventDisplay) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val options = PastEventDisplay.entries
+    val reduceMotion = rememberReduceMotion()
+    FullScreenPicker(
+        title = stringResource(R.string.settings_past_events),
+        onDismiss = onDismiss,
+        predictiveBack = true,
+    ) {
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp, vertical = 8.dp)
+                .height(PREVIEW_HEIGHT),
+            contentAlignment = Alignment.TopCenter,
+        ) {
+            Crossfade(
+                targetState = selected,
+                animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
+                label = "past-events-preview",
+            ) { shown ->
+                Box(
+                    modifier = Modifier
+                        .clip(PREVIEW_SHAPE)
+                        .background(MaterialTheme.colorScheme.surface)
+                        .clipToBounds(),
+                ) {
+                    PastEventsPreview(mode = shown)
+                }
+            }
+        }
+        PickerDescription(stringResource(R.string.settings_past_events_hint))
+        options.forEachIndexed { index, mode ->
+            val isSelected = mode == selected
+            GroupedRow(
+                title = stringResource(pastEventDisplayLabelRes(mode)),
+                position = positionOf(index, options.size),
+                selected = isSelected,
+                trailing = if (isSelected) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
+                // Applies straight away; the preview above is the confirmation.
+                onClick = { onSelect(mode) },
+            )
+        }
+    }
+}
+
+/**
+ * A stand-in agenda day in a given [mode]: three events on today, the first two
+ * already finished. The times are fixed rather than derived from the clock, so
+ * the preview reads the same at any hour — what varies is only what [mode] does
+ * to the two finished rows.
+ */
+@Composable
+private fun PastEventsPreview(mode: PastEventDisplay, modifier: Modifier = Modifier) {
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    val titles = listOf(
+        stringResource(R.string.settings_past_events_sample_morning),
+        stringResource(R.string.settings_past_events_sample_midday),
+        stringResource(R.string.settings_past_events_sample_evening),
+    )
+    val sample = remember(today, zone, titles) { samplePastDay(today, zone, titles) }
+    // Hiding drops the finished rows outright; showing and dimming keep them,
+    // and only dimming fades them — the same three-way split AgendaContent makes.
+    val visible = if (mode == PastEventDisplay.HIDE) sample.filterNot { it.hasPassed } else sample
+
+    Column(
+        modifier = modifier
+            .fillMaxWidth()
+            .clipToBounds()
+            // A preview is a picture, not a control: swallow touches before the
+            // rows' own clickables see them, and keep it out of the reading order —
+            // the options below already say what is selected.
+            .pointerInput(Unit) {
+                awaitPointerEventScope {
+                    while (true) {
+                        awaitPointerEvent(PointerEventPass.Initial).changes.forEach { it.consume() }
+                    }
+                }
+            }
+            .clearAndSetSemantics { },
+    ) {
+        AgendaDayHeader(date = today, today = today, onOpenDay = {})
+        visible.forEachIndexed { index, row ->
+            AgendaEventRow(
+                event = row.event,
+                day = today,
+                zone = zone,
+                position = positionOf(index, visible.size),
+                dimmed = mode == PastEventDisplay.DIM && row.hasPassed,
+                onClick = {},
+            )
+        }
+    }
+}
+
+/** One stand-in row plus whether it counts as finished. */
+private class SampleRow(val event: EventInstance, val hasPassed: Boolean)
+
+/**
+ * Today's stand-in events, [titles] in order: two finished (morning, midday) and
+ * one still to come.
+ *
+ * Colours are raw ARGB on purpose — that is what the provider hands out for an
+ * event, so a theme token here would misrepresent what the agenda renders.
+ */
+private fun samplePastDay(today: LocalDate, zone: TimeZone, titles: List<String>): List<SampleRow> =
+    listOf(
+        sampleRow(1, titles[0], today, zone, 9, 10, 0xFF3F7BD4.toInt(), hasPassed = true),
+        sampleRow(2, titles[1], today, zone, 12, 13, 0xFFCE5B4C.toInt(), hasPassed = true),
+        sampleRow(3, titles[2], today, zone, 18, 19, 0xFF4E9A6A.toInt(), hasPassed = false),
+    )
+
+private fun sampleRow(
+    id: Long,
+    title: String,
+    day: LocalDate,
+    zone: TimeZone,
+    startHour: Int,
+    endHour: Int,
+    color: Int,
+    hasPassed: Boolean,
+): SampleRow = SampleRow(
+    event = EventInstance(
+        instanceId = id,
+        eventId = id,
+        calendarId = 1L,
+        title = title,
+        start = day.atTime(startHour, 0).toInstant(zone),
+        end = day.atTime(endHour, 0).toInstant(zone),
+        isAllDay = false,
+        color = color,
+        location = null,
+    ),
+    hasPassed = hasPassed,
+)
+
+/** Room for the day header plus its three two-line rows, so hiding shortens the
+ *  list inside a box that keeps its height instead of the page jumping a row. */
+private val PREVIEW_HEIGHT = 288.dp
+private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsCommon.kt

