Merge pull request 'release: v2.11.0' (!48) from release/v2.11.0 into main

Reviewed-on: #48

.gitea/ISSUE_TEMPLATE/crash_report.md

@@ -5,6 +5,7 @@ title: "Crash: "
 labels:
   - bug
   - crash
+  - priority:high
 ---
 
 <!--

.gitea/ISSUE_TEMPLATE/feature_request.md

@@ -3,7 +3,7 @@ name: Feature request
 about: Suggest an idea or improvement
 title: ""
 labels:
-  - enhancement
+  - feat
 ---
 
 ### What would you like Calendula to do?

.gitea/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,19 @@
+---
+name: Question
+about: Ask how something works or get help using Calendula
+title: ""
+labels:
+  - question
+---
+
+### Your question
+
+
+### What you've tried
+<!-- so far, if anything -->
+
+
+### Context
+- Calendula version: <!-- Settings → bottom of the screen -->
+- Android version:
+- Device:

.planning/ROADMAP.md

@@ -230,7 +230,7 @@ pass on the existing controls; new toggles ride in with their own features.
 
 **Tier 3 — platform reach (depends on Tier 2)**
 7. ~~Home-screen widget — built on the agenda data source from #6~~ *(done, v2.5.0 — agenda + month widgets)*
-8. App shortcuts: ~~launcher long-press → New event~~ *(done, v2.5.0)*; optional quick-settings tile still open
+8. App shortcuts: ~~launcher long-press → New event~~ *(done, v2.5.0)*; ~~quick-settings tile~~ *(done, v2.8.0 — "New event" QS tile)*
 
 **Tier 4 — reliability, data-safety & interop** *(re-ranked 2026-06-17)*
 9. **Reminders — defaults + delivery reliability** *(shipped v2.6.0)* — global
@@ -251,37 +251,38 @@ pass on the existing controls; new toggles ride in with their own features.
     decision (snooze must re-fire an alarm).
 
 **Tier 5 — close the read/write gap on the event model** *(opened 2026-06-22)*
-12. **Attendee editing** *(next — promoted from the gated "Locations & People"
-    bucket, owner says high-importance 2026-06-22)* — attendees are already
-    *read* (queried, mapped, shown on the detail screen since v0.6) but the
-    event form can't *write* them, the last big read-only gap in the event
-    model. Add an attendees section to `EventEditScreen` / `EventForm`: add by
-    typed email (contact-picker entry can follow later), edit/remove rows, set
-    role (required / optional) — writing `CalendarContract.Attendees` rows on
-    insert + dirty-checked update, mirroring the reminders-diff pattern.
-    **Caveat to resolve first:** writing `Attendees` rows triggers sync-adapter
-    *invitation* behavior that differs by backend (Google auto-emails invites;
-    DAVx5/CalDAV writes the `ATTENDEE` property and lets the server decide) —
-    decide and document what Calendula promises before building. Full sketch in
-    "Attendee editing" under Locations & People below.
+12. **Attendee editing** *(shipped — merged into release/v2.8.0, `feat/attendee-editing`
+    MR !29 / commit `b0f34ff`, 2026-06-22)* — closed the last big read-only gap in
+    the event model: attendees were already *read* (queried, mapped, shown on the
+    detail screen since v0.6) and are now *writable* from the form. An attendees
+    section on `EventEditScreen` / `EventForm` adds by typed email **or** the
+    no-permission contact picker, edits/removes rows, and sets role (required /
+    optional) — writing `CalendarContract.Attendees` rows on insert + dirty-checked
+    update, mirroring the reminders-diff pattern. The sync-adapter *invitation*
+    caveat was **settled record-only** (Calendula never sends invites; the backend
+    decides delivery) — full sketch + decision in "Attendee editing" under Locations
+    & People below.
 
 **Gated — explicit go/no-go before any work (mostly INTERNET-permission calls)**
 - Remote calendar create/edit (re-implements DAVx5; INTERNET + credential storage)
-- Locations & People — contact address picker (no-permission, one-shot) is the safe entry; OSM autocomplete needs INTERNET
+- Locations & People — the no-permission contact pickers already shipped (location v2.8.0, attendee email v2.8.0); what remains gated is OSM autocomplete (needs INTERNET)
 - Move event to another calendar — sync-adapter minefield (copy+delete model)
 
 **Bottom — deprioritised, not important**
 - Duplicate event (detail action → prefilled create form) — moved here
   2026-06-17; cheap but low value, pick up only if asked
 
-**Unranked / fill-in** — pinch-to-zoom time scale, tablet/foldable layouts,
-full-text search. Pulled in opportunistically, not sequenced.
+**Unranked / fill-in** — pinch-to-zoom time scale, tablet/foldable layouts.
+Pulled in opportunistically, not sequenced.
 
 Tier 4 is now fully shipped (#9 reminders defaults v2.6.0, #10 `.ics`
-export/import v2.7.0, #11 snooze/dismiss in release/v2.8.0; drag-drop rejected).
-**Next committed work is Tier 5 #12 — attendee editing** (the last read-only gap
-in the event model). After it: the theme-group ideas and Tier 2/3 leftovers
-(quick-settings tile, now-line, week numbers in month, full-text search).
+export/import v2.7.0, #11 snooze/dismiss in release/v2.8.0; drag-drop rejected),
+and Tier 5 #12 — attendee editing — shipped in release/v2.8.0, closing the last
+read-only gap in the event model. v2.8.0 also cleared most Tier 2/3 leftovers —
+full-text search, the "New event" Quick Settings tile, and the now-line all
+shipped there. **No tier work is currently committed as next;** the remaining
+candidates are unscheduled theme-group ideas (pinch-to-zoom, tablet/foldable,
+accessibility pass) plus the gated go/no-go items.
 
 ## Navigation & views
 
@@ -291,24 +292,22 @@ in the event model). After it: the theme-group ideas and Tier 2/3 leftovers
 - Agenda view (fourth view: upcoming events grouped by day; also the
   natural data source for a future widget)
 - Jump to date — drawer date picker (un-cut from V1)
-- Current-time "now" line in day/week — standard in every calendar, cheap,
-  currently absent. Daily-driver polish.
-- Week numbers in the **month** grid — week view already shows the badge
-  (`WeekNumberBadge`, `WeekScreen.kt`); extend to month for ISO/European users.
+- ~~Current-time "now" line in day/week~~ **shipped v2.8.0**
+- Week numbers in the **month** grid — **rejected** (owner decision): clutters
+  the view and shrinks the day cells; the badge stays week-view-only.
 - Pinch-to-zoom time scale in day/week
 - Tablet / foldable layouts *(was v3.0)*
-- Full-text search *(was v3.0)* — promote out of "fill-in": for a daily driver
-  with real event history, finding an event is core completeness, not optional.
+- ~~Full-text search~~ **shipped v2.8.0** — for a daily driver with real event
+  history, finding an event is core completeness, not optional.
 
 ## Event editing & creation
 
 - Duplicate event (detail action → prefilled create form)
-- **Per-event color** (`Events.EVENT_COLOR`, OptionCard picker in the form)
-  *(next)* — chosen to follow the in-progress tap-to-create + calendar
-  management work: reuses the color-picker component and palette plumbing
-  being built for local calendar management, and finishes the create/edit
-  theme. `EVENT_COLOR` / `EVENT_COLOR_KEY` from the calendar's color list
-  (`Colors` table, `TYPE_EVENT`); falls back to the calendar color when unset.
+- ~~**Per-event color**~~ *(shipped v2.4.0)* — `EVENT_COLOR` / `EVENT_COLOR_KEY`
+  from the calendar's color list (`Colors` table, `TYPE_EVENT`), OptionCard
+  picker in the form, falling back to the calendar color when unset. Reused the
+  color-picker component and palette plumbing from local calendar management and
+  finished the create/edit theme.
 
 ## Calendars & accounts
 
@@ -337,7 +336,63 @@ in the event model). After it: the theme-group ideas and Tier 2/3 leftovers
   `.ics` file (SAF); restore is the bulk-import path (pick a calendar, dedup by
   UID). Closed the silent data-loss gap.
 
-## Reminders — defaults & delivery reliability *(implemented 2026-06-17, `feat/default-reminders` — pending on-device review)*
+### Disable a calendar in-app *(captured 2026-06-25)*
+
+A second, heavier visibility level **above** the existing per-view filter. Today
+the drawer's calendar filter (`hiddenCalendarIds` in `CalendarPrefs`) only hides
+a calendar's *events* from the month/week/day/agenda views — the calendar itself
+still clutters the drawer filter list, the event-form calendar picker, and the
+import target picker. "Disable" removes a calendar from the app's surfaces
+entirely; "hide" stays the lightweight, frequently-toggled control.
+
+**Two-level model (both kept):**
+- **Hidden** (existing) — `hiddenCalendarIds`; a quick per-view checkbox in the
+  drawer. Toggles events on/off in the views; the calendar stays listed
+  everywhere. Operates only over the *enabled* calendars.
+- **Disabled** (new) — the calendar is gone from the app: not in the drawer
+  filter list, not in the event-form picker, not in the import picker, and its
+  events never appear (it's gated out of `instances()` like a hidden one). It
+  remains visible **only** in Settings → Calendars, where the enable/disable
+  toggle lives, so it can be brought back.
+
+**Storage — app-side (DataStore), mirrors the hidden set.** Add
+`disabledCalendarIds: Set<Long>` + `setDisabledCalendarIds(...)` to
+`CalendarPrefs` (comma-separated string key, same shape as `hiddenCalendarIds`).
+**Does not touch** `CalendarContract.Calendars.VISIBLE` / `SYNC_EVENTS` — purely
+a Calendula-local preference, so other calendar apps are unaffected and the sync
+adapters stay out of it (privacy-clean, reversible).
+
+**Where the disabled set is applied:**
+- `CalendarRepositoryImpl.instances()` + `searchEvents()` — exclude
+  `calendarId ∈ (hidden ∪ disabled)` so a disabled calendar's events never show
+  and aren't searchable. (`repository.calendars()` itself stays unfiltered/raw —
+  the screens that need everything still get everything.)
+- `FilterViewModel.state` — drop disabled calendars from the drawer filter list
+  (you can't hide/show what's disabled).
+- `EventEditViewModel.writableCalendars` — exclude disabled, so you can't create
+  into a calendar you've removed from the app. Handle the last-used-calendar
+  preselect falling on a now-disabled calendar (fall back to first enabled
+  writable).
+- `ImportViewModel` — exclude disabled from the import target list.
+- `CalendarsScreen` / `CalendarsViewModel` — the **only** surface that lists
+  disabled calendars; add `setDisabled(id, Boolean)` and a per-calendar toggle.
+
+**UI — Settings → Calendars (no new tab).** Add an enable/disable control to each
+row on the existing `CalendarsScreen` (both the local and the synced/read-only
+groups — disabling is an app-side view choice, independent of write access).
+Disabled rows render visibly de-emphasised (dimmed) but keep the toggle so
+they're re-enableable. Follow the project dialog/list conventions (M3 grouped
+list, `option-card-modal-style-default` if a confirm/selection surface is needed).
+
+**Decided behaviour:**
+- All calendars disabled → views show the existing empty state.
+- A disabled calendar that still holds events: events simply vanish from
+  views/search until re-enabled (no data touched — it's a filter, not a delete).
+- Deep links / notifications pointing at an event in a disabled calendar still
+  open its detail screen — detail is a direct id lookup, not an `instances()`
+  query, so disabling never strands an existing link.
+
+## Reminders — defaults & delivery reliability *(shipped v2.6.0; built on `feat/default-reminders`)*
 
 Two themes bundled because both are "make reminders trustworthy" — the core of
 the "Calendula is your only calendar app" promise.
@@ -414,18 +469,20 @@ it directly undermines the feature's premise, so it rides in here.
   settings so users can verify delivery on their specific OEM (Samsung / Xiaomi
   are notorious for suppressing it).
 
-### Open decisions (resolve before building)
+### Decisions made (as shipped in v2.6.0)
 
-1. Self-schedule via `AlarmManager` vs trust the provider broadcast
-   (reliability vs simplicity + battery cost).
-2. All-day reminder representation (minutes-before vs absolute time-of-day).
-3. Where per-calendar overrides live in the UI (rows on the Calendars screen vs
-   a list inside the Notifications sub-page).
+1. **Provider broadcast kept** — did not self-schedule via `AlarmManager`; the
+   battery-optimisation exemption is the reliability lever (simplicity + battery
+   cost won over the exact-alarm subsystem).
+2. **All-day reminders = minutes-before-midnight** (day-scale presets); absolute
+   time-of-day ("9am the day before") deferred — see the deferred list above.
+3. **Per-calendar overrides live in the Notifications sub-page** (override list),
+   governing timed events only.
 
-### Later (round two)
+### Round two
 
-- Snooze + dismiss actions on the notification (snooze needs an
-  exact-alarm / WorkManager decision) — Tier 4 #13.
+- ~~Snooze + dismiss actions on the notification~~ *(shipped in release/v2.8.0,
+  Tier 4 #11)* — snooze re-fires a snooze-only exact alarm.
 
 ## Sharing & interop
 
@@ -438,8 +495,8 @@ it directly undermines the feature's premise, so it rides in here.
 ## Platform & launchers
 
 - ~~Home-screen widget~~ **shipped v2.5.0** — agenda + month widgets
-- ~~App shortcuts (launcher long-press → New event)~~ **shipped v2.5.0** —
-  optional quick-settings tile still open
+- ~~App shortcuts (launcher long-press → New event)~~ **shipped v2.5.0**
+- ~~"New event" Quick Settings tile~~ **shipped v2.8.0**
 
 ## Quality & reliability
 
@@ -455,9 +512,10 @@ it directly undermines the feature's premise, so it rides in here.
 Beyond classic calendar-client scope; discussed, deliberately not planned
 in detail yet:
 
-- **Contact address picker** for the location field via the system picker
-  (`ACTION_PICK` on postal addresses) — one-shot, needs no READ_CONTACTS,
-  fits the privacy story. Same mechanism later for picking emails.
+- ~~**Contact address picker** for the location field via the system picker
+  (`ACTION_PICK`)~~ **shipped v2.8.0** — one-shot, needs no READ_CONTACTS, fits
+  the privacy story. The same no-permission mechanism was then reused for the
+  attendee email picker (v2.8.0).
 - **OSM address autocomplete** in the location field (type "Brandenburger
   Tor" → tap suggestion → resolved address inserted). Backend would be
   Photon (Nominatim's public policy forbids autocomplete). **Requires the

CHANGELOG.md

@@ -5,6 +5,75 @@ 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).
 
+## [2.11.0] — 2026-06-27
+
+### Added
+- Start the week on any day. The **Week starts on** setting (Settings →
+  Appearance) now offers every weekday — not just Monday or Sunday — alongside
+  the automatic, locale-based default. Thanks to @zmaherdev for the suggestion
+  ([#3]).
+- Choose a 12- or 24-hour clock. A new **Time format** setting (Settings →
+  Appearance) lets you force a 12-hour (2:00 PM) or 24-hour (14:00) clock, or
+  follow the system setting automatically. It applies everywhere times appear —
+  the week and day timelines, agenda, event details, search and reminders — so
+  the format is now consistent across the whole app. Thanks to @zmaherdev for
+  the suggestion ([#6]).
+- Optional hour lines in the timeline. A new **Hour lines** switch (Settings →
+  Appearance) draws a faint separator at each hour in the week and day views,
+  making it easier to see when events start and end. Off by default. Thanks to
+  @zmaherdev for the suggestion ([#5]).
+- Limit how far ahead the agenda looks, and switch it on the fly. New **Agenda
+  range** and **Agenda widget range** settings (Settings → Appearance) let the
+  agenda screen and its home-screen widget each show just today, the rest of this
+  week, the rest of this month, a rolling 7 or 30 days, or a custom number of
+  days — "This week" follows your week-start. The agenda also gains a bar at the
+  top naming the exact dates in view, with a button to switch the range just for
+  the current session (it resets when you reopen the app); the bar can be turned
+  off. Thanks to @zmaherdev for the suggestion ([#4]).
+- Automatic backup of local calendars. A new **Automatic backup** option
+  (Settings → Calendars → Backup) periodically exports your local calendars to an
+  `.ics` file in a folder you choose, on an interval you set (from 30 minutes up).
+  Useful for file-based syncing such as Syncthing, or simply as a safety net — it
+  is a one-way export and never touches your synced accounts. Thanks to @shield
+  for the discussion that inspired it ([#7], [#8]).
+- Field icons in the event-form settings. Each optional-field toggle (Settings →
+  Event form) now shows the same icon the field uses in the new-event form, so
+  the list is easier to scan.
+- Help translate Calendula. A **Help translate** link at the top of **Settings →
+  App language** opens the project's Weblate, where you can add or improve a
+  language in your browser — no coding needed. Contributions in any language are
+  welcome.
+
+### Changed
+- Tidied **Settings → Appearance** into clearer groups (theme & colour, calendar,
+  agenda), and the agenda's empty state now reads "You're all caught up".
+- Reworked **Settings → Calendars**. Local and synced calendars are now grouped
+  into collapsible, source-branded cards — each account shows its app's icon —
+  with a per-account menu to enable or disable all of its calendars at once or
+  open the account in its source app.
+- Reorganised **Settings → Notifications**: reliable-delivery and snooze settings
+  moved up with the other global reminder options, and the per-calendar reminder
+  overrides now fold into a single expandable section.
+- Moved **Add Quick Settings tile** out of the event-form section to its own
+  top-level entry in Settings.
+
+## [2.10.0] — 2026-06-25
+
+### Added
+- Turn a calendar off across the whole app. Settings → Calendars now has a
+  switch on every calendar — both your own and synced ones. Switching one off
+  removes it everywhere: its events disappear from all views and search, and it
+  drops out of the drawer's hide/show filter, the event-form calendar picker and
+  the import target picker. Unlike hiding (the quick per-view checkbox in the
+  drawer), a disabled calendar leaves the app entirely until you turn it back on.
+  Nothing is deleted and no other app is affected — it's a Calendula-only view
+  choice — so you can re-enable it any time from the same screen, where disabled
+  calendars stay listed but dimmed.
+- An optional way to support development. Settings → About now has a "Support
+  development" button that opens Ko-fi in your browser. It's a plain donation
+  link with no perks attached, and it needs no new permissions — Calendula still
+  has no internet access of its own and just hands the link to your browser.
+
 ## [2.9.0] — 2026-06-25
 
 ### Added
@@ -610,3 +679,9 @@ automatically, with zero telemetry and no internet permission.
 
 [#1]: https://codeberg.org/jlmakiola/calendula/issues/1
 [#2]: https://codeberg.org/jlmakiola/calendula/issues/2
+[#3]: https://codeberg.org/jlmakiola/calendula/issues/3
+[#4]: https://codeberg.org/jlmakiola/calendula/issues/4
+[#5]: https://codeberg.org/jlmakiola/calendula/issues/5
+[#6]: https://codeberg.org/jlmakiola/calendula/issues/6
+[#7]: https://codeberg.org/jlmakiola/calendula/issues/7
+[#8]: https://codeberg.org/jlmakiola/calendula/issues/8

README.md

@@ -15,6 +15,12 @@ Reads, writes, and reminds — on top of the system calendar, with zero network
 <a href="LICENSE"><img src="https://img.shields.io/badge/License-MIT-green" alt="MIT License"></a>
 </p>
 
+<p>
+<a href="https://f-droid.org/packages/de.jeanlucmakiola.calendula/"><img src="https://fdroid.gitlab.io/artwork/badge/get-it-on.png" alt="Get it on F-Droid" height="56"></a>
+&nbsp;
+<a href="https://ko-fi.com/jeanlucmakiola"><img src="https://storage.ko-fi.com/cdn/brandasset/v2/support_me_on_kofi_badge_beige.png" alt="Support me on Ko-fi" height="56"></a>
+</p>
+
 <p>
 <img src="fastlane/metadata/android/en-US/images/phoneScreenshots/01-week.png" width="19%" alt="Week view">&nbsp;
 <img src="fastlane/metadata/android/en-US/images/phoneScreenshots/02-month.png" width="19%" alt="Month view">&nbsp;
@@ -62,19 +68,27 @@ database, no sync stack reinvented.
 
 - Real Material 3 Expressive throughout — dynamic color (Android 12+),
   expressive motion and shapes, light/dark theme
-- German and English UI, per-app language setting
+- German and English UI, per-app language setting — and [open to community
+  translations](#-translations)
 - **Zero telemetry, zero analytics, no internet permission** — your data
   never leaves the device
 
 ## 📦 Install
 
-Calendula ships through a self-hosted F-Droid repository; every version tag
-is built, signed, and published there automatically.
+### F-Droid (recommended)
 
-1. Install an F-Droid client ([F-Droid](https://f-droid.org), Droid-ify, Neo
-   Store, …).
-2. Add the repository — open this link on your phone, or paste it under
-   *Settings → Repositories → Add*:
+Calendula is on the **official [F-Droid](https://f-droid.org) repository** —
+just search for **Calendula** in any F-Droid client, or
+[install it from f-droid.org](https://f-droid.org/packages/de.jeanlucmakiola.calendula/).
+
+### Self-hosted repo (latest builds)
+
+New versions are built, signed, and published to a self-hosted repository the
+moment each tag lands — usually a few days ahead of the official repo, which
+rebuilds on F-Droid's own schedule. Add it for the freshest builds:
+
+1. In your F-Droid client, open *Settings → Repositories → Add* (or open the
+   link below on your phone):
 
    ```
    https://apps.dev.jeanlucmakiola.de/dev/fdroid/repo?fingerprint=C2C0640402BF458FC0ED957AF0B37AA4C14022E72F89CE90B5965B458CF73425
@@ -84,36 +98,27 @@ is built, signed, and published there automatically.
    fingerprint (SHA-256):
    `C2C0 6404 02BF 458F C0ED 957A F0B3 7AA4 C140 22E7 2F89 CE90 B596 5B45 8CF7 3425`</sub>
 
-3. Refresh, search for **Calendula**, install. Updates arrive like any
-   other F-Droid app.
+2. Refresh, search for **Calendula**, install.
 
-Alternatively, build from source — see below.
+Both channels share the same signing key, so you can switch between them
+without reinstalling. Or build from source — see below.
 
-## 🛠 Building
+## 📚 Documentation
 
-Requires Android SDK 36+ and JDK 17. The Gradle wrapper is checked in:
+- **[Building from source](docs/BUILDING.md)** — requirements and Gradle tasks
+- **[Architecture](docs/ARCHITECTURE.md)** — the layered design and key pipelines
+- **[Roadmap](.planning/ROADMAP.md)** — what's shipped and what's next
 
-```bash
-./gradlew assembleDebug   # debug APK
-./gradlew test            # JVM unit tests
-./gradlew lint            # Android lint
-```
+## 🌍 Translations
 
-If your default JDK is not 17, set `JAVA_HOME` explicitly.
+Calendula ships in German and English, and you're warmly invited to add your
+language. Translations are managed on a self-hosted **Weblate**:
 
-## 🏗 Architecture
+**→ [Help translate Calendula](https://weblate.dev.jeanlucmakiola.de/engage/calendula/)**
 
-Single-activity Compose app, layered `UI → Repository → DataSource →
-CalendarContract`, observer-driven refresh, JVM-first tests. The full tour —
-including the recurring-write and reminder pipelines — lives in
-[docs/ARCHITECTURE.md](docs/ARCHITECTURE.md).
-
-## 🗺 Roadmap
-
-Shipped: read (v1.0), write (v1.1–v2.0), reminder delivery (v1.4).
-Next up: power-user features — widget, search, tablet layouts. The living
-roadmap is in [.planning/ROADMAP.md](.planning/ROADMAP.md), the release
-history in [CHANGELOG.md](CHANGELOG.md).
+No coding needed — register on the Weblate server, pick (or request) a language,
+and translate the strings in your browser. You can also reach this link in the
+app from the top of **Settings → App language**.
 
