refactor(translations): move Help translate into the App language page

Per review, it shouldn't be a top-level Settings entry: the "Help translate"
link now sits at the top of the full-screen App language picker (OptionPicker
gains an optional header slot). Updated README + changelog wording to match.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -30,10 +30,32 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   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
 
@@ -661,3 +683,5 @@ automatically, with zero telemetry and no internet permission.
 [#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

@@ -68,7 +68,8 @@ 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
 
@@ -108,6 +109,17 @@ without reinstalling. Or build from source — see below.
 - **[Architecture](docs/ARCHITECTURE.md)** — the layered design and key pipelines
 - **[Roadmap](.planning/ROADMAP.md)** — what's shipped and what's next
 
+## 🌍 Translations
+
+Calendula ships in German and English, and you're warmly invited to add your
+language. Translations are managed on a self-hosted **Weblate**:
+
+**→ [Help translate Calendula](https://weblate.dev.jeanlucmakiola.de/engage/calendula/)**
+
+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
 
 [MIT](LICENSE) — Jean-Luc Makiola, 2026

app/build.gradle.kts

@@ -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/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/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/SettingsPrefs.kt

@@ -5,6 +5,7 @@ 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
@@ -327,6 +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(',')
@@ -366,9 +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. */

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
@@ -26,20 +30,28 @@ 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.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
@@ -61,20 +73,33 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringArrayResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
-import androidx.compose.ui.text.font.FontWeight
 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
@@ -82,7 +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". */
@@ -104,6 +128,7 @@ fun CalendarsScreen(
     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
@@ -144,10 +169,15 @@ fun CalendarsScreen(
             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,
         )
     }
 }
@@ -162,13 +192,22 @@ private fun CalendarsList(
     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) {
@@ -184,6 +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) {
@@ -208,70 +254,37 @@ 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))
-        }
+        // What the per-calendar / per-account switches below actually do.
         HintText(stringResource(R.string.calendars_disable_hint))
-        val localCount = local.size + 1
-        local.forEachIndexed { index, calendar ->
-            val disabled = calendar.id in disabledIds
-            GroupedRow(
-                title = calendar.displayName,
-                summary = calendar.description,
-                position = positionOf(index, localCount),
-                dimmed = disabled,
-                leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
-                trailing = {
-                    EnableSwitch(
-                        calendarName = calendar.displayName,
-                        enabled = !disabled,
-                        onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
-                    )
-                },
-                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.
-        if (local.isNotEmpty()) {
-            Spacer(Modifier.height(16.dp))
-            SectionHeader(stringResource(R.string.calendars_backup_header))
-            HintText(stringResource(R.string.calendars_backup_hint))
-            GroupedRow(
-                title = stringResource(R.string.calendars_backup_action),
-                position = Position.Alone,
-                leading = { LeadingAvatar(Icons.Default.FileDownload) },
-                onClick = {
-                    runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
-                },
-            )
-        }
-
-        Spacer(Modifier.height(16.dp))
-
-        // Synced calendars — read-only, grouped by account, each with a
-        // per-account "manage in source app" link.
-        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 ->
+        // 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,
-                        position = positionOf(index, cals.size),
+                        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 = {
@@ -281,17 +294,118 @@ private fun CalendarsList(
                                 onToggle = { enabled -> onSetDisabled(calendar.id, !enabled) },
                             )
                         },
+                        onClick = { onEdit(calendar) },
                     )
                 }
             }
-        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)) }
-            },
+        }
+
+        // Backup — local calendars have no sync, so a .ics export is their only
+        // safety net. Offered only when there is something to back up.
+        if (local.isNotEmpty()) {
+            Spacer(Modifier.height(16.dp))
+            SectionHeader(stringResource(R.string.calendars_backup_header))
+            HintText(stringResource(R.string.calendars_backup_hint))
+            // One connected card: the one-time export on top, then automatic
+            // backup (and its folder/interval rows when on).
+            GroupedRow(
+                title = stringResource(R.string.calendars_backup_action),
+                position = Position.Top,
+                leading = { LeadingAvatar(Icons.Default.FileDownload) },
+                onClick = {
+                    runCatching { createBackup.launch("calendula-backup-${LocalDate.now()}.ics") }
+                },
+            )
+            GroupedRow(
+                title = stringResource(R.string.calendars_auto_backup),
+                summary = stringResource(R.string.calendars_auto_backup_hint),
+                position = if (autoBackup.enabled) Position.Middle else Position.Bottom,
+                leading = { LeadingAvatar(Icons.Default.Schedule) },
+                trailing = {
+                    Switch(checked = autoBackup.enabled, onCheckedChange = onSetAutoBackupEnabled)
+                },
+                onClick = { onSetAutoBackupEnabled(!autoBackup.enabled) },
+            )
+            if (autoBackup.enabled) {
+                GroupedRow(
+                    title = stringResource(R.string.calendars_auto_backup_folder),
+                    summary = rememberFolderName(autoBackup.folderUri)
+                        ?: stringResource(R.string.calendars_auto_backup_folder_unset),
+                    position = Position.Middle,
+                    onClick = { runCatching { pickFolder.launch(null) } },
+                )
+                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 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) ->
+                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) },
+                                )
+                            },
+                        )
+                    }
+                }
+            }
+    }
+
+    if (showInterval) {
+        BackupIntervalDialog(
+            currentMinutes = autoBackup.intervalMinutes,
+            onConfirm = onSetAutoBackupInterval,
+            onDismiss = { showInterval = false },
         )
     }
 }
@@ -498,32 +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(
@@ -542,25 +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(
@@ -581,6 +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

@@ -1,13 +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
@@ -16,6 +22,7 @@ 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
@@ -33,9 +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() {
 
@@ -63,6 +72,22 @@ class CalendarsViewModel @Inject constructor(
                 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()
 
@@ -123,6 +148,63 @@ class CalendarsViewModel @Inject constructor(
         }
     }
 
+    /**
+     * 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 {
@@ -136,6 +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

@@ -140,6 +140,7 @@ fun GroupedRow(
     summary: String? = null,
     selected: Boolean = false,
     dimmed: Boolean = false,
+    container: Color? = null,
     minHeight: Dp = 72.dp,
     leading: @Composable (() -> Unit)? = null,
     trailing: @Composable (() -> Unit)? = null,
@@ -198,10 +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/Picker.kt

@@ -86,8 +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(

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
@@ -1019,9 +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),
                     )
                 }
             }
@@ -1638,28 +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.

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

@@ -39,6 +39,7 @@ 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
@@ -47,6 +48,7 @@ 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
@@ -109,6 +111,8 @@ 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
@@ -220,6 +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()
@@ -261,6 +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
@@ -291,6 +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))
+            },
         )
     }
 }
@@ -612,8 +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,
@@ -644,20 +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) },
-            )
-        }
     }
 }
 
@@ -709,6 +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(
@@ -746,69 +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(
@@ -818,7 +796,7 @@ private fun NotificationsScreen(
             } else {
                 stringResource(R.string.settings_reliable_delivery_hint)
             },
-            position = Position.Alone,
+            position = Position.Top,
             trailing = if (batteryExempt) {
                 {
                     Icon(
@@ -834,13 +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) {
@@ -1061,17 +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) {

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>
@@ -309,6 +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>
@@ -321,6 +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>
@@ -345,7 +356,10 @@
     <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>
@@ -359,6 +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>
@@ -404,6 +438,7 @@
     <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). -->

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

@@ -21,8 +21,30 @@
   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.
 

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" }