@@ -0,0 +1,156 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import android.content.Context
+import android.content.Intent
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+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.clip
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.core.net.toUri
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
+import de.jeanlucmakiola.calendula.ui.common.reminderLeadTimeLabel
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.locale.currentLocale
+
+/**
+ * Pieces shared by the settings hub and its sub-screens (`*Settings.kt`). Each
+ * sub-screen owns whatever only it uses; anything two of them need lives here.
+ */
+
+/**
+ * Token-based accent for a leading icon chip (container / on-container pair).
+ * Neutral chips stay grey; accents are drawn from the M3 scheme so they adapt
+ * to theme, dark mode and dynamic colour.
+ *
+ * The chips are a scanning aid, so the rule is **no two rows in one group share
+ * an accent** — a group in a single colour carries no more information than no
+ * colour at all. [Neutral] is not a fourth colour to rotate through but a
+ * deliberate step back, for rows that are reference or last-resort rather than
+ * somewhere you routinely go.
+ */
+internal enum class ChipAccent { Neutral, Primary, Secondary, Tertiary }
+
+/**
+ * Leading circular icon chip. Colours come from the M3 scheme via a container /
+ * on-container token pair, so each accent stays correctly paired across theme,
+ * dark mode and dynamic colour.
+ */
+@Composable
+internal fun CategoryIcon(icon: ImageVector, accent: ChipAccent) {
+    val scheme = MaterialTheme.colorScheme
+    val (background, iconColor) = when (accent) {
+        ChipAccent.Neutral -> scheme.surfaceContainerHighest to scheme.onSurfaceVariant
+        ChipAccent.Primary -> scheme.primaryContainer to scheme.onPrimaryContainer
+        ChipAccent.Secondary -> scheme.secondaryContainer to scheme.onSecondaryContainer
+        ChipAccent.Tertiary -> scheme.tertiaryContainer to scheme.onTertiaryContainer
+    }
+    Box(
+        modifier = Modifier
+            .size(40.dp)
+            .clip(CircleShape)
+            .background(background),
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            imageVector = icon,
+            contentDescription = null,
+            tint = iconColor,
+            modifier = Modifier.size(22.dp),
+        )
+    }
+}
+
+/**
+ * A small primary-coloured group label, matching the Calendars settings screen.
+ *
+ * Starts on [GroupedListInset] — the cards' own edge — so a header, the hint
+ * under it and the group it names all share one left margin.
+ */
+@Composable
+internal 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,
+        ),
+    )
+}
+
+/** Muted supporting text under a [SectionHeader], matching the form-fields hint. */
+@Composable
+internal fun SettingsHint(text: String) {
+    Text(
+        text = text,
+        style = MaterialTheme.typography.bodyMedium,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(horizontal = GroupedListInset, vertical = 4.dp),
+    )
+}
+
+internal fun openUrl(context: Context, url: String) {
+    val intent = Intent(Intent.ACTION_VIEW, url.toUri())
+    runCatching { context.startActivity(intent) }
+}
+
+/** Label for a global-default choice: empty → "None", else the lead times joined. */
+@Composable
+internal fun reminderChoiceLabel(minutes: List<Int>): String {
+    if (minutes.isEmpty()) return stringResource(R.string.reminder_none)
+    return minutes.map { reminderLeadTimeLabel(it) }.joinToString(", ")
+}
+
+/**
+ * Lead times offered for the all-day default — day-scale, since a "minutes
+ * before midnight" reminder on an all-day event is rarely what's wanted. Shared
+ * with the contact special-dates calendars, whose events are all all-day.
+ */
+internal val ALLDAY_REMINDER_PRESETS = listOf(0, 1_440, 2_880, 10_080)
+
+/**
+ * A minute-of-day ("09:00") in the app's *own* 12/24-hour convention — the same
+ * [LocalUse24HourFormat] the agenda and event rows read, so a time shown in
+ * settings can't disagree with the times shown everywhere else.
+ */
+@Composable
+internal fun settingsTimeOfDay(minutesOfDay: Int): String =
+    formatMinuteOfDay(minutesOfDay, LocalUse24HourFormat.current, currentLocale())
+
+/**
+ * Second line for an all-day lead-time row: the clock time it fires at.
+ *
+ * An all-day occurrence has no time of its own, so a reminder's stored offset
+ * only decides *which day* it belongs to — the hour always comes from the
+ * global "show all-day reminders at" setting (see
+ * [de.jeanlucmakiola.calendula.domain.reminders.planReminders]). Naming it on
+ * every row is what makes "At time of event" readable on an all-day default at
+ * all: it means that day at 09:00, not midnight.
+ *
+ * Shared by the notification defaults, the per-calendar overrides and the
+ * contact special-dates calendars — all three read the same one setting.
+ */
+@Composable
+internal fun allDayFiringTimeSummary(allDayReminderTimeMinutes: Int): @Composable (Int) -> String? {
+    val summary = stringResource(
+        R.string.settings_allday_reminder_fires_at,
+        settingsTimeOfDay(allDayReminderTimeMinutes),
+    )
+    return { summary }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsUiState.kt

@@ -13,6 +13,8 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 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.widget.WidgetSize
 
 /**
  * Settings screen state (M4). Persisted preferences are instant to read, so
@@ -37,6 +39,8 @@ data class SettingsUiState(
     val dimCompletedEvents: Boolean = false,
     /** Whether the Month grid shows calendar-week numbers in a left gutter (#25). */
     val showWeekNumbers: Boolean = false,
+    /** Whether the jump-to-today control sits in the top bar instead of the FAB (#60). */
+    val todayButtonInToolbar: Boolean = false,
     /** How far ahead the in-app Agenda screen shows events (v2.11). */
     val agendaScreenRange: AgendaRange = AgendaRange.Month,
     /** How far ahead the agenda widget shows events (v2.11). */
@@ -45,10 +49,14 @@ data class SettingsUiState(
     val agendaShowToday: Boolean = true,
     /** Whether the agenda shows its top range bar — header + switcher (v2.11). */
     val agendaShowRangeBar: Boolean = true,
+    /** The size step the agenda widget draws its text at (#51). */
+    val widgetSize: WidgetSize = WidgetSize.SMALL,
     /** The calendar view the app opens on, and the home of the view back stack (M1). */
     val defaultView: CalendarView = CalendarView.Week,
     /** Which views the top-bar quick-switch button cycles through, and their order (#24). */
     val quickSwitchConfig: QuickSwitchConfig = QuickSwitchConfig.Default,
+    /** How the Month view lays itself out: pages, continuous scroll, or split (#38, #53). */
+    val monthViewStyle: MonthViewStyle = MonthViewStyle.Paged,
     /** Order of the views in the navigation drawer (#24); every view is always listed. */
     val drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     /** Optional event-form fields shown by default (rest behind "more fields"). */

