docs(design): contact special-dates calendars + per-calendar multiple reminders

Capture the full design for surfacing contact birthdays/anniversaries/custom dates as auto-updating local calendars (Codeberg #15), plus the #14 prerequisite (per-calendar multiple default reminders). One local calendar per type to reuse existing per-calendar color/visibility/reminder infra; one-way mirror with field-level managed events keyed on contact LOOKUP_KEY. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-30 14:58:14 +02:00
22 changed files with 430 additions and 435 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,28 +5,6 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

-## [Unreleased]
-
-### Added
- Set more than one default reminder per calendar. A calendar's default
-  reminders — and the global defaults under Settings → Notifications — can now
-  hold several lead times instead of just one, so new events can start with, say,
-  a reminder a week before *and* one on the day. The reminder pickers are now
-  multi-select; per-calendar overrides can still inherit the global default or
-  turn reminders off entirely. Thanks to @moonj for the suggestion ([#14]).
-
-### Fixed
- Disabled calendars no longer notify. Reminders for events in a calendar you
-  have disabled (Settings → Calendars) are now suppressed instead of still
-  popping up — matching how a disabled calendar's events already stay hidden
-  everywhere else in the app ([#17]).
- Editing a single occurrence of a recurring event works again. Choosing **Only
-  this event** and saving a change to one event in a repeating series silently
-  did nothing — the change was rejected and the edit form simply reappeared with
-  nothing applied. The edited occurrence is now stored correctly, so the change
-  lands on just that one event and leaves the rest of the series untouched
-  ([#16]).
-
 ## [2.12.0] — 2026-06-28

 ### Added
@@ -751,6 +729,3 @@ automatically, with zero telemetry and no internet permission.
 [#10]: https://codeberg.org/jlmakiola/calendula/issues/10
 [#12]: https://codeberg.org/jlmakiola/calendula/issues/12
 [#13]: https://codeberg.org/jlmakiola/calendula/issues/13
-[#14]: https://codeberg.org/jlmakiola/calendula/issues/14
-[#16]: https://codeberg.org/jlmakiola/calendula/issues/16
-[#17]: https://codeberg.org/jlmakiola/calendula/issues/17
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -90,8 +90,6 @@ android {

    buildFeatures {
        compose = true
-        // BuildConfig.DEBUG gates the in-app debug ribbon (see DebugRibbon).
-        buildConfig = true
    }

    // Don't embed AGP's dependency-metadata block in the APK signing block. It's
--- a/app/src/debug/res/values/colors.xml
+++ b/app/src/debug/res/values/colors.xml
@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-    Debug-only launcher-icon background. Production is slate (#5C6B7A); the
-    debug build paints the adaptive-icon background burnt orange instead, so the
-    debug icon reads at a glance as "not the real app" on the home screen. The
-    off-white foreground mark contrasts on both. See drawable/ic_launcher_background.
-->
-<resources>
-    <color name="ic_launcher_background">#FFB23B00</color>
-</resources>
--- a/app/src/debug/res/values/strings.xml
+++ b/app/src/debug/res/values/strings.xml
@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-    Debug-build resource overrides. Merged on top of src/main for the `debug`
-    build type only (release/releaseTest keep the production values), so the
-    debug app is unmistakable on the launcher: its own label, alongside the
-    real app thanks to the `.debug` applicationId suffix.
-->
-<resources>
-    <string name="app_name">Calendula Debug</string>
-</resources>
--- a/app/src/main/java/de/jeanlucmakiola/calendula/MainActivity.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/MainActivity.kt
@@ -8,7 +8,6 @@ import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.isSystemInDarkTheme
-import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
@@ -30,7 +29,6 @@ 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.common.DebugRibbon
 import de.jeanlucmakiola.calendula.ui.crash.CrashReportActivity
 import de.jeanlucmakiola.calendula.ui.crash.CrashReportDialog
 import de.jeanlucmakiola.calendula.ui.crash.submitCrashReport
@@ -103,24 +101,19 @@ class MainActivity : AppCompatActivity() {
                darkTheme = darkTheme,
                dynamicColor = settings.dynamicColor,
            ) {
-                Box(modifier = Modifier.fillMaxSize()) {
-                    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 },
-                        )
-                    }
-                    // A persistent corner marker so a debug build is never
-                    // mistaken for the production app; compiled out of release.
-                    if (BuildConfig.DEBUG) DebugRibbon()
+                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(
--- a/app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapper.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapper.kt
@@ -118,14 +118,8 @@ internal fun buildEventUpdateValues(
 * provider clone the series row and apply these on top. Unlike the series
 * update there is no dirty check — the exception is a fresh row, so every
 * form-backed column is written (empty optionals as explicit NULLs, since the
- * clone starts from the parent's values).
- *
- * The occurrence's length travels as DURATION, never DTEND: the provider
- * rejects DTEND on an exception outright (`CalendarProvider2`:
- * "Exceptions can't overwrite dtend") and derives the instance end from
- * DTSTART + DURATION itself, clearing the inherited RRULE in the process. This
- * matches how AOSP Calendar/Etar write exceptions; sending DTEND is what made
- * "only this event" fail on-device (Codeberg #16).
+ * clone starts from the parent's values). An exception is a single event:
+ * DTEND, never RRULE/DURATION.
 */
 internal fun buildOccurrenceExceptionValues(
    form: EventForm,
@@ -137,7 +131,7 @@ internal fun buildOccurrenceExceptionValues(
    put(CalendarContract.Events.TITLE, form.title.trim())
    put(CalendarContract.Events.ALL_DAY, if (form.isAllDay) 1 else 0)
    put(CalendarContract.Events.DTSTART, times.dtStartMillis)
-    put(CalendarContract.Events.DURATION, times.toRfc2445Duration(form.isAllDay))
+    put(CalendarContract.Events.DTEND, times.dtEndMillis)
    put(CalendarContract.Events.EVENT_TIMEZONE, times.timezone)
    put(CalendarContract.Events.AVAILABILITY, form.availability.toProviderValue())
    put(CalendarContract.Events.ACCESS_LEVEL, form.accessLevel.toProviderValue())
--- a/app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefs.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefs.kt
@@ -276,36 +276,35 @@ class SettingsPrefs @Inject constructor(
    }

    /**
-     * The default reminder lead times (minutes before start) prefilled on new
-     * **timed** events. The empty list = no default reminder — the prior
-     * behaviour, kept as the factory default so existing users aren't surprised by
-     * reminders they never asked for. Stored as a comma-joined list of minutes, or
-     * "none"/empty for no reminder (also the unset state). A legacy single value
-     * ("30") parses transparently to a one-element list. Per-calendar overrides in
-     * [perCalendarReminderOverride] take precedence; all-day events instead use
+     * The default reminder lead time (minutes before start) prefilled on new
+     * **timed** events. `null` = no default reminder — the prior behaviour, kept
+     * as the factory default so existing users aren't surprised by reminders they
+     * never asked for. Stored as a string so "none" is distinct from a numeric
+     * value (and from an unset key, which is also "none"). Per-calendar overrides
+     * in [perCalendarReminderOverride] take precedence; all-day events instead use
     * [defaultAllDayReminderMinutes]. Resolve with [resolveDefaultReminder].
     */
-    val defaultReminderMinutes: Flow<List<Int>> = store.data.map { prefs ->
-        prefs[DEFAULT_REMINDER_KEY].toReminderList()
+    val defaultReminderMinutes: Flow<Int?> = store.data.map { prefs ->
+        prefs[DEFAULT_REMINDER_KEY].toReminderMinutes()
    }

-    suspend fun setDefaultReminderMinutes(minutes: List<Int>) {
-        store.edit { it[DEFAULT_REMINDER_KEY] = minutes.toStoredReminders() }
+    suspend fun setDefaultReminderMinutes(minutes: Int?) {
+        store.edit { it[DEFAULT_REMINDER_KEY] = minutes?.toString() ?: NONE }
    }