 ## 📜 License
 

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 = 20900
-        versionName = "2.9.0"
+        versionCode = 21100
+        versionName = "2.11.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -152,6 +152,9 @@ dependencies {
 
     implementation(libs.androidx.datastore.preferences)
 
+    implementation(libs.androidx.work.runtime.ktx)
+    implementation(libs.androidx.documentfile)
+
     implementation(libs.androidx.glance.appwidget)
     implementation(libs.androidx.glance.material3)
 

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

@@ -1,8 +1,16 @@
 package de.jeanlucmakiola.calendula
 
 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.backup.BackupWorker
 import de.jeanlucmakiola.calendula.data.crash.CrashReporter
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
 
 /**
  * Application entry point. Registered as android:name=".CalendulaApp"
@@ -16,5 +24,24 @@ class CalendulaApp : Application() {
         // Install first thing so startup crashes are captured too (privacy-
         // respecting, on-device; the user submits the report by hand).
         CrashReporter.install(this)
+        reconcileAutoBackup()
+    }
+
+    /**
+     * Bring the scheduled auto-backup work back in line with the saved settings
+     * on every launch — re-arms it after a reinstall and, crucially, cancels any
+     * orphaned work once backup has been turned off.
+     */
+    private fun reconcileAutoBackup() {
+        val deps = EntryPointAccessors.fromApplication(this, BackupWorker.Deps::class.java)
+        CoroutineScope(SupervisorJob() + Dispatchers.Default).launch {
+            val prefs = deps.settingsPrefs()
+            BackupScheduler.apply(
+                context = this@CalendulaApp,
+                enabled = prefs.autoBackupEnabled.first(),
+                intervalMinutes = prefs.autoBackupIntervalMinutes.first(),
+                hasFolder = prefs.autoBackupFolderUri.first() != null,
+            )
+        }
     }
 }

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

@@ -9,10 +9,13 @@ import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.runtime.CompositionLocalProvider
 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.core.content.IntentCompat
 import androidx.core.net.toUri
 import androidx.hilt.navigation.compose.hiltViewModel
@@ -20,7 +23,10 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import dagger.hilt.android.AndroidEntryPoint
 import de.jeanlucmakiola.calendula.data.crash.CrashReporter
 import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
+import de.jeanlucmakiola.calendula.data.prefs.is24Hour
 import de.jeanlucmakiola.calendula.ui.RootScreen
+import de.jeanlucmakiola.calendula.ui.common.LocalShowHourLines
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.WidgetNavRequest
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.crash.CrashReportActivity
@@ -81,19 +87,31 @@ class MainActivity : AppCompatActivity() {
                 ThemeMode.LIGHT -> false
                 ThemeMode.DARK -> true
             }
+            // The app-wide clock convention: the time-format preference resolved
+            // against the device's 24-hour system setting, provided once here so
+            // every time label reads it via LocalUse24HourFormat.
+            val context = LocalContext.current
+            val use24Hour = remember(settings.timeFormat, context) {
+                settings.timeFormat.is24Hour(android.text.format.DateFormat.is24HourFormat(context))
+            }
             CalendulaTheme(
                 darkTheme = darkTheme,
                 dynamicColor = settings.dynamicColor,
             ) {
-                RootScreen(
-                    modifier = Modifier.fillMaxSize(),
-                    requestedDetailKey = requestedDetailKey,
-                    onDetailKeyConsumed = { requestedDetailKey = null },
-                    widgetNavRequest = requestedNav,
-                    onWidgetNavConsumed = { requestedNav = null },
-                    requestedImportUri = requestedImportUri,
-                    onImportConsumed = { requestedImportUri = null },
-                )
+                CompositionLocalProvider(
+                    LocalUse24HourFormat provides use24Hour,
+                    LocalShowHourLines provides settings.showHourLines,
+                ) {
+                    RootScreen(
+                        modifier = Modifier.fillMaxSize(),
+                        requestedDetailKey = requestedDetailKey,
+                        onDetailKeyConsumed = { requestedDetailKey = null },
+                        widgetNavRequest = requestedNav,
+                        onWidgetNavConsumed = { requestedNav = null },
+                        requestedImportUri = requestedImportUri,
+                        onImportConsumed = { requestedImportUri = null },
+                    )
+                }
                 pendingCrashReport?.let { report ->
                     CrashReportDialog(
                         report = report,

app/src/main/java/de/jeanlucmakiola/calendula/data/backup/AutoBackup.kt

@@ -0,0 +1,176 @@
+package de.jeanlucmakiola.calendula.data.backup
+
+import android.Manifest
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import android.util.Log
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationManagerCompat
+import androidx.core.content.ContextCompat
+import androidx.core.net.toUri
+import androidx.work.CoroutineWorker
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.ExistingWorkPolicy
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import androidx.work.WorkerParameters
+import dagger.hilt.EntryPoint
+import dagger.hilt.InstallIn
+import dagger.hilt.android.EntryPointAccessors
+import dagger.hilt.components.SingletonComponent
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
+import de.jeanlucmakiola.calendula.data.ics.IcsExporter
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
+import kotlinx.coroutines.flow.first
+import java.util.concurrent.TimeUnit
+import kotlin.time.Clock
+
+/**
+ * Schedules and runs the automatic periodic `.ics` backup of local calendars
+ * (issue #8). One-way export only — it mirrors the manual "Back up" into a
+ * user-chosen folder on an interval; it is not a sync. Stays INTERNET-free:
+ * everything is local provider reads + a local file write.
+ */
+object BackupScheduler {
+
+    private const val WORK_NAME = "auto-backup"
+    private const val WORK_NAME_NOW = "auto-backup-now"
+
+    /**
+     * Reconcile the scheduled work with the current settings: enqueue a unique
+     * periodic request when backup is on and a folder is set, otherwise cancel
+     * it. WorkManager persists the request across reboots on its own.
+     *
+     * The first run is delayed by one interval so it never overlaps an immediate
+     * [runNow] (two simultaneous writes would race and leave a "(1)" duplicate).
+     */
+    fun apply(context: Context, enabled: Boolean, intervalMinutes: Long, hasFolder: Boolean) {
+        val workManager = WorkManager.getInstance(context)
+        if (!enabled || !hasFolder) {
+            workManager.cancelUniqueWork(WORK_NAME)
+            // Also cancel any pending immediate run — otherwise a failing run-now
+            // keeps retrying after the user has turned backup off.
+            workManager.cancelUniqueWork(WORK_NAME_NOW)
+            return
+        }
+        // WorkManager's own floor is 15 min; the UI floors the user choice at 30.
+        val interval = intervalMinutes.coerceAtLeast(15L)
+        val request = PeriodicWorkRequestBuilder<BackupWorker>(interval, TimeUnit.MINUTES)
+            .setInitialDelay(interval, TimeUnit.MINUTES)
+            .build()
+        workManager.enqueueUniquePeriodicWork(
+            WORK_NAME,
+            ExistingPeriodicWorkPolicy.UPDATE,
+            request,
+        )
+    }
+
+    /**
+     * Run one export immediately (e.g. right after enabling or changing the
+     * folder) for instant feedback. Unique + REPLACE so rapid taps coalesce into
+     * a single run rather than racing each other.
+     */
+    fun runNow(context: Context) {
+        WorkManager.getInstance(context).enqueueUniqueWork(
+            WORK_NAME_NOW,
+            ExistingWorkPolicy.REPLACE,
+            OneTimeWorkRequestBuilder<BackupWorker>().build(),
+        )
+    }
+}
+
+/**
+ * Exports the local calendars to `calendula-backup.ics` in the configured folder,
+ * overwriting the previous file. Pulls its collaborators through a Hilt
+ * [EntryPoint] so it works under WorkManager's default (no-arg) worker factory —
+ * no custom factory / Application wiring needed. Records the outcome for the
+ * settings status line, and notifies after repeated failures.
+ */
+class BackupWorker(
+    appContext: Context,
+    params: WorkerParameters,
+) : CoroutineWorker(appContext, params) {
+
+    @EntryPoint
+    @InstallIn(SingletonComponent::class)
+    interface Deps {
+        fun settingsPrefs(): SettingsPrefs
+        fun repository(): CalendarRepository
+        fun exporter(): IcsExporter
+    }
+
+    override suspend fun doWork(): Result {
+        val deps = EntryPointAccessors.fromApplication(applicationContext, Deps::class.java)
+        val prefs = deps.settingsPrefs()
+        // Respect the toggle even for already-queued work: if backup was turned
+        // off, no-op (and don't retry) so a lingering run can't revive itself.
+        if (!prefs.autoBackupEnabled.first()) return Result.success()
+        val folder = prefs.autoBackupFolderUri.first()
+            ?: return Result.failure() // nothing to write to — leave scheduling to settings
+        val now = System.currentTimeMillis()
+        return try {
+            val events = deps.repository().exportEvents()
+            val content = IcsWriter().writeCalendar(events, Clock.System.now())
+            deps.exporter().writeToFolder(folder.toUri(), BACKUP_FILE_NAME, content)
+            prefs.recordAutoBackupRun(success = true, atMillis = now)
+            Result.success()
+        } catch (e: Exception) {
+            prefs.recordAutoBackupRun(success = false, atMillis = now)
+            if (prefs.autoBackupStatus.first().consecutiveFailures >= FAILURE_NOTIFY_THRESHOLD) {
+                notifyFailure(applicationContext)
+            }
+            Log.w(TAG, "Automatic backup failed", e)
+            Result.retry()
+        }
+    }
+
+    private fun notifyFailure(context: Context) {
+        val canPost = Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU ||
+            ContextCompat.checkSelfPermission(context, Manifest.permission.POST_NOTIFICATIONS) ==
+            PackageManager.PERMISSION_GRANTED
+        if (!canPost) return
+        val manager = NotificationManagerCompat.from(context)
+        manager.createNotificationChannel(
+            NotificationChannel(
+                CHANNEL_ID,
+                context.getString(R.string.backup_channel_name),
+                NotificationManager.IMPORTANCE_LOW,
+            ).apply { description = context.getString(R.string.backup_channel_description) },
+        )
+        val launch = context.packageManager.getLaunchIntentForPackage(context.packageName)
+        val tap = launch?.let {
+            PendingIntent.getActivity(
+                context, 0, it,
+                PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+            )
+        }
+        val notification = NotificationCompat.Builder(context, CHANNEL_ID)
+            .setSmallIcon(R.drawable.ic_notification)
+            .setContentTitle(context.getString(R.string.backup_failed_title))
+            .setContentText(context.getString(R.string.backup_failed_text))
+            .setCategory(NotificationCompat.CATEGORY_ERROR)
+            .setAutoCancel(true)
+            .apply { tap?.let(::setContentIntent) }
+            .build()
+        try {
+            manager.notify(NOTIFICATION_ID, notification)
+        } catch (e: SecurityException) {
+            Log.w(TAG, "Could not post backup-failure notification", e)
+        }
+    }
+
+    companion object {
+        const val BACKUP_FILE_NAME = "calendula-backup.ics"
+        private const val FAILURE_NOTIFY_THRESHOLD = 2
+        private const val CHANNEL_ID = "backup"
+        private const val NOTIFICATION_ID = 2
+        private const val TAG = "BackupWorker"
+    }
+}

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

@@ -14,6 +14,7 @@ import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOn
@@ -55,11 +56,12 @@ class CalendarRepositoryImpl @Inject constructor(
             .reQuery { dataSource.calendars() }
             .flowOn(io)
 
-    // Instances are filtered by the app-side hidden-calendar set (M3): an event
-    // is dropped whenever the user has hidden its calendar. Re-runs when the
-    // provider ticks *or* the hidden set changes — toggling a calendar in the
-    // filter sheet updates every view immediately. [calendars] stays unfiltered
-    // so the filter sheet can list and re-enable hidden calendars.
+    // Instances are filtered by the app-side hidden ∪ disabled calendar sets
+    // (M3): an event is dropped whenever the user has hidden *or* disabled its
+    // calendar. Re-runs when the provider ticks *or* either set changes —
+    // toggling a calendar in the filter sheet or the calendar manager updates
+    // every view immediately. [calendars] stays unfiltered so those screens can
+    // list and re-enable hidden/disabled calendars.
     override fun instances(range: ClosedRange<Instant>): Flow<List<EventInstance>> =
         combine(
             ticks
@@ -71,10 +73,17 @@ class CalendarRepositoryImpl @Inject constructor(
                     )
                 },
             prefs.hiddenCalendarIds,
-        ) { instances, hidden ->
-            if (hidden.isEmpty()) instances
-            else instances.filterNot { it.calendarId in hidden }
-        }.flowOn(io)
+            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
+            // either makes both re-emit and combine briefly surfaces the same
+            // list twice — collapse the duplicate so views don't re-render for it.
+            .distinctUntilChanged()
+            .flowOn(io)
 
     override suspend fun eventDetail(eventId: Long): EventDetail = withContext(io) {
         dataSource.eventDetail(eventId) ?: throw NoSuchEventException(eventId)
@@ -82,9 +91,9 @@ class CalendarRepositoryImpl @Inject constructor(
 
     override suspend fun searchEvents(query: String): List<EventInstance> = withContext(io) {
         if (query.isBlank()) return@withContext emptyList()
-        val hidden = prefs.hiddenCalendarIds.first()
+        val excluded = prefs.hiddenCalendarIds.first() + prefs.disabledCalendarIds.first()
         dataSource.searchEvents(query)
-            .let { if (hidden.isEmpty()) it else it.filterNot { e -> e.calendarId in hidden } }
+            .let { if (excluded.isEmpty()) it else it.filterNot { e -> e.calendarId in excluded } }
     }
 
     override suspend fun eventColorPalette(calendarId: Long): List<EventColorOption> =

app/src/main/java/de/jeanlucmakiola/calendula/data/ics/IcsExporter.kt

@@ -3,6 +3,7 @@ package de.jeanlucmakiola.calendula.data.ics
 import android.content.Context
 import android.net.Uri
 import androidx.core.content.FileProvider
+import androidx.documentfile.provider.DocumentFile
 import dagger.hilt.android.qualifiers.ApplicationContext
 import java.io.File
 import java.io.IOException
@@ -28,6 +29,36 @@ class IcsExporter @Inject constructor(
         } ?: throw IOException("Could not open output stream for export (scheme=${uri.scheme})")
     }
 
+    /**
+     * Write [content] to [fileName] inside the persisted SAF tree [folder],
+     * overwriting it if it already exists (the automatic-backup destination).
+     * Requires a persisted write grant on [folder]. Throws on failure.
+     */
+    fun writeToFolder(folder: Uri, fileName: String, content: String) {
+        val dir = DocumentFile.fromTreeUri(context, folder)
+            ?: throw IOException("Backup folder is not accessible")
+        if (!dir.exists() || !dir.canWrite()) {
+            throw IOException("Backup folder is missing or not writable")
+        }
+        // Reuse the canonical file if present and clean up any "name (1).ics"
+        // duplicates SAF may have created if two runs ever raced — so we always
+        // converge on a single overwritten file.
+        val base = fileName.substringBeforeLast('.')
+        val ext = fileName.substringAfterLast('.', "")
+        var target: DocumentFile? = null
+        for (child in dir.listFiles()) {
+            val name = child.name ?: continue
+            when {
+                name == fileName -> target = child
+                name.startsWith("$base (") && name.endsWith(".$ext") -> child.delete()
+            }
+        }
+        val file = target
+            ?: dir.createFile(MIME_CALENDAR, fileName)
+            ?: throw IOException("Could not create backup file in the chosen folder")
+        writeDocument(file.uri, content)
+    }
+
     /**
      * Stage [content] in a private cache file and return a shareable content
      * Uri for an `ACTION_SEND`. [fileName] is the suggested `.ics` name shown to
@@ -42,5 +73,6 @@ class IcsExporter @Inject constructor(
 
     private companion object {
         const val SHARE_DIR = "shared_ics"
+        const val MIME_CALENDAR = "text/calendar"
     }
 }

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

@@ -39,6 +39,31 @@ class CalendarPrefs @Inject constructor(
         }
     }
 
+    /**
+     * App-side preference for "calendars the user has disabled in this app" — a
+     * heavier level than [hiddenCalendarIds]. A disabled calendar is removed from
+     * every surface (drawer filter, event-form picker, import picker) and its
+     * events never appear; it stays listed only in Settings → Calendars so it can
+     * be re-enabled. Stored exactly like the hidden set; never touches the
+     * system's VISIBLE/SYNC_EVENTS flags, so other calendar apps are unaffected.
+     */
+    val disabledCalendarIds: Flow<Set<Long>> = store.data.map { prefs ->
+        prefs[DISABLED_IDS_KEY].orEmpty()
+            .split(',')
+            .mapNotNull { it.trim().toLongOrNull() }
+            .toSet()
+    }
+
+    suspend fun setDisabledCalendarIds(ids: Set<Long>) {
+        store.edit { prefs ->
+            if (ids.isEmpty()) {
+                prefs.remove(DISABLED_IDS_KEY)
+            } else {
+                prefs[DISABLED_IDS_KEY] = ids.sorted().joinToString(",")
+            }
+        }
+    }
+
     /**
      * The calendar the user last created an event in; preselected in the
      * event form. Null until the first event is created.
@@ -53,6 +78,7 @@ 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 LAST_USED_CALENDAR_KEY = longPreferencesKey("last_used_calendar_id")
     }
 }

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

@@ -5,8 +5,12 @@ import androidx.datastore.preferences.core.Preferences
 import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.intPreferencesKey
+import androidx.datastore.preferences.core.longPreferencesKey
 import androidx.datastore.preferences.core.stringPreferencesKey
 import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
+import de.jeanlucmakiola.calendula.ui.agenda.parseAgendaRange
+import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
@@ -19,18 +23,39 @@ import javax.inject.Singleton
 /** Light/dark override. SYSTEM follows the device setting. */
 enum class ThemeMode { SYSTEM, LIGHT, DARK }
 
-/** Week-start override. AUTO derives the first day from the active locale. */
-enum class WeekStartPref { AUTO, MONDAY, SUNDAY }
+/**
+ * Week-start override. [Auto] derives the first day from the active locale;
+ * [Day] pins a specific weekday (any of the seven).
+ */
+sealed interface WeekStartPref {
+    data object Auto : WeekStartPref
+    data class Day(val day: DayOfWeek) : WeekStartPref
+}
 
 /**
- * Resolve the preference to a concrete first-day-of-week. AUTO reads the
- * locale's convention (e.g. Monday in DE, Sunday in en-US).
+ * Clock convention for time-of-day labels. AUTO follows the device's 24-hour
+ * system setting; the others force a 12- or 24-hour clock app-wide.
+ */
+enum class TimeFormatPref { AUTO, TWELVE_HOUR, TWENTY_FOUR_HOUR }
+
+/**
+ * Resolve to a concrete 24-hour flag. AUTO defers to [systemIs24Hour] (the
+ * device's `DateFormat.is24HourFormat` value).
+ */
+fun TimeFormatPref.is24Hour(systemIs24Hour: Boolean): Boolean = when (this) {
+    TimeFormatPref.AUTO -> systemIs24Hour
+    TimeFormatPref.TWELVE_HOUR -> false
+    TimeFormatPref.TWENTY_FOUR_HOUR -> true
+}
+
+/**
+ * Resolve the preference to a concrete first-day-of-week. [WeekStartPref.Auto]
+ * reads the locale's convention (e.g. Monday in DE, Sunday in en-US).
  */
 fun WeekStartPref.resolveFirstDay(locale: Locale): DayOfWeek = when (this) {
-    WeekStartPref.MONDAY -> DayOfWeek.MONDAY
-    WeekStartPref.SUNDAY -> DayOfWeek.SUNDAY
+    is WeekStartPref.Day -> day
     // java.time.DayOfWeek.value is ISO 1..7 (Mon..Sun) — same numbering kotlinx uses.
-    WeekStartPref.AUTO -> DayOfWeek(WeekFields.of(locale).firstDayOfWeek.value)
+    WeekStartPref.Auto -> DayOfWeek(WeekFields.of(locale).firstDayOfWeek.value)
 }
 
 /**
@@ -55,7 +80,7 @@ class SettingsPrefs @Inject constructor(
     }
 
     val weekStart: Flow<WeekStartPref> = store.data.map { prefs ->
-        prefs[WEEK_START_KEY].toEnum(WeekStartPref.AUTO)
+        parseWeekStart(prefs[WEEK_START_KEY])
     }
 
     suspend fun setThemeMode(mode: ThemeMode) {
@@ -67,7 +92,62 @@ class SettingsPrefs @Inject constructor(
     }
 
     suspend fun setWeekStart(pref: WeekStartPref) {
-        store.edit { it[WEEK_START_KEY] = pref.name }
+        store.edit { it[WEEK_START_KEY] = pref.storageValue() }
+    }
+
+    /** Clock convention for time-of-day labels (v2.11). Defaults to AUTO (system). */
+    val timeFormat: Flow<TimeFormatPref> = store.data.map { prefs ->
+        prefs[TIME_FORMAT_KEY].toEnum(TimeFormatPref.AUTO)
+    }
+
+    suspend fun setTimeFormat(pref: TimeFormatPref) {
+        store.edit { it[TIME_FORMAT_KEY] = pref.name }
+    }
+
+    /**
+     * Whether the week/day timeline draws a faint separator line at each hour
+     * (v2.11). Defaults to OFF — the historical clean look; users opt in.
+     */
+    val showHourLines: Flow<Boolean> = store.data.map { prefs ->
+        prefs[SHOW_HOUR_LINES_KEY] ?: false
+    }
+
+    suspend fun setShowHourLines(enabled: Boolean) {
+        store.edit { it[SHOW_HOUR_LINES_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
+     * widget's [agendaWidgetRange].
+     */
+    val agendaScreenRange: Flow<AgendaRange> = store.data.map { prefs ->
+        parseAgendaRange(prefs[AGENDA_SCREEN_RANGE_KEY], AgendaRange.Month)
+    }
+
+    suspend fun setAgendaScreenRange(range: AgendaRange) {
+        store.edit { it[AGENDA_SCREEN_RANGE_KEY] = range.storageValue() }
+    }
+
+    /** How far ahead the agenda **widget** shows events (v2.11). Defaults to Month. */
+    val agendaWidgetRange: Flow<AgendaRange> = store.data.map { prefs ->
+        parseAgendaRange(prefs[AGENDA_WIDGET_RANGE_KEY], AgendaRange.Month)
+    }
+
+    suspend fun setAgendaWidgetRange(range: AgendaRange) {
+        store.edit { it[AGENDA_WIDGET_RANGE_KEY] = range.storageValue() }
+    }
+
+    /**
+     * Whether the agenda shows its top range bar — the "showing …" header and
+     * the session range switcher (v2.11). Default ON.
+     */
+    val agendaShowRangeBar: Flow<Boolean> = store.data.map { prefs ->
+        prefs[AGENDA_SHOW_RANGE_BAR_KEY] ?: true
+    }
+
+    suspend fun setAgendaShowRangeBar(enabled: Boolean) {
+        store.edit { it[AGENDA_SHOW_RANGE_BAR_KEY] = enabled }
     }
 
     /**
@@ -248,6 +328,52 @@ class SettingsPrefs @Inject constructor(
         }
     }
 