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsViewModel.kt

@@ -10,6 +10,8 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.data.appname.LauncherName
+import de.jeanlucmakiola.calendula.data.appname.LauncherNameManager
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesCalendarSpec
 import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesScheduler
@@ -25,6 +27,7 @@ import de.jeanlucmakiola.calendula.data.prefs.SpecialDatesStalledReason
 import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
 import de.jeanlucmakiola.calendula.data.prefs.TimeFormatPref
 import de.jeanlucmakiola.calendula.data.prefs.WeekStartPref
+import de.jeanlucmakiola.calendula.data.reminders.ReminderScanner
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventFormField
 import de.jeanlucmakiola.calendula.domain.FontRole
@@ -33,17 +36,22 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.calendula.ui.theme.AppFontSettings
 import de.jeanlucmakiola.calendula.ui.theme.FONT_CUSTOM_TOKEN
+import de.jeanlucmakiola.calendula.widget.WidgetSize
 import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_PAST_DISPLAY_KEY
 import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_RANGE_KEY
 import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_SHOW_TODAY_STATE_KEY
+import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_SIZE_KEY
 import de.jeanlucmakiola.calendula.widget.agenda.AgendaWidget
 import de.jeanlucmakiola.calendula.widget.month.MonthWidget
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
@@ -62,15 +70,22 @@ class SettingsViewModel @Inject constructor(
     repository: CalendarRepository,
     private val specialDatesEngine: SpecialDatesSyncEngine,
     specialDatesSpec: SpecialDatesCalendarSpec,
+    private val launcherNameManager: LauncherNameManager,
+    private val reminderScanner: ReminderScanner,
     @IoDispatcher private val io: CoroutineDispatcher,
     @ApplicationContext private val appContext: Context,
 ) : ViewModel() {
 
     private val dynamicColorAvailable = Build.VERSION.SDK_INT >= Build.VERSION_CODES.S
 
-    /** Writable calendars — the only ones that take a per-calendar reminder override. */
+    /**
+     * Writable calendars that are switched on — the only ones that take a
+     * per-calendar reminder override. A calendar switched off in Settings →
+     * Calendars is `VISIBLE = 0`, so the provider schedules no alarms for it and
+     * a default reminder configured there could never fire (#75).
+     */
     private val writableCalendars: Flow<List<CalendarSource>> = repository.calendars()
-        .map { calendars -> calendars.filter { it.canModifyContents } }
+        .map { calendars -> calendars.filter { it.canModifyContents && it.isVisibleInSystem } }
         .catch { emit(emptyList()) }
 
     val state: StateFlow<SettingsUiState> =
@@ -124,8 +139,9 @@ class SettingsViewModel @Inject constructor(
                     prefs.showWeekNumbers,
                     prefs.agendaShowToday,
                     prefs.softenCalendarColors,
-                ) { hourLines, weekNumbers, showToday, soften ->
+                    prefs.todayButtonInToolbar,
-                    DisplayToggles(hourLines, weekNumbers, showToday, soften)
+                ) { hourLines, weekNumbers, showToday, soften, todayInToolbar ->
+                    DisplayToggles(hourLines, weekNumbers, showToday, soften, todayInToolbar)
                 },
             ) { view, screenRange, widgetRange, timeFormat, toggles ->
                 ViewSettings(
@@ -134,6 +150,7 @@ class SettingsViewModel @Inject constructor(
                     showWeekNumbers = toggles.showWeekNumbers,
                     agendaShowToday = toggles.agendaShowToday,
                     softenColors = toggles.softenColors,
+                    todayButtonInToolbar = toggles.todayButtonInToolbar,
                 )
             },
             combine(
@@ -143,8 +160,13 @@ class SettingsViewModel @Inject constructor(
                 prefs.dimCompletedEvents,
                 // View customisation (#24) folded into one flow so it fits this
                 // group — the outer combine is already at its five-arg limit.
-                combine(prefs.quickSwitchConfig, prefs.drawerViewOrder) { quickSwitch, drawer ->
+                combine(
-                    ViewCustomization(quickSwitch, drawer)
+                    prefs.quickSwitchConfig,
+                    prefs.drawerViewOrder,
+                    prefs.monthViewStyle,
+                    prefs.widgetSize,
+                ) { quickSwitch, drawer, monthStyle, widgetSize ->
+                    ViewCustomization(quickSwitch, drawer, monthStyle, widgetSize)
                 },
             ) { showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization ->
                 MiscSettings(showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization)
@@ -159,12 +181,15 @@ class SettingsViewModel @Inject constructor(
                 showWeekNumbers = views.showWeekNumbers,
                 agendaShowToday = views.agendaShowToday,
                 softenColors = views.softenColors,
+                todayButtonInToolbar = views.todayButtonInToolbar,
                 agendaShowRangeBar = misc.showRangeBar,
                 autofocusEventTitle = misc.autofocusEventTitle,
                 pastEventDisplay = misc.pastEventDisplay,
                 dimCompletedEvents = misc.dimCompletedEvents,
                 quickSwitchConfig = misc.viewCustomization.quickSwitch,
                 drawerViewOrder = misc.viewCustomization.drawerOrder,
+                monthViewStyle = misc.viewCustomization.monthViewStyle,
+                widgetSize = misc.viewCustomization.widgetSize,
                 allowColorOnUnsupportedCalendars = defaults.allowColor,
                 defaultReminderMinutes = defaults.defaultReminder,
                 defaultAllDayReminderMinutes = defaults.allDayReminder,
@@ -199,6 +224,28 @@ class SettingsViewModel @Inject constructor(
         initialValue = AppFontSettings(),
     )
 