    /**
-     * The default reminder lead times prefilled on new **all-day** events, in
+     * The default reminder lead time prefilled on new **all-day** events, in
     * minutes before the start of the day. All-day events want day-scale lead
     * times ("1 day before"), so they have their own default rather than reusing
-     * the timed one. Empty list = no default. Per-calendar overrides do **not**
-     * apply to all-day events — they always use this global value.
+     * the timed one. `null` = no default. Per-calendar overrides do **not** apply
+     * to all-day events — they always use this global value.
     */
-    val defaultAllDayReminderMinutes: Flow<List<Int>> = store.data.map { prefs ->
-        prefs[DEFAULT_ALLDAY_REMINDER_KEY].toReminderList()
+    val defaultAllDayReminderMinutes: Flow<Int?> = store.data.map { prefs ->
+        prefs[DEFAULT_ALLDAY_REMINDER_KEY].toReminderMinutes()
    }

-    suspend fun setDefaultAllDayReminderMinutes(minutes: List<Int>) {
-        store.edit { it[DEFAULT_ALLDAY_REMINDER_KEY] = minutes.toStoredReminders() }
+    suspend fun setDefaultAllDayReminderMinutes(minutes: Int?) {
+        store.edit { it[DEFAULT_ALLDAY_REMINDER_KEY] = minutes?.toString() ?: NONE }
    }

    /**
@@ -342,13 +341,13 @@ class SettingsPrefs @Inject constructor(
    /**
     * Per-calendar overrides of [defaultReminderMinutes] for **timed** events,
     * keyed by calendar id. A calendar **present** in the map overrides the global
-     * timed default for its new events: an **empty** list means "no reminder", a
-     * non-empty list means those lead times. A calendar **absent** from the map
-     * inherits the global default. Serialised as `id=value;id=value`, where a value
-     * is a comma-joined minute list or `none` for an explicit no-reminder override.
-     * (All-day events ignore this and use [defaultAllDayReminderMinutes].)
+     * timed default for its new events: a `null` value means "no reminder", an int
+     * means that lead time. A calendar **absent** from the map inherits the global
+     * default. Serialised as `id=value;id=value`, with `none` for an explicit
+     * no-reminder override. (All-day events ignore this and use
+     * [defaultAllDayReminderMinutes].)
     */
-    val perCalendarReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
+    val perCalendarReminderOverride: Flow<Map<Long, Int?>> = store.data.map { prefs ->
        parseReminderOverrides(prefs[CALENDAR_REMINDER_OVERRIDE_KEY])
    }

@@ -365,7 +364,7 @@ class SettingsPrefs @Inject constructor(
     * events, with the same semantics as [perCalendarReminderOverride] (absent =
     * inherit the global all-day default; present null = no reminder).
     */
-    val perCalendarAllDayReminderOverride: Flow<Map<Long, List<Int>>> = store.data.map { prefs ->
+    val perCalendarAllDayReminderOverride: Flow<Map<Long, Int?>> = store.data.map { prefs ->
        parseReminderOverrides(prefs[CALENDAR_ALLDAY_REMINDER_OVERRIDE_KEY])
    }

@@ -496,46 +495,43 @@ sealed interface CalendarReminderOverride {
    data object Inherit : CalendarReminderOverride
    /** Explicit "no reminder" for this calendar, regardless of the global default. */
    data object None : CalendarReminderOverride
-    /** Specific lead times in minutes before the event start (non-empty). */
-    data class Minutes(val minutes: List<Int>) : CalendarReminderOverride
+    /** A specific lead time in minutes before the event start. */
+    data class Minutes(val minutes: Int) : CalendarReminderOverride
 }

 /**
- * The lead times to prefill on a new event: the matching per-calendar override
+ * The lead time to prefill on a new event: the matching per-calendar override
 * if [calendarId] has one for this event kind, otherwise the global default for
 * that kind. All-day events consult [allDayOverrides] / [allDayGlobal]; timed
- * events consult [timedOverrides] / [timedGlobal]. The empty list = no reminder.
- * Pure so it can be unit-tested.
+ * events consult [timedOverrides] / [timedGlobal]. `null` = no reminder. Pure so
+ * it can be unit-tested.
 */
 fun resolveDefaultReminder(
-    timedGlobal: List<Int>,
-    allDayGlobal: List<Int>,
-    timedOverrides: Map<Long, List<Int>>,
-    allDayOverrides: Map<Long, List<Int>>,
+    timedGlobal: Int?,
+    allDayGlobal: Int?,
+    timedOverrides: Map<Long, Int?>,
+    allDayOverrides: Map<Long, Int?>,
    calendarId: Long?,
    isAllDay: Boolean,
-): List<Int> {
+): Int? {
    val overrides = if (isAllDay) allDayOverrides else timedOverrides
    val global = if (isAllDay) allDayGlobal else timedGlobal
    return if (calendarId != null && overrides.containsKey(calendarId)) {
-        overrides.getValue(calendarId)
+        overrides[calendarId]
    } else {
        global
    }
 }

-/**
- * Apply a [CalendarReminderOverride] to an override map ([Inherit] removes the
- * key; [None] and an empty [Minutes] both store the empty list).
- */
-private fun MutableMap<Long, List<Int>>.applyOverride(
+/** Apply a [CalendarReminderOverride] to an override map ([Inherit] removes the key). */
+private fun MutableMap<Long, Int?>.applyOverride(
    calendarId: Long,
    override: CalendarReminderOverride,
 ) {
    when (override) {
        CalendarReminderOverride.Inherit -> remove(calendarId)
-        CalendarReminderOverride.None -> put(calendarId, emptyList())
-        is CalendarReminderOverride.Minutes -> put(calendarId, override.minutes.normalizeReminders())
+        CalendarReminderOverride.None -> put(calendarId, null)
+        is CalendarReminderOverride.Minutes -> put(calendarId, override.minutes)
    }
 }

@@ -561,36 +557,24 @@ private fun parseWeekStart(stored: String?): WeekStartPref = when (stored) {
 private const val NONE = "none"
 private const val ENTRY_SEP = ";"
 private const val KEY_VALUE_SEP = "="
-private const val LIST_SEP = ","

-/** Distinct, ascending lead times — the canonical form stored and resolved. */
-private fun List<Int>.normalizeReminders(): List<Int> = distinct().sorted()
-
-/**
- * Parse a stored reminder value into lead times. `null`/empty/"none" → empty
- * list; a comma-joined list → its minutes; a legacy single value ("30") → a
- * one-element list. Non-numeric parts are dropped defensively.
- */
-private fun String?.toReminderList(): List<Int> = when {
-    this == null || isEmpty() || this == NONE -> emptyList()
-    else -> split(LIST_SEP).mapNotNull { it.trim().toIntOrNull() }.normalizeReminders()
+private fun String?.toReminderMinutes(): Int? = when (this) {
+    null, "", NONE -> null
+    else -> toIntOrNull()
 }

-/** Serialise lead times for storage: "none" when empty, else comma-joined. */
-private fun List<Int>.toStoredReminders(): String =
-    if (isEmpty()) NONE else normalizeReminders().joinToString(LIST_SEP) { it.toString() }
-
-private fun parseReminderOverrides(stored: String?): Map<Long, List<Int>> {
+private fun parseReminderOverrides(stored: String?): Map<Long, Int?> {
    if (stored.isNullOrBlank()) return emptyMap()
    return stored.split(ENTRY_SEP).mapNotNull { entry ->
        val parts = entry.split(KEY_VALUE_SEP).takeIf { it.size == 2 } ?: return@mapNotNull null
        val id = parts[0].toLongOrNull() ?: return@mapNotNull null
-        id to parts[1].toReminderList()
+        val value = if (parts[1] == NONE) null else parts[1].toIntOrNull() ?: return@mapNotNull null
+        id to value
    }.toMap()
 }