+    // --- Automatic backup (issue #8) ------------------------------------
+
+    /** Whether periodic automatic `.ics` export of local calendars is on. Default OFF. */
+    val autoBackupEnabled: Flow<Boolean> = store.data.map { it[AUTO_BACKUP_ENABLED_KEY] ?: false }
+
+    suspend fun setAutoBackupEnabled(enabled: Boolean) {
+        store.edit { it[AUTO_BACKUP_ENABLED_KEY] = enabled }
+    }
+
+    /** Export interval in minutes. Default daily; floored at [MIN_BACKUP_INTERVAL]. */
+    val autoBackupIntervalMinutes: Flow<Long> = store.data.map { prefs ->
+        (prefs[AUTO_BACKUP_INTERVAL_KEY] ?: DEFAULT_BACKUP_INTERVAL).coerceAtLeast(MIN_BACKUP_INTERVAL)
+    }
+
+    suspend fun setAutoBackupIntervalMinutes(minutes: Long) {
+        store.edit { it[AUTO_BACKUP_INTERVAL_KEY] = minutes.coerceAtLeast(MIN_BACKUP_INTERVAL) }
+    }
+
+    /** Persisted SAF tree Uri of the destination folder, or null if unset. */
+    val autoBackupFolderUri: Flow<String?> = store.data.map { it[AUTO_BACKUP_FOLDER_KEY] }
+
+    suspend fun setAutoBackupFolderUri(uri: String?) {
+        store.edit { prefs ->
+            if (uri == null) prefs.remove(AUTO_BACKUP_FOLDER_KEY) else prefs[AUTO_BACKUP_FOLDER_KEY] = uri
+        }
+    }
+
+    /** Outcome of the last automatic run, for the settings status line. */
+    val autoBackupStatus: Flow<BackupStatus> = store.data.map { prefs ->
+        BackupStatus(
+            lastRun = prefs[AUTO_BACKUP_LAST_RUN_KEY] ?: 0L,
+            lastSuccess = prefs[AUTO_BACKUP_LAST_SUCCESS_KEY] ?: true,
+            consecutiveFailures = prefs[AUTO_BACKUP_FAILURES_KEY] ?: 0,
+        )
+    }
+
+    /** Record an automatic run's outcome; resets the failure streak on success. */
+    suspend fun recordAutoBackupRun(success: Boolean, atMillis: Long) {
+        store.edit { prefs ->
+            prefs[AUTO_BACKUP_LAST_RUN_KEY] = atMillis
+            prefs[AUTO_BACKUP_LAST_SUCCESS_KEY] = success
+            val failures = prefs[AUTO_BACKUP_FAILURES_KEY] ?: 0
+            prefs[AUTO_BACKUP_FAILURES_KEY] = if (success) 0 else failures + 1
+        }
+    }
+
     private fun parseFormFields(stored: String?): Set<EventFormField> = when (stored) {
         null -> DEFAULT_FORM_FIELDS
         else -> stored.split(',')
@@ -259,6 +385,11 @@ class SettingsPrefs @Inject constructor(
         internal val THEME_MODE_KEY = stringPreferencesKey("theme_mode")
         internal val DYNAMIC_COLOR_KEY = booleanPreferencesKey("dynamic_color")
         internal val WEEK_START_KEY = stringPreferencesKey("week_start")
+        internal val AGENDA_SCREEN_RANGE_KEY = stringPreferencesKey("agenda_screen_range")
+        internal val AGENDA_WIDGET_RANGE_KEY = stringPreferencesKey("agenda_widget_range")
+        internal val AGENDA_SHOW_RANGE_BAR_KEY = booleanPreferencesKey("agenda_show_range_bar")
+        internal val TIME_FORMAT_KEY = stringPreferencesKey("time_format")
+        internal val SHOW_HOUR_LINES_KEY = booleanPreferencesKey("show_hour_lines")
         internal val DEFAULT_VIEW_KEY = stringPreferencesKey("default_view")
         internal val FORM_FIELDS_KEY = stringPreferencesKey("event_form_default_fields")
         internal val REMINDERS_ENABLED_KEY = booleanPreferencesKey("reminders_enabled")
@@ -282,9 +413,27 @@ class SettingsPrefs @Inject constructor(
             stringPreferencesKey("per_calendar_allday_reminder_override")
         internal val DEFAULT_FORM_FIELDS =
             setOf(EventFormField.Location, EventFormField.Description)
+        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")
+        internal val AUTO_BACKUP_LAST_RUN_KEY = longPreferencesKey("auto_backup_last_run")
+        internal val AUTO_BACKUP_LAST_SUCCESS_KEY = booleanPreferencesKey("auto_backup_last_success")
+        internal val AUTO_BACKUP_FAILURES_KEY = intPreferencesKey("auto_backup_failures")
+        /** Default automatic-backup interval: daily. */
+        const val DEFAULT_BACKUP_INTERVAL = 1_440L
+        /** Floor for the automatic-backup interval (also above WorkManager's 15-min limit). */
+        const val MIN_BACKUP_INTERVAL = 30L
     }
 }
 
+/** Snapshot of the automatic backup's last outcome (see [SettingsPrefs.autoBackupStatus]). */
+data class BackupStatus(
+    /** Epoch millis of the last run, or 0 if it has never run. */
+    val lastRun: Long,
+    val lastSuccess: Boolean,
+    val consecutiveFailures: Int,
+)
+
 /** A calendar's reminder-default override (see [SettingsPrefs.perCalendarReminderOverride]). */
 sealed interface CalendarReminderOverride {
     /** No override — the calendar uses the global default. */
@@ -331,6 +480,25 @@ private fun MutableMap<Long, Int?>.applyOverride(
     }
 }
 
+/** Sentinel stored for [WeekStartPref.Auto]; days store their [DayOfWeek.name]. */
+private const val WEEK_START_AUTO = "AUTO"
+
+private fun WeekStartPref.storageValue(): String = when (this) {
+    WeekStartPref.Auto -> WEEK_START_AUTO
+    is WeekStartPref.Day -> day.name
+}
+
+/**
+ * Parse the stored week-start value. "AUTO"/null/garbage → [WeekStartPref.Auto];
+ * a [DayOfWeek] name → [WeekStartPref.Day]. The legacy "MONDAY"/"SUNDAY" enum
+ * values migrate transparently, since both are valid day names.
+ */
+private fun parseWeekStart(stored: String?): WeekStartPref = when (stored) {
+    null, WEEK_START_AUTO -> WeekStartPref.Auto
+    else -> DayOfWeek.entries.firstOrNull { it.name == stored }
+        ?.let { WeekStartPref.Day(it) } ?: WeekStartPref.Auto
+}
+
 private const val NONE = "none"
 private const val ENTRY_SEP = ";"
 private const val KEY_VALUE_SEP = "="

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

@@ -46,7 +46,7 @@ class EventReminderReceiver : BroadcastReceiver() {
                 if (settingsPrefs.remindersEnabled.first()) {
                     val now = System.currentTimeMillis()
                     val due = alertStore.dueAlerts(now)
-                    due.forEach(notifier::post)
+                    due.forEach { notifier.post(it) }
                     alertStore.markFired(due.map { it.alertId }, now)
                 }
             } finally {

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

@@ -14,6 +14,9 @@ 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.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.data.prefs.is24Hour
+import kotlinx.coroutines.flow.first
 import java.time.ZoneId
 import java.util.Locale
 import javax.inject.Inject
@@ -29,6 +32,7 @@ import javax.inject.Singleton
 @Singleton
 class ReminderNotifier @Inject constructor(
     @ApplicationContext private val context: Context,
+    private val settingsPrefs: SettingsPrefs,
 ) {
 
     /** False when the user declined `POST_NOTIFICATIONS` or muted the app. */
@@ -39,15 +43,18 @@ class ReminderNotifier @Inject constructor(
         return granted && NotificationManagerCompat.from(context).areNotificationsEnabled()
     }
 
-    fun post(alert: ReminderAlert) {
+    suspend fun post(alert: ReminderAlert) {
         ensureChannel()
         val title = alert.title.ifBlank { context.getString(R.string.event_untitled) }
+        val is24Hour = settingsPrefs.timeFormat.first()
+            .is24Hour(android.text.format.DateFormat.is24HourFormat(context))
         val time = reminderTimeText(
             beginMillis = alert.beginMillis,
             endMillis = alert.endMillis,
             isAllDay = alert.isAllDay,
             zone = ZoneId.systemDefault(),
             locale = Locale.getDefault(),
+            is24Hour = is24Hour,
         )
         val text = listOfNotNull(time, alert.location).joinToString(" · ")
         val notification = NotificationCompat.Builder(context, CHANNEL_ID)

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.reminders
 
+import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
 import java.time.Instant
 import java.time.ZoneId
 import java.time.ZoneOffset
@@ -25,6 +26,7 @@ fun reminderTimeText(
     isAllDay: Boolean,
     zone: ZoneId,
     locale: Locale,
+    is24Hour: Boolean,
 ): String {
     if (isAllDay) {
         val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
@@ -40,16 +42,18 @@ fun reminderTimeText(
         }
     }
 
-    val timeFormat = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT).withLocale(locale)
+    val timeFormat = timeOfDayFormatter(is24Hour, locale)
     val begin = Instant.ofEpochMilli(beginMillis).atZone(zone)
     val end = Instant.ofEpochMilli(endMillis).atZone(zone)
     return if (begin.toLocalDate() == end.toLocalDate()) {
         timeFormat.format(begin) + RANGE + timeFormat.format(end)
     } else {
-        val dateTimeFormat = DateTimeFormatter
-            .ofLocalizedDateTime(FormatStyle.MEDIUM, FormatStyle.SHORT)
-            .withLocale(locale)
-        dateTimeFormat.format(begin) + RANGE + dateTimeFormat.format(end)
+        // Cross-day: medium date + the chosen short time, joined per side. Built
+        // from the two formatters (not ofLocalizedDateTime) so the 12/24h choice
+        // applies to the time portion too.
+        val dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
+        val dateTime = { z: java.time.ZonedDateTime -> "${dateFormat.format(z)}, ${timeFormat.format(z)}" }
+        dateTime(begin) + RANGE + dateTime(end)
     }
 }
 

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

@@ -0,0 +1,111 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
+import java.time.format.FormatStyle
+import java.util.Locale
+
+/**
+ * How far ahead the agenda (screen or widget) shows events, starting at today.
+ *
+ * Two flavours:
+ * - **Rolling** windows of a fixed length: [Day] (today), [Week] (7 days),
+ *   [Month] (30 days), [Custom] (1–365 days). These never degenerate.
+ * - **Calendar-aligned** windows that end at a period boundary: [ThisWeek] runs
+ *   through the end of the current week (respecting the week-start preference —
+ *   a Monday start means "everything before next Monday"); [ThisMonth] runs
+ *   through the last day of the current month. These shrink as the period ends.
+ */
+sealed interface AgendaRange {
+    data object Day : AgendaRange
+    data object Week : AgendaRange
+    data object Month : AgendaRange
+    data object ThisWeek : AgendaRange
+    data object ThisMonth : AgendaRange
+    data class Custom(val days: Int) : AgendaRange
+
+    companion object {
+        /** Allowed bounds for a [Custom] day count. */
+        const val MIN_CUSTOM_DAYS = 1
+        const val MAX_CUSTOM_DAYS = 365
+    }
+}
+
+private const val DAYS_PER_WEEK = 7
+
+/**
+ * Inclusive number of days the window spans, starting at (and including)
+ * [anchor]. The calendar-aligned ranges depend on the anchor day and, for
+ * [AgendaRange.ThisWeek], the [weekStart] preference.
+ */
+fun AgendaRange.dayCount(anchor: LocalDate, weekStart: DayOfWeek): Int = when (this) {
+    AgendaRange.Day -> 1
+    AgendaRange.Week -> DAYS_PER_WEEK
+    AgendaRange.Month -> 30
+    AgendaRange.ThisWeek -> {
+        // Days elapsed since the week's first day (0 when today *is* the start),
+        // so the window is the rest of the week through the day before it repeats.
+        val sinceWeekStart = ((anchor.dayOfWeek.ordinal - weekStart.ordinal) + DAYS_PER_WEEK) % DAYS_PER_WEEK
+        DAYS_PER_WEEK - sinceWeekStart
+    }
+    AgendaRange.ThisMonth -> {
+        val daysInMonth = YearMonth.of(anchor.year, anchor.month.ordinal + 1).lengthOfMonth()
+        daysInMonth - anchor.day + 1
+    }
+    is AgendaRange.Custom -> days.coerceIn(AgendaRange.MIN_CUSTOM_DAYS, AgendaRange.MAX_CUSTOM_DAYS)
+}
+
+/** Stored representation: a fixed token, or `CUSTOM:<days>`. */
+fun AgendaRange.storageValue(): String = when (this) {
+    AgendaRange.Day -> "DAY"
+    AgendaRange.Week -> "WEEK"
+    AgendaRange.Month -> "MONTH"
+    AgendaRange.ThisWeek -> "THIS_WEEK"
+    AgendaRange.ThisMonth -> "THIS_MONTH"
+    is AgendaRange.Custom -> "$CUSTOM_PREFIX$days"
+}
+
+/** Parse a stored value; unknown/garbage falls back to [default]. */
+fun parseAgendaRange(stored: String?, default: AgendaRange): AgendaRange = when {
+    stored == "DAY" -> AgendaRange.Day
+    stored == "WEEK" -> AgendaRange.Week
+    stored == "MONTH" -> AgendaRange.Month
+    stored == "THIS_WEEK" -> AgendaRange.ThisWeek
+    stored == "THIS_MONTH" -> AgendaRange.ThisMonth
+    stored != null && stored.startsWith(CUSTOM_PREFIX) -> {
+        val days = stored.removePrefix(CUSTOM_PREFIX).toIntOrNull()
+        if (days != null) {
+            AgendaRange.Custom(days.coerceIn(AgendaRange.MIN_CUSTOM_DAYS, AgendaRange.MAX_CUSTOM_DAYS))
+        } else {
+            default
+        }
+    }
+    else -> default
+}
+
+/**
+ * The concrete span the range covers, starting at [start] through [end]
+ * (inclusive), for a human-readable header:
+ * - [AgendaRange.Day] → a single medium date ("27 Jun 2026")
+ * - [AgendaRange.ThisMonth] → month and year ("June 2026")
+ * - everything else → "start – end" ("27 Jun – 3 Jul 2026")
+ */
+fun agendaRangeWindowSummary(
+    range: AgendaRange,
+    start: LocalDate,
+    end: LocalDate,
+    locale: Locale,
+): String {
+    val javaStart = java.time.LocalDate.of(start.year, start.month.ordinal + 1, start.day)
+    val javaEnd = java.time.LocalDate.of(end.year, end.month.ordinal + 1, end.day)
+    val medium = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
+    return when (range) {
+        AgendaRange.Day -> medium.format(javaStart)
+        AgendaRange.ThisMonth -> DateTimeFormatter.ofPattern("LLLL yyyy", locale).format(javaStart)
+        else -> "${DateTimeFormatter.ofPattern("d MMM", locale).format(javaStart)} – ${medium.format(javaEnd)}"
+    }
+}
+
+private const val CUSTOM_PREFIX = "CUSTOM:"

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

@@ -2,22 +2,26 @@ 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
 import androidx.compose.foundation.layout.PaddingValues
+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.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.EventAvailable
+import androidx.compose.material.icons.filled.Coffee
+import androidx.compose.material.icons.filled.DateRange
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
 import androidx.compose.material3.DrawerValue
@@ -35,7 +39,10 @@ import androidx.compose.material3.TopAppBarScrollBehavior
 import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 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.clip
@@ -47,6 +54,8 @@ 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.AgendaRangePicker
+import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.calendula.ui.common.calendarAnimateItem
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
@@ -58,6 +67,9 @@ import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.ui.common.positionOf
+import de.jeanlucmakiola.calendula.ui.common.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
@@ -88,11 +100,13 @@ fun AgendaScreen(
     val scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior()
     val drawerState = rememberDrawerState(DrawerValue.Closed)
     val scope = rememberCoroutineScope()
+    var showRangePicker by remember { mutableStateOf(false) }
 
     val isOnToday = when (val s = state) {
         is AgendaUiState.Success -> s.anchor == s.today
         else -> true
     }
+    val successState = state as? AgendaUiState.Success
 
     ModalNavigationDrawer(
         drawerState = drawerState,
@@ -135,18 +149,129 @@ fun AgendaScreen(
                 )
             },
         ) { innerPadding ->
-            AgendaContent(
-                state = state,
-                onRetry = viewModel::goToToday,
-                onEventClick = onEventClick,
+            Column(
                 modifier = Modifier
-                    .padding(innerPadding)
-                    .fillMaxSize(),
+                    .fillMaxSize()
+                    .padding(innerPadding),
+            ) {
+                // One bar at the top: the "showing …" header on the left and the
+                // session range switcher on the right (one settings toggle).
+                successState?.takeIf { it.showRangeBar }?.let { s ->
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(start = 28.dp, end = 16.dp, top = 8.dp, bottom = 8.dp),
+                    ) {
+                        AgendaRangeBanner(
+                            range = s.range,
+                            start = s.anchor,
+                            end = s.rangeEnd,
+                            modifier = Modifier.weight(1f),
+                        )
+                        AgendaRangePill(
+                            range = s.range,
+                            isOverride = s.rangeIsOverride,
+                            onClick = { showRangePicker = true },
+                        )
+                    }
+                }
+                AgendaContent(
+                    state = state,
+                    onRetry = viewModel::goToToday,
+                    onEventClick = onEventClick,
+                    modifier = Modifier
+                        .weight(1f)
+                        .fillMaxWidth(),
+                )
+            }
+        }
+    }
+
+    if (showRangePicker) {
+        AgendaRangePicker(
+            title = stringResource(R.string.settings_agenda_range),
+            description = stringResource(R.string.agenda_range_override_hint),
+            selected = successState?.range ?: AgendaRange.Month,
+            onSelect = viewModel::setRangeOverride,
+            onDismiss = { showRangePicker = false },
+        )
+    }
+}
+
+/**
+ * A compact tonal pill showing the agenda's current range. Tapping it opens the
+ * range picker as a session-only override. Filled with the primary container
+ * while an override is active, so the temporary state is obvious.
+ */
+@Composable
+private fun AgendaRangePill(
+    range: AgendaRange,
+    isOverride: Boolean,
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val container = if (isOverride) {
+        MaterialTheme.colorScheme.primaryContainer
+    } else {
+        MaterialTheme.colorScheme.surfaceContainerHigh
+    }
+    val content = if (isOverride) {
+        MaterialTheme.colorScheme.onPrimaryContainer
+    } else {
+        MaterialTheme.colorScheme.onSurfaceVariant
+    }
+    Surface(
+        color = container,
+        contentColor = content,
+        shape = RoundedCornerShape(50),
+        modifier = modifier.clickable(onClick = onClick),
+    ) {
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 10.dp),
+        ) {
+            Icon(
+                imageVector = Icons.Filled.DateRange,
+                contentDescription = null,
+                modifier = Modifier.size(18.dp),
+            )
+            Spacer(Modifier.width(8.dp))
+            Text(
+                text = agendaRangeLabel(range),
+                style = MaterialTheme.typography.labelLarge,
             )
         }
     }
 }
 
+/**
+ * A header naming the concrete window currently shown, e.g. "Showing all events
+ * for · Today, 27 Jun 2026" / "This week, 27 Jun – 3 Jul" / "This month, June 2026".
+ */
+@Composable
+private fun AgendaRangeBanner(
+    range: AgendaRange,
+    start: LocalDate,
+    end: LocalDate,
+    modifier: Modifier = Modifier,
+) {
+    val locale = currentLocale()
+    val window = agendaRangeWindowSummary(range, start, end, locale)
+    Column(modifier = modifier) {
+        Text(
+            text = stringResource(R.string.agenda_range_showing_label),
+            style = MaterialTheme.typography.labelMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        Text(
+            text = "${agendaRangeLabel(range)}, $window",
+            style = MaterialTheme.typography.titleMedium,
+            color = MaterialTheme.colorScheme.onSurface,
+        )
+    }
+}
+
 @Composable
 private fun AgendaContent(
     state: AgendaUiState,
@@ -254,7 +379,7 @@ private fun AgendaEmpty(modifier: Modifier = Modifier) {
         horizontalAlignment = Alignment.CenterHorizontally,
     ) {
         Icon(
-            imageVector = Icons.Filled.EventAvailable,
+            imageVector = Icons.Filled.Coffee,
             contentDescription = null,
             tint = MaterialTheme.colorScheme.onSurfaceVariant,
             modifier = Modifier.size(48.dp),
@@ -265,13 +390,6 @@ private fun AgendaEmpty(modifier: Modifier = Modifier) {
             style = MaterialTheme.typography.titleMedium,
             textAlign = TextAlign.Center,
         )
-        Spacer(Modifier.height(4.dp))
-        Text(
-            text = stringResource(R.string.agenda_empty_subtitle),
-            style = MaterialTheme.typography.bodyMedium,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
     }
 }
 
@@ -338,15 +456,17 @@ private fun agendaTimeSummary(event: EventInstance): String {
     val time = if (event.isAllDay) {
         stringResource(R.string.event_detail_all_day)
     } else {
-        "${formatTime(event.start)} – ${formatTime(event.end)}"
+        val is24Hour = LocalUse24HourFormat.current
+        val locale = currentLocale()
+        "${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): String {
+private fun formatTime(instant: Instant, is24Hour: Boolean, locale: Locale): String {
     val t = instant.toLocalDateTime(zone).time
-    return "%02d:%02d".format(t.hour, t.minute)
+    return formatTimeOfDay(t.hour, t.minute, is24Hour, locale)
 }
 
 private fun formatAgendaDate(date: LocalDate): String {

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

@@ -53,5 +53,13 @@ sealed interface AgendaUiState {
         val anchor: LocalDate,
         val today: LocalDate,
         val days: List<AgendaDay>,
+        /** The range currently in effect — the saved default or a session override. */
+        val range: AgendaRange,
+        /** True when [range] is a temporary in-view override of the saved default. */
+        val rangeIsOverride: Boolean,
+        /** Last day the current [range] covers (inclusive), for the range header. */
+        val rangeEnd: LocalDate,
+        /** Whether to show the top range bar — header + switcher (toggle, on by default). */
+        val showRangeBar: Boolean,
     ) : AgendaUiState
 }

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

@@ -5,6 +5,8 @@ import androidx.lifecycle.viewModelScope
 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.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
@@ -17,10 +19,13 @@ 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
@@ -30,16 +35,24 @@ import kotlin.time.Clock
 import kotlin.time.Instant
 import javax.inject.Inject
 
-/** How far ahead the agenda loads events from its anchor day. */
-internal const val AGENDA_WINDOW_DAYS = 60
-
 @OptIn(ExperimentalCoroutinesApi::class)
 @HiltViewModel
 class AgendaViewModel @Inject constructor(
     private val repository: CalendarRepository,
+    settingsPrefs: SettingsPrefs,
     @IoDispatcher private val io: CoroutineDispatcher,
 ) : ViewModel() {
 
+    // The saved agenda range plus the range-bar visibility toggle.
+    private val agendaSettings = combine(
+        settingsPrefs.agendaScreenRange,
+        settingsPrefs.agendaShowRangeBar,
+    ) { range, showBar -> AgendaSettings(range, showBar) }
+
+    // First day of the week, for the calendar-aligned "this week" range.
+    private val weekStartDay = settingsPrefs.weekStart
+        .map { it.resolveFirstDay(Locale.getDefault()) }
+
     private val zone = TimeZone.currentSystemDefault()
 
     private val todayDate: LocalDate
@@ -48,14 +61,32 @@ class AgendaViewModel @Inject constructor(
     private val _anchor = MutableStateFlow(todayDate)
     val anchor: StateFlow<LocalDate> = _anchor
 
-    val state: StateFlow<AgendaUiState> = _anchor
-        .flatMapLatest { anchor ->
-            val range = agendaRange(anchor, AGENDA_WINDOW_DAYS, zone)
+    // A transient, in-view override of the saved agenda range. Held in memory
+    // (not persisted), so it survives view switches and rotation within the
+    // session but resets to the saved default when the app is relaunched.
+    private val _rangeOverride = MutableStateFlow<AgendaRange?>(null)
+
+    val state: StateFlow<AgendaUiState> =
+        combine(_anchor, agendaSettings, _rangeOverride, weekStartDay) { anchor, settings, override, weekStart ->
+            AgendaParams(
+                anchor = anchor,
+                range = override ?: settings.range,
+                rangeIsOverride = override != null && override != settings.range,
+                weekStart = weekStart,
+                showRangeBar = settings.showBar,
+            )
+        }
+        .flatMapLatest { params ->
+            val window = agendaRange(
+                params.anchor,
+                params.range.dayCount(params.anchor, params.weekStart) - 1,
+                zone,
+            )
             combine(
                 repository.calendars(),
-                repository.instances(range),
+                repository.instances(window),
             ) { calendars, instances ->
-                buildState(anchor, calendars, instances)
+                buildState(params, calendars, instances)
             }
         }
         .catch { emit(AgendaUiState.Failure(FailureReason.ProviderUnavailable)) }
@@ -75,16 +106,47 @@ class AgendaViewModel @Inject constructor(
         _anchor.value = date
     }
 