+    /**
+     * The launcher-label choice (issue #44). Backed by the manifest aliases'
+     * component-enabled state rather than a stored preference, so it's read
+     * imperatively via [LauncherNameManager] and held here in its own flow — the
+     * main settings combine is already at its arity limit and this isn't a
+     * DataStore flow anyway.
+     *
+     * Seeded with the manifest default and corrected off-thread rather than read
+     * in the initializer: `getComponentEnabledSetting` is a binder round-trip to
+     * system_server, and this ViewModel is constructed on the main thread while
+     * Settings is opening. The row it feeds is well below the fold, so the
+     * one-frame correction is never visible.
+     */
+    private val _launcherName = MutableStateFlow(LauncherName.CALENDULA)
+    val launcherName: StateFlow<LauncherName> = _launcherName.asStateFlow()
+
+    init {
+        viewModelScope.launch {
+            _launcherName.value = withContext(io) { launcherNameManager.current() }
+        }
+    }
+
     // Emitted when a picked font file couldn't be read as a font; the screen
     // surfaces it and the previous selection stays put.
     private val _fontImportFailed = MutableSharedFlow<Unit>(extraBufferCapacity = 1)
@@ -234,6 +281,7 @@ class SettingsViewModel @Inject constructor(
         val showWeekNumbers: Boolean,
         val agendaShowToday: Boolean,
         val softenColors: Boolean,
+        val todayButtonInToolbar: Boolean,
     )
 
     private data class DisplayToggles(
@@ -241,6 +289,7 @@ class SettingsViewModel @Inject constructor(
         val showWeekNumbers: Boolean,
         val agendaShowToday: Boolean,
         val softenColors: Boolean,
+        val todayButtonInToolbar: Boolean,
     )
 
     private data class MiscSettings(
@@ -254,6 +303,8 @@ class SettingsViewModel @Inject constructor(
     private data class ViewCustomization(
         val quickSwitch: QuickSwitchConfig,
         val drawerOrder: List<CalendarView>,
+        val monthViewStyle: MonthViewStyle,
+        val widgetSize: WidgetSize,
     )
 
     /** Contact special-dates sub-page (issue #15); its own flow — the main state is full. */
@@ -432,6 +483,28 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.setAgendaShowRangeBar(enabled) }
     }
 
+    /**
+     * Set the size the agenda widget draws its text at (#51). Pushed into every
+     * instance's Glance state and recomposed — the same reliable-update path as
+     * [setAgendaWidgetRange], since `updateAll` alone won't re-run the data
+     * preamble a live session already ran.
+     *
+     * Agenda-only on purpose: the month widget sizes itself from the space it is
+     * given and always has, so it takes no size setting (#103).
+     */
+    fun setWidgetSize(size: WidgetSize) {
+        viewModelScope.launch {
+            prefs.setWidgetSize(size)
+            widgetRefreshMutex.withLock {
+                val manager = GlanceAppWidgetManager(appContext)
+                manager.getGlanceIds(AgendaWidget::class.java).forEach { id ->
+                    updateAppWidgetState(appContext, id) { it[AGENDA_SIZE_KEY] = size.name }
+                }
+                AgendaWidget().updateAll(appContext)
+            }
+        }
+    }
+
     fun setAgendaShowToday(enabled: Boolean) {
         viewModelScope.launch {
             prefs.setAgendaShowToday(enabled)
@@ -460,6 +533,26 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.setShowWeekNumbers(enabled) }
     }
 
+    fun setTodayButtonInToolbar(enabled: Boolean) {
+        viewModelScope.launch { prefs.setTodayButtonInToolbar(enabled) }
+    }
+
+    /**
+     * Switch the launcher label between "Calendula" and "Calendar" (issue #44).
+     * The card highlights immediately, then settles on whatever the component
+     * state actually reports — the two `setComponentEnabledSetting` calls are
+     * binder round-trips, so they don't belong on the main thread either.
+     */
+    fun setLauncherName(name: LauncherName) {
+        _launcherName.value = name
+        viewModelScope.launch {
+            _launcherName.value = withContext(io) {
+                launcherNameManager.set(name)
+                launcherNameManager.current()
+            }
+        }
+    }
+
     fun setPastEventDisplay(mode: PastEventDisplay) {
         viewModelScope.launch {
             prefs.setPastEventDisplay(mode)
@@ -510,12 +603,24 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.updateQuickSwitch { it.copy(order = order) } }
     }
 
+    fun setMonthViewStyle(style: MonthViewStyle) {
+        viewModelScope.launch { prefs.setMonthViewStyle(style) }
+    }
+
     fun setDrawerViewOrder(order: List<CalendarView>) {
         viewModelScope.launch { prefs.setDrawerViewOrder(order) }
     }
 
+    /**
+     * A scan follows the write, in that order. Switching reminders off cancels
+     * the scan alarm, so switching them back on has to arm a new one — nothing
+     * else would until a provider change or the daily worker came along (#75).
+     */
     fun setRemindersEnabled(enabled: Boolean) {
-        viewModelScope.launch { prefs.setRemindersEnabled(enabled) }
+        viewModelScope.launch {
+            prefs.setRemindersEnabled(enabled)
+            reminderScanner.scan()
+        }
     }
 
     fun setAutofocusEventTitle(enabled: Boolean) {
@@ -530,8 +635,12 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.setDefaultAllDayReminderMinutes(minutes) }
     }
 
+    /** The armed alarm was planned for the old hour, so re-plan against the new one. */
     fun setAllDayReminderTimeMinutes(minutesOfDay: Int) {
-        viewModelScope.launch { prefs.setAllDayReminderTimeMinutes(minutesOfDay) }
+        viewModelScope.launch {
+            prefs.setAllDayReminderTimeMinutes(minutesOfDay)
+            reminderScanner.scan()
+        }
     }
 