-private fun serializeReminderOverrides(map: Map<Long, List<Int>>): String =
-    map.entries.joinToString(ENTRY_SEP) { (id, minutes) -> "$id$KEY_VALUE_SEP${minutes.toStoredReminders()}" }
+private fun serializeReminderOverrides(map: Map<Long, Int?>): String =
+    map.entries.joinToString(ENTRY_SEP) { (id, minutes) -> "$id$KEY_VALUE_SEP${minutes ?: NONE}" }

 private inline fun <reified E : Enum<E>> String?.toEnum(default: E): E =
    this?.let { stored -> enumValues<E>().firstOrNull { it.name == stored } } ?: default
--- a/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/EventReminderReceiver.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/EventReminderReceiver.kt
@@ -8,7 +8,6 @@ import android.content.pm.PackageManager
 import android.provider.CalendarContract
 import androidx.core.content.ContextCompat
 import dagger.hilt.android.AndroidEntryPoint
-import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -17,17 +16,6 @@ import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import javax.inject.Inject

-/**
- * The due alerts that should actually surface as notifications: everything
- * except alerts whose calendar the user has disabled in-app (mirroring the
- * event filtering in CalendarRepositoryImpl). The caller still marks the full
- * due set fired, so suppressed alerts are not re-broadcast by the provider.
- */
-internal fun postableAlerts(
-    due: List<ReminderAlert>,
-    disabledCalendarIds: Set<Long>,
-): List<ReminderAlert> = due.filterNot { it.calendarId in disabledCalendarIds }
-
 /**
 * Becomes the app that turns the calendar provider's reminder alarms into
 * visible notifications (the Etar model — the provider broadcasts
@@ -44,7 +32,6 @@ class EventReminderReceiver : BroadcastReceiver() {
    @Inject lateinit var alertStore: ReminderAlertStore
    @Inject lateinit var notifier: ReminderNotifier
    @Inject lateinit var settingsPrefs: SettingsPrefs
-    @Inject lateinit var calendarPrefs: CalendarPrefs

    override fun onReceive(context: Context, intent: Intent) {
        if (intent.action != CalendarContract.ACTION_EVENT_REMINDER) return
@@ -59,11 +46,7 @@ class EventReminderReceiver : BroadcastReceiver() {
                if (settingsPrefs.remindersEnabled.first()) {
                    val now = System.currentTimeMillis()
                    val due = alertStore.dueAlerts(now)
-                    val disabled = calendarPrefs.disabledCalendarIds.first()
-                    // Suppress reminders for disabled calendars, but still mark
-                    // every due alert fired so the provider stops re-broadcasting
-                    // the suppressed ones.
-                    postableAlerts(due, disabled).forEach { notifier.post(it) }
+                    due.forEach { notifier.post(it) }
                    alertStore.markFired(due.map { it.alertId }, now)
                }
            } finally {
--- a/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderActionReceiver.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderActionReceiver.kt
@@ -75,7 +75,6 @@ class ReminderActionReceiver : BroadcastReceiver() {

        private const val EXTRA_ALERT_ID = "alert_id"
        private const val EXTRA_EVENT_ID = "event_id"
-        private const val EXTRA_CALENDAR_ID = "calendar_id"
        private const val EXTRA_BEGIN = "begin"
        private const val EXTRA_END = "end"
        private const val EXTRA_TITLE = "title"
@@ -88,7 +87,6 @@ class ReminderActionReceiver : BroadcastReceiver() {
                this.action = action
                putExtra(EXTRA_ALERT_ID, alert.alertId)
                putExtra(EXTRA_EVENT_ID, alert.eventId)
-                putExtra(EXTRA_CALENDAR_ID, alert.calendarId)
                putExtra(EXTRA_BEGIN, alert.beginMillis)
                putExtra(EXTRA_END, alert.endMillis)
                putExtra(EXTRA_TITLE, alert.title)
@@ -115,7 +113,6 @@ class ReminderActionReceiver : BroadcastReceiver() {
            return ReminderAlert(
                alertId = intent.getLongExtra(EXTRA_ALERT_ID, 0L),
                eventId = intent.getLongExtra(EXTRA_EVENT_ID, 0L),
-                calendarId = intent.getLongExtra(EXTRA_CALENDAR_ID, 0L),
                beginMillis = intent.getLongExtra(EXTRA_BEGIN, 0L),
                endMillis = intent.getLongExtra(EXTRA_END, 0L),
                title = intent.getStringExtra(EXTRA_TITLE).orEmpty(),
--- a/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlertStore.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlertStore.kt
@@ -16,7 +16,6 @@ import javax.inject.Singleton
 data class ReminderAlert(
    val alertId: Long,
    val eventId: Long,
-    val calendarId: Long,
    val beginMillis: Long,
    val endMillis: Long,
    /** Raw event title; may be blank — the notifier substitutes "(no title)". */
@@ -67,12 +66,11 @@ class AndroidReminderAlertStore @Inject constructor(
                    ReminderAlert(
                        alertId = c.getLong(0),
                        eventId = c.getLong(1),
-                        calendarId = c.getLong(2),
-                        beginMillis = c.getLong(3),
-                        endMillis = c.getLong(4),
-                        title = c.getString(5).orEmpty(),
-                        location = c.getString(6)?.takeIf { it.isNotBlank() },
-                        isAllDay = c.getInt(7) == 1,
+                        beginMillis = c.getLong(2),
+                        endMillis = c.getLong(3),
+                        title = c.getString(4).orEmpty(),
+                        location = c.getString(5)?.takeIf { it.isNotBlank() },
+                        isAllDay = c.getInt(6) == 1,
                    ),
                )
            }
@@ -104,7 +102,6 @@ class AndroidReminderAlertStore @Inject constructor(
        val PROJECTION = arrayOf(
            CalendarContract.CalendarAlerts._ID,
            CalendarContract.CalendarAlerts.EVENT_ID,
-            CalendarContract.CalendarAlerts.CALENDAR_ID,
            CalendarContract.CalendarAlerts.BEGIN,
            CalendarContract.CalendarAlerts.END,
            CalendarContract.CalendarAlerts.TITLE,
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/common/DebugRibbon.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/common/DebugRibbon.kt
@@ -1,50 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.BoxScope
-import androidx.compose.foundation.layout.offset
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.width
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.rotate
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import androidx.compose.ui.zIndex
-
-/**
- * A Flutter-style "DEBUG" corner ribbon, drawn across the top-right corner of
- * the app. Deliberately a stark, un-themed marker (not a product component) so a
- * debug build is unmistakable at a glance — gate it on `BuildConfig.DEBUG` at the
- * call site so it never reaches a release build. Non-interactive: it's a plain
- * label with no pointer handler, so taps fall through to whatever is beneath it.
- *
- * Drop it in as the last child of a full-screen [androidx.compose.foundation.layout.Box]
- * so it overlays the UI.
- */
-@Composable
-fun BoxScope.DebugRibbon() {
-    Text(
-        text = "DEBUG",
-        color = Color.White,
-        fontSize = 10.sp,
-        fontWeight = FontWeight.Bold,
-        letterSpacing = 1.sp,
-        textAlign = TextAlign.Center,
-        modifier = Modifier
-            .align(Alignment.TopEnd)
-            .zIndex(1f)
-            // Push the band out so its midline crosses the very corner, then
-            // rotate it to the classic 45° ribbon.
-            .offset(x = 36.dp, y = 24.dp)
-            .rotate(45f)
-            .background(Color(0xFFB23B00))
-            .width(140.dp)
-            .padding(vertical = 2.dp),
-    )
-}
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/common/Picker.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/common/Picker.kt
@@ -13,7 +13,6 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Check
-import androidx.compose.material3.Checkbox
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -27,7 +26,6 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
@@ -113,15 +111,10 @@ fun <T> OptionPicker(
 }