+    /** Temporarily override the agenda range for this session (the bottom-left pill). */
+    fun setRangeOverride(range: AgendaRange) {
+        _rangeOverride.value = range
+    }
+
+    private data class AgendaSettings(
+        val range: AgendaRange,
+        val showBar: Boolean,
+    )
+
+    private data class AgendaParams(
+        val anchor: LocalDate,
+        val range: AgendaRange,
+        val rangeIsOverride: Boolean,
+        val weekStart: DayOfWeek,
+        val showRangeBar: Boolean,
+    )
+
     private fun buildState(
-        anchor: LocalDate,
+        params: AgendaParams,
         calendars: List<CalendarSource>,
         instances: List<EventInstance>,
     ): AgendaUiState {
         if (calendars.isEmpty()) {
             return AgendaUiState.Failure(FailureReason.NoCalendarsConfigured)
         }
+        val anchor = params.anchor
         val days = groupAgendaDays(anchor, instances, zone)
-        return AgendaUiState.Success(anchor = anchor, today = todayDate, days = days)
+        val rangeEnd = anchor.plus(
+            params.range.dayCount(anchor, params.weekStart) - 1,
+            DateTimeUnit.DAY,
+        )
+        return AgendaUiState.Success(
+            anchor = anchor,
+            today = todayDate,
+            days = days,
+            range = params.range,
+            rangeIsOverride = params.rangeIsOverride,
+            rangeEnd = rangeEnd,
+            showRangeBar = params.showRangeBar,
+        )
     }
 }
 

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

@@ -4,13 +4,17 @@ import android.accounts.AccountManager
 import android.content.Context
 import android.content.Intent
 import android.provider.Settings
+import android.text.format.DateUtils
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
@@ -26,25 +30,33 @@ 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.Notes
+import androidx.compose.material.icons.automirrored.filled.OpenInNew
 import androidx.compose.material.icons.filled.Add
 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.Edit
 import androidx.compose.material.icons.filled.FileDownload
-import androidx.compose.material.icons.filled.OpenInNew
+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.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
@@ -58,20 +70,36 @@ 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.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringArrayResource
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.input.KeyboardCapitalization
 import androidx.compose.ui.unit.dp
+import androidx.core.graphics.drawable.toBitmap
+import androidx.core.net.toUri
+import androidx.documentfile.provider.DocumentFile
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.ui.common.CALENDAR_COLOR_PALETTE
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.DialogAmountField
+import de.jeanlucmakiola.calendula.ui.common.DialogUnitDropdown
+import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
+import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
 import de.jeanlucmakiola.calendula.ui.common.predictiveBack
 import de.jeanlucmakiola.calendula.ui.common.CollapsingScaffold
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
@@ -79,7 +107,6 @@ import de.jeanlucmakiola.calendula.ui.common.GroupedRow
 import de.jeanlucmakiola.calendula.ui.common.InlineTextField
 import de.jeanlucmakiola.calendula.ui.common.Position
 import de.jeanlucmakiola.calendula.ui.common.pastelize
-import de.jeanlucmakiola.calendula.ui.common.positionOf
 import java.time.LocalDate
 
 /** Sentinel [editorId] meaning "the editor is composing a new calendar". */
@@ -98,8 +125,10 @@ fun CalendarsScreen(
     viewModel: CalendarsViewModel = hiltViewModel(),
 ) {
     val calendars by viewModel.calendars.collectAsStateWithLifecycle()
+    val disabledIds by viewModel.disabledCalendarIds.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
@@ -134,14 +163,21 @@ fun CalendarsScreen(
         CalendarsList(
             local = calendars.filter { it.isLocal },
             synced = calendars.filterNot { it.isLocal },
+            disabledIds = disabledIds,
             error = error,
             onConsumeError = viewModel::consumeError,
             backupResult = backupResult,
             onExportBackup = viewModel::exportBackup,
             onConsumeBackupResult = viewModel::consumeBackupResult,
+            autoBackup = autoBackup,
+            onSetAutoBackupEnabled = viewModel::setAutoBackupEnabled,
+            onSetAutoBackupInterval = viewModel::setAutoBackupIntervalMinutes,
+            onSetAutoBackupFolder = viewModel::setAutoBackupFolder,
             onBack = onBack,
             onAdd = { editorSession++; editorId = NEW_CALENDAR_ID },
             onEdit = { calendar -> editorSession++; editorId = calendar.id },
+            onSetDisabled = viewModel::setDisabled,
+            onSetAccountDisabled = viewModel::setAccountDisabled,
         )
     }
 }
@@ -150,17 +186,28 @@ fun CalendarsScreen(
 private fun CalendarsList(
     local: List<CalendarSource>,
     synced: List<CalendarSource>,
+    disabledIds: Set<Long>,
     error: Boolean,
     onConsumeError: () -> Unit,
     backupResult: BackupResult?,
     onExportBackup: (android.net.Uri) -> Unit,
     onConsumeBackupResult: () -> Unit,
+    autoBackup: AutoBackupUiState,
+    onSetAutoBackupEnabled: (Boolean) -> Unit,
+    onSetAutoBackupInterval: (Long) -> Unit,
+    onSetAutoBackupFolder: (android.net.Uri) -> Unit,
     onBack: () -> Unit,
     onAdd: () -> Unit,
     onEdit: (CalendarSource) -> Unit,
+    onSetDisabled: (Long, Boolean) -> Unit,
+    onSetAccountDisabled: (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 localExpanded by remember { mutableStateOf(true) }
     val writeErrorText = stringResource(R.string.calendars_write_error)
 
     LaunchedEffect(error) {
@@ -176,6 +223,13 @@ private fun CalendarsList(
         contract = ActivityResultContracts.CreateDocument("text/calendar"),
     ) { uri -> uri?.let(onExportBackup) }
 
+    // SAF folder picker for the automatic-backup destination; the VM persists the
+    // write grant so background runs can keep writing to it.
+    val pickFolder = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocumentTree(),
+    ) { uri -> uri?.let(onSetAutoBackupFolder) }
+    var showInterval by remember { mutableStateOf(false) }
+
     val backupFailedText = stringResource(R.string.calendars_backup_failed)
     LaunchedEffect(backupResult) {
         when (val r = backupResult) {
@@ -200,36 +254,51 @@ private fun CalendarsList(
         onBack = onBack,
         snackbarHost = { SnackbarHost(snackbarHostState) },
     ) {
-        // Local (device-only) calendars — the calendars the app owns. The
-        // "Add calendar" entry closes the group as its final row.
-        SectionHeader(stringResource(R.string.calendars_local_header))
-        if (local.isEmpty()) {
-            HintText(stringResource(R.string.calendars_local_empty))
-        }
-        val localCount = local.size + 1
-        local.forEachIndexed { index, calendar ->
-            GroupedRow(
-                title = calendar.displayName,
-                summary = calendar.description,
-                position = positionOf(index, localCount),
-                leading = { CalendarColorChip(calendar.color) },
-                trailing = {
-                    Icon(
-                        Icons.Default.Edit,
-                        contentDescription = stringResource(R.string.calendars_edit_title),
-                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                        modifier = Modifier.size(20.dp),
+        // What the per-calendar / per-account switches below actually do.
+        HintText(stringResource(R.string.calendars_disable_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 }
+        CalendarGroup(
+            title = stringResource(R.string.calendars_local_header),
+            expanded = localExpanded,
+            bodyHasRows = local.isNotEmpty(),
+            headerDisabled = localDisabled,
+            leading = { Box(dimIf(localDisabled)) { LeadingAvatar(Icons.Default.PhoneAndroid) } },
+            manageIcon = Icons.Default.Add,
+            manageLabel = stringResource(R.string.calendars_add),
+            onManage = onAdd,
+            onToggleExpand = { localExpanded = !localExpanded },
+            showToggleAll = local.isNotEmpty(),
+            allEnabled = local.none { it.id in disabledIds },
+            onToggleAll = { enabled -> onSetAccountDisabled(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
+                    GroupedRow(
+                        title = calendar.displayName,
+                        summary = calendar.description,
+                        position = if (index == local.lastIndex) Position.Bottom else Position.Middle,
+                        container = MaterialTheme.colorScheme.surfaceContainerHighest,
+                        dimmed = disabled,
+                        leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
+                        trailing = {
+                            EnableSwitch(
+                                calendarName = calendar.displayName,
+                                enabled = !disabled,
+                                onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
+                            )
+                        },
+                        onClick = { onEdit(calendar) },
                     )
-                },
-                onClick = { onEdit(calendar) },
-            )
+                }
+            }
         }
-        GroupedRow(
-            title = stringResource(R.string.calendars_add),
-            position = positionOf(local.size, localCount),
-            leading = { AddAvatar() },
-            onClick = onAdd,
-        )
 
         // Backup — local calendars have no sync, so a .ics export is their only
         // safety net. Offered only when there is something to back up.
@@ -237,42 +306,106 @@ private fun CalendarsList(
             Spacer(Modifier.height(16.dp))
             SectionHeader(stringResource(R.string.calendars_backup_header))
             HintText(stringResource(R.string.calendars_backup_hint))
+            // One connected card: the one-time export on top, then automatic
+            // backup (and its folder/interval rows when on).
             GroupedRow(
                 title = stringResource(R.string.calendars_backup_action),
-                position = Position.Alone,
+                position = Position.Top,
                 leading = { LeadingAvatar(Icons.Default.FileDownload) },
                 onClick = {
                     runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
                 },
             )
+            GroupedRow(
+                title = stringResource(R.string.calendars_auto_backup),
+                summary = stringResource(R.string.calendars_auto_backup_hint),
+                position = if (autoBackup.enabled) Position.Middle else Position.Bottom,
+                leading = { LeadingAvatar(Icons.Default.Schedule) },
+                trailing = {
+                    Switch(checked = autoBackup.enabled, onCheckedChange = onSetAutoBackupEnabled)
+                },
+                onClick = { onSetAutoBackupEnabled(!autoBackup.enabled) },
+            )
+            if (autoBackup.enabled) {
+                GroupedRow(
+                    title = stringResource(R.string.calendars_auto_backup_folder),
+                    summary = rememberFolderName(autoBackup.folderUri)
+                        ?: stringResource(R.string.calendars_auto_backup_folder_unset),
+                    position = Position.Middle,
+                    onClick = { runCatching { pickFolder.launch(null) } },
+                )
+                GroupedRow(
+                    title = stringResource(R.string.calendars_auto_backup_interval),
+                    summary = backupIntervalLabel(autoBackup.intervalMinutes),
+                    position = Position.Bottom,
+                    onClick = { showInterval = true },
+                )
+                HintText(backupStatusText(autoBackup.status))
+            }
         }
 
         Spacer(Modifier.height(16.dp))
 
-        // Synced calendars — read-only, grouped by account, each with a
-        // per-account "manage in source app" link.
+        // Synced calendars — read-only, grouped by account. Each account is a
+        // collapsible group whose header opens the source app (icon) and toggles
+        // all of its calendars at once (switch).
         SectionHeader(stringResource(R.string.calendars_synced_header))
         HintText(stringResource(R.string.calendars_synced_hint))
         synced
             .groupBy { it.accountName.ifBlank { it.accountType } }
             .forEach { (account, cals) ->
-                AccountHeader(account = account, accountType = cals.first().accountType)
-                cals.forEachIndexed { index, calendar ->
-                    GroupedRow(
-                        title = calendar.displayName,
-                        position = positionOf(index, cals.size),
-                        leading = { CalendarColorChip(calendar.color) },
-                    )
+                val expanded = account !in collapsedAccounts
+                val accountType = cals.first().accountType
+                val accountDisabled = cals.all { it.id in disabledIds }
+                Spacer(Modifier.height(16.dp))
+                CalendarGroup(
+                    title = account,
+                    expanded = expanded,
+                    bodyHasRows = true,
+                    headerDisabled = accountDisabled,
+                    leading = { Box(dimIf(accountDisabled)) { SourceLogo(accountType) } },
+                    manageIcon = Icons.AutoMirrored.Filled.OpenInNew,
+                    manageLabel = stringResource(R.string.calendars_manage_in_app),
+                    onManage = {
+                        runCatching { context.startActivity(sourceAppIntent(context, accountType)) }
+                    },
+                    onToggleExpand = {
+                        collapsedAccounts = if (expanded) {
+                            collapsedAccounts + account
+                        } else {
+                            collapsedAccounts - account
+                        }
+                    },
+                    showToggleAll = true,
+                    allEnabled = cals.none { it.id in disabledIds },
+                    onToggleAll = { enabled -> onSetAccountDisabled(cals.map { it.id }, !enabled) },
+                ) {
+                    cals.forEachIndexed { index, calendar ->
+                        val disabled = calendar.id in disabledIds
+                        GroupedRow(
+                            title = calendar.displayName,
+                            position = if (index == cals.lastIndex) Position.Bottom else Position.Middle,
+                            container = MaterialTheme.colorScheme.surfaceContainerHighest,
+                            dimmed = disabled,
+                            leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
+                            trailing = {
+                                EnableSwitch(
+                                    calendarName = calendar.displayName,
+                                    enabled = !disabled,
+                                    onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
+                                )
+                            },
+                        )
+                    }
                 }
             }
-        Spacer(Modifier.height(8.dp))
-        GroupedRow(
-            title = stringResource(R.string.calendars_add_account),
-            position = Position.Alone,
-            leading = { AddAvatar() },
-            onClick = {
-                runCatching { context.startActivity(Intent(Settings.ACTION_ADD_ACCOUNT)) }
-            },
+    }
+
+    if (showInterval) {
+        BackupIntervalDialog(
+            currentMinutes = autoBackup.intervalMinutes,
+            onConfirm = onSetAutoBackupInterval,
+            onDismiss = { showInterval = false },
         )
     }
 }
@@ -424,6 +557,30 @@ private fun CalendarEditor(
     }
 }
 
+/**
+ * The per-row enable/disable control. Checked = the calendar is shown in the
+ * app; unchecking disables it (events, filters and pickers all drop it) without
+ * touching any provider data. Carries its own content description so the toggle
+ * is self-describing to screen readers even on a dimmed row.
+ */
+@Composable
+private fun EnableSwitch(
+    calendarName: String,
+    enabled: Boolean,
+    onToggle: (Boolean) -> Unit,
+) {
+    val label = stringResource(R.string.calendars_show_in_app_a11y, calendarName)
+    Switch(
+        checked = enabled,
+        onCheckedChange = onToggle,
+        modifier = Modifier.semantics { contentDescription = label },
+    )
+}
+
+/** Fade a leading element to the M3 disabled emphasis when [disabled]. */
+private fun dimIf(disabled: Boolean): Modifier =
+    if (disabled) Modifier.alpha(0.38f) else Modifier
+
 /** Tonal field card matching the event editor's design (icon + content). */
 @Composable
 private fun EditorCard(
@@ -455,32 +612,178 @@ private fun EditorCard(
     }
 }
 
+/**
+ * One collapsible calendar group rendered as a connected card. The header row is
+ * the card's top (tap to expand/collapse): a [leading] source mark (the account
+ * app's logo, or a device chip for local), the group [title] and a trailing
+ * overflow (⋮) menu holding the account-level actions — enable/disable every
+ * calendar at once (when [showToggleAll]) and the manage/add action
+ * ([manageIcon] / [manageLabel] → [onManage]). The group's calendars render as
+ * the rows below via [body].
+ *
+ * The header keeps the standard row colour; the calendars it reveals sit one tone
+ * darker, so the group reads as a header over nested content. Once [headerDisabled]
+ * (every calendar switched off) the header fades to the disabled emphasis so the
+ * whole group reads as off — not just via the menu. [bodyHasRows] is false when no
+ * calendar rows follow (e.g. an empty local group), so the header stays a
+ * standalone card rather than a top edge with nothing beneath it.
+ */
 @Composable
-private fun AccountHeader(account: String, accountType: String) {
-    val context = LocalContext.current
-    Row(
-        modifier = Modifier
-            .fillMaxWidth()
-            .padding(start = 28.dp, end = 16.dp, top = 16.dp, bottom = 4.dp),
-        verticalAlignment = Alignment.CenterVertically,
+private fun CalendarGroup(
+    title: String,
+    expanded: Boolean,
+    bodyHasRows: Boolean,
+    headerDisabled: Boolean,
+    leading: @Composable () -> Unit,
+    manageIcon: ImageVector,
+    manageLabel: String,
+    onManage: () -> Unit,
+    onToggleExpand: () -> Unit,
+    showToggleAll: Boolean,
+    allEnabled: Boolean,
+    onToggleAll: (Boolean) -> Unit,
+    body: @Composable ColumnScope.() -> Unit,
+) {
+    GroupedRow(
+        title = title,
+        position = if (expanded && bodyHasRows) Position.Top else Position.Alone,
+        dimmed = headerDisabled,
+        leading = leading,
+        trailing = {
+            CalendarGroupMenu(
+                title = title,
+                showToggleAll = showToggleAll,
+                allEnabled = allEnabled,
+                onToggleAll = onToggleAll,
+                manageIcon = manageIcon,
+                manageLabel = manageLabel,
+                onManage = onManage,
+            )
+        },
+        onClick = onToggleExpand,
+    )
+    AnimatedVisibility(
+        visible = expanded,
+        enter = calendarExpandEnter(),
+        exit = calendarCollapseExit(),
     ) {
-        Text(
-            text = account,
-            style = MaterialTheme.typography.titleSmall,
-            fontWeight = FontWeight.SemiBold,
-            modifier = Modifier.weight(1f),
-        )
-        OutlinedButton(onClick = {
-            runCatching { context.startActivity(sourceAppIntent(context, accountType)) }
-        }) {
-            Icon(Icons.Default.OpenInNew, contentDescription = null, modifier = Modifier.size(16.dp))
-            Spacer(Modifier.width(6.dp))
-            Text(stringResource(R.string.calendars_manage_in_app))
+        Column(content = body)
+    }
+}
+
+/**
+ * The account header's overflow (⋮) menu: the two account-level actions that
+ * don't fit on one line — "Enable/Disable all" (when [showToggleAll]) and the
+ * manage/add action. A rounded, tonal dropdown matching the app's surfaces, with
+ * the two actions divided for clear separation.
+ */
+@Composable
+private fun CalendarGroupMenu(
+    title: String,
+    showToggleAll: Boolean,
+    allEnabled: Boolean,
+    onToggleAll: (Boolean) -> Unit,
+    manageIcon: ImageVector,
+    manageLabel: String,
+    onManage: () -> Unit,
+) {
+    var open by remember { mutableStateOf(false) }
+    Box {
+        IconButton(onClick = { open = true }) {
+            Icon(
+                Icons.Default.MoreVert,
+                contentDescription = stringResource(R.string.calendars_account_menu_a11y, title),
+            )
+        }
+        DropdownMenu(
+            expanded = open,
+            onDismissRequest = { open = false },
+            shape = RoundedCornerShape(20.dp),
+            // A distinct tone + a lifted shadow so the menu reads as floating
+            // above the cards (which sit at surfaceContainerHigh) rather than
+            // blending into them.
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLowest,
+            tonalElevation = 0.dp,
+            shadowElevation = 6.dp,
+        ) {
+            if (showToggleAll) {
+                DropdownMenuItem(
+                    text = {
+                        Text(
+                            stringResource(
+                                if (allEnabled) R.string.calendars_disable_all
+                                else R.string.calendars_enable_all,
+                            ),
+                        )
+                    },
+                    leadingIcon = {
+                        Icon(
+                            if (allEnabled) Icons.Default.VisibilityOff else Icons.Default.Visibility,
+                            contentDescription = null,
+                        )
+                    },
+                    onClick = {
+                        open = false
+                        onToggleAll(!allEnabled)
+                    },
+                )
+                HorizontalDivider(Modifier.padding(horizontal = 12.dp, vertical = 4.dp))
+            }
+            DropdownMenuItem(
+                text = { Text(manageLabel) },
+                leadingIcon = { Icon(manageIcon, contentDescription = null) },
+                onClick = {
+                    open = false
+                    onManage()
+                },
+            )
         }
     }
 }
 
-/** Neutral circular chip carrying an arbitrary icon — matches [AddAvatar]'s shape. */
+/**
+ * The source app's launcher icon (Google Calendar, DAVx5, Nextcloud, …) as a
+ * round 40dp chip, so each synced account is recognisable at a glance. We load
+ * whatever app owns the account from [PackageManager] rather than bundling brand
+ * logos — always accurate, nothing to license. Falls back to a neutral cloud
+ * chip when no installed app resolves for the account.
+ */
+@Composable
+private fun SourceLogo(accountType: String) {
+    val context = LocalContext.current
+    val logo = remember(accountType) { sourceAppLogo(context, accountType) }
+    if (logo != null) {
+        Image(
+            bitmap = logo,
+            contentDescription = null,
+            contentScale = ContentScale.Crop,
+            modifier = Modifier
+                .size(40.dp)
+                .clip(CircleShape),
+        )
+    } else {
+        LeadingAvatar(Icons.Default.Cloud)
+    }
+}
+
+/** The launcher icon of the app backing [accountType], preferring the human-facing app. */
+private fun sourceAppLogo(context: Context, accountType: String): ImageBitmap? {
+    val pm = context.packageManager
+    val candidates = buildList {
+        curatedSourcePackage(accountType)?.let { add(it) }
+        AccountManager.get(context).authenticatorTypes
+            .firstOrNull { it.type.equals(accountType, ignoreCase = true) }
+            ?.packageName
+            ?.let { add(it) }
+    }
+    for (pkg in candidates) {
+        val bitmap = runCatching { pm.getApplicationIcon(pkg).toBitmap() }.getOrNull()
+        if (bitmap != null) return bitmap.asImageBitmap()
+    }
+    return null
+}
+
+/** Neutral circular chip carrying an arbitrary icon (e.g. the local-device mark). */
 @Composable
 private fun LeadingAvatar(icon: ImageVector) {
     Box(
@@ -499,25 +802,6 @@ private fun LeadingAvatar(icon: ImageVector) {
     }
 }
 
-/** Neutral circular chip with a "+" — the leading icon for add-actions. */
-@Composable
-private fun AddAvatar() {
-    Box(
-        modifier = Modifier
-            .size(40.dp)
-            .clip(CircleShape)
-            .background(MaterialTheme.colorScheme.surfaceContainerHighest),
-        contentAlignment = Alignment.Center,
-    ) {
-        Icon(
-            Icons.Default.Add,
-            contentDescription = null,
-            tint = MaterialTheme.colorScheme.onSurfaceVariant,
-            modifier = Modifier.size(22.dp),
-        )
-    }
-}
-
 @Composable
 private fun SectionHeader(text: String) {
     Text(
@@ -538,6 +822,95 @@ private fun HintText(text: String) {
     )
 }
 
+/** 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
  * own authenticator package (resolved from [AccountManager], no permission

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

@@ -1,12 +1,19 @@
 package de.jeanlucmakiola.calendula.ui.calendars
 
+import android.content.Context
+import android.content.Intent
 import android.net.Uri
 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.backup.BackupScheduler
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
+import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
+import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
 import kotlinx.coroutines.CoroutineDispatcher
@@ -15,6 +22,8 @@ import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
@@ -31,8 +40,11 @@ import javax.inject.Inject
  */
 @HiltViewModel
 class CalendarsViewModel @Inject constructor(
+    @ApplicationContext private val context: Context,
     private val repository: CalendarRepository,
     private val icsExporter: IcsExporter,
+    private val prefs: CalendarPrefs,
+    private val settingsPrefs: SettingsPrefs,
     @IoDispatcher private val io: CoroutineDispatcher,
 ) : ViewModel() {
 
@@ -46,6 +58,36 @@ 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,
+        settingsPrefs.autoBackupIntervalMinutes,
+        settingsPrefs.autoBackupFolderUri,
+        settingsPrefs.autoBackupStatus,
+    ) { enabled, interval, folder, status ->
+        AutoBackupUiState(enabled, interval, folder, status)
+    }
+        .flowOn(io)
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = AutoBackupUiState(),
+        )
+
     private val _error = MutableStateFlow(false)
     val error: StateFlow<Boolean> = _error.asStateFlow()
 
@@ -93,6 +135,76 @@ class CalendarsViewModel @Inject constructor(
         repository.deleteCalendar(id)
     }
 