     fun setSnoozeMinutes(minutes: Int) {

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SpecialDatesSettings.kt

@@ -0,0 +1,327 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import android.Manifest
+import android.content.Context
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+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.shape.RoundedCornerShape
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+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.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.contacts.hasContactsPermission
+import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
+import de.jeanlucmakiola.calendula.ui.common.ReminderDefaultPicker
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.InlineTextField
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.reminders.ReminderOverride
+
+// ---------------------------------------------------------------------------
+// Contact special dates (issue #15)
+// ---------------------------------------------------------------------------
+
+@Composable
+internal fun SpecialDatesScreen(
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+) {
+    val state by viewModel.specialDatesState.collectAsStateWithLifecycle()
+    // The all-day reminder hour lives in the general settings state; the reminder
+    // picker below names it, since that is when these reminders actually fire.
+    val settings by viewModel.state.collectAsStateWithLifecycle()
+    val context = LocalContext.current
+
+    // READ_CONTACTS is requested only here, on enable — never at startup. On a
+    // grant we either enable (if turning on) or just re-sync (clearing a stalled
+    // banner after the permission was re-granted).
+    val permissionLauncher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+    ) { granted ->
+        if (granted) {
+            if (!state.enabled) viewModel.setSpecialDatesEnabled(true) else viewModel.syncSpecialDatesNow()
+        }
+    }
+    val requestOrEnable: () -> Unit = {
+        if (context.hasContactsPermission()) {
+            viewModel.setSpecialDatesEnabled(true)
+        } else {
+            permissionLauncher.launch(Manifest.permission.READ_CONTACTS)
+        }
+    }
+
+    var confirmDisableAll by remember { mutableStateOf(false) }
+    var confirmDisableType by remember { mutableStateOf<SpecialDateType?>(null) }
+    var editTemplate by remember { mutableStateOf<SpecialDateType?>(null) }
+    var reminderPickerType by remember { mutableStateOf<SpecialDateType?>(null) }
+
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_special_dates),
+        onBack = onBack,
+        predictiveBack = true,
+    ) {
+        // Paused banner: the permission was revoked after enabling.
+        if (state.enabled && state.stalledPermission) {
+            Surface(
+                shape = RoundedCornerShape(16.dp),
+                color = MaterialTheme.colorScheme.errorContainer,
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Column(Modifier.padding(16.dp)) {
+                    Text(
+                        text = stringResource(R.string.settings_special_dates_paused_title),
+                        style = MaterialTheme.typography.titleSmall,
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                    )
+                    Text(
+                        text = stringResource(R.string.settings_special_dates_paused_hint),
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                    )
+                    Spacer(Modifier.height(8.dp))
+                    FilledTonalButton(
+                        onClick = { permissionLauncher.launch(Manifest.permission.READ_CONTACTS) },
+                    ) { Text(stringResource(R.string.settings_special_dates_grant)) }
+                }
+            }
+            Spacer(Modifier.height(16.dp))
+        }
+
+        GroupedRow(
+            title = stringResource(R.string.settings_special_dates_enable),
+            summary = stringResource(R.string.settings_special_dates_enable_hint),
+            position = Position.Alone,
+            trailing = {
+                Switch(
+                    checked = state.enabled,
+                    onCheckedChange = { want -> if (want) requestOrEnable() else confirmDisableAll = true },
+                )
+            },
+            onClick = { if (state.enabled) confirmDisableAll = true else requestOrEnable() },
+        )
+
+        if (state.enabled) {
+            // Per-type card: the toggle, and while on, its title format and its
+            // calendar-wide reminder.
+            SpecialDateType.entries.forEachIndexed { index, type ->
+                Spacer(Modifier.height(if (index == 0) 24.dp else 16.dp))
+                val on = type in state.types
+                GroupedRow(
+                    title = stringResource(specialDateTypeLabel(type)),
+                    position = if (on) Position.Top else Position.Alone,
+                    trailing = {
+                        Switch(
+                            checked = on,
+                            onCheckedChange = { want ->
+                                if (want) viewModel.setSpecialDateTypeEnabled(type, true)
+                                else confirmDisableType = type
+                            },
+                        )
+                    },
+                    onClick = {
+                        if (on) confirmDisableType = type else viewModel.setSpecialDateTypeEnabled(type, true)
+                    },
+                )
+                if (on) {
+                    GroupedRow(
+                        title = stringResource(R.string.settings_special_dates_template),
+                        summary = state.titleTemplates[type].orEmpty(),
+                        position = Position.Middle,
+                        onClick = { editTemplate = type },
+                    )
+                    GroupedRow(
+                        title = stringResource(R.string.settings_special_dates_reminders),
+                        summary = reminderChoiceLabel(specialDatesReminderMinutes(state.reminderChoices[type])),
+                        position = Position.Bottom,
+                        onClick = { reminderPickerType = type },