 /**
- * Reminder-default picker, full-screen and **multi-select**: each [presets]
- * lead time (plus any chosen custom value) is a checkbox row that toggles
- * independently, so a default can carry several reminders ("1 week before" *and*
- * "on the day"). A per-calendar picker ([allowInherit]) gains an exclusive "Use
- * default reminder" row above the list; choosing it defers to the global default
- * and clears the checked times. With nothing checked and inherit off, the choice
- * is [CalendarReminderOverride.None] (an explicit no-reminder). A "Custom" row
- * expands an inline number field plus a unit selector to add an arbitrary lead
- * time to the set. Changes apply live via [onSelect]; the user leaves via back.
+ * Reminder-default picker, full-screen: the grouped list (with an optional "Use
+ * default reminder" row and a "None" row), the [presets] as lead-time rows, and
+ * a "Custom" row that expands an inline number field plus a segmented unit
+ * selector. Returns the choice as a [CalendarReminderOverride].
 */
@Composable
 fun ReminderDefaultPicker(
@@ -132,74 +125,57 @@ fun ReminderDefaultPicker(
    onSelect: (CalendarReminderOverride) -> Unit,
    onDismiss: () -> Unit,
 ) {
-    // Optimistic local state: the chosen override is authoritative while the
-    // picker is open, so quick successive toggles compose on each other instead
-    // of racing the round-trip through the settings flow (which would drop a
-    // toggle made before the previous write echoes back). Seeded once on open;
-    // the picker leaves composition on dismiss, so reopening re-reads [selected].
-    var current by remember { mutableStateOf(selected) }
-    val inherits = current is CalendarReminderOverride.Inherit
-    val selectedMinutes = (current as? CalendarReminderOverride.Minutes)?.minutes.orEmpty()
-    // Presets plus any selected custom (non-preset) values, each as its own row.
-    val rows = presets + selectedMinutes.filter { it !in presets }.sorted()
+    val selectedMinutes = (selected as? CalendarReminderOverride.Minutes)?.minutes
+    val customSelected = selectedMinutes != null && selectedMinutes !in presets
+    val seed = decomposeReminder(selectedMinutes?.takeIf { customSelected })

    var customExpanded by rememberSaveable { mutableStateOf(false) }
-    var amountText by rememberSaveable { mutableStateOf("") }
-    var unit by rememberSaveable { mutableStateOf(ReminderUnit.Minutes) }
+    var amountText by rememberSaveable { mutableStateOf(seed.first) }
+    var unit by rememberSaveable { mutableStateOf(seed.second) }

-    fun apply(override: CalendarReminderOverride) {
-        current = override
-        onSelect(override)
+    val options = buildList {
+        if (allowInherit) add(CalendarReminderOverride.Inherit)
+        add(CalendarReminderOverride.None)
+        presets.forEach { add(CalendarReminderOverride.Minutes(it)) }
    }
-    // Emit the override for a new set of minutes: empty collapses to None, which
-    // (with inherit unchosen) reads as an explicit "no reminder".
-    fun emit(minutes: List<Int>) {
-        val norm = minutes.distinct().sorted()
-        apply(
-            if (norm.isEmpty()) {
-                CalendarReminderOverride.None
-            } else {
-                CalendarReminderOverride.Minutes(norm)
-            },
-        )
-    }
-    fun toggle(minute: Int) =
-        emit(if (minute in selectedMinutes) selectedMinutes - minute else selectedMinutes + minute)
+    val rowCount = options.size + 1 // + the custom row

    FullScreenPicker(title = title, onDismiss = onDismiss) {
-        // Exclusive "use default" choice (per-calendar only): its own group above
-        // the multi-select list, since inheriting is mutually exclusive with
-        // picking specific times.
-        if (allowInherit) {
+        options.forEachIndexed { index, option ->
+            val isSelected = option == selected
            GroupedRow(
-                title = stringResource(R.string.reminder_use_default),
-                position = Position.Alone,
-                selected = inherits,
-                trailing = if (inherits) {
+                title = reminderOverrideLabel(option),
+                position = positionOf(index, rowCount),
+                selected = isSelected,
+                trailing = if (isSelected) {
                    { SelectedCheck() }
                } else {
                    null
                },
-                onClick = { apply(CalendarReminderOverride.Inherit) },
-            )
-            Spacer(Modifier.height(24.dp))
-        }
-        val rowCount = rows.size + 1 // + the custom row
-        rows.forEachIndexed { index, minute ->
-            val checked = minute in selectedMinutes
-            GroupedRow(
-                title = reminderLeadTimeLabel(minute),
-                position = positionOf(index, rowCount),
-                selected = checked,
-                trailing = { Checkbox(checked = checked, onCheckedChange = { toggle(minute) }) },
-                onClick = { toggle(minute) },
+                onClick = {
+                    onSelect(option)
+                    onDismiss()
+                },
            )
        }
        // When expanded, the Custom row connects downward into the editor card
        // so the two read as one grouped container (the per-calendar pattern).
        GroupedRow(
-            title = stringResource(R.string.event_edit_reminder_custom),
-            position = if (customExpanded) Position.Top else positionOf(rows.size, rowCount),
+            title = if (customSelected) {
+                stringResource(
+                    R.string.reminder_custom_with_value,
+                    reminderLeadTimeLabel(selectedMinutes!!),
+                )
+            } else {
+                stringResource(R.string.event_edit_reminder_custom)
+            },
+            position = if (customExpanded) Position.Top else positionOf(options.size, rowCount),
+            selected = customSelected,
+            trailing = if (customSelected) {
+                { SelectedCheck() }
+            } else {
+                null
+            },
            onClick = { customExpanded = !customExpanded },
        )
        AnimatedVisibility(
@@ -213,9 +189,8 @@ fun ReminderDefaultPicker(
                unit = unit,
                onUnitChange = { unit = it },
                onConfirm = { minutes ->
-                    emit(selectedMinutes + minutes)
-                    amountText = ""
-                    customExpanded = false
+                    onSelect(CalendarReminderOverride.Minutes(minutes))
+                    onDismiss()
                },
            )
        }
@@ -453,3 +428,18 @@ fun agendaRangeLabel(range: AgendaRange): String = when (range) {
    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)
+    CalendarReminderOverride.None -> stringResource(R.string.reminder_none)
+    is CalendarReminderOverride.Minutes -> reminderLeadTimeLabel(override.minutes)
+}
+
+/** Seed the custom editor: the largest exact unit for [minutes] (null → empty). */
+private fun decomposeReminder(minutes: Int?): Pair<String, ReminderUnit> = when {
+    minutes == null -> "" to ReminderUnit.Minutes
+    minutes % 10_080 == 0 -> (minutes / 10_080).toString() to ReminderUnit.Weeks
+    minutes % 1_440 == 0 -> (minutes / 1_440).toString() to ReminderUnit.Days
+    minutes % 60 == 0 -> (minutes / 60).toString() to ReminderUnit.Hours
+    else -> minutes.toString() to ReminderUnit.Minutes
+}
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditViewModel.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditViewModel.kt
@@ -108,10 +108,10 @@ class EventEditViewModel @Inject constructor(
    )

    private data class ReminderDefaults(
-        val timed: List<Int>,
-        val allDay: List<Int>,
-        val timedOverrides: Map<Long, List<Int>>,
-        val allDayOverrides: Map<Long, List<Int>>,
+        val timed: Int?,
+        val allDay: Int?,
+        val timedOverrides: Map<Long, Int?>,
+        val allDayOverrides: Map<Long, Int?>,
    )