+    /**
+     * Enable or disable a calendar app-side. Disabling removes it from every
+     * surface but Settings → Calendars (and hides its events) without touching
+     * provider data — purely a reversible Calendula-local view choice.
+     */
+    fun setDisabled(id: Long, disabled: Boolean) {
+        viewModelScope.launch {
+            val current = prefs.disabledCalendarIds.first()
+            val next = if (disabled) current + id else current - id
+            if (next != current) prefs.setDisabledCalendarIds(next)
+        }
+    }
+
+    /**
+     * Enable or disable every calendar of one account in a single write — the
+     * "toggle all" affordance on an account header. Done as one set update so the
+     * per-calendar [setDisabled] calls can't race each other.
+     */
+    fun setAccountDisabled(ids: Collection<Long>, disabled: Boolean) {
+        viewModelScope.launch {
+            val current = prefs.disabledCalendarIds.first()
+            val next = if (disabled) current + ids else current - ids.toSet()
+            if (next != current) prefs.setDisabledCalendarIds(next)
+        }
+    }
+
+    // --- Automatic backup (issue #8) ------------------------------------
+
+    fun setAutoBackupEnabled(enabled: Boolean) {
+        viewModelScope.launch {
+            settingsPrefs.setAutoBackupEnabled(enabled)
+            reschedule()
+            // Give immediate feedback when turning it on with a folder already set.
+            if (enabled && settingsPrefs.autoBackupFolderUri.first() != null) {
+                BackupScheduler.runNow(context)
+            }
+        }
+    }
+
+    fun setAutoBackupIntervalMinutes(minutes: Long) {
+        viewModelScope.launch {
+            settingsPrefs.setAutoBackupIntervalMinutes(minutes)
+            reschedule()
+        }
+    }
+
+    /** Persist the chosen destination folder (taking a durable write grant) and run once. */
+    fun setAutoBackupFolder(uri: Uri) {
+        viewModelScope.launch {
+            runCatching {
+                context.contentResolver.takePersistableUriPermission(
+                    uri,
+                    Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION,
+                )
+            }
+            settingsPrefs.setAutoBackupFolderUri(uri.toString())
+            reschedule()
+            if (settingsPrefs.autoBackupEnabled.first()) BackupScheduler.runNow(context)
+        }
+    }
+
+    private suspend fun reschedule() {
+        BackupScheduler.apply(
+            context = context,
+            enabled = settingsPrefs.autoBackupEnabled.first(),
+            intervalMinutes = settingsPrefs.autoBackupIntervalMinutes.first(),
+            hasFolder = settingsPrefs.autoBackupFolderUri.first() != null,
+        )
+    }
+
     private inline fun write(crossinline block: suspend () -> Unit) {
         viewModelScope.launch {
             try {
@@ -106,6 +218,14 @@ class CalendarsViewModel @Inject constructor(
     }
 }
 
+/** Automatic-backup settings + last-run status for the Backup section. */
+data class AutoBackupUiState(
+    val enabled: Boolean = false,
+    val intervalMinutes: Long = SettingsPrefs.DEFAULT_BACKUP_INTERVAL,
+    val folderUri: String? = null,
+    val status: BackupStatus = BackupStatus(lastRun = 0L, lastSuccess = true, consecutiveFailures = 0),
+)
+
 /** Outcome of a whole-calendar backup, surfaced once to the screen. */
 sealed interface BackupResult {
     data class Success(val eventCount: Int) : BackupResult

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

@@ -0,0 +1,44 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.annotation.StringRes
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.Notes
+import androidx.compose.material.icons.filled.EventAvailable
+import androidx.compose.material.icons.filled.Lock
+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.Repeat
+import androidx.compose.ui.graphics.vector.ImageVector
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.EventFormField
+
+/**
+ * The shared label and icon for each optional [EventFormField]. Both the event
+ * editor (which shows these fields) and the settings screen (which toggles their
+ * defaults) draw from this one mapping, so a field reads the same wherever it
+ * appears.
+ */
+@StringRes
+fun eventFormFieldLabel(field: EventFormField): Int = when (field) {
+    EventFormField.Location -> R.string.event_detail_location
+    EventFormField.Description -> R.string.event_detail_description
+    EventFormField.Reminders -> R.string.event_detail_reminders
+    EventFormField.Recurrence -> R.string.event_detail_recurrence
+    EventFormField.Availability -> R.string.event_edit_availability
+    EventFormField.Visibility -> R.string.event_edit_visibility
+    EventFormField.Color -> R.string.event_edit_color
+    EventFormField.Attendees -> R.string.event_edit_attendees
+}
+
+fun eventFormFieldIcon(field: EventFormField): ImageVector = when (field) {
+    EventFormField.Location -> Icons.Default.Place
+    EventFormField.Description -> Icons.AutoMirrored.Filled.Notes
+    EventFormField.Reminders -> Icons.Default.Notifications
+    EventFormField.Recurrence -> Icons.Default.Repeat
+    EventFormField.Availability -> Icons.Default.EventAvailable
+    EventFormField.Visibility -> Icons.Default.Lock
+    EventFormField.Color -> Icons.Default.Palette
+    EventFormField.Attendees -> Icons.Default.People
+}

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

@@ -127,7 +127,9 @@ fun CollapsingScaffold(
  * One row in a grouped list: an M3 [ListItem] over a tonal [Surface] whose
  * corner radii come from its [position] (so a run of rows reads as a single
  * rounded card). Corners round further on press. A null [onClick] makes the
- * row non-interactive (e.g. read-only entries).
+ * row non-interactive (e.g. read-only entries). [dimmed] fades the headline and
+ * summary to the M3 disabled emphasis while leaving the [trailing] control at
+ * full opacity — for rows that are present but switched off.
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -137,6 +139,8 @@ fun GroupedRow(
     modifier: Modifier = Modifier,
     summary: String? = null,
     selected: Boolean = false,
+    dimmed: Boolean = false,
+    container: Color? = null,
     minHeight: Dp = 72.dp,
     leading: @Composable (() -> Unit)? = null,
     trailing: @Composable (() -> Unit)? = null,
@@ -168,6 +172,16 @@ fun GroupedRow(
             supportingColor = MaterialTheme.colorScheme.onSecondaryContainer,
             trailingIconColor = MaterialTheme.colorScheme.onSecondaryContainer,
         )
+    } else if (dimmed) {
+        // M3 disabled emphasis (0.38α) on the text/leading; the trailing control
+        // stays full-opacity so the toggle reads as live even on a faded row.
+        val muted = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.38f)
+        ListItemDefaults.colors(
+            containerColor = Color.Transparent,
+            headlineColor = muted,
+            leadingIconColor = muted,
+            supportingColor = muted,
+        )
     } else {
         ListItemDefaults.colors(containerColor = Color.Transparent)
     }
@@ -185,10 +199,10 @@ fun GroupedRow(
         .fillMaxWidth()
         .padding(horizontal = 16.dp)
         .then(gap)
-    val containerColor = if (selected) {
-        MaterialTheme.colorScheme.secondaryContainer
-    } else {
-        MaterialTheme.colorScheme.surfaceContainerHigh
+    val containerColor = when {
+        selected -> MaterialTheme.colorScheme.secondaryContainer
+        container != null -> container
+        else -> MaterialTheme.colorScheme.surfaceContainerHigh
     }
     if (onClick != null) {
         Surface(

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

@@ -0,0 +1,38 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.drawBehind
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Color
+
+/**
+ * Whether the week/day timeline draws an hour separator line, from the
+ * `showHourLines` preference. Provided once at the app root (like
+ * [LocalUse24HourFormat]) so the timeline reads it without ViewModel plumbing.
+ * Defaults to off — the historical clean look.
+ */
+val LocalShowHourLines = staticCompositionLocalOf { false }
+
+/**
+ * Draw a faint separator line at the top of each hour (1..23) when [show] is
+ * true. Applied to a day column's content so each line sits over the column's
+ * background but beneath the event blocks. [hourHeightPx] is one hour's pixel
+ * height; [color] is resolved by the caller from the theme.
+ */
+fun Modifier.hourSeparatorLines(show: Boolean, hourHeightPx: Float, color: Color): Modifier =
+    if (!show) {
+        this
+    } else {
+        drawBehind {
+            for (hour in 1 until 24) {
+                val y = hour * hourHeightPx
+                drawLine(
+                    color = color,
+                    start = Offset(0f, y),
+                    end = Offset(size.width, y),
+                    strokeWidth = 1f,
+                )
+            }
+        }
+    }

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

@@ -7,6 +7,7 @@ import androidx.compose.foundation.layout.ColumnScope
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -30,6 +31,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalView
+import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.window.Dialog
@@ -37,6 +39,7 @@ import androidx.compose.ui.window.DialogProperties
 import androidx.compose.ui.window.DialogWindowProvider
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 
 /**
  * Shared full-screen scaffold for selection pickers: a full-bleed [Dialog] that
@@ -83,8 +86,10 @@ fun <T> OptionPicker(
     label: @Composable (T) -> String,
     onSelect: (T) -> Unit,
     onDismiss: () -> Unit,
+    header: (@Composable ColumnScope.() -> Unit)? = null,
 ) {
     FullScreenPicker(title = title, onDismiss = onDismiss) {
+        header?.invoke(this)
         options.forEachIndexed { index, option ->
             val isSelected = option == selected
             GroupedRow(
@@ -260,6 +265,17 @@ private fun CustomReminderEditor(
     }
 }
 
+/** A short explanatory paragraph shown under a picker's title, above the rows. */
+@Composable
+private fun PickerDescription(text: String) {
+    Text(
+        text = text,
+        style = MaterialTheme.typography.bodyMedium,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+    )
+}
+
 @Composable
 private fun SelectedCheck() {
     Icon(
@@ -269,6 +285,149 @@ private fun SelectedCheck() {
     )
 }
 
+/**
+ * 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.
+ */
+@Composable
+fun AgendaRangePicker(
+    title: String,
+    description: String,
+    selected: AgendaRange,
+    onSelect: (AgendaRange) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val calendarAligned = listOf(AgendaRange.Day, AgendaRange.ThisWeek, AgendaRange.ThisMonth)
+    val rolling = listOf(AgendaRange.Week, AgendaRange.Month)
+    val rollingRowCount = rolling.size + 1 // + the custom row
+    val customSelected = selected is AgendaRange.Custom
+
+    var customExpanded by rememberSaveable { mutableStateOf(false) }
+    var amountText by rememberSaveable {
+        mutableStateOf((selected as? AgendaRange.Custom)?.days?.toString() ?: "")
+    }
+
+    val rangeRow: @Composable (AgendaRange, Position) -> Unit = { option, position ->
+        val isSelected = option == selected
+        GroupedRow(
+            title = agendaRangeLabel(option),
+            position = position,
+            selected = isSelected,
+            trailing = if (isSelected) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
+            onClick = {
+                onSelect(option)
+                onDismiss()
+            },
+        )
+    }
+
+    FullScreenPicker(title = title, onDismiss = onDismiss) {
+        PickerDescription(description)
+
+        // Calendar-aligned windows.
+        calendarAligned.forEachIndexed { index, option ->
+            rangeRow(option, positionOf(index, calendarAligned.size))
+        }
+
+        Spacer(Modifier.height(12.dp))
+
+        // Rolling windows + custom.
+        rolling.forEachIndexed { index, option ->
+            rangeRow(option, positionOf(index, rollingRowCount))
+        }
+        GroupedRow(
+            title = if (customSelected) {
+                agendaRangeLabel(selected)
+            } else {
+                stringResource(R.string.agenda_range_custom)
+            },
+            position = if (customExpanded) Position.Top else positionOf(rolling.size, rollingRowCount),
+            selected = customSelected,
+            trailing = if (customSelected) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
+            onClick = { customExpanded = !customExpanded },
+        )
+        AnimatedVisibility(
+            visible = customExpanded,
+            enter = calendarExpandEnter(),
+            exit = calendarCollapseExit(),
+        ) {
+            CustomDaysEditor(
+                amountText = amountText,
+                onAmountChange = { amountText = it },
+                onConfirm = { days ->
+                    onSelect(AgendaRange.Custom(days))
+                    onDismiss()
+                },
+            )
+        }
+    }
+}
+
+/** The expanded "Custom" day-count editor: an amount field (1–365) and Set. */
+@Composable
+private fun CustomDaysEditor(
+    amountText: String,
+    onAmountChange: (String) -> Unit,
+    onConfirm: (Int) -> Unit,
+) {
+    val days = amountText.toIntOrNull()
+        ?.takeIf { it in AgendaRange.MIN_CUSTOM_DAYS..AgendaRange.MAX_CUSTOM_DAYS }
+    Surface(
+        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        shape = RoundedCornerShape(topStart = 6.dp, topEnd = 6.dp, bottomStart = 22.dp, bottomEnd = 22.dp),
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp),
+    ) {
+        Row(
+            modifier = Modifier.padding(16.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            DialogAmountField(
+                value = amountText,
+                onValueChange = onAmountChange,
+                placeholder = "30",
+            )
+            Spacer(Modifier.width(16.dp))
+            Text(
+                text = days?.let { pluralStringResource(R.plurals.agenda_range_days, it, it) }
+                    ?: stringResource(R.string.agenda_range_custom_hint),
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.weight(1f),
+            )
+            Spacer(Modifier.width(16.dp))
+            FilledTonalButton(
+                onClick = { days?.let(onConfirm) },
+                enabled = days != null,
+            ) {
+                Text(stringResource(R.string.reminder_custom_set))
+            }
+        }
+    }
+}
+
+/** Human label for an [AgendaRange] (used by the picker rows and settings summary). */
+@Composable
+fun agendaRangeLabel(range: AgendaRange): String = when (range) {
+    AgendaRange.Day -> stringResource(R.string.agenda_range_day)
+    AgendaRange.ThisWeek -> stringResource(R.string.agenda_range_this_week)
+    AgendaRange.ThisMonth -> stringResource(R.string.agenda_range_this_month)
+    AgendaRange.Week -> stringResource(R.string.agenda_range_week)
+    AgendaRange.Month -> stringResource(R.string.agenda_range_month)
+    is AgendaRange.Custom -> pluralStringResource(R.plurals.agenda_range_days, range.days, range.days)
+}
+
 @Composable
 private fun reminderOverrideLabel(override: CalendarReminderOverride): String = when (override) {
     CalendarReminderOverride.Inherit -> stringResource(R.string.reminder_use_default)

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

@@ -0,0 +1,57 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.staticCompositionLocalOf
+import java.time.LocalTime
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+/**
+ * The resolved clock convention for the whole UI: `true` = 24-hour ("14:00"),
+ * `false` = 12-hour ("2:00 PM"). Provided once at the app root from the
+ * `TimeFormatPref` preference resolved against the device's 24-hour system
+ * setting, so every time label reads it without per-screen plumbing. Defaults
+ * to 24-hour for previews and any composition that forgets to provide it.
+ */
+val LocalUse24HourFormat = staticCompositionLocalOf { true }
+
+private const val PATTERN_24 = "HH:mm"
+private const val PATTERN_12 = "h:mm a"
+private const val HOUR_PATTERN_12 = "h a"
+
+/** A time-of-day [DateTimeFormatter] for the resolved convention and [locale]. */
+fun timeOfDayFormatter(is24Hour: Boolean, locale: Locale): DateTimeFormatter =
+    DateTimeFormatter.ofPattern(if (is24Hour) PATTERN_24 else PATTERN_12, locale)
+
+/**
+ * Format a wall-clock time (hour 0..23, minute 0..59) honouring the resolved
+ * [is24Hour] convention and [locale]: 24h → "14:00", 12h → "2:00 PM". Pure, so
+ * it can be unit-tested and used off the main thread (widget, notifications).
+ */
+fun formatTimeOfDay(hour: Int, minute: Int, is24Hour: Boolean, locale: Locale): String =
+    LocalTime.of(hour.coerceIn(0, 23), minute.coerceIn(0, 59))
+        .format(timeOfDayFormatter(is24Hour, locale))
+
+/**
+ * Format minutes-from-midnight (0..1440) as a time label. The end-of-day value
+ * 1440 renders as "24:00" in 24h (its established reading) and as midnight
+ * ("12:00 AM") in 12h, which has no 24:00 equivalent.
+ */
+fun formatMinuteOfDay(minutes: Int, is24Hour: Boolean, locale: Locale): String = when {
+    minutes >= MINUTES_PER_DAY && is24Hour -> "24:00"
+    minutes >= MINUTES_PER_DAY -> formatTimeOfDay(0, 0, is24Hour = false, locale)
+    else -> formatTimeOfDay(minutes / 60, minutes % 60, is24Hour, locale)
+}
+
+/**
+ * The compact hour-only label for a timeline gutter: 24h → "13" (zero-padded,
+ * the prior look); 12h → "1 PM".
+ */
+fun formatHourLabel(hour: Int, is24Hour: Boolean, locale: Locale): String =
+    if (is24Hour) {
+        "%02d".format(hour)
+    } else {
+        LocalTime.of(hour.coerceIn(0, 23), 0)
+            .format(DateTimeFormatter.ofPattern(HOUR_PATTERN_12, locale))
+    }
+
+private const val MINUTES_PER_DAY = 1_440

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

@@ -80,7 +80,12 @@ import de.jeanlucmakiola.calendula.ui.common.rememberReduceMotion
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
-import de.jeanlucmakiola.calendula.ui.week.MINUTES_PER_DAY
+import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.LocalShowHourLines
+import de.jeanlucmakiola.calendula.ui.common.formatHourLabel
+import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
+import de.jeanlucmakiola.calendula.ui.common.hourSeparatorLines
 import de.jeanlucmakiola.calendula.ui.week.TimedBlock
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
@@ -466,6 +471,8 @@ private fun Timeline(
 ) {
     val totalHeight = HOUR_HEIGHT * 24
     val dark = isSystemInDarkTheme()
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
 
     Box(modifier = Modifier.fillMaxSize()) {
         // Gutter and day column are two scroll viewports that SHARE one scroll
@@ -488,7 +495,7 @@ private fun Timeline(
                     ) {
                         if (h > 0) {
                             Text(
-                                text = "%02d".format(h),
+                                text = formatHourLabel(h, use24Hour, locale),
                                 style = MaterialTheme.typography.labelSmall,
                                 color = MaterialTheme.colorScheme.onSurfaceVariant,
                                 modifier = Modifier
@@ -534,6 +541,8 @@ private fun DayColumnCard(
     modifier: Modifier = Modifier,
 ) {
     val hourPx = with(LocalDensity.current) { HOUR_HEIGHT.toPx() }
+    val showHourLines = LocalShowHourLines.current
+    val hourLineColor = MaterialTheme.colorScheme.outlineVariant
     Card(
         // Plain rectangular column — the soft corners come from the outer
         // rounded scroll viewport, so inner rounding would look odd at the edges.
@@ -546,6 +555,9 @@ private fun DayColumnCard(
         BoxWithConstraints(
             modifier = Modifier
                 .fillMaxSize()
+                // Faint hour separators sit over the column background but under
+                // the event blocks (drawBehind paints before the children).
+                .hourSeparatorLines(showHourLines, hourPx, hourLineColor)
                 // Tap an empty slot to create an event there. Taps on event
                 // blocks are consumed by their own click handler first, so this
                 // only fires on the column background. Snaps to the tapped hour.
@@ -589,7 +601,10 @@ private fun EventBlock(
     modifier: Modifier = Modifier,
 ) {
     val title = block.event.title.ifBlank { stringResource(R.string.event_untitled) }
-    val timeLabel = "${minToHm(block.startMin)}–${minToHm(block.endMin)}"
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
+    val timeLabel = "${minToHm(block.startMin, use24Hour, locale)}–" +
+        minToHm(block.endMin, use24Hour, locale)
     val showTime = block.endMin - block.startMin >= 45
     Box(
         modifier = modifier
@@ -635,8 +650,8 @@ private fun DayLoading() {
     }
 }
 
-private fun minToHm(min: Int): String =
-    if (min >= MINUTES_PER_DAY) "24:00" else "%02d:%02d".format(min / 60, min % 60)
+private fun minToHm(min: Int, is24Hour: Boolean, locale: Locale): String =
+    formatMinuteOfDay(min, is24Hour, locale)
 
 private fun formatDayTitle(date: LocalDate): String {
     val locale = Locale.getDefault()

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

@@ -95,6 +95,8 @@ import de.jeanlucmakiola.calendula.ui.common.predictiveBack
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.OptionCard
 import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
 import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.ui.common.recurrenceText
 import de.jeanlucmakiola.calendula.ui.common.reminderLeadTimeLabel
@@ -781,7 +783,7 @@ private fun formatWhen(
     val zid = ZoneId.of(zone.id)
     val dateFull = DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).withLocale(locale)
     val dateMedium = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
-    val timeShort = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT).withLocale(locale)
+    val timeShort = timeOfDayFormatter(LocalUse24HourFormat.current, locale)
 
     val startLdt = instance.start.toJavaLocalDateTime(zid)
     val allDayLabel = stringResource(R.string.event_detail_all_day)

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

@@ -43,7 +43,6 @@ import androidx.compose.material.icons.filled.EventAvailable
 import androidx.compose.material.icons.filled.Lock
 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.Person
 import androidx.compose.material.icons.filled.PersonAdd
 import androidx.compose.material.icons.filled.Place
@@ -123,6 +122,8 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarDatePickerDialog
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
 import de.jeanlucmakiola.calendula.ui.common.DialogAmountField
 import de.jeanlucmakiola.calendula.ui.common.DialogUnitDropdown
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldIcon
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldLabel
 import de.jeanlucmakiola.calendula.ui.common.MILLIS_PER_DAY
 import de.jeanlucmakiola.calendula.ui.common.InlineTextField
 import de.jeanlucmakiola.calendula.ui.common.OptionCard
@@ -132,6 +133,8 @@ import de.jeanlucmakiola.calendula.ui.common.REMINDER_PRESETS
 import de.jeanlucmakiola.calendula.ui.common.ReminderUnit
 import de.jeanlucmakiola.calendula.ui.common.TimePickerAlert
 import de.jeanlucmakiola.calendula.ui.common.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.pastelize
@@ -1017,9 +1020,9 @@ private fun FieldPickerDialog(
             Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
                 hiddenFields.forEach { field ->
                     OptionCard(
-                        label = stringResource(fieldLabel(field)),
+                        label = stringResource(eventFormFieldLabel(field)),
                         onClick = { onSelect(field) },
-                        icon = fieldIcon(field),
+                        icon = eventFormFieldIcon(field),
                     )
                 }
             }
@@ -1636,28 +1639,6 @@ private fun readContactAddress(context: Context, uri: Uri): String? =
     }
 
 
-private fun fieldLabel(field: EventFormField): Int = when (field) {
-    EventFormField.Location -> R.string.event_detail_location
-    EventFormField.Description -> R.string.event_detail_description
-    EventFormField.Reminders -> R.string.event_detail_reminders
-    EventFormField.Recurrence -> R.string.event_detail_recurrence
-    EventFormField.Availability -> R.string.event_edit_availability
-    EventFormField.Visibility -> R.string.event_edit_visibility
-    EventFormField.Color -> R.string.event_edit_color
-    EventFormField.Attendees -> R.string.event_edit_attendees
-}
-
-private fun fieldIcon(field: EventFormField): ImageVector = when (field) {
-    EventFormField.Location -> Icons.Default.Place
-    EventFormField.Description -> Icons.AutoMirrored.Filled.Notes
-    EventFormField.Reminders -> Icons.Default.Notifications
-    EventFormField.Recurrence -> Icons.Default.Repeat
-    EventFormField.Availability -> Icons.Default.EventAvailable
-    EventFormField.Visibility -> Icons.Default.Lock
-    EventFormField.Color -> Icons.Default.Palette
-    EventFormField.Attendees -> Icons.Default.People
-}
-
 /**
  * Visibility selector: one card per level, each with its own icon; the
  * current level is highlighted. Tap picks and closes.
@@ -1891,8 +1872,9 @@ private fun ScheduleRow(
     val dateFormat = remember(locale) {
         DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
     }
-    val timeFormat = remember(locale) {
-        DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT).withLocale(locale)
+    val use24Hour = LocalUse24HourFormat.current
+    val timeFormat = remember(locale, use24Hour) {
+        timeOfDayFormatter(use24Hour, locale)
     }
     // Tappable values read as links (primary), like the location on the
     // detail screen; errors flip them to the error colour.