+                    )
+                }
+            }
+
+            Spacer(Modifier.height(24.dp))
+            GroupedRow(
+                title = stringResource(R.string.settings_special_dates_show_year),
+                summary = stringResource(R.string.settings_special_dates_show_year_hint),
+                position = Position.Top,
+                trailing = {
+                    Switch(
+                        checked = state.showYear,
+                        onCheckedChange = viewModel::setSpecialDatesShowYear,
+                    )
+                },
+                onClick = { viewModel.setSpecialDatesShowYear(!state.showYear) },
+            )
+            GroupedRow(
+                title = stringResource(R.string.settings_special_dates_sync_now),
+                summary = specialDatesLastRunLabel(context, state.lastRun),
+                position = Position.Bottom,
+                onClick = viewModel::syncSpecialDatesNow,
+            )
+
+            Spacer(Modifier.height(24.dp))
+            Text(
+                text = stringResource(R.string.settings_special_dates_calendar_hint),
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(horizontal = 16.dp),
+            )
+        }
+    }
+
+    if (confirmDisableAll) {
+        SpecialDatesDisableDialog(
+            message = stringResource(R.string.settings_special_dates_disable_all_message),
+            onConfirm = { viewModel.setSpecialDatesEnabled(false); confirmDisableAll = false },
+            onDismiss = { confirmDisableAll = false },
+        )
+    }
+    confirmDisableType?.let { type ->
+        SpecialDatesDisableDialog(
+            message = stringResource(
+                R.string.settings_special_dates_disable_type_message,
+                stringResource(specialDateTypeLabel(type)),
+            ),
+            onConfirm = { viewModel.setSpecialDateTypeEnabled(type, false); confirmDisableType = null },
+            onDismiss = { confirmDisableType = null },
+        )
+    }
+    editTemplate?.let { type ->
+        SpecialDatesTemplateDialog(
+            initial = state.titleTemplates[type].orEmpty(),
+            onConfirm = { viewModel.setSpecialDatesTitleTemplate(type, it); editTemplate = null },
+            onDismiss = { editTemplate = null },
+        )
+    }
+    reminderPickerType?.let { type ->
+        ReminderDefaultPicker(
+            title = stringResource(R.string.settings_special_dates_reminders),
+            presets = ALLDAY_REMINDER_PRESETS,
+            selected = state.reminderChoices[type] ?: ReminderOverride.None,
+            // Managed calendars own their reminders outright — no "inherit global".
+            allowInherit = false,
+            onSelect = { viewModel.setSpecialDatesReminders(type, it) },
+            onDismiss = { reminderPickerType = null },
+            // Special dates are all-day events, so their reminders fire at the
+            // one global all-day hour like any other all-day reminder.
+            leadTimeSummary = allDayFiringTimeSummary(settings.allDayReminderTimeMinutes),
+        )
+    }
+}
+
+/** The lead-time list backing a managed calendar's reminder choice (for the summary label). */
+private fun specialDatesReminderMinutes(choice: ReminderOverride?): List<Int> =
+    (choice as? ReminderOverride.Minutes)?.minutes.orEmpty()
+
+@Composable
+private fun SpecialDatesDisableDialog(
+    message: String,
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.settings_special_dates_disable_title)) },
+        text = { Text(message) },
+        confirmButton = {
+            TextButton(onClick = onConfirm) {
+                Text(stringResource(R.string.settings_special_dates_disable_confirm))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.dialog_cancel))
+            }
+        },
+    )
+}
+
+@Composable
+private fun SpecialDatesTemplateDialog(
+    initial: String,
+    onConfirm: (String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var text by rememberSaveable { mutableStateOf(initial) }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.settings_special_dates_template)) },
+        text = {
+            Column {
+                // The app's borderless input over a tonal surface (the dialog
+                // convention — see DialogControls), not Material's outlined field.
+                Surface(
+                    color = MaterialTheme.colorScheme.surfaceContainerHighest,
+                    shape = RoundedCornerShape(12.dp),
+                ) {
+                    InlineTextField(
+                        value = text,
+                        onValueChange = { text = it },
+                        placeholder = stringResource(R.string.settings_special_dates_template),
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 14.dp, vertical = 12.dp),
+                    )
+                }
+                Spacer(Modifier.height(8.dp))
+                Text(
+                    text = stringResource(R.string.settings_special_dates_template_hint),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = { onConfirm(text) },
+                enabled = text.isNotBlank(),
+            ) { Text(stringResource(R.string.dialog_save)) }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(stringResource(R.string.dialog_cancel))
+            }
+        },
+    )
+}
+
+private fun specialDateTypeLabel(type: SpecialDateType): Int = when (type) {
+    SpecialDateType.Birthday -> R.string.settings_special_dates_type_birthday
+    SpecialDateType.Anniversary -> R.string.settings_special_dates_type_anniversary
+    SpecialDateType.Custom -> R.string.settings_special_dates_type_custom
+}
+
+@Composable
+private fun specialDatesLastRunLabel(context: Context, lastRun: Long): String =
+    if (lastRun <= 0L) {
+        stringResource(R.string.settings_special_dates_never_synced)
+    } else {
+        stringResource(
+            R.string.settings_special_dates_last_synced,
+            android.text.format.DateUtils.getRelativeTimeSpanString(
+                lastRun,
+                System.currentTimeMillis(),
+                android.text.format.DateUtils.MINUTE_IN_MILLIS,
+            ).toString(),
+        )
+    }

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/ViewsSettings.kt

@@ -0,0 +1,428 @@
+package de.jeanlucmakiola.calendula.ui.settings
+
+import android.text.format.DateFormat
+import androidx.annotation.StringRes
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.DragHandle
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+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.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
+import de.jeanlucmakiola.calendula.data.prefs.TimeFormatPref
+import de.jeanlucmakiola.calendula.data.prefs.WeekStartPref
+import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
+import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
+import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
+import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
+import de.jeanlucmakiola.calendula.ui.common.icon
+import de.jeanlucmakiola.calendula.ui.common.labelRes
+import de.jeanlucmakiola.calendula.ui.month.labelRes
+import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.OptionPicker
+import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.ReorderableColumn
+import de.jeanlucmakiola.floret.components.ReorderableRowHeight
+import de.jeanlucmakiola.floret.locale.currentLocale
+import kotlinx.datetime.DayOfWeek
+import java.time.format.TextStyle as JavaTextStyle
+
+/**
+ * Views: everything that changes how a calendar view reads, grouped by the view
+ * it belongs to, plus the two cross-view ordering lists (#24, #69).
+ *
+ * The first group holds what applies everywhere (default view, week start, time
+ * format); the rest are per-view. Anything that styles the *app* rather than a
+ * view (theme, fonts) is in [AppearanceScreen]; the widget's own copies of the
+ * agenda settings are in [WidgetsScreen].
+ *
+ * The quick-switch cycle and the navigation-drawer list are two independent
+ * orders — a view disabled in the quick-switch cycle is still reachable from the
+ * drawer, which always lists every view. The switch needs at least two targets,
+ * so the last [QuickSwitchConfig.MIN_ENABLED] enabled views can't be turned off.
+ */
+@Composable
+internal fun ViewsScreen(
+    state: SettingsUiState,
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+) {
+    var showMonthStyle by remember { mutableStateOf(false) }
+    var showDefaultView by remember { mutableStateOf(false) }
+    var showWeekStart by remember { mutableStateOf(false) }
+    var showTimeFormat by remember { mutableStateOf(false) }
+    var showPastEvents by remember { mutableStateOf(false) }
+    var showAgendaScreenRange by remember { mutableStateOf(false) }
+
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_views),
+        onBack = onBack,
+        predictiveBack = true,
+    ) {
+        val config = state.quickSwitchConfig
+
+        // What holds for every view, above the per-view groups.
+        SectionHeader(stringResource(R.string.settings_views_all_header))
+        GroupedRow(
+            title = stringResource(R.string.settings_default_view),
+            summary = stringResource(state.defaultView.labelRes),
+            position = Position.Top,
+            onClick = { showDefaultView = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_week_start),
+            summary = weekStartLabel(state.weekStart),
+            position = Position.Middle,
+            onClick = { showWeekStart = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_time_format),
+            summary = timeFormatLabel(state.timeFormat),
+            position = Position.Middle,
+            onClick = { showTimeFormat = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_today_toolbar),
+            summary = stringResource(R.string.settings_today_toolbar_summary),
+            position = Position.Middle,
+            trailing = {
+                Switch(
+                    checked = state.todayButtonInToolbar,
+                    onCheckedChange = viewModel::setTodayButtonInToolbar,
+                )
+            },
+            onClick = { viewModel.setTodayButtonInToolbar(!state.todayButtonInToolbar) },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_dim_completed),
+            summary = stringResource(R.string.settings_dim_completed_summary),
+            position = Position.Bottom,
+            trailing = {
+                Switch(
+                    checked = state.dimCompletedEvents,
+                    onCheckedChange = viewModel::setDimCompletedEvents,
+                )
+            },
+            onClick = { viewModel.setDimCompletedEvents(!state.dimCompletedEvents) },
+        )
+
+        Spacer(Modifier.height(8.dp))
+        SectionHeader(stringResource(R.string.settings_month_header))
+        GroupedRow(
+            title = stringResource(R.string.settings_month_view_style),
+            summary = stringResource(state.monthViewStyle.labelRes),
+            position = Position.Top,
+            onClick = { showMonthStyle = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_week_numbers),
+            summary = stringResource(R.string.settings_week_numbers_summary),
+            position = Position.Bottom,
+            trailing = {
+                Switch(
+                    checked = state.showWeekNumbers,
+                    onCheckedChange = viewModel::setShowWeekNumbers,
+                )
+            },
+            onClick = { viewModel.setShowWeekNumbers(!state.showWeekNumbers) },
+        )
+
+        Spacer(Modifier.height(8.dp))
+        SectionHeader(stringResource(R.string.settings_week_day_header))
+        GroupedRow(
+            title = stringResource(R.string.settings_hour_lines),
+            summary = stringResource(R.string.settings_hour_lines_summary),
+            position = Position.Alone,
+            trailing = {
+                Switch(
+                    checked = state.showHourLines,
+                    onCheckedChange = viewModel::setShowHourLines,
+                )
+            },
+            onClick = { viewModel.setShowHourLines(!state.showHourLines) },
+        )
+
+        Spacer(Modifier.height(8.dp))
+        SectionHeader(stringResource(R.string.settings_agenda_header))
+        GroupedRow(
+            title = stringResource(R.string.settings_agenda_range),
+            summary = agendaRangeLabel(state.agendaScreenRange),
+            position = Position.Top,
+            onClick = { showAgendaScreenRange = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_past_events),
+            summary = pastEventDisplayLabel(state.pastEventDisplay),
+            position = Position.Middle,
+            onClick = { showPastEvents = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_agenda_show_today),
+            summary = stringResource(R.string.settings_agenda_show_today_hint),
+            position = Position.Middle,
+            trailing = {
+                Switch(
+                    checked = state.agendaShowToday,
+                    onCheckedChange = viewModel::setAgendaShowToday,
+                )
+            },
+            onClick = { viewModel.setAgendaShowToday(!state.agendaShowToday) },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_agenda_range_bar),
+            summary = stringResource(R.string.settings_agenda_range_bar_hint),
+            position = Position.Bottom,
+            trailing = {
+                Switch(
+                    checked = state.agendaShowRangeBar,
+                    onCheckedChange = viewModel::setAgendaShowRangeBar,
+                )
+            },
+            onClick = { viewModel.setAgendaShowRangeBar(!state.agendaShowRangeBar) },
+        )
+
+        Spacer(Modifier.height(24.dp))
+        SectionHeader(stringResource(R.string.settings_quick_switch_header))
+        SettingsHint(stringResource(R.string.settings_quick_switch_hint))
+        Spacer(Modifier.height(8.dp))
+        // Turning a view off is blocked once only the minimum remain enabled.
+        val canDisable = config.enabled.size > QuickSwitchConfig.MIN_ENABLED
+        ReorderableColumn(
+            items = config.order,
+            keyOf = { it },
+            onReorder = { viewModel.setQuickSwitchOrder(it) },
+        ) { view, position, dragHandle, isDragging ->
+            val checked = view in config.enabled
+            ViewRow(
+                view = view,
+                position = position,