    private data class ExternalInputs(
@@ -260,7 +260,7 @@ class EventEditViewModel @Inject constructor(
            // Re-check after suspending: bail if the form closed or the user edited.
            val form = _form.value ?: return@launch
            if (_editTarget.value != null || _remindersTouched.value) return@launch
-            val reminders = resolveDefaultReminder(
+            val default = resolveDefaultReminder(
                timedGlobal = defaults.timed,
                allDayGlobal = defaults.allDay,
                timedOverrides = defaults.timedOverrides,
@@ -268,6 +268,7 @@ class EventEditViewModel @Inject constructor(
                calendarId = targetId,
                isAllDay = form.isAllDay,
            )
+            val reminders = listOfNotNull(default)
            _form.value = form.copy(reminders = reminders)
            // Surface the section so an auto-applied default is visible and
            // removable, even when Reminders isn't a default-shown field.
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsScreen.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsScreen.kt
@@ -969,7 +969,7 @@ private fun NotificationsScreen(
            presets = REMINDER_PRESETS,
            selected = state.defaultReminderMinutes.toReminderChoice(),
            allowInherit = false,
-            onSelect = { viewModel.setDefaultReminderMinutes(it.toMinutesList()) },
+            onSelect = { viewModel.setDefaultReminderMinutes(it.toMinutesOrNull()) },
            onDismiss = { showDefaultReminder = false },
        )
    }
@@ -979,7 +979,7 @@ private fun NotificationsScreen(
            presets = ALLDAY_REMINDER_PRESETS,
            selected = state.defaultAllDayReminderMinutes.toReminderChoice(),
            allowInherit = false,
-            onSelect = { viewModel.setDefaultAllDayReminderMinutes(it.toMinutesList()) },
+            onSelect = { viewModel.setDefaultAllDayReminderMinutes(it.toMinutesOrNull()) },
            onDismiss = { showAllDayReminder = false },
        )
    }
@@ -1028,13 +1028,13 @@ private fun NotificationsScreen(
 /** Which calendar + event kind a per-calendar reminder-override dialog targets. */
 private data class OverrideTarget(val calendarId: Long, val isAllDay: Boolean)

-/** A global default (empty = none) as a picker choice for selection highlighting. */
-private fun List<Int>.toReminderChoice(): CalendarReminderOverride =
-    if (isEmpty()) CalendarReminderOverride.None else CalendarReminderOverride.Minutes(this)
+/** A global default (null = none) as a picker choice for selection highlighting. */
+private fun Int?.toReminderChoice(): CalendarReminderOverride =
+    if (this == null) CalendarReminderOverride.None else CalendarReminderOverride.Minutes(this)

 /** A picked choice as global-default minutes (Inherit isn't offered for globals). */
-private fun CalendarReminderOverride.toMinutesList(): List<Int> =
-    (this as? CalendarReminderOverride.Minutes)?.minutes ?: emptyList()
+private fun CalendarReminderOverride.toMinutesOrNull(): Int? =
+    (this as? CalendarReminderOverride.Minutes)?.minutes

 /**
 * Whether Calendula is exempt from battery optimisation, re-read on every
@@ -1109,33 +1109,27 @@ private fun formatTimeOfDay(context: Context, minutesOfDay: Int): String {
 }

 /** The stored override for [calendarId], as a picker choice (absent → inherit). */
-private fun Map<Long, List<Int>>.choiceFor(calendarId: Long): CalendarReminderOverride = when {
+private fun Map<Long, Int?>.choiceFor(calendarId: Long): CalendarReminderOverride = when {
    !containsKey(calendarId) -> CalendarReminderOverride.Inherit
-    this.getValue(calendarId).isEmpty() -> CalendarReminderOverride.None
-    else -> CalendarReminderOverride.Minutes(this.getValue(calendarId))
+    this[calendarId] == null -> CalendarReminderOverride.None
+    else -> CalendarReminderOverride.Minutes(this.getValue(calendarId)!!)
 }

-/** Label for a global-default choice: empty → "None", else the lead times joined. */
+/** Label for a global-default choice: null → "None", else the lead time. */
@Composable
-private fun reminderChoiceLabel(minutes: List<Int>): String {
-    if (minutes.isEmpty()) return stringResource(R.string.reminder_none)
-    // reminderLeadTimeLabel is @Composable, so resolve each part in a loop rather
-    // than a (non-composable) joinToString transform.
-    val parts = ArrayList<String>(minutes.size)
-    for (m in minutes) parts.add(reminderLeadTimeLabel(m))
-    return parts.joinToString(", ")
-}
+private fun reminderChoiceLabel(minutes: Int?): String =
+    if (minutes == null) stringResource(R.string.reminder_none) else reminderLeadTimeLabel(minutes)

 /** Row summary for a calendar: its override, or the inherited global default. */
@Composable
 private fun calendarOverrideSummary(
    choice: CalendarReminderOverride,
-    globalDefault: List<Int>,
+    globalDefault: Int?,
 ): String = when (choice) {
    CalendarReminderOverride.Inherit ->
        stringResource(R.string.settings_calendar_reminder_inherits, reminderChoiceLabel(globalDefault))
    CalendarReminderOverride.None -> stringResource(R.string.reminder_none)
-    is CalendarReminderOverride.Minutes -> reminderChoiceLabel(choice.minutes)
+    is CalendarReminderOverride.Minutes -> reminderLeadTimeLabel(choice.minutes)
 }

 // ---------------------------------------------------------------------------
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsUiState.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsUiState.kt
@@ -44,24 +44,24 @@ data class SettingsUiState(
    /** Whether Calendula posts reminder notifications (v1.4). */
    val remindersEnabled: Boolean = true,
    /**
-     * The default reminder lead times (minutes) prefilled on new timed events;
-     * empty = no default reminder. Per-calendar overrides take precedence.
+     * The default reminder lead time (minutes) prefilled on new timed events;
+     * null = no default reminder. Per-calendar overrides take precedence.
     */
-    val defaultReminderMinutes: List<Int> = emptyList(),
-    /** The default reminder lead times prefilled on new all-day events; empty = none. */
-    val defaultAllDayReminderMinutes: List<Int> = emptyList(),
+    val defaultReminderMinutes: Int? = null,
+    /** The default reminder lead time prefilled on new all-day events; null = none. */
+    val defaultAllDayReminderMinutes: Int? = null,
    /** Wall-clock time (minutes from midnight) all-day reminders fire at; default 09:00. */
    val allDayReminderTimeMinutes: Int = SettingsPrefs.DEFAULT_ALLDAY_REMINDER_TIME,
    /** How long the notification "Snooze" action defers a reminder; default 10 min. */
    val snoozeMinutes: Int = SettingsPrefs.DEFAULT_SNOOZE_MINUTES,
    /**
     * Per-calendar overrides of [defaultReminderMinutes] for timed events: a
-     * calendar present in the map overrides the global default (empty value = no
+     * calendar present in the map overrides the global default (null value = no
     * reminder); absent = inherit the global default.
     */
-    val perCalendarReminderOverride: Map<Long, List<Int>> = emptyMap(),
+    val perCalendarReminderOverride: Map<Long, Int?> = emptyMap(),
    /** Per-calendar overrides of [defaultAllDayReminderMinutes] for all-day events. */
-    val perCalendarAllDayReminderOverride: Map<Long, List<Int>> = emptyMap(),
+    val perCalendarAllDayReminderOverride: Map<Long, Int?> = emptyMap(),
    /** Writable calendars, shown as per-calendar reminder-override rows. */
    val writableCalendars: List<CalendarSource> = emptyList(),
    /**
--- a/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsViewModel.kt
+++ b/app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsViewModel.kt
@@ -139,15 +139,15 @@ class SettingsViewModel @Inject constructor(

    private data class ReminderDefaults(
        val allowColor: Boolean,
-        val defaultReminder: List<Int>,
-        val allDayReminder: List<Int>,
+        val defaultReminder: Int?,
+        val allDayReminder: Int?,
        val allDayReminderTime: Int,
        val snoozeMinutes: Int,
    )

    private data class ReminderOverrides(
-        val timed: Map<Long, List<Int>>,
-        val allDay: Map<Long, List<Int>>,
+        val timed: Map<Long, Int?>,
+        val allDay: Map<Long, Int?>,
        val calendars: List<CalendarSource>,
    )

@@ -255,11 +255,11 @@ class SettingsViewModel @Inject constructor(
        viewModelScope.launch { prefs.setAutofocusEventTitle(enabled) }
    }

-    fun setDefaultReminderMinutes(minutes: List<Int>) {
+    fun setDefaultReminderMinutes(minutes: Int?) {
        viewModelScope.launch { prefs.setDefaultReminderMinutes(minutes) }
    }