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

@@ -121,10 +121,18 @@ class EventEditViewModel @Inject constructor(
         val allowColorOnUnsupported: Boolean,
     )
 
-    /** Writable calendars — the only valid event targets. */
-    private val writableCalendars: Flow<List<CalendarSource>> = repository.calendars()
-        .map { calendars -> calendars.filter { it.canModifyContents } }
-        .catch { emit(emptyList()) }
+    /**
+     * Writable calendars — the only valid event targets. Disabled calendars are
+     * excluded, so you can't create into a calendar you've removed from the app;
+     * a last-used preselect landing on a now-disabled calendar falls back to the
+     * first remaining writable one (handled by [resolvedCalendarId] and [state]).
+     */
+    private val writableCalendars: Flow<List<CalendarSource>> = combine(
+        repository.calendars(),
+        prefs.disabledCalendarIds,
+    ) { calendars, disabled ->
+        calendars.filter { it.canModifyContents && it.id !in disabled }
+    }.catch { emit(emptyList()) }
 
     /** The target calendar id, resolved exactly as the form shows it. */
     private val resolvedCalendarId: Flow<Long?> = combine(

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

@@ -30,11 +30,16 @@ class FilterViewModel @Inject constructor(
         combine(
             repository.calendars(),
             prefs.hiddenCalendarIds,
-        ) { calendars, hidden ->
-            if (calendars.isEmpty()) {
+            prefs.disabledCalendarIds,
+        ) { calendars, hidden, disabled ->
+            // Disabled calendars are gone from the app entirely — they don't
+            // belong in the drawer's hide/show list (you can't hide what's
+            // already disabled). They live only in Settings → Calendars.
+            val enabled = calendars.filterNot { it.id in disabled }
+            if (enabled.isEmpty()) {
                 FilterUiState.Failure(FailureReason.NoCalendarsConfigured)
             } else {
-                FilterUiState.Success(groupByAccount(calendars, hidden))
+                FilterUiState.Success(groupByAccount(enabled, hidden))
             }
         }
             .catch { emit(FilterUiState.Failure(FailureReason.ProviderUnavailable)) }

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

@@ -7,6 +7,7 @@ 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.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
@@ -56,6 +57,7 @@ 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() {
 
@@ -79,11 +81,17 @@ class ImportViewModel @Inject constructor(
                     form = parsed.events.single().toEventForm(TimeZone.currentSystemDefault()),
                     warnings = parsed.warnings,
                 )
-                else -> ImportUiState.Many(
-                    events = parsed.events,
-                    warnings = parsed.warnings,
-                    calendars = repository.calendars().first().filter { it.canModifyContents },
-                )
+                else -> {
+                    // A disabled calendar is removed from the app, so it can't be
+                    // an import target — exclude it alongside the read-only ones.
+                    val disabled = prefs.disabledCalendarIds.first()
+                    ImportUiState.Many(
+                        events = parsed.events,
+                        warnings = parsed.warnings,
+                        calendars = repository.calendars().first()
+                            .filter { it.canModifyContents && it.id !in disabled },
+                    )
+                }
             }
         }
     }

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

@@ -54,6 +54,8 @@ import de.jeanlucmakiola.calendula.ui.common.GroupedRow
 import de.jeanlucmakiola.calendula.ui.common.InlineTextField
 import de.jeanlucmakiola.calendula.ui.common.Position
 import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
 import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.ui.common.positionOf
 import java.time.Instant as JavaInstant
@@ -217,12 +219,11 @@ private fun searchSummary(event: EventInstance): String {
     val dateText = remember(locale) {
         DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
     }.format(start)
+    val use24Hour = LocalUse24HourFormat.current
     val timeText = if (event.isAllDay) {
         stringResource(R.string.event_detail_all_day)
     } else {
-        remember(locale) {
-            DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT).withLocale(locale)
-        }.format(start)
+        remember(locale, use24Hour) { timeOfDayFormatter(use24Hour, locale) }.format(start)
     }
     val base = "$dateText · $timeText"
     return event.location?.takeIf { it.isNotBlank() }?.let { "$base · $it" } ?: base

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

@@ -39,14 +39,18 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.BugReport
 import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.Dashboard
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.ExpandLess
 import androidx.compose.material.icons.filled.ExpandMore
+import androidx.compose.material.icons.filled.Favorite
 import androidx.compose.material.icons.filled.Gavel
 import androidx.compose.material.icons.filled.Language
 import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.Palette
+import androidx.compose.material.icons.filled.Translate
 import androidx.compose.material.icons.filled.Tune
+import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
@@ -82,6 +86,7 @@ import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.data.crash.CrashReporter
 import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
 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.domain.EventFormField
 import de.jeanlucmakiola.calendula.qs.NewEventTileService
@@ -90,6 +95,8 @@ import de.jeanlucmakiola.calendula.ui.crash.openIssueTracker
 import de.jeanlucmakiola.calendula.ui.crash.submitCrashReport
 import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
 import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
+import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
+import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.calendula.ui.common.CollapsingScaffold
 import de.jeanlucmakiola.calendula.ui.common.GroupedRow
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
@@ -103,7 +110,12 @@ import de.jeanlucmakiola.calendula.ui.common.TimePickerAlert
 import de.jeanlucmakiola.calendula.ui.common.positionOf
 import de.jeanlucmakiola.calendula.ui.common.reminderLeadTimeLabel
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
+import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldIcon
+import de.jeanlucmakiola.calendula.ui.common.eventFormFieldLabel
+import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalTime
+import java.time.format.TextStyle as JavaTextStyle
 import java.util.Calendar
 
 /** The settings sub-screens reached from the hub's category rows. */
@@ -212,6 +224,12 @@ private fun SettingsHub(
             onClick = onManageCalendars,
         )
         LanguageRow(position = Position.Middle)
+        // One-tap add of the "New event" Quick Settings tile. The system prompt
+        // is API 33+; on older versions the tile is still addable manually from
+        // the QS editor, so the row simply doesn't appear here.
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            QuickSettingsTileRow(position = Position.Middle)
+        }
         ReportProblemRow(position = Position.Bottom)
 
         AppVersionText()
@@ -253,6 +271,24 @@ private fun ReportProblemRow(position: Position) {
     }
 }
 
+/**
+ * Asks the system to add the "New event" Quick Settings tile (API 33+). A
+ * top-level action row, like [ReportProblemRow] — the tile is a system-surface
+ * shortcut, not part of any one settings category.
+ */
+@RequiresApi(Build.VERSION_CODES.TIRAMISU)
+@Composable
+private fun QuickSettingsTileRow(position: Position) {
+    val context = LocalContext.current
+    GroupedRow(
+        title = stringResource(R.string.settings_qs_tile),
+        summary = stringResource(R.string.settings_qs_tile_hint),
+        position = position,
+        leading = { CategoryIcon(Icons.Default.Dashboard, ChipAccent.Neutral) },
+        onClick = { requestAddQsTile(context) },
+    )
+}
+
 @Composable
 private fun LanguageRow(position: Position) {
     val context = LocalContext.current
@@ -283,6 +319,18 @@ private fun LanguageRow(position: Position) {
                 AppLanguage.apply(it)
             },
             onDismiss = { showDialog = false },
+            // Invite contributions right where users pick their language.
+            header = {
+                val translateUrl = stringResource(R.string.about_translate_url)
+                GroupedRow(
+                    title = stringResource(R.string.settings_translate),
+                    summary = stringResource(R.string.settings_translate_hint),
+                    position = Position.Alone,
+                    leading = { CategoryIcon(Icons.Default.Translate, ChipAccent.Neutral) },
+                    onClick = { openUrl(context, translateUrl) },
+                )
+                Spacer(Modifier.height(16.dp))
+            },
         )
     }
 }
@@ -292,6 +340,7 @@ private fun AboutCard() {
     val context = LocalContext.current
     val sourceUrl = stringResource(R.string.about_source_url)
     val licenseUrl = stringResource(R.string.about_license_url)
+    val supportUrl = stringResource(R.string.about_support_url)
 
     Surface(
         color = MaterialTheme.colorScheme.surfaceContainerHigh,
@@ -350,6 +399,19 @@ private fun AboutCard() {
                     Text(stringResource(R.string.settings_license))
                 }
             }
+            Spacer(Modifier.height(8.dp))
+            FilledTonalButton(
+                onClick = { openUrl(context, supportUrl) },
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Icon(
+                    Icons.Default.Favorite,
+                    contentDescription = null,
+                    modifier = Modifier.size(18.dp),
+                )
+                Spacer(Modifier.width(8.dp))
+                Text(stringResource(R.string.settings_about_support))
+            }
         }
     }
 }
@@ -408,24 +470,22 @@ private fun AppearanceScreen(
 ) {
     var showTheme by remember { mutableStateOf(false) }
     var showWeekStart by remember { mutableStateOf(false) }
+    var showTimeFormat by remember { mutableStateOf(false) }
     var showDefaultView by remember { mutableStateOf(false) }
+    var showAgendaScreenRange by remember { mutableStateOf(false) }
+    var showAgendaWidgetRange by remember { mutableStateOf(false) }
 
     CollapsingScaffold(
         title = stringResource(R.string.settings_section_appearance),
         onBack = onBack,
     ) {
+        // 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_default_view),
-            summary = stringResource(state.defaultView.labelRes),
-            position = Position.Middle,
-            onClick = { showDefaultView = true },
-        )
         GroupedRow(
             title = stringResource(R.string.settings_dynamic_color),
             summary = if (state.dynamicColorAvailable) {
@@ -433,7 +493,7 @@ private fun AppearanceScreen(
             } else {
                 stringResource(R.string.settings_dynamic_color_unavailable)
             },
-            position = Position.Middle,
+            position = Position.Bottom,
             trailing = {
                 Switch(
                     checked = state.dynamicColor,
@@ -447,12 +507,68 @@ private fun AppearanceScreen(
                 null
             },
         )
+
+        Spacer(Modifier.height(16.dp))
+
+        // Calendar — view, week, and timeline formatting
+        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.Bottom,
+            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_hour_lines),
+            summary = stringResource(R.string.settings_hour_lines_summary),
+            position = Position.Bottom,
+            trailing = {
+                Switch(
+                    checked = state.showHourLines,
+                    onCheckedChange = viewModel::setShowHourLines,
+                )
+            },
+            onClick = { viewModel.setShowHourLines(!state.showHourLines) },
+        )
+
+        Spacer(Modifier.height(16.dp))
+
+        // Agenda
+        GroupedRow(
+            title = stringResource(R.string.settings_agenda_range),
+            summary = agendaRangeLabel(state.agendaScreenRange),
+            position = Position.Top,
+            onClick = { showAgendaScreenRange = true },
+        )
+        GroupedRow(
+            title = stringResource(R.string.settings_agenda_widget_range),
+            summary = agendaRangeLabel(state.agendaWidgetRange),
+            position = Position.Middle,
+            onClick = { showAgendaWidgetRange = true },
+        )
+        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) },
+        )
     }
 
     if (showTheme) {
@@ -468,13 +584,41 @@ private fun AppearanceScreen(
     if (showWeekStart) {
         OptionPicker(
             title = stringResource(R.string.settings_week_start),
-            options = WeekStartPref.entries,
+            options = WEEK_START_OPTIONS,
             selected = state.weekStart,
             label = { weekStartLabel(it) },
             onSelect = viewModel::setWeekStart,
             onDismiss = { showWeekStart = false },
         )
     }
+    if (showAgendaScreenRange) {
+        AgendaRangePicker(
+            title = stringResource(R.string.settings_agenda_range),
+            description = stringResource(R.string.settings_agenda_range_hint),
+            selected = state.agendaScreenRange,
+            onSelect = viewModel::setAgendaScreenRange,
+            onDismiss = { showAgendaScreenRange = false },
+        )
+    }
+    if (showAgendaWidgetRange) {
+        AgendaRangePicker(
+            title = stringResource(R.string.settings_agenda_widget_range),
+            description = stringResource(R.string.settings_agenda_widget_range_hint),
+            selected = state.agendaWidgetRange,
+            onSelect = viewModel::setAgendaWidgetRange,
+            onDismiss = { showAgendaWidgetRange = false },
+        )
+    }
+    if (showTimeFormat) {
+        OptionPicker(
+            title = stringResource(R.string.settings_time_format),
+            options = TimeFormatPref.entries,
+            selected = state.timeFormat,
+            label = { timeFormatLabel(it) },
+            onSelect = viewModel::setTimeFormat,
+            onDismiss = { showTimeFormat = false },
+        )
+    }
     if (showDefaultView) {
         OptionPicker(
             title = stringResource(R.string.settings_default_view),
@@ -508,8 +652,17 @@ private fun EventFormScreen(
         fields.forEachIndexed { index, field ->
             val checked = field in state.defaultFormFields
             GroupedRow(
-                title = stringResource(formFieldLabel(field)),
+                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,
@@ -540,20 +693,6 @@ private fun EventFormScreen(
                 )
             },
         )
-
-        // One-tap add of the "New event" Quick Settings tile. The system prompt
-        // is API 33+; on older versions the tile is still addable manually from
-        // the QS editor, so the row simply doesn't appear there.
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
-            Spacer(Modifier.height(24.dp))
-            val context = LocalContext.current
-            GroupedRow(
-                title = stringResource(R.string.settings_qs_tile),
-                summary = stringResource(R.string.settings_qs_tile_hint),
-                position = Position.Alone,
-                onClick = { requestAddQsTile(context) },
-            )
-        }
     }
 }
 
@@ -605,6 +744,7 @@ private fun NotificationsScreen(
     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(
@@ -642,69 +782,11 @@ private fun NotificationsScreen(
             onClick = { showAllDayReminderTime = true },
         )
 
-        // Per-calendar overrides: each writable calendar may keep, drop, or
-        // replace the global default — separately for timed and all-day events.
-        if (state.writableCalendars.isNotEmpty()) {
-            Spacer(Modifier.height(24.dp))
-            Text(
-                text = stringResource(R.string.settings_calendar_reminders_hint),
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                modifier = Modifier.padding(horizontal = 16.dp, vertical = 4.dp),
-            )
-            state.writableCalendars.forEach { calendar ->
-                Spacer(Modifier.height(16.dp))
-                val expanded = calendar.id in expandedCalendars
-                // Calendar card; tapping expands it into a grouped list of three
-                // (the card + the timed and all-day override 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 = calendarExpandEnter(),
-                    exit = calendarCollapseExit(),
-                ) {
-                    Column {
-                        val timed = state.perCalendarReminderOverride.choiceFor(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.choiceFor(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) },
-                        )
-                    }
-                }
-            }
-        }
-
-        // Delivery reliability: Android's battery optimisation can delay or drop
-        // the calendar provider's reminder broadcast. A soft, optional exemption
-        // (system-settings deep-link, no special permission) improves on-time
-        // delivery; shown as live status, reversible by the user at any time.
+        // 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(
@@ -714,7 +796,7 @@ private fun NotificationsScreen(
             } else {
                 stringResource(R.string.settings_reliable_delivery_hint)
             },
-            position = Position.Alone,
+            position = Position.Top,
             trailing = if (batteryExempt) {
                 {
                     Icon(
@@ -730,13 +812,88 @@ private fun NotificationsScreen(
         )
 
         // Snooze: how long the notification's "Snooze" action defers a reminder.
-        Spacer(Modifier.height(24.dp))
         GroupedRow(
             title = stringResource(R.string.settings_snooze_duration),
             summary = snoozeDurationLabel(state.snoozeMinutes),
-            position = Position.Alone,
+            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 = calendarExpandEnter(),
+                exit = calendarCollapseExit(),
+            ) {
+                Column {
+                    state.writableCalendars.forEach { calendar ->
+                        Spacer(Modifier.height(16.dp))
+                        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 = calendarExpandEnter(),
+                            exit = calendarCollapseExit(),
+                        ) {
+                            Column {
+                                val timed = state.perCalendarReminderOverride.choiceFor(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.choiceFor(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) {
@@ -957,17 +1114,6 @@ private fun openUrl(context: Context, url: String) {
     runCatching { context.startActivity(intent) }
 }
 
-private fun formFieldLabel(field: EventFormField): Int = when (field) {
-    EventFormField.Location -> R.string.event_detail_location
-    EventFormField.Description -> R.string.event_detail_description
-    EventFormField.Reminders -> R.string.event_detail_reminders
-    EventFormField.Recurrence -> R.string.event_detail_recurrence
-    EventFormField.Availability -> R.string.event_edit_availability
-    EventFormField.Visibility -> R.string.event_edit_visibility
-    EventFormField.Color -> R.string.event_edit_color
-    EventFormField.Attendees -> R.string.event_edit_attendees
-}
-
 @Composable
 private fun themeLabel(mode: ThemeMode): String = stringResource(
     when (mode) {
@@ -977,12 +1123,25 @@ private fun themeLabel(mode: ThemeMode): String = stringResource(
     },
 )
 
+/** 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
-private fun weekStartLabel(pref: WeekStartPref): String = stringResource(
+private 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) {
-        WeekStartPref.AUTO -> R.string.settings_week_start_auto
-        WeekStartPref.MONDAY -> R.string.settings_week_start_monday
-        WeekStartPref.SUNDAY -> R.string.settings_week_start_sunday
+        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
     },
 )
 

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

@@ -2,9 +2,11 @@ package de.jeanlucmakiola.calendula.ui.settings
 
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 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.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 
 /**
@@ -17,7 +19,17 @@ data class SettingsUiState(
     val themeMode: ThemeMode = ThemeMode.SYSTEM,
     val dynamicColor: Boolean = true,
     val dynamicColorAvailable: Boolean = true,
-    val weekStart: WeekStartPref = WeekStartPref.AUTO,
+    val weekStart: WeekStartPref = WeekStartPref.Auto,
+    /** Clock convention for time labels (v2.11). AUTO follows the system setting. */
+    val timeFormat: TimeFormatPref = TimeFormatPref.AUTO,
+    /** Whether the week/day timeline draws an hour separator line (v2.11). */
+    val showHourLines: 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). */
+    val agendaWidgetRange: AgendaRange = AgendaRange.Month,
+    /** Whether the agenda shows its top range bar — header + switcher (v2.11). */
+    val agendaShowRangeBar: Boolean = true,
     /** The calendar view the app opens on, and the home of the view back stack (M1). */
     val defaultView: CalendarView = CalendarView.Week,
     /** Optional event-form fields shown by default (rest behind "more fields"). */

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

@@ -1,17 +1,28 @@
 package de.jeanlucmakiola.calendula.ui.settings
 
+import android.content.Context
 import android.os.Build
+import androidx.glance.appwidget.GlanceAppWidgetManager
+import androidx.glance.appwidget.state.updateAppWidgetState
+import androidx.glance.appwidget.updateAll
 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.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.prefs.CalendarReminderOverride
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 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.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventFormField
+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.widget.agenda.AGENDA_RANGE_KEY
+import de.jeanlucmakiola.calendula.widget.agenda.AgendaWidget
+import de.jeanlucmakiola.calendula.widget.month.MonthWidget
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -20,12 +31,15 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import javax.inject.Inject
 
 @HiltViewModel
 class SettingsViewModel @Inject constructor(
     private val prefs: SettingsPrefs,
     repository: CalendarRepository,
+    @ApplicationContext private val appContext: Context,
 ) : ViewModel() {
 
     private val dynamicColorAvailable = Build.VERSION.SDK_INT >= Build.VERSION_CODES.S
@@ -73,10 +87,24 @@ class SettingsViewModel @Inject constructor(
             ) { overrides, allDayOverrides, calendars ->
                 ReminderOverrides(overrides, allDayOverrides, calendars)
             },
-            prefs.defaultView,
-        ) { base, defaults, overrides, defaultView ->
+            combine(
+                prefs.defaultView,
+                prefs.agendaScreenRange,
+                prefs.agendaWidgetRange,
+                prefs.timeFormat,
+                prefs.showHourLines,
+            ) { view, screenRange, widgetRange, timeFormat, showHourLines ->
+                ViewSettings(view, screenRange, widgetRange, timeFormat, showHourLines)
+            },
+            prefs.agendaShowRangeBar,
+        ) { base, defaults, overrides, views, showRangeBar ->
             base.copy(
-                defaultView = defaultView,
+                defaultView = views.defaultView,
+                agendaScreenRange = views.agendaScreenRange,
+                agendaWidgetRange = views.agendaWidgetRange,
+                timeFormat = views.timeFormat,
+                showHourLines = views.showHourLines,
+                agendaShowRangeBar = showRangeBar,
                 allowColorOnUnsupportedCalendars = defaults.allowColor,
                 defaultReminderMinutes = defaults.defaultReminder,
                 defaultAllDayReminderMinutes = defaults.allDayReminder,
@@ -92,6 +120,12 @@ class SettingsViewModel @Inject constructor(
             initialValue = SettingsUiState(dynamicColorAvailable = dynamicColorAvailable),
         )
 
+    // Serialises widget redraws so a rapid flip-and-flip-back can't run two
+    // updateAll calls at once — concurrent calls coalesce around a stale read
+    // and can leave the widget on the intermediate value. Held sequentially,
+    // the last call reads the final committed pref and renders it.
+    private val widgetRefreshMutex = Mutex()
+
     private data class ReminderDefaults(
         val allowColor: Boolean,
         val defaultReminder: Int?,
@@ -106,6 +140,14 @@ class SettingsViewModel @Inject constructor(
         val calendars: List<CalendarSource>,
     )
 
+    private data class ViewSettings(
+        val defaultView: CalendarView,
+        val agendaScreenRange: AgendaRange,
+        val agendaWidgetRange: AgendaRange,
+        val timeFormat: TimeFormatPref,
+        val showHourLines: Boolean,
+    )
+
     fun setThemeMode(mode: ThemeMode) {
         viewModelScope.launch { prefs.setThemeMode(mode) }
     }
@@ -115,7 +157,48 @@ class SettingsViewModel @Inject constructor(
     }
 
     fun setWeekStart(pref: WeekStartPref) {
-        viewModelScope.launch { prefs.setWeekStart(pref) }
+        viewModelScope.launch {
+            prefs.setWeekStart(pref)
+            // Both widgets depend on the week start (month weekday header; the
+            // agenda widget's "this week" range).
+            widgetRefreshMutex.withLock {
+                AgendaWidget().updateAll(appContext)
+                MonthWidget().updateAll(appContext)
+            }
+        }
+    }
+
+    fun setAgendaScreenRange(range: AgendaRange) {
+        viewModelScope.launch { prefs.setAgendaScreenRange(range) }
+    }
+
+    fun setAgendaWidgetRange(range: AgendaRange) {
+        viewModelScope.launch {
+            prefs.setAgendaWidgetRange(range)
+            widgetRefreshMutex.withLock {
+                // Push the range into each instance's Glance state and recompose.
+                // The widget reads it via currentState, so this reflects reliably
+                // even when updateAll only recomposes a live session (it does not
+                // re-run provideGlance's data preamble).
+                val manager = GlanceAppWidgetManager(appContext)
+                manager.getGlanceIds(AgendaWidget::class.java).forEach { id ->
+                    updateAppWidgetState(appContext, id) { it[AGENDA_RANGE_KEY] = range.storageValue() }
+                }
+                AgendaWidget().updateAll(appContext)
+            }
+        }
+    }
+
+    fun setAgendaShowRangeBar(enabled: Boolean) {
+        viewModelScope.launch { prefs.setAgendaShowRangeBar(enabled) }
+    }
+
+    fun setTimeFormat(pref: TimeFormatPref) {
+        viewModelScope.launch { prefs.setTimeFormat(pref) }
+    }
+
+    fun setShowHourLines(enabled: Boolean) {
+        viewModelScope.launch { prefs.setShowHourLines(enabled) }
     }
 
     fun setDefaultView(view: CalendarView) {

app/src/main/java/de/jeanlucmakiola/calendula/ui/week/WeekScreen.kt

@@ -83,6 +83,11 @@ import de.jeanlucmakiola.calendula.ui.common.calendarSlideTransition
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
 import de.jeanlucmakiola.calendula.ui.common.rememberReduceMotion
 import de.jeanlucmakiola.calendula.ui.common.currentLocale
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.LocalShowHourLines
+import de.jeanlucmakiola.calendula.ui.common.formatHourLabel
+import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
+import de.jeanlucmakiola.calendula.ui.common.hourSeparatorLines
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.calendula.ui.common.pastelize
@@ -572,6 +577,8 @@ private fun Timeline(
 ) {
     val totalHeight = HOUR_HEIGHT * 24
     val dark = isSystemInDarkTheme()
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
 