+                isDragging = isDragging,
+                dragHandle = dragHandle,
+                dimmed = !checked,
+                trailing = {
+                    Switch(
+                        checked = checked,
+                        // Keep the last two on: with fewer, the pill can't switch.
+                        enabled = !checked || canDisable,
+                        onCheckedChange = { on -> viewModel.setQuickSwitchViewEnabled(view, on) },
+                    )
+                },
+            )
+        }
+
+        Spacer(Modifier.height(24.dp))
+        SectionHeader(stringResource(R.string.settings_drawer_order_header))
+        SettingsHint(stringResource(R.string.settings_drawer_order_hint))
+        Spacer(Modifier.height(8.dp))
+        ReorderableColumn(
+            items = state.drawerViewOrder,
+            keyOf = { it },
+            onReorder = { viewModel.setDrawerViewOrder(it) },
+        ) { view, position, dragHandle, isDragging ->
+            ViewRow(
+                view = view,
+                position = position,
+                isDragging = isDragging,
+                dragHandle = dragHandle,
+            )
+        }
+    }
+
+    if (showMonthStyle) {
+        MonthViewStylePicker(
+            selected = state.monthViewStyle,
+            // The preview is a real grid, so it uses the real week start too.
+            weekStart = state.weekStart.resolveFirstDay(currentLocale()),
+            onSelect = viewModel::setMonthViewStyle,
+            onDismiss = { showMonthStyle = false },
+        )
+    }
+    if (showDefaultView) {
+        OptionPicker(
+            title = stringResource(R.string.settings_default_view),
+            header = { PickerDescription(stringResource(R.string.settings_default_view_hint)) },
+            predictiveBack = true,
+            options = IMPLEMENTED_VIEWS,
+            selected = state.defaultView,
+            label = { stringResource(it.labelRes) },
+            // The same icon each view carries in the drawer and the switcher
+            // pill, so the row is matched to the view by eye, not by reading.
+            leading = {
+                Icon(
+                    imageVector = it.icon,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            },
+            onSelect = viewModel::setDefaultView,
+            onDismiss = { showDefaultView = false },
+        )
+    }
+    if (showWeekStart) {
+        WeekStartPicker(
+            selected = state.weekStart,
+            // The preview is a real grid, so it uses the user's own month style.
+            monthStyle = state.monthViewStyle,
+            options = WEEK_START_OPTIONS,
+            onSelect = viewModel::setWeekStart,
+            onDismiss = { showWeekStart = false },
+        )
+    }
+    if (showTimeFormat) {
+        val locale = currentLocale()
+        val systemIs24Hour = DateFormat.is24HourFormat(LocalContext.current)
+        OptionPicker(
+            title = stringResource(R.string.settings_time_format),
+            header = { PickerDescription(stringResource(R.string.settings_time_format_hint)) },
+            predictiveBack = true,
+            options = TimeFormatPref.entries,
+            selected = state.timeFormat,
+            label = { timeFormatLabel(it) },
+            // Each option renders the same sample time the way it would write
+            // it — an afternoon one, since that is where 12h and 24h diverge.
+            // "Automatic" additionally says which of the two it resolves to now.
+            summary = { pref ->
+                val sample = formatTimeOfDay(
+                    hour = SAMPLE_HOUR,
+                    minute = SAMPLE_MINUTE,
+                    is24Hour = when (pref) {
+                        TimeFormatPref.AUTO -> systemIs24Hour
+                        TimeFormatPref.TWELVE_HOUR -> false
+                        TimeFormatPref.TWENTY_FOUR_HOUR -> true
+                    },
+                    locale = locale,
+                )
+                if (pref == TimeFormatPref.AUTO) {
+                    stringResource(R.string.settings_time_format_auto_summary, sample)
+                } else {
+                    sample
+                }
+            },
+            onSelect = viewModel::setTimeFormat,
+            onDismiss = { showTimeFormat = false },
+        )
+    }
+    if (showPastEvents) {
+        PastEventsPicker(
+            selected = state.pastEventDisplay,
+            onSelect = viewModel::setPastEventDisplay,
+            onDismiss = { showPastEvents = false },
+        )
+    }
+    if (showAgendaScreenRange) {
+        AgendaRangePicker(
+            title = stringResource(R.string.settings_agenda_range),
+            description = stringResource(R.string.settings_agenda_range_hint),
+            selected = state.agendaScreenRange,
+            // Resolving each option to real dates needs the same week start the
+            // agenda itself windows by.
+            weekStart = state.weekStart.resolveFirstDay(currentLocale()),
+            onSelect = viewModel::setAgendaScreenRange,
+            onDismiss = { showAgendaScreenRange = false },
+        )
+    }
+}
+
+/** Sample time the format options render: afternoon, where 12h and 24h differ. */
+private const val SAMPLE_HOUR = 14
+private const val SAMPLE_MINUTE = 30
+
+/** One reorderable view row: the view's icon and name, an optional [trailing]
+ *  control, and a drag handle carrying the [dragHandle] gesture modifier. */
+@Composable
+private fun ViewRow(
+    view: CalendarView,
+    position: Position,
+    isDragging: Boolean,
+    dragHandle: Modifier,
+    dimmed: Boolean = false,
+    trailing: @Composable (() -> Unit)? = null,
+) {
+    GroupedRow(
+        title = stringResource(view.labelRes),
+        position = position,
+        dimmed = dimmed,
+        minHeight = ReorderableRowHeight,
+        // The reorderable column owns the inter-row spacing (uniform pitch).
+        gapBelow = false,
+        container = if (isDragging) MaterialTheme.colorScheme.secondaryContainer else null,
+        leading = {
+            Icon(
+                imageVector = view.icon,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        },
+        trailing = {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                trailing?.invoke()
+                if (trailing != null) Spacer(Modifier.width(8.dp))
+                Box(
+                    modifier = dragHandle.size(48.dp),
+                    contentAlignment = Alignment.Center,
+                ) {
+                    Icon(
+                        imageVector = Icons.Default.DragHandle,
+                        contentDescription = stringResource(R.string.reorder_drag_handle),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+        },
+    )
+}
+
+/** Picker options: "Follow system" first, then Monday…Sunday in ISO order. */
+private val WEEK_START_OPTIONS: List<WeekStartPref> =
+    listOf(WeekStartPref.Auto) + DayOfWeek.entries.map { WeekStartPref.Day(it) }
+
+@Composable
+internal fun weekStartLabel(pref: WeekStartPref): String = when (pref) {
+    WeekStartPref.Auto -> stringResource(R.string.settings_week_start_auto)
+    // Localised full weekday name, so any of the seven days reads naturally
+    // without a per-day string resource.
+    is WeekStartPref.Day -> java.time.DayOfWeek.of(pref.day.ordinal + 1)
+        .getDisplayName(JavaTextStyle.FULL, currentLocale())
+}
+
+@Composable
+private fun timeFormatLabel(pref: TimeFormatPref): String = stringResource(
+    when (pref) {
+        TimeFormatPref.AUTO -> R.string.settings_time_format_auto
+        TimeFormatPref.TWELVE_HOUR -> R.string.settings_time_format_12h
+        TimeFormatPref.TWENTY_FOUR_HOUR -> R.string.settings_time_format_24h
+    },
+)
+
+@Composable
+private fun pastEventDisplayLabel(mode: PastEventDisplay): String =
+    stringResource(pastEventDisplayLabelRes(mode))
+
+/** Shared with [PastEventsPicker], which needs the id rather than the string. */
+@StringRes
+internal fun pastEventDisplayLabelRes(mode: PastEventDisplay): Int = when (mode) {
+    PastEventDisplay.SHOW -> R.string.settings_past_events_show
+    PastEventDisplay.DIM -> R.string.settings_past_events_dim
+    PastEventDisplay.HIDE -> R.string.settings_past_events_hide
+}