-    fun setDefaultAllDayReminderMinutes(minutes: List<Int>) {
+    fun setDefaultAllDayReminderMinutes(minutes: Int?) {
        viewModelScope.launch { prefs.setDefaultAllDayReminderMinutes(minutes) }
    }

--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -316,6 +316,7 @@
    <string name="reminder_none">Keine</string>
    <string name="reminder_use_default">Standard-Erinnerung verwenden</string>
    <string name="reminder_custom_amount">Anzahl</string>
+    <string name="reminder_custom_with_value">Benutzerdefiniert (%1$s)</string>
    <string name="reminder_custom_set">Übernehmen</string>
    <string name="settings_calendar_reminders_hint">Standard pro Kalender überschreiben — getrennt für Termine mit Uhrzeit und ganztägige Termine. Ein Kalender kann den Standard übernehmen, weglassen oder einen eigenen festlegen.</string>
    <string name="settings_calendar_reminder_inherits">Standard (%1$s)</string>
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -324,6 +324,7 @@
    <string name="reminder_none">None</string>
    <string name="reminder_use_default">Use default reminder</string>
    <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>
--- a/app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapperTest.kt
+++ b/app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapperTest.kt
@@ -199,12 +199,11 @@ class EventWriteMapperTest {
        assertThat(values[CalendarContract.Events.TITLE]).isEqualTo("Moved")
        assertThat(values[CalendarContract.Events.EVENT_LOCATION]).isEqualTo("Berlin")
        assertThat(values[CalendarContract.Events.DTSTART]).isEqualTo(1_781_164_800_000L)
-        // The occurrence's length travels as DURATION, never DTEND — the provider
-        // rejects DTEND on an exception ("Exceptions can't overwrite dtend") and
-        // derives the end from DTSTART + DURATION, clearing the inherited RRULE.
-        assertThat(values[CalendarContract.Events.DURATION]).isEqualTo("P5400S")
-        assertThat(values).doesNotContainKey(CalendarContract.Events.DTEND)
+        assertThat(values[CalendarContract.Events.DTEND])
+            .isEqualTo(1_781_164_800_000L + 5_400_000L)
+        // A single occurrence never carries its own rule.
        assertThat(values).doesNotContainKey(CalendarContract.Events.RRULE)
+        assertThat(values).doesNotContainKey(CalendarContract.Events.DURATION)
    }

    @Test
--- a/app/src/test/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefsTest.kt
+++ b/app/src/test/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefsTest.kt
@@ -183,38 +183,22 @@ class SettingsPrefsTest {
    }

    @Test
-    fun `default reminder is empty until set`(@TempDir tempDir: Path) = runTest {
+    fun `default reminder is none until set`(@TempDir tempDir: Path) = runTest {
        val prefs = SettingsPrefs(newDataStore(tempDir))
-        assertThat(prefs.defaultReminderMinutes.first()).isEmpty()
+        assertThat(prefs.defaultReminderMinutes.first()).isNull()
    }

    @Test
-    fun `default reminder round-trips none, single, and multiple lead times`(@TempDir tempDir: Path) = runTest {
+    fun `default reminder round-trips, including none`(@TempDir tempDir: Path) = runTest {
        val prefs = SettingsPrefs(newDataStore(tempDir))
-        prefs.setDefaultReminderMinutes(listOf(30))
-        assertThat(prefs.defaultReminderMinutes.first()).containsExactly(30)
-        // Several lead times persist, normalised to distinct ascending order.
-        prefs.setDefaultReminderMinutes(listOf(10_080, 0, 30, 30))
-        assertThat(prefs.defaultReminderMinutes.first()).containsExactly(0, 30, 10_080).inOrder()
-        prefs.setDefaultReminderMinutes(emptyList())
-        assertThat(prefs.defaultReminderMinutes.first()).isEmpty()
+        prefs.setDefaultReminderMinutes(30)
+        assertThat(prefs.defaultReminderMinutes.first()).isEqualTo(30)
+        prefs.setDefaultReminderMinutes(null)
+        assertThat(prefs.defaultReminderMinutes.first()).isNull()
    }

    @Test
-    fun `legacy single-value default reminder parses as a one-element list`(@TempDir tempDir: Path) = runTest {
-        val store = newDataStore(tempDir)
-        val prefs = SettingsPrefs(store)
-        // The pre-multi-reminder format stored a bare integer string.
-        store.updateData { p ->
-            val m = p.toMutablePreferences()
-            m[SettingsPrefs.DEFAULT_REMINDER_KEY] = "30"
-            m
-        }
-        assertThat(prefs.defaultReminderMinutes.first()).containsExactly(30)
-    }
-
-    @Test
-    fun `garbage stored default reminder reads as empty`(@TempDir tempDir: Path) = runTest {
+    fun `garbage stored default reminder reads as none`(@TempDir tempDir: Path) = runTest {
        val store = newDataStore(tempDir)
        val prefs = SettingsPrefs(store)
        store.updateData { p ->
@@ -222,7 +206,7 @@ class SettingsPrefsTest {
            m[SettingsPrefs.DEFAULT_REMINDER_KEY] = "soon"
            m
        }
-        assertThat(prefs.defaultReminderMinutes.first()).isEmpty()
+        assertThat(prefs.defaultReminderMinutes.first()).isNull()
    }

    @Test
@@ -230,16 +214,16 @@ class SettingsPrefsTest {
        val prefs = SettingsPrefs(newDataStore(tempDir))
        assertThat(prefs.perCalendarReminderOverride.first()).isEmpty()

-        prefs.setCalendarReminderOverride(7L, CalendarReminderOverride.Minutes(listOf(15, 10_080)))
+        prefs.setCalendarReminderOverride(7L, CalendarReminderOverride.Minutes(15))
        prefs.setCalendarReminderOverride(9L, CalendarReminderOverride.None)
        prefs.perCalendarReminderOverride.first().let { map ->
-            assertThat(map).containsExactly(7L, listOf(15, 10_080), 9L, emptyList<Int>())
+            assertThat(map).containsExactly(7L, 15, 9L, null)
        }

-        // Inherit drops the override entirely (absent != an empty-list value).
+        // Inherit drops the override entirely (absent != null value).
        prefs.setCalendarReminderOverride(9L, CalendarReminderOverride.Inherit)
        prefs.perCalendarReminderOverride.first().let { map ->
-            assertThat(map).containsExactly(7L, listOf(15, 10_080))
+            assertThat(map).containsExactly(7L, 15)
            assertThat(map.containsKey(9L)).isFalse()
        }
    }
@@ -247,48 +231,48 @@ class SettingsPrefsTest {
    @Test
    fun `all-day default round-trips, including none`(@TempDir tempDir: Path) = runTest {
        val prefs = SettingsPrefs(newDataStore(tempDir))
-        assertThat(prefs.defaultAllDayReminderMinutes.first()).isEmpty()
-        prefs.setDefaultAllDayReminderMinutes(listOf(1_440))
-        assertThat(prefs.defaultAllDayReminderMinutes.first()).containsExactly(1_440)
-        prefs.setDefaultAllDayReminderMinutes(emptyList())
-        assertThat(prefs.defaultAllDayReminderMinutes.first()).isEmpty()
+        assertThat(prefs.defaultAllDayReminderMinutes.first()).isNull()
+        prefs.setDefaultAllDayReminderMinutes(1_440)
+        assertThat(prefs.defaultAllDayReminderMinutes.first()).isEqualTo(1_440)
+        prefs.setDefaultAllDayReminderMinutes(null)
+        assertThat(prefs.defaultAllDayReminderMinutes.first()).isNull()
    }

    @Test
    fun `per-calendar all-day override round-trips independently of the timed one`(@TempDir tempDir: Path) = runTest {
        val prefs = SettingsPrefs(newDataStore(tempDir))
-        prefs.setCalendarReminderOverride(7L, CalendarReminderOverride.Minutes(listOf(15)))
-        prefs.setCalendarAllDayReminderOverride(7L, CalendarReminderOverride.Minutes(listOf(1_440)))
-        assertThat(prefs.perCalendarReminderOverride.first()).containsExactly(7L, listOf(15))
-        assertThat(prefs.perCalendarAllDayReminderOverride.first()).containsExactly(7L, listOf(1_440))
+        prefs.setCalendarReminderOverride(7L, CalendarReminderOverride.Minutes(15))
+        prefs.setCalendarAllDayReminderOverride(7L, CalendarReminderOverride.Minutes(1_440))
+        assertThat(prefs.perCalendarReminderOverride.first()).containsExactly(7L, 15)
+        assertThat(prefs.perCalendarAllDayReminderOverride.first()).containsExactly(7L, 1_440)
        // Clearing the all-day override leaves the timed one untouched.
        prefs.setCalendarAllDayReminderOverride(7L, CalendarReminderOverride.Inherit)
        assertThat(prefs.perCalendarAllDayReminderOverride.first()).isEmpty()
-        assertThat(prefs.perCalendarReminderOverride.first()).containsExactly(7L, listOf(15))
+        assertThat(prefs.perCalendarReminderOverride.first()).containsExactly(7L, 15)
    }

    @Test
    fun `resolveDefaultReminder picks the kind-matching override or global`() {
-        val timed = mapOf(7L to listOf(15, 10_080), 9L to emptyList<Int>())
-        val allDay = mapOf(7L to listOf(2_880))
+        val timed = mapOf(7L to 15, 9L to null)
+        val allDay = mapOf(7L to 2_880)
        fun resolve(calendarId: Long?, isAllDay: Boolean) = resolveDefaultReminder(
-            timedGlobal = listOf(30),
-            allDayGlobal = listOf(1_440),
+            timedGlobal = 30,
+            allDayGlobal = 1_440,
            timedOverrides = timed,
            allDayOverrides = allDay,
            calendarId = calendarId,
            isAllDay = isAllDay,
        )
-        // Timed: multi-value override, explicit none, inherit global, no calendar.
-        assertThat(resolve(7L, isAllDay = false)).containsExactly(15, 10_080).inOrder()
-        assertThat(resolve(9L, isAllDay = false)).isEmpty()
-        assertThat(resolve(5L, isAllDay = false)).containsExactly(30)
-        assertThat(resolve(null, isAllDay = false)).containsExactly(30)
+        // Timed: minutes override, explicit none, inherit global, no calendar.
+        assertThat(resolve(7L, isAllDay = false)).isEqualTo(15)
+        assertThat(resolve(9L, isAllDay = false)).isNull()
+        assertThat(resolve(5L, isAllDay = false)).isEqualTo(30)
+        assertThat(resolve(null, isAllDay = false)).isEqualTo(30)
        // All-day: its own override wins; absent → all-day global; a timed-only
        // override (cal 9) does not bleed into all-day.
-        assertThat(resolve(7L, isAllDay = true)).containsExactly(2_880)
-        assertThat(resolve(9L, isAllDay = true)).containsExactly(1_440)
-        assertThat(resolve(5L, isAllDay = true)).containsExactly(1_440)
+        assertThat(resolve(7L, isAllDay = true)).isEqualTo(2_880)
+        assertThat(resolve(9L, isAllDay = true)).isEqualTo(1_440)
+        assertThat(resolve(5L, isAllDay = true)).isEqualTo(1_440)
    }

    @Test
--- a/app/src/test/java/de/jeanlucmakiola/calendula/data/reminders/PostableAlertsTest.kt
+++ b/app/src/test/java/de/jeanlucmakiola/calendula/data/reminders/PostableAlertsTest.kt
@@ -1,55 +0,0 @@
-package de.jeanlucmakiola.calendula.data.reminders
-
-import com.google.common.truth.Truth.assertThat
-import org.junit.jupiter.api.Test
-
-class PostableAlertsTest {
-
-    private fun alert(alertId: Long, calendarId: Long) = ReminderAlert(
-        alertId = alertId,
-        eventId = alertId * 10,
-        calendarId = calendarId,
-        beginMillis = 0L,
-        endMillis = 0L,
-        title = "Event $alertId",
-        location = null,
-        isAllDay = false,
-    )
-
-    @Test
-    fun `keeps alerts when no calendar is disabled`() {
-        val due = listOf(alert(1, calendarId = 100), alert(2, calendarId = 200))
-
-        val postable = postableAlerts(due, disabledCalendarIds = emptySet())
-
-        assertThat(postable).isEqualTo(due)
-    }
-
-    @Test
-    fun `drops alerts for a disabled calendar`() {
-        val keep = alert(1, calendarId = 100)
-        val drop = alert(2, calendarId = 200)
-
-        val postable = postableAlerts(listOf(keep, drop), disabledCalendarIds = setOf(200))
-
-        assertThat(postable).containsExactly(keep)
-    }
-
-    @Test
-    fun `drops every alert when all their calendars are disabled`() {
-        val due = listOf(alert(1, calendarId = 100), alert(2, calendarId = 100))
-
-        val postable = postableAlerts(due, disabledCalendarIds = setOf(100))
-
-        assertThat(postable).isEmpty()
-    }
-
-    @Test
-    fun `keeps multiple alerts from the same enabled calendar`() {
-        val due = listOf(alert(1, calendarId = 100), alert(2, calendarId = 100))
-
-        val postable = postableAlerts(due, disabledCalendarIds = setOf(999))
-
-        assertThat(postable).isEqualTo(due)
-    }
-}
--- a/docs/design/contact-special-dates.md
+++ b/docs/design/contact-special-dates.md
@@ -0,0 +1,229 @@
+# Design: Contact special-dates calendars (+ per-calendar multiple reminders)
+
+Status: **design / not yet implemented**
+Date: 2026-06-30
+Tracking: Codeberg #15 (feature), Codeberg #14 (prerequisite)
+
+This document captures the full design for surfacing contact birthdays —
+and, by extension, anniversaries and custom dates — as auto-updating local
+calendars in Calendula. It also specifies #14 (per-calendar *multiple*
+default reminders), which is a hard prerequisite and ships first.
+
+The two pieces are deliberately split across **two branches / two
+shipments**:
+
+- `feat/per-calendar-multi-reminders` — #14, ships first.
+- `feat/contact-special-dates` — #15, builds on #14.
+
+They *may* release together depending on timing, but #14 is independently
+useful and is the foundation the special-dates calendars lean on.
+
+---
+
+## Why this is worth doing carefully
+
+Calendula's identity is privacy: **no INTERNET permission**, and historically
+**no `READ_CONTACTS`** — guest-picking uses a one-shot `ACTION_PICK` so the app
+never holds the contacts permission (`EventEditScreen.kt:446-460`).
+
+This feature **declares `READ_CONTACTS`** for the first time. That is a
+deliberate, owner-approved shift, mitigated by:
+
+- The permission is **opt-in and feature-gated** — requested only when the user
+  enables the feature, never at startup.
+- Everything stays **offline**. Contacts are read locally and mirrored into a
+  local calendar; nothing leaves the device.
+- The mirror is **one-way** (contacts → calendar). Calendula never writes to
+  Contacts.
+
+Store listing / About copy will need to explain the optional permission.
+
+---
+
+## Prerequisite — #14: per-calendar *multiple* default reminders
+
+### Today
+
+- Events already support **multiple reminders** — `EventForm.reminders:
+  List<Int>` (`EventForm.kt:24`), each written as a separate
+  `CalendarContract.Reminders` row (`CalendarDataSource.kt:620-630`), each
+  firing independently. The runtime/notification path is done.
+- The **defaults** layer is single-valued, though:
+  - Global: `defaultReminderMinutes` / `defaultAllDayReminderMinutes` — single
+    `Int` (`SettingsPrefs.kt:287,302`).
+  - Per-calendar override: `perCalendarReminderOverride: Map<Long, Int?>` and
+    the all-day variant (`SettingsPrefs.kt:350-381`), resolved by
+    `resolveDefaultReminder()` (`SettingsPrefs.kt:509-524`).
+  - UI: expandable per-calendar override section
+    (`SettingsScreen.kt:879-953`); `ReminderDefaultPicker` (`:956+`).
+
+### The change
+
+Widen the **defaults**, not the runtime, from one reminder to a list:
+
+1. Resolution model `Int` → `List<Int>` in global defaults + per-calendar
+   override + `resolveDefaultReminder()`. The DataStore string format already
+   parses `id=value;id=value` (`SettingsPrefs.kt:576-577`); `value` becomes a
+   comma-separated list. Keep the `Inherit / None / Minutes` override states
+   (`CalendarReminderOverride`, `SettingsPrefs.kt:493-500`) — `Minutes` carries
+   a list.
+2. `ReminderDefaultPicker` → multi-select. Mirror the event-form multi-reminder
+   UI rather than inventing new interaction.
+3. New events seed `EventForm.reminders` from the **resolved list** instead of
+   a single value.
+
+No new permissions, no provider changes, no scheduling changes. Type widening
+plus one picker upgrade.
+
+### Why it gates #15
+
+Each special-dates calendar is a normal local calendar, so it inherits the
+**per-calendar reminder default** for free. A birthdays calendar is useless
+without lead time (the reporter literally asked for "a week before *and* on the
+day") — that requires *multiple* defaults, i.e. #14.
+
+---
+
+## #15: Contact special-dates calendars
+
+### Core model: one-way mirror, one local calendar per type
+
+Contacts → **separate local calendars per type**:
+
+- "Birthdays"
+- "Anniversaries"
+- "Custom dates" (everything else / `TYPE_OTHER` / `TYPE_CUSTOM`)
+
+Separate-per-type is the key architectural decision: each is a normal local
+calendar (`createLocalCalendar()`, `CalendarDataSource.kt:238-260`), so the
+**existing per-calendar infra applies for free**:
+
+- **Color** → existing per-calendar color.
+- **Show/hide** → existing calendar visibility.
+- **Default reminders** → per-calendar override from #14.
+
+This shrinks the new surface dramatically: anniversaries and custom dates are
+near copy-paste of birthdays (same engine, different `ContactsContract` data
+kind, one extra local calendar each), and the settings sub-page does **not**
+need to reinvent color/visibility/reminders.
+
+### Events: field-level managed, not read-only
+
+Calendula manages a few fields; the user owns the rest.
+
+- **Managed** (overwritten on every sync, disabled in the editor for these
+  events): title, start date, recurrence (`FREQ=YEARLY`), existence.
+- **User-owned** (seeded once on insert, never touched again by sync):
+  location, reminders, notes, busy/free.
+
+The rule that makes this safe: sync performs a **targeted column update**
+(managed columns only), **never delete-and-reinsert**. Reminders live in
+separate rows, so once seeded they are simply never re-touched. A user can move
+a birthday reminder to "2 weeks before" or add a location and neither is
+clobbered.
+
+In the editor, when an event belongs to a managed calendar: disable the
+title/date/recurrence fields; allow the rest.
+
+### Reconciliation identity
+
+Stamp each event with the contact's `LOOKUP_KEY` in `Events.SYNC_DATA1` (ours,
+since it's a local calendar). Sync becomes an idempotent diff keyed on it:
+
+- contact added → insert
+- birthday/date changed → targeted update of managed columns
+- contact or date removed → delete the event
+
+Getting this wrong = duplicate birthdays on every sync, so the identity key is
+non-negotiable.
+
+### Data source
+
+`ContactsContract.Data` rows of `Event.CONTENT_ITEM_TYPE`, split by
+`Event.TYPE`:
+
+- `TYPE_BIRTHDAY` → Birthdays calendar
+- `TYPE_ANNIVERSARY` → Anniversaries calendar
+- `TYPE_OTHER` / `TYPE_CUSTOM` (+ label) → Custom dates calendar
+
+### Dates: year-less + age
+
+Many contacts store `--MM-DD` (no year). Handle both:
+
+- **Year present:** anchor `DTSTART` at that year; `FREQ=YEARLY`. We can show
+  age ("Jane turns 30") when the show-age option is on.
+- **Year absent:** `FREQ=YEARLY` from an arbitrary anchor year; no age shown.
+
+Recurrence support is already there: `FREQ=YEARLY` + `UNTIL`/`COUNT`/`INTERVAL`
+(`Recurrence.kt:32-174`).
+
+### Auto-update cadence
+
+Birthdays change rarely, so nothing live/expensive:
+
+- Sync **on enable**, **on app foreground**, and a **daily WorkManager** job
+  (catches new/edited/deleted contacts even if the app isn't opened).
+- **No `ContentObserver`** — needs the process alive and buys almost nothing
+  for once-a-year events.
+
+### Permission + lifecycle
+
+- **Enable:** request `READ_CONTACTS` (feature-gated, contextual — mirror the
+  contextual `WRITE_CALENDAR` pattern at `EventEditScreen.kt:216-231`). On
+  grant, create the enabled calendars and run the first sync.
+- **Disable:** delete the managed calendars + their events (with a confirm).
+- **Permission revoked in system settings:** detect on next sync; surface that
+  the feature is stalled rather than failing silently.
+
+### Configurable settings sub-page
+
+Enabling the feature reveals a **dedicated sub-page** (not inline rows). Because
+color/visibility/reminders already live in normal calendar settings, the
+sub-page only carries the genuinely new knobs:
+
+- Master enable toggle.
+- Per-type toggles: Birthdays / Anniversaries / Custom dates.
+- Title/display template, e.g. `"{name}'s birthday"` (new translatable string).
+- Show-age toggle (only meaningful when the year is known).
+- (Possibly) sync-cadence / "sync now".
+- Pointer to the normal calendar settings for color, visibility, reminders.
+
+The owner wants this broadly configurable — keep the sub-page the home for
+display/behaviour options, and lean on existing per-calendar settings for the
+rest.
+
+---
+
+## Open questions / deferred
+
+- Title template: free-form vs a small set of presets. Start with one good
+  localized default; revisit configurability.
+- Whether "Custom dates" is one bucket or split further by label. Start: one
+  bucket.
+- Contact scope: all contacts vs per-account/group filtering. Start: all;
+  filtering is a later refinement.
+
+## Task outline
+
+### #14 — per-calendar multiple default reminders (`feat/per-calendar-multi-reminders`)
+- [ ] Widen global + per-calendar reminder defaults `Int` → `List<Int>`
+      (`SettingsPrefs.kt`), keep `Inherit/None/Minutes(list)`.
+- [ ] `resolveDefaultReminder()` returns a list.
+- [ ] `ReminderDefaultPicker` → multi-select (mirror event-form UI).
+- [ ] Seed new events' `EventForm.reminders` from the resolved list.
+- [ ] Migration / parse compatibility for existing single-value stored prefs.
+- [ ] Tests: resolution, parse round-trip, all-day variant.
+
+### #15 — contact special-dates (`feat/contact-special-dates`)
+- [ ] Declare `READ_CONTACTS`; feature-gated contextual request on enable.
+- [ ] Per-type local calendars (create on enable, delete on disable+confirm).
+- [ ] Contacts reader: `Event` rows by `TYPE`, year-less handling.
+- [ ] Sync engine: idempotent diff keyed on `LOOKUP_KEY` in `SYNC_DATA1`;
+      targeted managed-column updates; seed user-owned fields on insert only.
+- [ ] `FREQ=YEARLY` event generation + age (when year known).
+- [ ] Auto-update: on enable, on foreground, daily WorkManager.
+- [ ] Editor: disable managed fields for managed-calendar events.
+- [ ] Revoked-permission detection + stalled-state surface.
+- [ ] Settings sub-page: enable, per-type toggles, title template, show-age.
+- [ ] Translatable strings (titles, sub-page).
+- [ ] About / store copy for the optional `READ_CONTACTS` permission.