     Box(modifier = Modifier.fillMaxSize()) {
         // Gutter and day columns are two scroll viewports that SHARE one scroll
@@ -595,7 +602,7 @@ private fun Timeline(
                     ) {
                         if (h > 0) {
                             Text(
-                                text = "%02d".format(h),
+                                text = formatHourLabel(h, use24Hour, locale),
                                 style = MaterialTheme.typography.labelSmall,
                                 color = MaterialTheme.colorScheme.onSurfaceVariant,
                                 modifier = Modifier
@@ -650,6 +657,8 @@ private fun DayColumnCard(
     modifier: Modifier = Modifier,
 ) {
     val hourPx = with(LocalDensity.current) { HOUR_HEIGHT.toPx() }
+    val showHourLines = LocalShowHourLines.current
+    val hourLineColor = MaterialTheme.colorScheme.outlineVariant
     Card(
         // Plain rectangular columns — the soft corners come from the outer
         // rounded scroll viewport, so inner rounding would look odd at the edges.
@@ -662,6 +671,9 @@ private fun DayColumnCard(
         BoxWithConstraints(
             modifier = Modifier
                 .fillMaxSize()
+                // Faint hour separators sit over the column background but under
+                // the event blocks (drawBehind paints before the children).
+                .hourSeparatorLines(showHourLines, hourPx, hourLineColor)
                 // Tap an empty slot to create an event there; taps on event
                 // blocks are consumed by their own handler first. Snaps to hour.
                 .pointerInput(date) {
@@ -704,7 +716,10 @@ private fun EventBlock(
     modifier: Modifier = Modifier,
 ) {
     val title = block.event.title.ifBlank { stringResource(R.string.event_untitled) }
-    val timeLabel = "${minToHm(block.startMin)}–${minToHm(block.endMin)}"
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
+    val timeLabel = "${minToHm(block.startMin, use24Hour, locale)}–" +
+        minToHm(block.endMin, use24Hour, locale)
     val showTime = block.endMin - block.startMin >= 45
     Box(
         modifier = modifier
@@ -773,8 +788,8 @@ private fun WeekLoading() {
     }
 }
 
-private fun minToHm(min: Int): String =
-    if (min >= MINUTES_PER_DAY) "24:00" else "%02d:%02d".format(min / 60, min % 60)
+private fun minToHm(min: Int, is24Hour: Boolean, locale: java.util.Locale): String =
+    formatMinuteOfDay(min, is24Hour, locale)
 
 private fun formatWeekRange(weekStart: LocalDate): String {
     val locale = Locale.getDefault()

app/src/main/java/de/jeanlucmakiola/calendula/widget/WidgetData.kt

@@ -4,9 +4,11 @@ import android.Manifest
 import android.content.Context
 import android.content.pm.PackageManager
 import androidx.core.content.ContextCompat
+import de.jeanlucmakiola.calendula.data.prefs.is24Hour
 import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaDay
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.agendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.groupAgendaDays
 import kotlinx.coroutines.flow.first
@@ -23,9 +25,6 @@ import kotlinx.datetime.toLocalDateTime
 import java.util.Locale
 import kotlin.time.Clock
 
-/** How far ahead the agenda widget loads (a month of upcoming events). */
-private const val AGENDA_WIDGET_DAYS = 30
-
 /**
  * How far either side of today the month widget pre-loads. The displayed month
  * is chosen reactively in the composition, so one wide read covers ~13 months of
@@ -46,7 +45,22 @@ internal fun Context.hasCalendarPermission(): Boolean =
 sealed interface AgendaWidgetData {
     /** Calendar permission not granted — the widget can't read events. */
     data object NeedsPermission : AgendaWidgetData
-    data class Ready(val today: LocalDate, val days: List<AgendaDay>) : AgendaWidgetData
+    data class Ready(
+        val today: LocalDate,
+        /**
+         * Days with events across the **widest** selectable window. The displayed
+         * range is sliced from this in the composition (read reactively from
+         * Glance state), so a range change is pure recomposition rather than a
+         * flaky widget session restart — the same approach the month widget uses.
+         */
+        val days: List<AgendaDay>,
+        /** Resolved clock convention for event time labels (the time-format pref). */
+        val is24Hour: Boolean,
+        /** First day of the week, for the calendar-aligned "this week" range. */
+        val weekStart: DayOfWeek,
+        /** Saved range pref — the fallback when an instance has no Glance state yet. */
+        val savedRange: AgendaRange,
+    ) : AgendaWidgetData
 }
 
 /**
@@ -91,9 +105,24 @@ internal suspend fun Context.loadAgendaWidgetData(): AgendaWidgetData {
     if (!hasCalendarPermission()) return AgendaWidgetData.NeedsPermission
     val zone = systemZone()
     val anchor = today(zone)
-    val repo = widgetEntryPoint().calendarRepository()
-    val instances = repo.instances(agendaRange(anchor, AGENDA_WIDGET_DAYS, zone)).first()
-    return AgendaWidgetData.Ready(today = anchor, days = groupAgendaDays(anchor, instances, zone))
+    val ep = widgetEntryPoint()
+    val prefs = ep.settingsPrefs()
+    val savedRange = prefs.agendaWidgetRange.first()
+    val weekStart = prefs.weekStart.first().resolveFirstDay(Locale.getDefault())
+    // Load the widest selectable window once; the displayed range is sliced in
+    // the composition from Glance state, so changing the range is a plain
+    // recomposition and never depends on the widget session restarting.
+    val window = agendaRange(anchor, AgendaRange.MAX_CUSTOM_DAYS - 1, zone)
+    val instances = ep.calendarRepository().instances(window).first()
+    val is24Hour = prefs.timeFormat.first()
+        .is24Hour(android.text.format.DateFormat.is24HourFormat(this))
+    return AgendaWidgetData.Ready(
+        today = anchor,
+        days = groupAgendaDays(anchor, instances, zone),
+        is24Hour = is24Hour,
+        weekStart = weekStart,
+        savedRange = savedRange,
+    )
 }
 
 /** One-shot wide read backing the month widget's grid for any nearby month. */

app/src/main/java/de/jeanlucmakiola/calendula/widget/agenda/AgendaWidget.kt

@@ -6,6 +6,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.glance.ColorFilter
 import androidx.glance.GlanceId
 import androidx.glance.GlanceModifier
@@ -24,6 +25,8 @@ import androidx.glance.appwidget.lazy.items
 import androidx.glance.appwidget.provideContent
 import androidx.glance.appwidget.updateAll
 import androidx.glance.background
+import androidx.glance.currentState
+import androidx.glance.state.PreferencesGlanceStateDefinition
 import androidx.glance.layout.Alignment
 import androidx.glance.layout.Box
 import androidx.glance.layout.Column
@@ -41,7 +44,11 @@ import androidx.glance.text.TextStyle
 import de.jeanlucmakiola.calendula.MainActivity
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
+import de.jeanlucmakiola.calendula.ui.agenda.dayCount
+import de.jeanlucmakiola.calendula.ui.agenda.parseAgendaRange
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
 import de.jeanlucmakiola.calendula.ui.common.pastelize
 import de.jeanlucmakiola.calendula.widget.AgendaWidgetData
 import de.jeanlucmakiola.calendula.widget.CalendulaGlanceTheme
@@ -62,8 +69,20 @@ import java.util.Locale
  * of events grouped under day headers (the Google "Schedule" widget model).
  * Reuses the app's [groupAgendaDays] grouping so it matches the in-app agenda.
  */
+/**
+ * Per-instance Glance state key holding the agenda range (as [AgendaRange.storageValue]).
+ * The range is read reactively in the composition ([currentState]) so a settings
+ * change is reflected by plain recomposition — `updateAll` does NOT reliably
+ * re-run the `provideGlance` preamble for a live widget session, so loading the
+ * range there and slicing it would silently keep the stale value (mirrors the
+ * month widget's MONTH_INDEX_KEY approach).
+ */
+internal val AGENDA_RANGE_KEY = stringPreferencesKey("agenda_range")
+
 class AgendaWidget : GlanceAppWidget() {
 
+    override val stateDefinition = PreferencesGlanceStateDefinition
+
     override suspend fun provideGlance(context: Context, id: GlanceId) {
         val data = context.loadAgendaWidgetData()
         val dark = (context.resources.configuration.uiMode and
@@ -101,12 +120,21 @@ private fun AgendaWidgetBody(data: AgendaWidgetData, dark: Boolean) {
         Spacer(GlanceModifier.height(4.dp))
         when (data) {
             AgendaWidgetData.NeedsPermission -> WidgetMessage(R.string.widget_needs_permission)
-            is AgendaWidgetData.Ready ->
-                if (data.days.isEmpty()) {
+            is AgendaWidgetData.Ready -> {
+                // Range read reactively from per-instance Glance state (falls back
+                // to the saved pref for a freshly placed widget), then the wide
+                // pre-loaded window is sliced to it — pure recomposition.
+                val range = parseAgendaRange(currentState(AGENDA_RANGE_KEY), data.savedRange)
+                val rangeEnd = data.today.plus(
+                    range.dayCount(data.today, data.weekStart) - 1,
+                    DateTimeUnit.DAY,
+                )
+                val visibleDays = data.days.filter { it.date <= rangeEnd }
+                if (visibleDays.isEmpty()) {
                     WidgetMessage(R.string.agenda_empty_title)
                 } else {
                     val rows = buildList {
-                        data.days.forEach { day ->
+                        visibleDays.forEach { day ->
                             add(AgendaRow.Header(day.date, data.today))
                             day.events.forEach { add(AgendaRow.Event(it)) }
                         }
@@ -115,11 +143,12 @@ private fun AgendaWidgetBody(data: AgendaWidgetData, dark: Boolean) {
                         items(rows.size) { index ->
                             when (val row = rows[index]) {
                                 is AgendaRow.Header -> DayHeaderRow(row.date, row.today)
-                                is AgendaRow.Event -> EventRow(row.event, dark)
+                                is AgendaRow.Event -> EventRow(row.event, dark, data.is24Hour)
                             }
                         }
                     }
                 }
+            }
         }
     }
 }
@@ -195,7 +224,7 @@ private fun DayHeaderRow(date: LocalDate, today: LocalDate) {
 }
 
 @Composable
-private fun EventRow(event: EventInstance, dark: Boolean) {
+private fun EventRow(event: EventInstance, dark: Boolean, is24Hour: Boolean) {
     val context = androidx.glance.LocalContext.current
     val title = event.title.ifBlank { context.getString(R.string.event_untitled) }
     Row(
@@ -230,7 +259,7 @@ private fun EventRow(event: EventInstance, dark: Boolean) {
                 style = TextStyle(color = GlanceTheme.colors.onSurface, fontSize = 14.sp),
             )
             Text(
-                text = eventTimeSummary(context, event),
+                text = eventTimeSummary(context, event, is24Hour),
                 maxLines = 1,
                 style = TextStyle(color = GlanceTheme.colors.onSurfaceVariant, fontSize = 12.sp),
             )
@@ -269,17 +298,17 @@ private fun agendaDayLabel(context: Context, date: LocalDate, today: LocalDate):
     return if (relative != null) "$relative · $formatted" else formatted
 }
 
-private fun eventTimeSummary(context: Context, event: EventInstance): String {
+private fun eventTimeSummary(context: Context, event: EventInstance, is24Hour: Boolean): String {
     val time = if (event.isAllDay) {
         context.getString(R.string.event_detail_all_day)
     } else {
-        "${formatTime(event.start)} – ${formatTime(event.end)}"
+        "${formatTime(event.start, is24Hour)} – ${formatTime(event.end, is24Hour)}"
     }
     val location = event.location?.takeIf { it.isNotBlank() }
     return if (location != null) "$time · $location" else time
 }
 
-private fun formatTime(instant: Instant): String {
+private fun formatTime(instant: Instant, is24Hour: Boolean): String {
     val t = instant.toLocalDateTime(zone()).time
-    return "%02d:%02d".format(t.hour, t.minute)
+    return formatTimeOfDay(t.hour, t.minute, is24Hour, Locale.getDefault())
 }

app/src/main/res/values-de/strings.xml

@@ -230,8 +230,7 @@
     <string name="agenda_today_action">Heute</string>
     <string name="agenda_header_today">Heute</string>
     <string name="agenda_header_tomorrow">Morgen</string>
-    <string name="agenda_empty_title">Nichts geplant</string>
-    <string name="agenda_empty_subtitle">Anstehende Termine erscheinen hier.</string>
+    <string name="agenda_empty_title">Alles erledigt</string>
 
     <!-- Terminsuche -->
     <string name="search_action">Suchen</string>
@@ -276,8 +275,31 @@
     <string name="settings_dynamic_color_unavailable">Erfordert Android 12 oder neuer</string>
     <string name="settings_week_start">Wochenstart</string>
     <string name="settings_week_start_auto">Automatisch</string>
-    <string name="settings_week_start_monday">Montag</string>
-    <string name="settings_week_start_sunday">Sonntag</string>
+    <string name="settings_time_format">Zeitformat</string>
+    <string name="settings_time_format_auto">Automatisch</string>
+    <string name="settings_time_format_12h">12-Stunden (2:00 PM)</string>
+    <string name="settings_time_format_24h">24-Stunden (14:00)</string>
+    <string name="settings_hour_lines">Stundenlinien</string>
+    <string name="settings_hour_lines_summary">Trennlinie zu jeder vollen Stunde in Wochen- und Tagesansicht anzeigen</string>
+    <string name="settings_agenda_range">Agenda-Zeitraum</string>
+    <string name="settings_agenda_range_hint">Wie weit im Voraus die Agenda-Ansicht Termine anzeigt.</string>
+    <string name="settings_agenda_widget_range">Agenda-Widget-Zeitraum</string>
+    <string name="settings_agenda_widget_range_hint">Wie weit im Voraus das Agenda-Widget auf dem Startbildschirm Termine anzeigt.</string>
+    <string name="settings_agenda_range_bar">Zeitraum-Leiste</string>
+    <string name="settings_agenda_range_bar_hint">Eine Leiste oben in der Agenda anzeigen, die den dargestellten Zeitraum benennt, mit einer Schaltfläche zum Wechseln des Zeitraums für die Sitzung</string>
+    <string name="agenda_range_day">Heute</string>
+    <string name="agenda_range_this_week">Diese Woche</string>
+    <string name="agenda_range_this_month">Dieser Monat</string>
+    <string name="agenda_range_week">Nächste 7 Tage</string>
+    <string name="agenda_range_month">Nächste 30 Tage</string>
+    <string name="agenda_range_custom">Benutzerdefiniert…</string>
+    <string name="agenda_range_custom_hint">Tage</string>
+    <string name="agenda_range_override_hint">Nur vorübergehend — wird beim erneuten Öffnen von Calendula auf deinen gespeicherten Zeitraum zurückgesetzt.</string>
+    <string name="agenda_range_showing_label">Alle anstehenden Termine für</string>
+    <plurals name="agenda_range_days">
+        <item quantity="one">%d Tag</item>
+        <item quantity="other">%d Tage</item>
+    </plurals>
     <string name="settings_section_event_form">Termin-Formular</string>
     <string name="settings_form_fields_hint">Standardmäßig angezeigte Felder — alles Weitere liegt hinter \"Weitere Felder\"</string>
     <string name="settings_color_unsupported">Farben auf nicht unterstützten Kalendern erlauben</string>
@@ -315,6 +337,7 @@
     <string name="settings_license_value">MIT</string>
     <string name="settings_about_author">von Jean-Luc Makiola</string>
     <string name="settings_about_source">Quellcode</string>
+    <string name="settings_about_support">Entwicklung unterstützen</string>
     <string name="settings_about_version">Version %1$s</string>
     <string name="settings_about_logo_desc">Calendula-App-Symbol</string>
     <string name="settings_report_problem">Problem melden</string>

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

@@ -197,6 +197,14 @@
         <item quantity="one">%d hour</item>
         <item quantity="other">%d hours</item>
     </plurals>
+    <plurals name="duration_days">
+        <item quantity="one">%d day</item>
+        <item quantity="other">%d days</item>
+    </plurals>
+    <plurals name="duration_weeks">
+        <item quantity="one">%d week</item>
+        <item quantity="other">%d weeks</item>
+    </plurals>
 
     <!-- Shared event strings -->
     <string name="event_untitled">(No title)</string>
@@ -231,8 +239,7 @@
     <string name="agenda_today_action">Today</string>
     <string name="agenda_header_today">Today</string>
     <string name="agenda_header_tomorrow">Tomorrow</string>
-    <string name="agenda_empty_title">Nothing scheduled</string>
-    <string name="agenda_empty_subtitle">Upcoming events will show up here.</string>
+    <string name="agenda_empty_title">You\'re all caught up</string>
 
     <!-- Event search -->
     <string name="search_action">Search</string>
@@ -269,8 +276,31 @@
     <string name="settings_dynamic_color_unavailable">Requires Android 12 or newer</string>
     <string name="settings_week_start">Week starts on</string>
     <string name="settings_week_start_auto">Automatic</string>
-    <string name="settings_week_start_monday">Monday</string>
-    <string name="settings_week_start_sunday">Sunday</string>
+    <string name="settings_time_format">Time format</string>
+    <string name="settings_time_format_auto">Automatic</string>
+    <string name="settings_time_format_12h">12-hour (2:00 PM)</string>
+    <string name="settings_time_format_24h">24-hour (14:00)</string>
+    <string name="settings_hour_lines">Hour lines</string>
+    <string name="settings_hour_lines_summary">Show a separator line at each hour in week and day view</string>
+    <string name="settings_agenda_range">Agenda range</string>
+    <string name="settings_agenda_range_hint">How far ahead the Agenda screen lists events.</string>
+    <string name="settings_agenda_widget_range">Agenda widget range</string>
+    <string name="settings_agenda_widget_range_hint">How far ahead the agenda home-screen widget lists events.</string>
+    <string name="settings_agenda_range_bar">Range bar</string>
+    <string name="settings_agenda_range_bar_hint">Show a bar at the top of the agenda naming the dates shown, with a button to switch the range for the session</string>
+    <string name="agenda_range_day">Today</string>
+    <string name="agenda_range_this_week">This week</string>
+    <string name="agenda_range_this_month">This month</string>
+    <string name="agenda_range_week">Next 7 days</string>
+    <string name="agenda_range_month">Next 30 days</string>
+    <string name="agenda_range_custom">Custom…</string>
+    <string name="agenda_range_custom_hint">Days</string>
+    <string name="agenda_range_override_hint">Just for now — resets to your saved range when you reopen Calendula.</string>
+    <string name="agenda_range_showing_label">Showing all upcoming events for</string>
+    <plurals name="agenda_range_days">
+        <item quantity="one">%d day</item>
+        <item quantity="other">%d days</item>
+    </plurals>
     <string name="settings_section_event_form">New event form</string>
     <string name="settings_form_fields_hint">Fields shown by default — everything else sits behind \"More fields\"</string>
     <string name="settings_color_unsupported">Allow colors on unsupported calendars</string>
@@ -287,6 +317,7 @@
     <string name="reminder_custom_amount">Amount</string>
     <string name="reminder_custom_with_value">Custom (%1$s)</string>
     <string name="reminder_custom_set">Set</string>
+    <string name="settings_calendar_reminders_title">Per-calendar reminders</string>
     <string name="settings_calendar_reminders_hint">Override the default per calendar — separately for timed and all-day events. A calendar can keep the default, drop it, or set its own.</string>
     <string name="settings_calendar_reminder_inherits">Default (%1$s)</string>
     <string name="settings_reliable_delivery">Reliable delivery</string>
@@ -299,6 +330,8 @@
     <string name="settings_section_language">Language</string>
     <string name="settings_language">App language</string>
     <string name="settings_language_auto">System default</string>
+    <string name="settings_translate">Help translate</string>
+    <string name="settings_translate_hint">Add or improve a language on Weblate</string>
     <!-- Hub category subtitles -->
     <string name="settings_appearance_subtitle">Theme, default view, week start</string>
     <string name="settings_event_form_subtitle">Default fields for new events</string>
@@ -308,6 +341,7 @@
     <string name="settings_license_value">MIT</string>
     <string name="settings_about_author">by Jean-Luc Makiola</string>
     <string name="settings_about_source">Source</string>
+    <string name="settings_about_support">Support development</string>
     <string name="settings_about_version">Version %1$s</string>
     <string name="settings_about_logo_desc">Calendula app icon</string>
     <string name="settings_report_problem">Report a problem</string>
@@ -318,9 +352,14 @@
     <string name="calendars_local_header">Your calendars</string>
     <string name="calendars_local_empty">No local calendars yet. Create one to keep events on this device only.</string>
     <string name="calendars_add">Add calendar</string>
+    <string name="calendars_disable_hint">Turn a calendar off to remove it from the app — its events, filters and pickers. Nothing is deleted, and you can turn it back on here anytime.</string>
+    <string name="calendars_show_in_app_a11y">Show \"%1$s\" in the app</string>
     <string name="calendars_synced_header">Synced calendars</string>
     <string name="calendars_synced_hint">These come from accounts on your device. Create and edit them in their own app.</string>
-    <string name="calendars_manage_in_app">Manage</string>
+    <string name="calendars_manage_in_app">Manage in app</string>
+    <string name="calendars_account_menu_a11y">More options for %1$s</string>
+    <string name="calendars_enable_all">Enable all</string>
+    <string name="calendars_disable_all">Disable all</string>
     <string name="calendars_add_account">Add account</string>
     <string name="calendars_new_title">New calendar</string>
     <string name="calendars_edit_title">Edit calendar</string>
@@ -334,6 +373,26 @@
     <string name="calendars_backup_header">Backup</string>
     <string name="calendars_backup_hint">Local calendars aren\'t synced anywhere, so export them to an .ics file to keep a copy.</string>
     <string name="calendars_backup_action">Export as .ics file</string>
+    <string name="calendars_auto_backup">Automatic backup</string>
+    <string name="calendars_auto_backup_hint">Periodically export your local calendars to a folder as an .ics file.</string>
+    <string name="calendars_auto_backup_folder">Backup folder</string>
+    <string name="calendars_auto_backup_folder_unset">Tap to choose a folder</string>
+    <string name="calendars_auto_backup_interval">Interval</string>
+    <string name="calendars_auto_backup_every">Every %1$s</string>
+    <string name="calendars_auto_backup_interval_min">Minimum 30 minutes.</string>
+    <string name="calendars_auto_backup_status_never">No automatic backup yet</string>
+    <string name="calendars_auto_backup_status_ok">Last backup: %1$s</string>
+    <string name="calendars_auto_backup_status_failed">Last backup failed: %1$s</string>
+    <string name="backup_channel_name">Backup</string>
+    <string name="backup_channel_description">Warns if automatic backups fail repeatedly.</string>
+    <string name="backup_failed_title">Automatic backup failed</string>
+    <string name="backup_failed_text">Calendula couldn\'t write the backup file. Check the backup folder in Settings.</string>
+    <string-array name="backup_interval_units">
+        <item>Minutes</item>
+        <item>Hours</item>
+        <item>Days</item>
+        <item>Weeks</item>
+    </string-array>
     <string name="calendars_backup_failed">Couldn\'t export the backup.</string>
     <plurals name="calendars_backup_done">
         <item quantity="one">Exported %d event.</item>
@@ -378,6 +437,8 @@
 
     <string name="about_source_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/calendula</string>
     <string name="about_license_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/calendula/src/branch/main/LICENSE</string>
+    <string name="about_support_url" translatable="false">https://ko-fi.com/jeanlucmakiola</string>
+    <string name="about_translate_url" translatable="false">https://weblate.dev.jeanlucmakiola.de/engage/calendula/</string>
 
     <!-- Crash reporting: a captured report the user can submit, by hand, as a
          Gitea issue (the app sends nothing automatically). -->

app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositoryImplTest.kt

@@ -170,6 +170,74 @@ class CalendarRepositoryImplTest {
         }
     }
 
+    @Test
+    fun `instances drops events whose calendar the user disabled`(@TempDir tempDir: Path) = runTest {
+        val prefs = newPrefs(tempDir)
+        prefs.setDisabledCalendarIds(setOf(2L))
+        val fake = FakeCalendarDataSource().apply {
+            instancesResult = { _, _ ->
+                listOf(
+                    makeEvent(10L, "Enabled", calendarId = 1L),
+                    makeEvent(11L, "Disabled", calendarId = 2L),
+                )
+            }
+        }
+        val repo = CalendarRepositoryImpl(fake, prefs, newSettings(tempDir), UnconfinedTestDispatcher(testScheduler))
+
+        val range = Instant.fromEpochMilliseconds(0)..Instant.fromEpochMilliseconds(10_000L)
+        repo.instances(range).test {
+            assertThat(awaitItem().map { it.title }).containsExactly("Enabled")
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
+    @Test
+    fun `instances applies the union of hidden and disabled sets`(@TempDir tempDir: Path) = runTest {
+        val prefs = newPrefs(tempDir)
+        prefs.setHiddenCalendarIds(setOf(2L))
+        prefs.setDisabledCalendarIds(setOf(3L))
+        val fake = FakeCalendarDataSource().apply {
+            instancesResult = { _, _ ->
+                listOf(
+                    makeEvent(10L, "Shown", calendarId = 1L),
+                    makeEvent(11L, "Hidden", calendarId = 2L),
+                    makeEvent(12L, "Disabled", calendarId = 3L),
+                )
+            }
+        }
+        val repo = CalendarRepositoryImpl(fake, prefs, newSettings(tempDir), UnconfinedTestDispatcher(testScheduler))
+
+        val range = Instant.fromEpochMilliseconds(0)..Instant.fromEpochMilliseconds(10_000L)
+        repo.instances(range).test {
+            assertThat(awaitItem().map { it.title }).containsExactly("Shown")
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
+    @Test
+    fun `instances re-emits when the disabled set changes`(@TempDir tempDir: Path) = runTest {
+        val prefs = newPrefs(tempDir)
+        val fake = FakeCalendarDataSource().apply {
+            instancesResult = { _, _ ->
+                listOf(
+                    makeEvent(10L, "A", calendarId = 1L),
+                    makeEvent(11L, "B", calendarId = 2L),
+                )
+            }
+        }
+        val repo = CalendarRepositoryImpl(fake, prefs, newSettings(tempDir), UnconfinedTestDispatcher(testScheduler))
+
+        val range = Instant.fromEpochMilliseconds(0)..Instant.fromEpochMilliseconds(10_000L)
+        repo.instances(range).test {
+            assertThat(awaitItem().map { it.title }).containsExactly("A", "B").inOrder()
+
+            prefs.setDisabledCalendarIds(setOf(2L))
+
+            assertThat(awaitItem().map { it.title }).containsExactly("A")
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
     @Test
     fun `createEvent delegates and returns the new id`(@TempDir tempDir: Path) = runTest {
         val fake = FakeCalendarDataSource().apply { nextInsertId = 77L }

app/src/test/java/de/jeanlucmakiola/calendula/data/prefs/CalendarPrefsTest.kt

@@ -50,4 +50,34 @@ class CalendarPrefsTest {
         }
         assertThat(prefs.hiddenCalendarIds.first()).isEqualTo(setOf(1L, 3L))
     }
+
+    @Test
+    fun `disabledCalendarIds defaults to empty when unset`(@TempDir tempDir: Path) = runTest {
+        val prefs = CalendarPrefs(newDataStore(tempDir))
+        assertThat(prefs.disabledCalendarIds.first()).isEmpty()
+    }
+
+    @Test
+    fun `setDisabledCalendarIds round-trips through DataStore`(@TempDir tempDir: Path) = runTest {
+        val prefs = CalendarPrefs(newDataStore(tempDir))
+        prefs.setDisabledCalendarIds(setOf(1L, 42L, 7L))
+        assertThat(prefs.disabledCalendarIds.first()).isEqualTo(setOf(1L, 42L, 7L))
+    }
+
+    @Test
+    fun `setting empty disabled set clears storage`(@TempDir tempDir: Path) = runTest {
+        val prefs = CalendarPrefs(newDataStore(tempDir))
+        prefs.setDisabledCalendarIds(setOf(1L))
+        prefs.setDisabledCalendarIds(emptySet())
+        assertThat(prefs.disabledCalendarIds.first()).isEmpty()
+    }
+
+    @Test
+    fun `hidden and disabled sets are stored independently`(@TempDir tempDir: Path) = runTest {
+        val prefs = CalendarPrefs(newDataStore(tempDir))
+        prefs.setHiddenCalendarIds(setOf(1L))
+        prefs.setDisabledCalendarIds(setOf(2L))
+        assertThat(prefs.hiddenCalendarIds.first()).isEqualTo(setOf(1L))
+        assertThat(prefs.disabledCalendarIds.first()).isEqualTo(setOf(2L))
+    }
 }

app/src/test/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefsTest.kt

@@ -5,6 +5,7 @@ import androidx.datastore.preferences.core.PreferenceDataStoreFactory
 import androidx.datastore.preferences.core.Preferences
 import com.google.common.truth.Truth.assertThat
 import de.jeanlucmakiola.calendula.domain.EventFormField
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.runTest
 import kotlinx.datetime.DayOfWeek
@@ -25,7 +26,7 @@ class SettingsPrefsTest {
         val prefs = SettingsPrefs(newDataStore(tempDir))
         assertThat(prefs.themeMode.first()).isEqualTo(ThemeMode.SYSTEM)
         assertThat(prefs.dynamicColor.first()).isTrue()
-        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.AUTO)
+        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.Auto)
     }
 
     @Test
@@ -43,10 +44,62 @@ class SettingsPrefsTest {
     }
 
     @Test
-    fun `week start round-trips`(@TempDir tempDir: Path) = runTest {
+    fun `week start round-trips any day`(@TempDir tempDir: Path) = runTest {
         val prefs = SettingsPrefs(newDataStore(tempDir))
-        prefs.setWeekStart(WeekStartPref.SUNDAY)
-        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.SUNDAY)
+        prefs.setWeekStart(WeekStartPref.Day(DayOfWeek.SATURDAY))
+        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.Day(DayOfWeek.SATURDAY))
+    }
+
+    @Test
+    fun `legacy MONDAY week-start value migrates to Day`(@TempDir tempDir: Path) = runTest {
+        val store = newDataStore(tempDir)
+        val prefs = SettingsPrefs(store)
+        store.updateData { p ->
+            val m = p.toMutablePreferences()
+            m[SettingsPrefs.WEEK_START_KEY] = "MONDAY"
+            m
+        }
+        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.Day(DayOfWeek.MONDAY))
+    }
+
+    @Test
+    fun `garbage week-start value falls back to Auto`(@TempDir tempDir: Path) = runTest {
+        val store = newDataStore(tempDir)
+        val prefs = SettingsPrefs(store)
+        store.updateData { p ->
+            val m = p.toMutablePreferences()
+            m[SettingsPrefs.WEEK_START_KEY] = "FUNDAY"
+            m
+        }
+        assertThat(prefs.weekStart.first()).isEqualTo(WeekStartPref.Auto)
+    }
+
+    @Test
+    fun `time format defaults to auto and round-trips`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        assertThat(prefs.timeFormat.first()).isEqualTo(TimeFormatPref.AUTO)
+        prefs.setTimeFormat(TimeFormatPref.TWELVE_HOUR)
+        assertThat(prefs.timeFormat.first()).isEqualTo(TimeFormatPref.TWELVE_HOUR)
+    }
+
+    @Test
+    fun `hour lines default off and round-trips`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        assertThat(prefs.showHourLines.first()).isFalse()
+        prefs.setShowHourLines(true)
+        assertThat(prefs.showHourLines.first()).isTrue()
+    }
+
+    @Test
+    fun `agenda ranges default to month and round-trip independently`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        assertThat(prefs.agendaScreenRange.first()).isEqualTo(AgendaRange.Month)
+        assertThat(prefs.agendaWidgetRange.first()).isEqualTo(AgendaRange.Month)
+
+        prefs.setAgendaScreenRange(AgendaRange.Custom(14))
+        prefs.setAgendaWidgetRange(AgendaRange.Week)
+        assertThat(prefs.agendaScreenRange.first()).isEqualTo(AgendaRange.Custom(14))
+        assertThat(prefs.agendaWidgetRange.first()).isEqualTo(AgendaRange.Week)
     }
 
     @Test
@@ -252,13 +305,15 @@ class SettingsPrefsTest {
 
     @Test
     fun `explicit week-start prefs resolve regardless of locale`() {
-        assertThat(WeekStartPref.MONDAY.resolveFirstDay(Locale.US)).isEqualTo(DayOfWeek.MONDAY)
-        assertThat(WeekStartPref.SUNDAY.resolveFirstDay(Locale.GERMANY)).isEqualTo(DayOfWeek.SUNDAY)
+        assertThat(WeekStartPref.Day(DayOfWeek.MONDAY).resolveFirstDay(Locale.US))
+            .isEqualTo(DayOfWeek.MONDAY)
+        assertThat(WeekStartPref.Day(DayOfWeek.SATURDAY).resolveFirstDay(Locale.GERMANY))
+            .isEqualTo(DayOfWeek.SATURDAY)
     }
 
     @Test
     fun `auto week start follows the locale convention`() {
-        assertThat(WeekStartPref.AUTO.resolveFirstDay(Locale.GERMANY)).isEqualTo(DayOfWeek.MONDAY)
-        assertThat(WeekStartPref.AUTO.resolveFirstDay(Locale.US)).isEqualTo(DayOfWeek.SUNDAY)
+        assertThat(WeekStartPref.Auto.resolveFirstDay(Locale.GERMANY)).isEqualTo(DayOfWeek.MONDAY)
+        assertThat(WeekStartPref.Auto.resolveFirstDay(Locale.US)).isEqualTo(DayOfWeek.SUNDAY)
     }
 }

app/src/test/java/de/jeanlucmakiola/calendula/data/reminders/ReminderTimeTextTest.kt

@@ -26,10 +26,24 @@ class ReminderTimeTextTest {
             isAllDay = false,
             zone = berlin,
             locale = Locale.GERMANY,
+            is24Hour = true,
         )
         assertThat(text).isEqualTo("09:30 – 10:00")
     }
 
+    @Test
+    fun `12-hour preference renders an am-pm time range`() {
+        val text = reminderTimeText(
+            beginMillis = millisAt(LocalDateTime.of(2026, 6, 11, 14, 0), berlin),
+            endMillis = millisAt(LocalDateTime.of(2026, 6, 11, 15, 0), berlin),
+            isAllDay = false,
+            zone = berlin,
+            locale = Locale.US,
+            is24Hour = false,
+        )
+        assertThat(text).isEqualTo("2:00 PM – 3:00 PM")
+    }
+
     @Test
     fun `timed event crossing midnight includes both dates`() {
         val text = reminderTimeText(
@@ -38,6 +52,7 @@ class ReminderTimeTextTest {
             isAllDay = false,
             zone = berlin,
             locale = Locale.GERMANY,
+            is24Hour = true,
         )
         assertThat(text).contains("11.06.2026")
         assertThat(text).contains("12.06.2026")
@@ -54,6 +69,7 @@ class ReminderTimeTextTest {
             // 02:00 in Berlin — naive local reading would shift the day.
             zone = berlin,
             locale = Locale.GERMANY,
+            is24Hour = true,
         )
         assertThat(text).isEqualTo("11.06.2026")
     }
@@ -66,6 +82,7 @@ class ReminderTimeTextTest {
             isAllDay = true,
             zone = berlin,
             locale = Locale.GERMANY,
+            is24Hour = true,
         )
         assertThat(text).isEqualTo("11.06.2026 – 12.06.2026")
     }
@@ -79,6 +96,7 @@ class ReminderTimeTextTest {
             isAllDay = true,
             zone = berlin,
             locale = Locale.GERMANY,
+            is24Hour = true,
         )
         assertThat(text).isEqualTo("11.06.2026")
     }

app/src/test/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaRangeTest.kt

@@ -0,0 +1,83 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import com.google.common.truth.Truth.assertThat
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import org.junit.jupiter.api.Test
+
+class AgendaRangeTest {
+
+    // A reference anchor: 2026-06-17 is a Wednesday.
+    private val wednesday = LocalDate(2026, 6, 17)
+
+    @Test
+    fun `rolling ranges have fixed 1, 7, 30 day counts regardless of anchor`() {
+        assertThat(AgendaRange.Day.dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(1)
+        assertThat(AgendaRange.Week.dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(7)
+        assertThat(AgendaRange.Month.dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(30)
+    }
+
+    @Test
+    fun `this week runs through the day before the week repeats`() {
+        // Mon-start week: Wed → Wed,Thu,Fri,Sat,Sun = 5 days (everything before next Monday).
+        assertThat(AgendaRange.ThisWeek.dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(5)
+        // On the first day of the week the whole 7 days remain.
+        val monday = LocalDate(2026, 6, 15)
+        assertThat(AgendaRange.ThisWeek.dayCount(monday, DayOfWeek.MONDAY)).isEqualTo(7)
+        // A Sunday-start week shifts the boundary: Wed → 4 days left (through Saturday).
+        assertThat(AgendaRange.ThisWeek.dayCount(wednesday, DayOfWeek.SUNDAY)).isEqualTo(4)
+    }
+
+    @Test
+    fun `this month runs through the last day of the month`() {
+        // June has 30 days: the 17th leaves 14 days (17..30 inclusive).
+        assertThat(AgendaRange.ThisMonth.dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(14)
+        // February 2026 (non-leap) has 28 days.
+        assertThat(AgendaRange.ThisMonth.dayCount(LocalDate(2026, 2, 20), DayOfWeek.MONDAY))
+            .isEqualTo(9)
+    }
+
+    @Test
+    fun `custom day count is clamped to bounds`() {
+        assertThat(AgendaRange.Custom(45).dayCount(wednesday, DayOfWeek.MONDAY)).isEqualTo(45)
+        assertThat(AgendaRange.Custom(0).dayCount(wednesday, DayOfWeek.MONDAY))
+            .isEqualTo(AgendaRange.MIN_CUSTOM_DAYS)
+        assertThat(AgendaRange.Custom(9_999).dayCount(wednesday, DayOfWeek.MONDAY))
+            .isEqualTo(AgendaRange.MAX_CUSTOM_DAYS)
+    }
+
+    @Test
+    fun `fixed ranges round-trip through storage`() {
+        listOf(
+            AgendaRange.Day,
+            AgendaRange.Week,
+            AgendaRange.Month,
+            AgendaRange.ThisWeek,
+            AgendaRange.ThisMonth,
+        ).forEach { range ->
+            assertThat(parseAgendaRange(range.storageValue(), default = AgendaRange.Day))
+                .isEqualTo(range)
+        }
+    }
+
+    @Test
+    fun `custom range round-trips through storage`() {
+        val range = AgendaRange.Custom(14)
+        assertThat(range.storageValue()).isEqualTo("CUSTOM:14")
+        assertThat(parseAgendaRange("CUSTOM:14", default = AgendaRange.Day))
+            .isEqualTo(AgendaRange.Custom(14))
+    }
+
+    @Test
+    fun `garbage and null fall back to the default`() {
+        assertThat(parseAgendaRange(null, default = AgendaRange.Month)).isEqualTo(AgendaRange.Month)
+        assertThat(parseAgendaRange("YEAR", default = AgendaRange.Week)).isEqualTo(AgendaRange.Week)
+        assertThat(parseAgendaRange("CUSTOM:abc", default = AgendaRange.Day)).isEqualTo(AgendaRange.Day)
+    }
+
+    @Test
+    fun `out-of-range custom value clamps on parse`() {
+        assertThat(parseAgendaRange("CUSTOM:9999", default = AgendaRange.Day))
+            .isEqualTo(AgendaRange.Custom(AgendaRange.MAX_CUSTOM_DAYS))
+    }
+}

app/src/test/java/de/jeanlucmakiola/calendula/ui/common/TimeFormatTest.kt

@@ -0,0 +1,37 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.jupiter.api.Test
+import java.util.Locale
+
+class TimeFormatTest {
+
+    @Test
+    fun `24-hour format is zero-padded HH mm`() {
+        assertThat(formatTimeOfDay(9, 5, is24Hour = true, Locale.US)).isEqualTo("09:05")
+        assertThat(formatTimeOfDay(14, 0, is24Hour = true, Locale.US)).isEqualTo("14:00")
+        assertThat(formatTimeOfDay(0, 0, is24Hour = true, Locale.US)).isEqualTo("00:00")
+    }
+
+    @Test
+    fun `12-hour format adds a localised am-pm marker`() {
+        assertThat(formatTimeOfDay(14, 0, is24Hour = false, Locale.US)).isEqualTo("2:00 PM")
+        assertThat(formatTimeOfDay(0, 30, is24Hour = false, Locale.US)).isEqualTo("12:30 AM")
+        assertThat(formatTimeOfDay(12, 0, is24Hour = false, Locale.US)).isEqualTo("12:00 PM")
+    }
+
+    @Test
+    fun `minute-of-day end-of-day renders 24 00 in 24h and midnight in 12h`() {
+        assertThat(formatMinuteOfDay(1_440, is24Hour = true, Locale.US)).isEqualTo("24:00")
+        assertThat(formatMinuteOfDay(1_440, is24Hour = false, Locale.US)).isEqualTo("12:00 AM")
+        assertThat(formatMinuteOfDay(13 * 60 + 15, is24Hour = true, Locale.US)).isEqualTo("13:15")
+    }
+
+    @Test
+    fun `hour label is zero-padded in 24h and compact am-pm in 12h`() {
+        assertThat(formatHourLabel(13, is24Hour = true, Locale.US)).isEqualTo("13")
+        assertThat(formatHourLabel(13, is24Hour = false, Locale.US)).isEqualTo("1 PM")
+        assertThat(formatHourLabel(1, is24Hour = false, Locale.US)).isEqualTo("1 AM")
+        assertThat(formatHourLabel(0, is24Hour = false, Locale.US)).isEqualTo("12 AM")
+    }
+}

docs/BUILDING.md

@@ -0,0 +1,24 @@
+# Building from source
+
+Calendula builds with the standard Android Gradle toolchain — no extra setup
+beyond the SDK and a JDK.
+
+## Requirements
+
+- **Android SDK 36+**
+- **JDK 17** — if your default JDK is not 17, set `JAVA_HOME` explicitly.
+
+The Gradle wrapper is checked in, so you don't need a system Gradle.
+
+## Common tasks
+
+```bash
+./gradlew assembleDebug   # debug APK → app/build/outputs/apk/debug/
+./gradlew test            # JVM unit tests
+./gradlew lint            # Android lint
+```
+
+## Release builds
+
+Release signing and the publishing pipeline are documented separately in
+[RELEASING.md](RELEASING.md).

docs/fdroid-official/de.jeanlucmakiola.calendula.yml

@@ -21,6 +21,7 @@ AuthorName: Jean-Luc Makiola
 SourceCode: https://gitea.jeanlucmakiola.de/makiolaj/calendula
 IssueTracker: https://gitea.jeanlucmakiola.de/makiolaj/calendula/issues
 Changelog: https://gitea.jeanlucmakiola.de/makiolaj/calendula/src/branch/main/CHANGELOG.md
+Donate: https://ko-fi.com/jeanlucmakiola
 
 AutoName: Calendula
 

fastlane/metadata/android/en-US/changelogs/21000.txt

@@ -0,0 +1,14 @@
+### Added
+- Turn a calendar off across the whole app. Settings → Calendars now has a
+  switch on every calendar — both your own and synced ones. Switching one off
+  removes it everywhere: its events disappear from all views and search, and it
+  drops out of the drawer's hide/show filter, the event-form calendar picker and
+  the import target picker. Unlike hiding (the quick per-view checkbox in the
+  drawer), a disabled calendar leaves the app entirely until you turn it back on.
+  Nothing is deleted and no other app is affected — it's a Calendula-only view
+  choice — so you can re-enable it any time from the same screen, where disabled
+  calendars stay listed but dimmed.
+- An optional way to support development. Settings → About now has a "Support
+  development" button that opens Ko-fi in your browser. It's a plain donation
+  link with no perks attached, and it needs no new permissions — Calendula still
+  has no internet access of its own and just hands the link to your browser.

fastlane/metadata/android/en-US/changelogs/21100.txt

@@ -0,0 +1,50 @@
+### Added
+- Start the week on any day. The **Week starts on** setting (Settings →
+  Appearance) now offers every weekday — not just Monday or Sunday — alongside
+  the automatic, locale-based default. Thanks to @zmaherdev for the suggestion
+  ([#3]).
+- Choose a 12- or 24-hour clock. A new **Time format** setting (Settings →
+  Appearance) lets you force a 12-hour (2:00 PM) or 24-hour (14:00) clock, or
+  follow the system setting automatically. It applies everywhere times appear —
+  the week and day timelines, agenda, event details, search and reminders — so
+  the format is now consistent across the whole app. Thanks to @zmaherdev for
+  the suggestion ([#6]).
+- Optional hour lines in the timeline. A new **Hour lines** switch (Settings →
+  Appearance) draws a faint separator at each hour in the week and day views,
+  making it easier to see when events start and end. Off by default. Thanks to
+  @zmaherdev for the suggestion ([#5]).
+- Limit how far ahead the agenda looks, and switch it on the fly. New **Agenda
+  range** and **Agenda widget range** settings (Settings → Appearance) let the
+  agenda screen and its home-screen widget each show just today, the rest of this
+  week, the rest of this month, a rolling 7 or 30 days, or a custom number of
+  days — "This week" follows your week-start. The agenda also gains a bar at the
+  top naming the exact dates in view, with a button to switch the range just for
+  the current session (it resets when you reopen the app); the bar can be turned
+  off. Thanks to @zmaherdev for the suggestion ([#4]).
+- Automatic backup of local calendars. A new **Automatic backup** option
+  (Settings → Calendars → Backup) periodically exports your local calendars to an
+  `.ics` file in a folder you choose, on an interval you set (from 30 minutes up).
+  Useful for file-based syncing such as Syncthing, or simply as a safety net — it
+  is a one-way export and never touches your synced accounts. Thanks to @shield
+  for the discussion that inspired it ([#7], [#8]).
+- Field icons in the event-form settings. Each optional-field toggle (Settings →
+  Event form) now shows the same icon the field uses in the new-event form, so
+  the list is easier to scan.
+- Help translate Calendula. A **Help translate** link at the top of **Settings →
+  App language** opens the project's Weblate, where you can add or improve a
+  language in your browser — no coding needed. Contributions in any language are
+  welcome.
+
+### Changed
+- Tidied **Settings → Appearance** into clearer groups (theme & colour, calendar,
+  agenda), and the agenda's empty state now reads "You're all caught up".
+- Reworked **Settings → Calendars**. Local and synced calendars are now grouped
+  into collapsible, source-branded cards — each account shows its app's icon —
+  with a per-account menu to enable or disable all of its calendars at once or
+  open the account in its source app.
+- Reorganised **Settings → Notifications**: reliable-delivery and snooze settings
+  moved up with the other global reminder options, and the per-calendar reminder
+  overrides now fold into a single expandable section.
+- Moved **Add Quick Settings tile** out of the event-form section to its own
+  top-level entry in Settings.
+

fdroid-metadata/de.jeanlucmakiola.calendula.yml

@@ -8,3 +8,4 @@ Categories:
 
 SourceCode: https://gitea.jeanlucmakiola.de/makiolaj/calendula
 IssueTracker: https://gitea.jeanlucmakiola.de/makiolaj/calendula/issues
+Donate: https://ko-fi.com/jeanlucmakiola

gradle/libs.versions.toml

@@ -26,10 +26,14 @@ lifecycleCompose = "2.10.0"
 androidxTestRules = "1.7.0"
 # Glance: 1.1.1 is the latest stable (1.2.0 is still rc, 1.3.0 alpha).
 glance = "1.1.1"
+work = "2.10.1"
+documentfile = "1.0.1"
 
 [libraries]
 # AndroidX core
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
+androidx-work-runtime-ktx = { group = "androidx.work", name = "work-runtime-ktx", version.ref = "work" }
+androidx-documentfile = { group = "androidx.documentfile", name = "documentfile", version.ref = "documentfile" }
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntime" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }