2.19.0 — drag to reschedule, bulk delete from search, onboarding wizard (#172)

Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/172

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

@@ -27,8 +27,10 @@ import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.curatedForPicker
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.EventSearch
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.Reminder
+import de.jeanlucmakiola.calendula.domain.SearchCandidate
 import de.jeanlucmakiola.calendula.domain.contacts.MANAGED_UID_PREFIX
 import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
@@ -62,12 +64,14 @@ interface CalendarDataSource {
     fun eventDetail(eventId: Long, allDayReminderTimeMinutes: Int): EventDetail?
 
     /**
-     * Master/one-off events whose title, description or location contains
-     * [query] (case-insensitive), across all calendars, newest first. Reads the
-     * Events table directly so the search is unbounded in time; exception rows
-     * are excluded (see [SearchProjection]). [query] is assumed non-blank.
+     * Master/one-off events that may match [query], across all calendars: every
+     * whitespace-separated token has to appear in the title, description or
+     * location. Reads the Events table directly so the search is unbounded in
+     * time; exception rows are excluded (see [SearchProjection]). A deliberate
+     * superset — [EventSearch] makes the final call and orders the hits.
+     * [query] is assumed non-blank.
      */
-    fun searchEvents(query: String): List<EventInstance>
+    fun searchEvents(query: String): List<SearchCandidate>
 
     /**
      * The event-colour palette the calendar's account publishes
@@ -585,20 +589,23 @@ class AndroidCalendarDataSource @Inject constructor(
         )?.use { c -> c.mapAllNotNull { CursorColumnReader(c).toEventInstance() } } ?: emptyList()
     }
 
-    override fun searchEvents(query: String): List<EventInstance> {
+    override fun searchEvents(query: String): List<SearchCandidate> {
         ensureObserversRegistered()
-        val trimmed = query.trim()
-        if (trimmed.isEmpty()) return emptyList()
-        // Escape the SQL LIKE wildcards so a literal % or _ in the query matches
-        // itself instead of acting as a wildcard.
-        val escaped = trimmed
-            .replace("\\", "\\\\")
-            .replace("%", "\\%")
-            .replace("_", "\\_")
-        val like = "%$escaped%"
-        val match = "${CalendarContract.Events.TITLE} LIKE ? ESCAPE '\\' OR " +
-            "${CalendarContract.Events.DESCRIPTION} LIKE ? ESCAPE '\\' OR " +
-            "${CalendarContract.Events.EVENT_LOCATION} LIKE ? ESCAPE '\\'"
+        val tokens = EventSearch.tokenize(query).take(MAX_SEARCH_TOKENS)
+        if (tokens.isEmpty()) return emptyList()
+        // Only a pre-filter: EventSearch re-checks every token, including the
+        // ones the cap above dropped.
+        val patterns = tokens.map { likePatterns(it) }
+        val match = patterns.joinToString(" AND ") { variants ->
+            variants.joinToString(" OR ", prefix = "(", postfix = ")") {
+                "${CalendarContract.Events.TITLE} LIKE ? ESCAPE '\\' OR " +
+                    "${CalendarContract.Events.DESCRIPTION} LIKE ? ESCAPE '\\' OR " +
+                    "${CalendarContract.Events.EVENT_LOCATION} LIKE ? ESCAPE '\\'"
+            }
+        }
+        val args = patterns
+            .flatMap { variants -> variants.flatMap { pattern -> List(3) { pattern } } }
+            .toTypedArray()
         val selection = "($match) AND " +
             "${CalendarContract.Events.DELETED} = 0 AND " +
             "${CalendarContract.Events.ORIGINAL_ID} IS NULL"
@@ -606,19 +613,17 @@ class AndroidCalendarDataSource @Inject constructor(
             CalendarContract.Events.CONTENT_URI,
             SearchProjection.COLUMNS,
             selection,
-            arrayOf(like, like, like),
+            args,
             CalendarContract.Events.DTSTART + " DESC",
         )?.use { c ->
             val reader = CursorColumnReader(c)
-            val out = ArrayList<EventInstance>(c.count)
+            val out = ArrayList<SearchCandidate>(c.count)
             while (c.moveToNext()) {
+                val description = reader.getString(SearchProjection.IDX_DESCRIPTION)
                 val base = reader.toSearchResult() ?: continue
-                // A recurring master's DTSTART is the series start; show its
-                // nearest occurrence instead so the date is the one the user
-                // actually cares about (and sorting reflects it).
-                val recurring = !reader.getString(SearchProjection.IDX_RRULE).isNullOrEmpty() ||
-                    !reader.getString(SearchProjection.IDX_RDATE).isNullOrEmpty()
-                out += if (recurring) {
+                // A recurring master's DTSTART is the series start; date the row
+                // by its nearest occurrence instead.
+                val event = if (base.isRecurring) {
                     nearestOccurrenceMillis(base.eventId)?.let { (begin, end) ->
                         base.copy(
                             start = begin.toKotlinInstantFromEpochMillis(),
@@ -628,11 +633,44 @@ class AndroidCalendarDataSource @Inject constructor(
                 } else {
                     base
                 }
+                // The raw title, so matching can't catch on the placeholder an
+                // untitled event is drawn with.
+                out += SearchCandidate(
+                    event = event,
+                    description = description,
+                    title = reader.getString(SearchProjection.IDX_TITLE),
+                )
             }
             out
         } ?: emptyList()
     }
 
+    /**
+     * One token as the `LIKE` patterns to OR together. SQLite folds case for
+     * ASCII only, so a token with cased non-ASCII letters is also queried lower-,
+     * upper- and title-cased, which is how "ärzte" reaches "Ärzte". Wildcarding
+     * those letters away instead would make "москва" `%______%` — a full scan.
+     */
+    private fun likePatterns(token: String): List<String> {
+        if (token.none { it.code > 127 && (it.isUpperCase() || it.isLowerCase()) }) {
+            return listOf(likePattern(token))
+        }
+        val lower = token.lowercase()
+        return listOf(token, lower, token.uppercase(), lower.replaceFirstChar(Char::uppercaseChar))
+            .distinct()
+            .map(::likePattern)
+    }
+
+    private fun likePattern(token: String): String {
+        val sb = StringBuilder("%")
+        for (c in token) {
+            // A literal wildcard from the query matches itself.
+            if (c == '%' || c == '_' || c == '\\') sb.append('\\')
+            sb.append(c)
+        }
+        return sb.append('%').toString()
+    }
+
     /**
      * The occurrence of [eventId] nearest to now: the soonest upcoming one
      * within [OCCURRENCE_WINDOW_MILLIS] ahead, else the most recent past one
@@ -1593,5 +1631,12 @@ class AndroidCalendarDataSource @Inject constructor(
          * next fires beyond it falls back to its series-start date.
          */
         const val OCCURRENCE_WINDOW_MILLIS = 2L * 365 * 24 * 60 * 60 * 1000
+
+        /**
+         * Tokens the SQL pre-filter is built from. Bounds the statement for a
+         * pasted paragraph; the ranker still requires every token, so a capped
+         * search returns fewer rows to check, never more hits.
+         */
+        const val MAX_SEARCH_TOKENS = 8
     }
 }

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

@@ -5,6 +5,7 @@ import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.SearchCandidate
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.IcsImportSummary
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
@@ -17,11 +18,11 @@ interface CalendarRepository {
     suspend fun eventDetail(eventId: Long): EventDetail
 
     /**
-     * Events whose title, description or location contains [query], with hidden
-     * calendars removed and newest first. Empty when [query] is blank. Searches
-     * the whole history/future (see [CalendarDataSource.searchEvents]).
+     * Candidate matches for [query] with hidden calendars removed; empty when
+     * [query] is blank. Searches the whole history/future and leaves matching
+     * and ranking to [de.jeanlucmakiola.calendula.domain.EventSearch].
      */
-    suspend fun searchEvents(query: String): List<EventInstance>
+    suspend fun searchEvents(query: String): List<SearchCandidate>
 
     /**
      * The event-colour palette a calendar's account publishes; empty when it

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

@@ -9,6 +9,7 @@ import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.SearchCandidate
 import de.jeanlucmakiola.calendula.domain.ics.IcsImportSummary
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import kotlinx.coroutines.CoroutineDispatcher
@@ -162,13 +163,13 @@ class CalendarRepositoryImpl @Inject constructor(
             ?: throw NoSuchEventException(eventId)
     }
 
-    override suspend fun searchEvents(query: String): List<EventInstance> = withContext(io) {
+    override suspend fun searchEvents(query: String): List<SearchCandidate> = withContext(io) {
         if (query.isBlank()) return@withContext emptyList()
         val excluded = prefs.hiddenCalendarIds.first() +
             prefs.pendingDisabledCalendarIds.first() +
             invisibleCalendarIds()
         dataSource.searchEvents(query)
-            .let { if (excluded.isEmpty()) it else it.filterNot { e -> e.calendarId in excluded } }
+            .let { if (excluded.isEmpty()) it else it.filterNot { c -> c.event.calendarId in excluded } }
     }
 
     override suspend fun eventColorPalette(calendarId: Long): List<EventColorOption> =

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

@@ -125,6 +125,7 @@ internal fun ColumnReader.toEventDetailCore(
         selfStatus = mapAttendeeStatus(getInt(EventDetailProjection.IDX_SELF_ATTENDEE_STATUS)),
         eventColor = eventColor,
         eventColorKey = eventColorKey,
+        isException = !isNull(EventDetailProjection.IDX_ORIGINAL_ID),
     )
 }
 

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

@@ -89,6 +89,9 @@ internal object EventDetailProjection {
         // Recurring rows carry DURATION instead of DTEND; the detail screen
         // needs it to render a series opened without a named occurrence.
         CalendarContract.Events.DURATION,
+        // Non-null on a modified-occurrence exception row; "no RRULE" alone
+        // can't tell an exception from a master (#68).
+        CalendarContract.Events.ORIGINAL_ID,
     )
 
     const val IDX_EVENT_ID = 0
@@ -110,6 +113,7 @@ internal object EventDetailProjection {
     const val IDX_SELF_ATTENDEE_STATUS = 16
     const val IDX_EVENT_COLOR_KEY = 17
     const val IDX_DURATION = 18
+    const val IDX_ORIGINAL_ID = 19
 }
 
 /**
@@ -176,6 +180,8 @@ internal object SearchProjection {
         // display its nearest occurrence, not the series-start DTSTART.
         CalendarContract.Events.RRULE,
         CalendarContract.Events.RDATE,
+        // Excerpted, not just filtered on: a hit has to show what it matched.
+        CalendarContract.Events.DESCRIPTION,
     )
 
     const val IDX_ID = 0
@@ -190,6 +196,7 @@ internal object SearchProjection {
     const val IDX_LOCATION = 9
     const val IDX_RRULE = 10
     const val IDX_RDATE = 11
+    const val IDX_DESCRIPTION = 12
 }
 
 /**

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

@@ -40,5 +40,7 @@ internal fun ColumnReader.toSearchResult(): EventInstance? {
         isAllDay = getInt(SearchProjection.IDX_ALL_DAY) != 0,
         color = color,
         location = getString(SearchProjection.IDX_LOCATION),
+        isRecurring = !getString(SearchProjection.IDX_RRULE).isNullOrEmpty() ||
+            !getString(SearchProjection.IDX_RDATE).isNullOrEmpty(),
     )
 }

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

@@ -550,8 +550,87 @@ class SettingsPrefs @Inject constructor(
         prefs[REMINDER_ONBOARDING_KEY] ?: false
     }
 
-    suspend fun setReminderOnboardingDone() {
-        store.edit { it[REMINDER_ONBOARDING_KEY] = true }
+    /** Cleared, not just set: the wizard's back button re-asks a step (#163). */
+    suspend fun setReminderOnboardingDone(done: Boolean = true) {
+        store.edit { it[REMINDER_ONBOARDING_KEY] = done }
+    }
+
+    /**
+     * Whether this install is a fresh one still owing the wizard's optional
+     * steps (#163). Armed on any launch that holds the calendar permission and
+     * has not finished the reminder step, and cleared again by
+     * [finishOnboardingWizard], so an existing user who revokes and re-grants
+     * the permission isn't re-onboarded.
+     */
+    val onboardingWizardArmed: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_WIZARD_ARMED_KEY] ?: false
+    }
+
+    suspend fun armOnboardingWizard() {
+        store.edit { prefs ->
+            if (prefs[REMINDER_ONBOARDING_KEY] != true) prefs[ONBOARDING_WIZARD_ARMED_KEY] = true
+        }
+    }
+
+    /** Whether the wizard's backup step has been answered (or skipped). */
+    val onboardingBackupDone: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_BACKUP_KEY] ?: false
+    }
+
+    suspend fun setOnboardingBackupDone(done: Boolean = true) {
+        store.edit { it[ONBOARDING_BACKUP_KEY] = done }
+    }
+
+    /** Whether the wizard's default-view step has been answered (or skipped). */
+    val onboardingViewDone: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_VIEW_KEY] ?: false
+    }
+
+    suspend fun setOnboardingViewDone(done: Boolean = true) {
+        store.edit { it[ONBOARDING_VIEW_KEY] = done }
+    }
+
+    /** Whether the wizard's month-style step has been answered (or skipped). */
+    val onboardingMonthStyleDone: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_MONTH_STYLE_KEY] ?: false
+    }
+
+    suspend fun setOnboardingMonthStyleDone(done: Boolean = true) {
+        store.edit { it[ONBOARDING_MONTH_STYLE_KEY] = done }
+    }
+
+    /**
+     * Whether the wizard's calendar-visibility notice has been read. Separate
+     * from [CalendarPrefs.visibilityNoticePending], which says whether this
+     * install has anything to announce at all.
+     */
+    val onboardingVisibilityDone: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_VISIBILITY_KEY] ?: false
+    }
+
+    suspend fun setOnboardingVisibilityDone(done: Boolean = true) {
+        store.edit { it[ONBOARDING_VISIBILITY_KEY] = done }
+    }
+
+    /** Whether the wizard's closing screen has been seen. */
+    val onboardingDoneShown: Flow<Boolean> = store.data.map { prefs ->
+        prefs[ONBOARDING_DONE_KEY] ?: false
+    }
+
+    suspend fun setOnboardingDoneShown(shown: Boolean = true) {
+        store.edit { it[ONBOARDING_DONE_KEY] = shown }
+    }
+
+    /**
+     * Close the wizard for good: the closing screen has been seen and the
+     * install stops counting as fresh, so a later revoke-and-re-grant is only
+     * the permission screen. One edit, so the plan can't see it half-closed.
+     */
+    suspend fun finishOnboardingWizard() {
+        store.edit { prefs ->
+            prefs[ONBOARDING_DONE_KEY] = true
+            prefs[ONBOARDING_WIZARD_ARMED_KEY] = false
+        }
     }
 
     /**
@@ -882,6 +961,14 @@ class SettingsPrefs @Inject constructor(
         internal const val MAX_EVENT_DURATION = 1_440
         internal val REMINDERS_ENABLED_KEY = booleanPreferencesKey("reminders_enabled")
         internal val REMINDER_ONBOARDING_KEY = booleanPreferencesKey("reminder_onboarding_done")
+        internal val ONBOARDING_WIZARD_ARMED_KEY = booleanPreferencesKey("onboarding_wizard_armed")
+        internal val ONBOARDING_BACKUP_KEY = booleanPreferencesKey("onboarding_backup_done")
+        internal val ONBOARDING_VIEW_KEY = booleanPreferencesKey("onboarding_view_done")
+        internal val ONBOARDING_MONTH_STYLE_KEY =
+            booleanPreferencesKey("onboarding_month_style_done")
+        internal val ONBOARDING_VISIBILITY_KEY =
+            booleanPreferencesKey("onboarding_visibility_done")
+        internal val ONBOARDING_DONE_KEY = booleanPreferencesKey("onboarding_done_shown")
         internal val ALLOW_COLOR_UNSUPPORTED_KEY =
             booleanPreferencesKey("allow_color_unsupported_calendars")
         internal val DEFAULT_REMINDER_KEY = stringPreferencesKey("default_reminder_minutes")

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

@@ -44,6 +44,14 @@ val CalendarSource.hasVisibilitySwitch: Boolean
 val CalendarSource.isEventTarget: Boolean
     get() = canModifyContents && isVisibleInSystem && !isManaged && !isNotSynced
 
+/**
+ * Whether this calendar's events may have their times rewritten by a drag (#68).
+ * Deliberately not [isEventTarget]: a managed event stays editable (reminders,
+ * notes) yet must never move, since the next contacts sync would put it back.
+ */
+val CalendarSource.allowsEventMove: Boolean
+    get() = canModifyContents && !isManaged
+
 /** Every state worth naming on this calendar's row, in reading order. */
 fun CalendarSource.stateLabels(): List<CalendarStateLabel> = buildList {
     if (isManaged) add(CalendarStateLabel.MANAGED)

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

@@ -0,0 +1,256 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atStartOfDayIn
+import kotlinx.datetime.number
+import kotlinx.datetime.plus
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Instant
+
+/** An event with the free text the search may have matched it on. */
+data class SearchCandidate(
+    val event: EventInstance,
+    val description: String? = null,
+    /** Null when the event has none: [EventInstance.title] is then a display
+     *  placeholder, which the query must not catch on. */
+    val title: String? = event.title,
+)
+
+/** A matched run inside one of a hit's texts, for highlighting. */
+data class MatchSpan(val start: Int, val end: Int)
+
+/** The part of a description a token matched, elided to what fits a row. */
+data class DescriptionSnippet(
+    val text: String,
+    val spans: List<MatchSpan>,
+)
+
+/** One result: the event, plus where the query matched it. */
+data class SearchHit(
+    val event: EventInstance,
+    val titleSpans: List<MatchSpan> = emptyList(),
+    val locationSpans: List<MatchSpan> = emptyList(),
+    val descriptionSnippet: DescriptionSnippet? = null,
+    /** Already over, so the row can say so. Finished-today counts. */
+    val isPast: Boolean = false,
+)
+
+/** One month's worth of hits, as the results list draws them under a header. */
+data class SearchMonth(
+    val year: Int,
+    /** 1–12, so the UI can build the month's first day for a localized label. */
+    val monthNumber: Int,
+    val hits: List<SearchHit>,
+)
+
+/** A finished search: a calendar of hits, plus the description-only ones. */
+data class SearchResults(
+    val months: List<SearchMonth>,
+    val inDescriptions: List<SearchHit>,
+) {
+    val isEmpty: Boolean get() = months.isEmpty() && inDescriptions.isEmpty()
+
+    /** Every hit, whichever section it sits in — for select-all and delete. */
+    val allHits: List<SearchHit> get() = months.flatMap { it.hits } + inDescriptions
+}
+
+/**
+ * Turning a typed query into the results list.
+ *
+ * An event has to carry *every* whitespace-separated token, each in any of
+ * title / location / description; case is folded in Kotlin rather than by SQL's
+ * ASCII-only `LIKE`, so "ärzte" finds "Ärzte".
+ *
+ * Results are a calendar, not a ranking: months from the current one, then
+ * forwards, then backwards, and inside a month what is still to come before
+ * what has passed. The day is the boundary, not the moment. A hit the query
+ * only reached through its description is held back in
+ * [SearchResults.inDescriptions] rather than dated among the real ones.
+ */
+object EventSearch {
+
+    /** Characters of description kept around the match in a row's snippet. */
+    private const val SNIPPET_LENGTH = 96
+
+    /** Characters of lead-in shown before the match, when there is room. */
+    private const val SNIPPET_LEAD = 24
+
+    private val WHITESPACE = Regex("\\s+")
+
+    /** Shared with the data layer so its SQL pre-filter tokenises identically. */
+    fun tokenize(query: String): List<String> =
+        query.trim().split(WHITESPACE).filter { it.isNotEmpty() }
+
+    /**
+     * Search [candidates] for [query], dropping any that don't carry every token.
+     * [now] marks a hit as over, [todayStart] is where it stops being current.
+     * [zone] places each event on the calendar through the span rule, so an
+     * all-day event keeps its own day whichever side of UTC we are on (#82).
+     */
+    fun search(
+        candidates: List<SearchCandidate>,
+        query: String,
+        now: Instant,
+        todayStart: Instant,
+        zone: TimeZone,
+    ): SearchResults {
+        val tokens = tokenize(query)
+        if (tokens.isEmpty()) return SearchResults(emptyList(), emptyList())
+
+        val today = todayStart.toLocalDateTime(zone).date
+        val matched = candidates.mapNotNull { candidate -> match(candidate, tokens, now, zone) }
+        val upcoming = { m: Matched -> m.event.spanLastDay(zone) >= today }
+        val order = compareBy<Matched> { if (upcoming(it)) 0 else 1 }
+            .thenComparator { a, b ->
+                // What is left reads forwards; what is behind us reads backwards
+                // from today, nearest first.
+                if (upcoming(a)) {
+                    a.event.dayStart(zone).compareTo(b.event.dayStart(zone))
+                } else {
+                    b.event.dayStart(zone).compareTo(a.event.dayStart(zone))
+                }
+            }
+
+        val (inDescriptions, dated) = matched.sortedWith(order).partition { it.descriptionOnly }
+        return SearchResults(
+            months = groupByMonth(dated, zone, todayStart),
+            inDescriptions = inDescriptions.map { it.hit },
+        )
+    }
+
+    /** Months from the current one, then forwards, then backwards. */
+    private fun groupByMonth(
+        dated: List<Matched>,
+        zone: TimeZone,
+        todayStart: Instant,
+    ): List<SearchMonth> {
+        val currentKey = monthKey(todayStart.toLocalDateTime(zone).date)
+        return dated
+            .groupBy { monthKey(it.event.spanFirstDay(zone)) }
+            .entries
+            .sortedWith(
+                compareBy<Map.Entry<Int, List<Matched>>> {
+                    when {
+                        it.key == currentKey -> 0
+                        it.key > currentKey -> 1
+                        else -> 2
+                    }
+                }.thenComparator { a, b ->
+                    if (a.key > currentKey) a.key.compareTo(b.key) else b.key.compareTo(a.key)
+                },
+            )
+            .map { (key, entries) ->
+                SearchMonth(
+                    year = key / 12,
+                    monthNumber = key % 12 + 1,
+                    hits = entries.map { it.hit },
+                )
+            }
+    }
+
+    /** Year and month as one comparable number. */
+    private fun monthKey(date: LocalDate): Int = date.year * 12 + (date.month.number - 1)
+
+    private fun match(
+        candidate: SearchCandidate,
+        tokens: List<String>,
+        now: Instant,
+        zone: TimeZone,
+    ): Matched? {
+        val title = candidate.title?.takeIf { it.isNotBlank() }
+        val location = candidate.event.location?.takeIf { it.isNotBlank() }
+        // Collapsed so a multi-line description matches the way it is drawn.
+        val description = candidate.description
+            ?.replace(WHITESPACE, " ")
+            ?.trim()
+            ?.takeIf { it.isNotEmpty() }
+
+        // Mid-word counts: "termin" has to keep finding "Zahnarzttermin".
+        val present = { token: String ->
+            title?.contains(token, ignoreCase = true) == true ||
+                location?.contains(token, ignoreCase = true) == true ||
+                description?.contains(token, ignoreCase = true) == true
+        }
+        if (!tokens.all(present)) return null
+
+        val descriptionSpans = description?.let { spansIn(it, tokens) }.orEmpty()
+        val titleSpans = title?.let { spansIn(it, tokens) }.orEmpty()
+        val locationSpans = location?.let { spansIn(it, tokens) }.orEmpty()
+        return Matched(
+            hit = SearchHit(
+                event = candidate.event,
+                titleSpans = titleSpans,
+                locationSpans = locationSpans,
+                descriptionSnippet = description
+                    ?.takeIf { descriptionSpans.isNotEmpty() }
+                    ?.let { snippet(it, descriptionSpans) },
+                isPast = candidate.event.dayEnd(zone) < now,
+            ),
+            // Nothing in the name or the place caught the query: it is only here
+            // for something in its notes.
+            descriptionOnly = titleSpans.isEmpty() && locationSpans.isEmpty(),
+        )
+    }
+
+    /** Every occurrence of every token in [text], merged where they overlap. */
+    private fun spansIn(text: String, tokens: List<String>): List<MatchSpan> {
+        val raw = mutableListOf<MatchSpan>()
+        for (token in tokens) {
+            var index = text.indexOf(token, startIndex = 0, ignoreCase = true)
+            while (index >= 0) {
+                raw += MatchSpan(index, index + token.length)
+                index = text.indexOf(token, startIndex = index + 1, ignoreCase = true)
+            }
+        }
+        if (raw.isEmpty()) return emptyList()
+        val sorted = raw.sortedBy { it.start }
+        val merged = mutableListOf(sorted.first())
+        for (span in sorted.drop(1)) {
+            val last = merged.last()
+            if (span.start <= last.end) {
+                merged[merged.lastIndex] = MatchSpan(last.start, maxOf(last.end, span.end))
+            } else {
+                merged += span
+            }
+        }
+        return merged
+    }
+
+    /**
+     * A window of [description] around its first match, elided at both ends,
+     * with the spans rebased onto it and any falling outside dropped.
+     */
+    private fun snippet(description: String, spans: List<MatchSpan>): DescriptionSnippet {
+        if (description.length <= SNIPPET_LENGTH) {
+            return DescriptionSnippet(description, spans)
+        }
+        val first = spans.first().start
+        val start = (first - SNIPPET_LEAD).coerceIn(0, (description.length - SNIPPET_LENGTH))
+        val end = (start + SNIPPET_LENGTH).coerceAtMost(description.length)
+        val prefix = if (start > 0) "…" else ""
+        val suffix = if (end < description.length) "…" else ""
+        val text = prefix + description.substring(start, end) + suffix
+        val shift = prefix.length - start
+        val rebased = spans
+            .filter { it.start >= start && it.end <= end }
+            .map { MatchSpan(it.start + shift, it.end + shift) }
+        return DescriptionSnippet(text, rebased)
+    }
+
+    private data class Matched(val hit: SearchHit, val descriptionOnly: Boolean) {
+        val event: EventInstance get() = hit.event
+    }
+
+    /**
+     * The event's first day as an instant in [zone]. An all-day event sits at
+     * UTC midnight, so its raw start would rank it on a day it isn't drawn on.
+     */
+    private fun EventInstance.dayStart(zone: TimeZone): Instant =
+        if (isAllDay) spanFirstDay(zone).atStartOfDayIn(zone) else start
+
+    /** The moment the event's last day is over in [zone], exclusive. */
+    private fun EventInstance.dayEnd(zone: TimeZone): Instant =
+        if (isAllDay) spanLastDay(zone).plus(1, DateTimeUnit.DAY).atStartOfDayIn(zone) else end
+}

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

@@ -0,0 +1,53 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.plus
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Instant
+
+/**
+ * The zone this form's wall-clock times mean, matching what the data layer
+ * resolves them in at write time: the form's own pinned zone, else [deviceZone].
+ */
+fun EventForm.resolvedZone(deviceZone: TimeZone): TimeZone =
+    timezone?.let { runCatching { TimeZone.of(it) }.getOrNull() } ?: deviceZone
+
+/**
+ * The form moved so it starts at [newStart], keeping its **instant** duration —
+ * a recurring event's length travels to the provider as `DURATION`, so keeping
+ * wall clock instead would rewrite the series' length across a DST boundary.
+ *
+ * All-day events are date-anchored — use [shiftedByDays]; this returns them
+ * untouched.
+ */
+fun EventForm.shiftedTo(newStart: Instant, deviceZone: TimeZone): EventForm {
+    if (isAllDay) return this
+    val zone = resolvedZone(deviceZone)
+    val span = end.toInstant(zone) - start.toInstant(zone)
+    return copy(
+        start = newStart.toLocalDateTime(zone),
+        end = (newStart + span).toLocalDateTime(zone),
+    )
+}
+
+/**
+ * The form moved [days] calendar days, keeping its time of day and its span.
+ * All-day events are pure date arithmetic; a timed one preserves its **instant**
+ * duration, for the same reason [shiftedTo] does.
+ */
+fun EventForm.shiftedByDays(days: Int, deviceZone: TimeZone): EventForm {
+    if (days == 0) return this
+    val newStart = LocalDateTime(start.date.plus(days, DateTimeUnit.DAY), start.time)
+    if (isAllDay) {
+        return copy(
+            start = newStart,
+            end = LocalDateTime(end.date.plus(days, DateTimeUnit.DAY), end.time),
+        )
+    }
+    val zone = resolvedZone(deviceZone)
+    val span = end.toInstant(zone) - start.toInstant(zone)
+    return copy(start = newStart, end = (newStart.toInstant(zone) + span).toLocalDateTime(zone))
+}

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

@@ -62,6 +62,11 @@ data class EventInstance(
     val isAllDay: Boolean,
     val color: Int,
     val location: String?,
+    /**
+     * Only search results, which read the series master, fill this in — the
+     * Instances query already yields one row per occurrence.
+     */
+    val isRecurring: Boolean = false,
 )
 
 /**
@@ -124,6 +129,12 @@ data class EventDetail(
     val eventColor: Int? = null,
     /** The event's `Events.EVENT_COLOR_KEY` (a calendar-palette key), or null. */
     val eventColorKey: String? = null,
+    /**
+     * True when this row is a modified occurrence of a series (`ORIGINAL_ID` is
+     * set) rather than a master, so a reschedule takes the plain whole-row path
+     * whatever [rrule] a sync adapter left on it.
+     */
+    val isException: Boolean = false,
 )
 
 /**

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

@@ -138,7 +138,7 @@ fun SimpleRecurrence.toRRule(zone: TimeZone = TimeZone.currentSystemDefault()):
     }
 }
 
-private val RRULE_DAY_CODES: Map<DayOfWeek, String> = mapOf(
+internal val RRULE_DAY_CODES: Map<DayOfWeek, String> = mapOf(
     DayOfWeek.MONDAY to "MO",
     DayOfWeek.TUESDAY to "TU",
     DayOfWeek.WEDNESDAY to "WE",

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

@@ -0,0 +1,48 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.LocalDate
+
+/**
+ * [rrule] re-anchored from an occurrence on [oldStart] to one on [newStart].
+ *
+ * `Events.RRULE` is written verbatim while DTSTART moves, so `FREQ=WEEKLY;BYDAY=MO`
+ * would keep naming Monday after the anchor became a Wednesday and the series
+ * would not move at all — `BYDAY` is re-derived from [newStart].
+ *
+ * Only weekly `BYDAY` is realigned, and only for a whole-day move: the rule has
+ * to agree with the series *anchor*, and weekday arithmetic is the only kind
+ * that survives the same wall-clock shift unchanged. Everything else returns
+ * null, as do rules one moved occurrence can't resolve (`BYDAY=MO,WE`, `2TH`,
+ * `BYSETPOS`). The accepted parts are a subset of [parseSimpleRecurrence], so
+ * anything realignable is also a rule [problems] can check the `UNTIL` of.
+ */
+fun realignRecurrence(rrule: String, oldStart: LocalDate, newStart: LocalDate): String? {
+    if (oldStart == newStart) return rrule
+    val prefix = if (rrule.startsWith("RRULE:")) "RRULE:" else ""
+    val parts = rrule.removePrefix("RRULE:").split(';').filter { it.isNotBlank() }
+    if (parts.isEmpty()) return null
+    var weekly = false
+    val rebuilt = parts.map { part ->
+        val eq = part.indexOf('=')
+        if (eq <= 0) return null
+        val key = part.substring(0, eq).uppercase()
+        val value = part.substring(eq + 1).trim()
+        when (key) {
+            "FREQ" -> {
+                weekly = value.equals("WEEKLY", ignoreCase = true)
+                part
+            }
+            "BYDAY" -> {
+                val old = RRULE_DAY_CODES[oldStart.dayOfWeek] ?: return null
+                if (!value.equals(old, ignoreCase = true)) return null
+                "BYDAY=${RRULE_DAY_CODES.getValue(newStart.dayOfWeek)}"
+            }
+            "INTERVAL", "COUNT", "UNTIL", "WKST" -> part
+            else -> return null
+        }
+    }
+    // BYDAY is only simple on a weekly rule, matching parseSimpleRecurrence.
+    if (!weekly && parts.any { it.substringBefore('=').trim().uppercase() == "BYDAY" }) return null
+    if (parts.none { it.substringBefore('=').trim().uppercase() == "FREQ" }) return null
+    return prefix + rebuilt.joinToString(";")
+}

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

@@ -10,6 +10,7 @@ import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
@@ -27,6 +28,10 @@ import de.jeanlucmakiola.calendula.ui.calendars.BackupScreen
 import de.jeanlucmakiola.calendula.ui.calendars.CalendarsScreen
 import de.jeanlucmakiola.floret.identity.fadeThrough
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.EventMoveHost
+import de.jeanlucmakiola.calendula.ui.common.EventMoveScope
+import de.jeanlucmakiola.calendula.ui.common.LocalEventMove
+import de.jeanlucmakiola.calendula.ui.common.RescheduleViewModel
 import de.jeanlucmakiola.calendula.ui.common.drillToDay
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
 import de.jeanlucmakiola.calendula.ui.common.selectView
@@ -294,6 +299,29 @@ fun CalendarHost(
         }
     }
 
+    // Drag to reschedule (#68). Hosted here so one instance serves every view and
+    // survives view switches; the calendar surfaces read it out of LocalEventMove.
+    val reschedule: RescheduleViewModel = hiltViewModel()
+    val movableCalendarIds by reschedule.movableCalendarIds.collectAsStateWithLifecycle()
+    val onEditEvent: (EventInstance) -> Unit = { event ->
+        val key = longArrayOf(
+            event.eventId,
+            event.start.toEpochMilliseconds(),
+            event.end.toEpochMilliseconds(),
+        )
+        heldEditKey = key
+        editKey = key
+    }
+    val moveScope = remember(movableCalendarIds, reschedule) {
+        EventMoveScope(
+            movableCalendarIds = movableCalendarIds,
+            move = reschedule::move,
+            inFlight = reschedule.inFlight,
+            undoStarted = reschedule.undoStarted,
+            edit = onEditEvent,
+        )
+    }
+
     val slideSpec = rememberCalendarSlideSpec()
 
     // Base-level back: pop the view stack while no overlay covers it (each overlay
@@ -311,6 +339,7 @@ fun CalendarHost(
         // navigation, so it fades through rather than sliding — paging *within* a
         // view keeps the directional slide. AnimatedContent keyed on the view type.
         val viewSwitch = fadeThrough()
+        CompositionLocalProvider(LocalEventMove provides moveScope) {
         AnimatedContent(
             targetState = view,
             transitionSpec = { viewSwitch },
@@ -367,6 +396,11 @@ fun CalendarHost(
                 )
             }
         }
+        }
+
+        // Scope prompt + confirmation/undo snackbar for a dropped event, declared
+        // right after the calendar views so later overlays cover it.
+        EventMoveHost(reschedule, modifier = Modifier.fillMaxSize())
 
         // Search overlay — below detail/edit in the Box so a tapped result's
         // detail screen draws on top, and closing it returns to the results.

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

@@ -2,12 +2,15 @@ package de.jeanlucmakiola.calendula.ui
 
 import android.Manifest
 import android.content.pm.PackageManager
-import androidx.compose.animation.Crossfade
-import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
-import androidx.compose.material3.MaterialTheme
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.togetherWith
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.SideEffect
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -22,13 +25,22 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
 import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesScheduler
 import de.jeanlucmakiola.calendula.data.contacts.hasContactsPermission
-import de.jeanlucmakiola.calendula.ui.calendars.CalendarVisibilityNoticeDialog
-import de.jeanlucmakiola.calendula.ui.calendars.CalendarVisibilityNoticeViewModel
-import de.jeanlucmakiola.calendula.ui.permission.PermissionScreen
-import de.jeanlucmakiola.calendula.ui.permission.ReminderOnboardingScreen
-import de.jeanlucmakiola.calendula.ui.permission.ReminderOnboardingViewModel
+import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
+import de.jeanlucmakiola.calendula.ui.onboarding.OnboardingStep
+import de.jeanlucmakiola.calendula.ui.onboarding.OnboardingSteps
+import de.jeanlucmakiola.calendula.ui.onboarding.OnboardingViewModel
+import de.jeanlucmakiola.calendula.ui.onboarding.onboardingSlideTransition
+import de.jeanlucmakiola.calendula.ui.onboarding.rememberOnboardingSlideSpec
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+
+/** What the root is showing: a wizard step, the app, or neither yet. */
+private sealed interface RootTarget {
+    /** DataStore has not emitted yet — render nothing rather than the wrong screen. */
+    data object Loading : RootTarget
+    data object App : RootTarget
+    data class Step(val step: OnboardingStep) : RootTarget
+}
 
-@OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun RootScreen(
     modifier: Modifier = Modifier,
@@ -76,58 +88,87 @@ fun RootScreen(
         onDispose { lifecycle.removeObserver(obs) }
     }
 
-    // Cross-fade the one-time onboarding gates so granting permission / finishing
-    // onboarding eases into the next screen instead of snapping. A fade carries no
-    // spatial motion, so it stays appropriate under "remove animations" too.
-    val gateSpec = MaterialTheme.motionScheme.fastEffectsSpec<Float>()
-    Crossfade(targetState = hasPermission, animationSpec = gateSpec, label = "permissionGate") { granted ->
-        if (granted) {
-            // Second onboarding gate (v1.4, one-time): reminder notifications.
-            // Null until DataStore's first emission — render nothing for that
-            // frame instead of flashing the wrong screen.
-            val reminderOnboarding: ReminderOnboardingViewModel = hiltViewModel()
-            val onboardingDone by reminderOnboarding.onboardingDone.collectAsStateWithLifecycle()
-            // One-time explainer for the switch to the device's own calendar
-            // visibility (#75), armed by the reconciler.
-            val visibilityNotice: CalendarVisibilityNoticeViewModel = hiltViewModel()
-            val noticePending by visibilityNotice.pending.collectAsStateWithLifecycle()
-            // Runs on entry however the permission was granted, including via
-            // Android's app-settings screen (caught by the ON_RESUME above).
-            LaunchedEffect(Unit) {
-                visibilityNotice.reconcile()
-                if (!grantedAtLaunch) reminderOnboarding.rearmAfterGrant()
+    val onboarding: OnboardingViewModel = hiltViewModel()
+    val plan by onboarding.plan.collectAsStateWithLifecycle()
+    // The grant is reported however it was taken, including via Android's
+    // app-settings screen (caught by the ON_RESUME above); arming the wizard
+    // hangs off that, not off the in-app callback.
+    LaunchedEffect(hasPermission) {
+        onboarding.setHasPermission(hasPermission)
+        if (hasPermission && !grantedAtLaunch) onboarding.onPermissionGranted()
+    }
+
+    // Arms the one-time explainer for the switch to the device's own calendar
+    // visibility (#75), which the wizard then carries as a step of its own.
+    LaunchedEffect(hasPermission) {
+        if (hasPermission) onboarding.reconcileCalendarVisibility()
+    }
+
+    val current = plan
+    val target: RootTarget = when {
+        current == null -> RootTarget.Loading
+        current.current == null -> RootTarget.App
+        else -> RootTarget.Step(current.current)
+    }
+
+    // Which way the flow is moving, so a step-back slides back. The app sorts
+    // after every step, so finishing the wizard reads as one more move forward.
+    val ordinal = when (target) {
+        RootTarget.Loading -> Int.MIN_VALUE
+        RootTarget.App -> Int.MAX_VALUE
+        is RootTarget.Step -> current?.steps?.indexOf(target.step) ?: 0
+    }
+    var lastOrdinal by remember { mutableIntStateOf(ordinal) }
+    val slideDir = if (ordinal < lastOrdinal) -1 else 1
+    SideEffect { lastOrdinal = ordinal }
+
+    val slideSpec = rememberOnboardingSlideSpec()
+    val fadeSpec = rememberCalendarFadeSpec()
+    val reduceMotion = rememberReduceMotion()
+    AnimatedContent(
+        targetState = target,
+        transitionSpec = {
+            // Coming off the blank first frame is not a step change.
+            if (initialState == RootTarget.Loading) {
+                fadeIn(fadeSpec).togetherWith(fadeOut(fadeSpec))
+            } else {
+                onboardingSlideTransition(
+                    slideDir = slideDir,
+                    spec = slideSpec,
+                    fadeSpec = fadeSpec,
+                    reduceMotion = reduceMotion,
+                )
             }
-            if (onboardingDone == true && noticePending) {
-                CalendarVisibilityNoticeDialog(onDismiss = visibilityNotice::dismiss)
-            }
-            Crossfade(targetState = onboardingDone, animationSpec = gateSpec, label = "onboardingGate") { done ->
-                when (done) {
-                    true -> CalendarHost(
-                        modifier = modifier,
-                        requestedDetailKey = requestedDetailKey,
-                        onDetailKeyConsumed = onDetailKeyConsumed,
-                        widgetNavRequest = widgetNavRequest,
-                        onWidgetNavConsumed = onWidgetNavConsumed,
-                        requestedImportUri = requestedImportUri,
-                        onImportConsumed = onImportConsumed,
-                        requestedInsertForm = requestedInsertForm,
-                        requestedInsertSource = requestedInsertSource,
-                        onInsertConsumed = onInsertConsumed,
-                        requestedEditKey = requestedEditKey,
-                        onEditKeyConsumed = onEditKeyConsumed,
-                    )
-                    false -> ReminderOnboardingScreen(
-                        onFinished = reminderOnboarding::finish,
-                        modifier = modifier,
-                    )
-                    null -> {}
-                }
-            }
-        } else {
-            PermissionScreen(
-                onGranted = { hasPermission = true },
+        },
+        label = "onboardingGate",
+    ) { shown ->
+        when (shown) {
+            RootTarget.Loading -> Unit
+            RootTarget.App -> CalendarHost(
                 modifier = modifier,
+                requestedDetailKey = requestedDetailKey,
+                onDetailKeyConsumed = onDetailKeyConsumed,
+                widgetNavRequest = widgetNavRequest,
+                onWidgetNavConsumed = onWidgetNavConsumed,
+                requestedImportUri = requestedImportUri,
+                onImportConsumed = onImportConsumed,
+                requestedInsertForm = requestedInsertForm,
+                requestedInsertSource = requestedInsertSource,
+                onInsertConsumed = onInsertConsumed,
+                requestedEditKey = requestedEditKey,
+                onEditKeyConsumed = onEditKeyConsumed,
             )
+            // Both halves of a transition read their position out of the live
+            // plan; the one the outgoing step was drawn with is already gone.
+            is RootTarget.Step -> current?.let { plan ->
+                OnboardingSteps(
+                    step = shown.step,
+                    plan = plan,
+                    viewModel = onboarding,
+                    onPermissionGranted = { hasPermission = true },
+                    modifier = modifier,
+                )
+            }
         }
     }
 }

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

@@ -276,7 +276,7 @@ private fun AgendaRangeBanner(
 }
 
 @Composable
-private fun AgendaContent(
+internal fun AgendaContent(
     state: AgendaUiState,
     pastDisplay: PastEventDisplay,
     showToday: Boolean,

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

@@ -0,0 +1,64 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
+import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
+import de.jeanlucmakiola.calendula.ui.common.sampleAgendaEvents
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.plus
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+
+/** How far ahead the agenda preview's stand-in window runs. */
+private const val PREVIEW_WINDOW_DAYS = 14
+
+/**
+ * A live, scaled-down Agenda view for the onboarding view chooser. Today and
+ * the day headers are real; only the events are stand-ins.
+ */
+@Composable
+internal fun AgendaViewPreview(
+    height: Dp,
+    modifier: Modifier = Modifier,
+) {
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    val state = remember(today, zone) { sampleAgendaState(today, zone) }
+
+    ScaledViewPreview(height = height, modifier = modifier) {
+        AgendaContent(
+            state = state,
+            // Stand-in events are all upcoming, so the past-event preference
+            // cannot change what the preview shows — keep it at the default.
+            pastDisplay = PastEventDisplay.SHOW,
+            showToday = true,
+            onRetry = {},
+            onEventClick = {},
+            onOpenDay = {},
+            modifier = Modifier.fillMaxSize(),
+        )
+    }
+}
+
+/** Sample agenda state, grouped through the same helper the live view uses. */
+private fun sampleAgendaState(today: LocalDate, zone: TimeZone): AgendaUiState.Success {
+    val windowEnd = today.plus(PREVIEW_WINDOW_DAYS, DateTimeUnit.DAY)
+    return AgendaUiState.Success(
+        anchor = today,
+        today = today,
+        days = groupAgendaDays(today, windowEnd, sampleAgendaEvents(today, zone), zone),
+        range = AgendaRange.Custom(PREVIEW_WINDOW_DAYS),
+        rangeIsOverride = false,
+        rangeEnd = windowEnd,
+        // The range bar belongs to the screen, not the list — the preview shows
+        // the list only.
+        showRangeBar = false,
+        zone = zone,
+    )
+}

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

@@ -1,71 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.calendars
-
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.VisibilityOff
-import androidx.compose.material3.AlertDialog
-import androidx.compose.material3.Icon
-import androidx.compose.material3.Text
-import androidx.compose.material3.TextButton
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.res.stringResource
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
-import dagger.hilt.android.lifecycle.HiltViewModel
-import de.jeanlucmakiola.calendula.R
-import de.jeanlucmakiola.calendula.data.calendar.CalendarVisibilityReconciler
-import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
-import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
-import kotlinx.coroutines.launch
-import javax.inject.Inject
-
-/**
- * The one-time notice that Calendula now follows the device's per-calendar
- * visibility (#75), armed by `CalendarVisibilityReconciler`. The app does not
- * switch those calendars back on — that would un-hide them everywhere else too.
- */
-@HiltViewModel
-class CalendarVisibilityNoticeViewModel @Inject constructor(
-    private val prefs: CalendarPrefs,
-    private val reconciler: CalendarVisibilityReconciler,
-) : ViewModel() {
-
-    /**
-     * Reconcile whenever the app comes up with the calendar permission held,
-     * rather than off one grant route: a permission granted on Android's
-     * app-settings screen never reaches the permission screen's callback.
-     */
-    fun reconcile() {
-        viewModelScope.launch { reconciler.run() }
-    }
-
-    val pending: StateFlow<Boolean> = prefs.visibilityNoticePending
-        .map { it == true }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = false,
-        )
-
-    fun dismiss() {
-        viewModelScope.launch { prefs.setVisibilityNoticePending(false) }
-    }
-}
-
-/** Plain informational dialog — one acknowledgement, nothing to decide. */
-@Composable
-fun CalendarVisibilityNoticeDialog(onDismiss: () -> Unit) {
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        icon = { Icon(Icons.Default.VisibilityOff, contentDescription = null) },
-        title = { Text(stringResource(R.string.calendars_visibility_notice_title)) },
-        text = { Text(stringResource(R.string.calendars_visibility_notice_message)) },
-        confirmButton = {
-            TextButton(onClick = onDismiss) {
-                Text(stringResource(R.string.dialog_ok))
-            }
-        },
-    )
-}

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

@@ -0,0 +1,75 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.Crossfade
+import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.snap
+import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+
+/**
+ * A timed block's own time label, crossfaded rather than replaced — the block
+ * slides to its new slot, so the label shouldn't change in a single frame.
+ */
+@OptIn(ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+fun BlockTimeLabel(label: String, color: Color, modifier: Modifier = Modifier) {
+    val spec: FiniteAnimationSpec<Float> = if (rememberReduceMotion()) {
+        snap()
+    } else {
+        MaterialTheme.motionScheme.fastEffectsSpec()
+    }
+    Crossfade(
+        targetState = label,
+        animationSpec = spec,
+        label = "block-time",
+        modifier = modifier,
+    ) { text ->
+        Text(
+            text = text,
+            style = MaterialTheme.typography.labelSmall,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            color = color,
+        )
+    }
+}
+
+/** Where a timed block sits in its column, after tweening. */
+@Immutable
+data class BlockPlacement(val x: Dp, val y: Dp, val width: Dp, val height: Dp)
+
+/**
+ * A timed block's placement, tweened rather than jumped. Continuity comes from
+ * the caller keying each block by identity; a block composed for the first time
+ * starts at its target, so nothing flies in on the first frame.
+ *
+ * A pinch-zoom rewrites the hour height every pointer frame, and the gutter and
+ * grid lines follow it instantly — so the tween stands down for the gesture
+ * rather than leaving the blocks trailing the ruler they are measured against.
+ */
+@OptIn(ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+fun animatedBlockPlacement(x: Dp, y: Dp, width: Dp, height: Dp): BlockPlacement {
+    val spec: FiniteAnimationSpec<Dp> = if (rememberReduceMotion() ||
+        LocalTimelineZoom.current.isPinching
+    ) {
+        snap()
+    } else {
+        MaterialTheme.motionScheme.fastSpatialSpec()
+    }
+    val animatedX by animateDpAsState(x, spec, label = "block-x")
+    val animatedY by animateDpAsState(y, spec, label = "block-y")
+    val animatedWidth by animateDpAsState(width, spec, label = "block-width")
+    val animatedHeight by animateDpAsState(height, spec, label = "block-height")
+    return BlockPlacement(animatedX, animatedY, animatedWidth, animatedHeight)
+}

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

@@ -0,0 +1,150 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.gestures.awaitEachGesture
+import androidx.compose.foundation.gestures.awaitFirstDown
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.layout.positionInRoot
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalHapticFeedback
+import androidx.compose.ui.platform.LocalViewConfiguration
+import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.unit.dp
+
+/** How far the finger may wander during the hold — well under touch slop. */
+private val PICKUP_TOLERANCE = 6.dp
+
+/**
+ * Pick an event block up with a long press and drag it, without
+ * `detectDragGesturesAfterLongPress`: the stock detector cancels as soon as an
+ * ancestor consumes or the finger leaves the block, which a
+ * `MIN_EVENT_FRACTION`-tall block loses immediately. Movement before the timeout
+ * is deliberately not consumed, so a scroll starting on top of a block survives.
+ */
+@Composable
+fun rememberEventDragSource(
+    enabled: Boolean,
+    key: Any?,
+    onPickUp: (pointerInRoot: Offset, blockInRoot: Offset, size: IntSize) -> Unit,
+    onMove: (pointerInRoot: Offset) -> Unit,
+    onDrop: () -> Unit,
+    onCancel: () -> Unit,
+): Modifier = rememberDragSurface(
+    enabled = enabled,
+    key = key,
+    onPickUp = { _, pointerInRoot, nodeInRoot, size ->
+        onPickUp(pointerInRoot, nodeInRoot, size)
+        true
+    },
+    onMove = onMove,
+    onDrop = onDrop,
+    onCancel = onCancel,
+)
+
+/**
+ * The same pickup, for a surface that carries many draggable pieces rather than
+ * being one itself — the month grid, whose chips are covered by a full-bleed tap
+ * layer. [onPickUp] receives the press position local to this node and answers
+ * whether anything is there; false abandons the gesture.
+ */
+@Composable
+fun rememberDragSurface(
+    enabled: Boolean,
+    key: Any?,
+    onPickUp: (local: Offset, pointerInRoot: Offset, nodeInRoot: Offset, size: IntSize) -> Boolean,
+    onMove: (pointerInRoot: Offset) -> Unit,
+    onDrop: () -> Unit,
+    onCancel: () -> Unit,
+): Modifier {
+    if (!enabled) return Modifier
+    val holdMillis = LocalViewConfiguration.current.longPressTimeoutMillis
+    val tolerance = with(LocalDensity.current) { PICKUP_TOLERANCE.toPx() }
+    val coordinates = remember { arrayOfNulls<LayoutCoordinates>(1) }
+    val currentPickUp by rememberUpdatedState(onPickUp)
+    val currentMove by rememberUpdatedState(onMove)
+    val currentDrop by rememberUpdatedState(onDrop)
+    val currentCancel by rememberUpdatedState(onCancel)
+
+    return Modifier
+        .onGloballyPositioned { coordinates[0] = it }
+        .pointerInput(key) {
+            awaitEachGesture {
+                val down = awaitFirstDown(requireUnconsumed = false)
+                val origin = down.position
+                val heldStill = withTimeoutOrNull(holdMillis) {
+                    while (true) {
+                        val main = awaitPointerEvent()
+                        val change = main.changes.firstOrNull { it.id == down.id } ?: break
+                        if (!change.pressed) break
+                        if (main.changes.count { it.pressed } > 1) break
+                        if ((change.position - origin).getDistance() > tolerance) break
+                        // An ancestor's claim only becomes visible once the whole
+                        // main pass has run, so look again on the final pass.
+                        val final = awaitPointerEvent(PointerEventPass.Final)
+                        if (final.changes.any { it.isConsumed }) break
+                    }
+                } == null
+                if (!heldStill) return@awaitEachGesture
+
+                val layout = coordinates[0]?.takeIf { it.isAttached } ?: return@awaitEachGesture
+                val took = currentPickUp(
+                    down.position,
+                    layout.localToRoot(down.position),
+                    layout.positionInRoot(),
+                    layout.size,
+                )
+                if (!took) return@awaitEachGesture
+                var dropped = false
+                try {
+                    // Driven on the initial pass, which runs parent → child: an
+                    // ancestor that outranks us (the pinch) has already consumed
+                    // by the time we look, and descendants — the month grid's
+                    // full-bleed tap layer — see our consumption.
+                    while (true) {
+                        val event = awaitPointerEvent(PointerEventPass.Initial)
+                        val change = event.changes.firstOrNull { it.id == down.id } ?: break
+                        if (change.isConsumed) break
+                        if (!change.pressed) {
+                            change.consume()
+                            dropped = true
+                            break
+                        }
+                        if (event.changes.count { it.pressed } > 1) break
+                        change.consume()
+                        coordinates[0]?.takeIf { it.isAttached }
+                            ?.let { currentMove(it.localToRoot(change.position)) }
+                    }
+                } finally {
+                    // Also reached when the pointer node is disposed mid-drag —
+                    // a cancel, not a drop, and must never write.
+                    if (dropped) currentDrop() else currentCancel()
+                }
+            }
+        }
+}
+
+/** A lift on pickup, then a tick every time the drop target snaps to a new slot. */
+@Composable
+fun DragSnapHaptics(slot: Any?) {
+    val haptics = LocalHapticFeedback.current
+    val previous = remember { arrayOfNulls<Any>(1) }
+    LaunchedEffect(slot) {
+        val had = previous[0]
+        previous[0] = slot
+        when {
+            slot == null -> Unit
+            had == null -> haptics.performHapticFeedback(HapticFeedbackType.LongPress)
+            had != slot -> haptics.performHapticFeedback(HapticFeedbackType.SegmentTick)
+        }
+    }
+}

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

@@ -0,0 +1,144 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.navigationBarsPadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.SnackChip
+import de.jeanlucmakiola.floret.components.SnackChipHeight
+import de.jeanlucmakiola.floret.components.SnackChipMargin
+import de.jeanlucmakiola.floret.locale.currentLocale
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
+import kotlinx.coroutines.delay
+import java.time.Instant
+import java.time.ZoneId
+import java.time.ZoneOffset
+import java.util.Locale
+
+/** How long the confirmation chip stays up, matching a short snackbar. */
+private const val CHIP_MILLIS = 4_000L
+
+/** How long an *undone* move stays up — shorter, since it offers nothing to act on. */
+private const val UNDONE_CHIP_MILLIS = 1_600L
+
+/** What the chip currently reads, kept past the outcome it was built from. */
+private data class ChipContent(val message: String, val undo: MoveUndo?)
+
+/** The FAB's own band at the bottom end, which the chip must not run into. */
+private val FAB_BAND = 88.dp
+
+/**
+ * The two surfaces a drag-and-drop reschedule needs on top of the calendar: the
+ * recurring-scope prompt, and the confirmation chip carrying Undo. None of the
+ * calendar screens sets a `snackbarHost`, so this hosts its own confirmation as
+ * a pill on the FAB's band, leaving the calendar visible behind it.
+ */
+@Composable
+fun EventMoveHost(viewModel: RescheduleViewModel, modifier: Modifier = Modifier) {
+    val prompt by viewModel.scopePrompt.collectAsStateWithLifecycle()
+    val outcome by viewModel.outcome.collectAsStateWithLifecycle()
+    val undoTick by viewModel.undoStarted.collectAsStateWithLifecycle()
+    val writeInFlight by viewModel.inFlight.collectAsStateWithLifecycle()
+    val locale = currentLocale()
+    val use24Hour = LocalUse24HourFormat.current
+
+    prompt?.let { pending ->
+        RecurringScopeDialog(
+            title = stringResource(R.string.event_move_recurring_title),
+            onSelect = viewModel::moveWithScope,
+            onDismiss = viewModel::cancelScope,
+            allowSeries = !pending.occurrenceOnly,
+            reason = stringResource(R.string.event_move_occurrence_only)
+                .takeIf { pending.occurrenceOnly },
+        )
+    }
+
+    val moved = outcome as? MoveOutcome.Moved
+    val movedLabel = moved?.let { formatMovedTo(it.startMillis, it.isAllDay, use24Hour, locale) }
+    val message = when (outcome) {
+        null -> null
+        is MoveOutcome.Moved -> stringResource(R.string.event_move_done, movedLabel.orEmpty())
+        MoveOutcome.Undone -> stringResource(R.string.event_move_undone)
+        MoveOutcome.WriteDenied -> stringResource(R.string.event_move_write_denied)
+        MoveOutcome.Gone -> stringResource(R.string.event_move_gone)
+        MoveOutcome.BlockedSeriesEnd -> stringResource(R.string.event_move_blocked_series_end)
+        MoveOutcome.Failed -> stringResource(R.string.event_move_failed)
+    }
+
+    // Held past the outcome being consumed so the chip has something to draw
+    // while it springs back out. Updated in composition rather than from an
+    // effect, which would land a frame late and open the chip on stale text.
+    val shown = remember { mutableStateOf(ChipContent("", null)) }
+    if (message != null && (shown.value.message != message || shown.value.undo != moved?.undo)) {
+        shown.value = ChipContent(message, moved?.undo)
+    }
+    val content = shown.value
+    // Restarted by the undo tick and held while a write is in flight: an undo
+    // tapped in the last moments of the window leaves the outcome at Moved on
+    // purpose, and this timer would otherwise fire mid-undo and close the chip
+    // just before the same chip has to say "undone".
+    LaunchedEffect(outcome, undoTick, writeInFlight) {
+        if (outcome == null || writeInFlight) return@LaunchedEffect
+        delay(if (outcome == MoveOutcome.Undone) UNDONE_CHIP_MILLIS else CHIP_MILLIS)
+        viewModel.consumeOutcome()
+    }
+
+    BoxWithConstraints(modifier = modifier.fillMaxSize()) {
+        val chipMaxWidth = maxWidth - FAB_BAND
+        // A FAB-height band at the bottom start with the FAB's own margin, so
+        // the chip lines up beside the bottom-end FAB.
+        Box(
+            modifier = Modifier
+                .align(Alignment.BottomStart)
+                .navigationBarsPadding()
+                .padding(start = SnackChipMargin, bottom = SnackChipMargin)
+                .height(SnackChipHeight),
+            contentAlignment = Alignment.CenterStart,
+        ) {
+            // The action goes away while a write runs: undo() refuses a second
+            // write anyway, so offering it would be a button that does nothing.
+            val undo = content.undo?.takeIf { !writeInFlight }
+            SnackChip(
+                visible = outcome != null,
+                message = content.message,
+                maxWidth = chipMaxWidth,
+                actionLabel = stringResource(R.string.event_move_undo).takeIf { undo != null },
+                onAction = undo?.let { { viewModel.undo(it) } },
+            )
+        }
+    }
+}
+
+/**
+ * "Fri, 7 Aug, 09:00" — the day, plus the time for a timed event. All-day events
+ * are read back on the UTC calendar day they are anchored to (#65, #82).
+ */
+private fun formatMovedTo(
+    startMillis: Long,
+    isAllDay: Boolean,
+    use24Hour: Boolean,
+    locale: Locale,
+): String {
+    val zone: ZoneId = if (isAllDay) ZoneOffset.UTC else ZoneId.systemDefault()
+    val skeleton = when {
+        isAllDay -> "EEEdMMM"
+        use24Hour -> "EEEdMMMHm"
+        else -> "EEEdMMMhm"
+    }
+    return localizedDateFormatter(locale, skeleton)
+        .format(Instant.ofEpochMilli(startMillis).atZone(zone))
+}

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

@@ -0,0 +1,109 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.CustomAccessibilityAction
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Drag-to-reschedule wiring (#68), provided once at `CalendarHost` and read by
+ * whichever event block is being composed. Null means moving is off entirely and
+ * blocks register no drag gesture at all.
+ */
+@Immutable
+class EventMoveScope(
+    /**
+     * Calendars whose events may be moved. Nothing below the UI enforces this —
+     * the repository writes whatever it is handed — so this gate is load-bearing.
+     */
+    val movableCalendarIds: Set<Long>,
+    /** False when the drop was refused outright, so nothing will be written. */
+    val move: (MoveRequest) -> Boolean,
+    /**
+     * True while a dropped event is being written, including the time its scope
+     * dialog is up. A flow rather than a value so this scope stays the same
+     * object across a move — every visible block reads it as a composition local.
+     */
+    val inFlight: StateFlow<Boolean>,
+    /** Ticks when an undo write begins — see `RescheduleViewModel.undoStarted`. */
+    val undoStarted: StateFlow<Int>,
+    /** Open an event in the edit form — the pointer-free route to the same change. */
+    val edit: (EventInstance) -> Unit,
+) {
+    fun allows(event: EventInstance): Boolean = event.calendarId in movableCalendarIds
+}
+
+val LocalEventMove = compositionLocalOf<EventMoveScope?> { null }
+
+private val NEVER_IN_FLIGHT = MutableStateFlow(false)
+
+private val NEVER_UNDONE = MutableStateFlow(0)
+
+/**
+ * Whether a dropped event is still being written — false wherever moving is off.
+ * The drag overlays hold a landed block on its target for this window.
+ */
+@Composable
+fun moveInFlight(): Boolean {
+    val flow = LocalEventMove.current?.inFlight ?: NEVER_IN_FLIGHT
+    return flow.collectAsStateWithLifecycle().value
+}
+
+/**
+ * Runs [onUndo] when an undo write begins, and never for one that began before
+ * this composable came on screen.
+ */
+@Composable
+fun OnUndoStarted(onUndo: () -> Unit) {
+    val flow = LocalEventMove.current?.undoStarted ?: NEVER_UNDONE
+    val tick by flow.collectAsStateWithLifecycle()
+    var seen by remember { mutableIntStateOf(tick) }
+    LaunchedEffect(tick) {
+        if (tick == seen) return@LaunchedEffect
+        seen = tick
+        onUndo()
+    }
+}
+
+/** Opacity the source block keeps while its floating copy travels. */
+const val GHOST_ALPHA: Float = 0.3f
+
+/**
+ * Opacity for a block whose copy is in flight: ghosted from the lift until the
+ * copy is handed back, then animated up rather than switched, so the block
+ * appears to travel to its new slot instead of vanishing and reappearing.
+ */
+@Composable
+fun ghostAlpha(lifted: Boolean): Float = animateFloatAsState(
+    targetValue = if (lifted) GHOST_ALPHA else 1f,
+    label = "ghost-alpha",
+).value
+
+/**
+ * A TalkBack action that opens [event] in the edit form, so rescheduling isn't
+ * pointer-only. Null when this event can't be moved.
+ */
+@Composable
+fun eventMoveAction(event: EventInstance): CustomAccessibilityAction? {
+    val move = LocalEventMove.current ?: return null
+    if (!move.allows(event)) return null
+    val label = stringResource(R.string.event_move_action)
+    return remember(event.instanceId, label, move) {
+        CustomAccessibilityAction(label) {
+            move.edit(event)
+            true
+        }
+    }
+}

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

@@ -0,0 +1,119 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.floret.locale.currentLocale
+
+/** Width of the hour gutter down the start edge of the day and week timelines. */
+val GUTTER_WIDTH = 48.dp
+
+/**
+ * Start inset for the gutter's content (week badge + hour labels) so it centres
+ * on the top bar's hamburger: with a 48dp gutter, 8dp lands the centre at 28dp,
+ * matching the icon button's centre.
+ */
+val GUTTER_CONTENT_START_INSET = 8.dp
+
+private val BADGE_HEIGHT = 20.dp
+
+/** How far the fixed hour labels recede while a block is being dragged. */
+private const val DIMMED_HOUR_ALPHA = 0.3f
+
+/**
+ * The timeline's hour gutter. Scrolls in sync with the day columns through the
+ * shared [scrollState], and while [dragController] holds a lifted block it dims
+ * the hour labels and floats a badge with the drag's current start time at the
+ * row the block would land on.
+ */
+@Composable
+fun HourGutter(
+    scrollState: ScrollState,
+    hourHeight: Dp,
+    dragController: TimelineDragController,
+    modifier: Modifier = Modifier,
+) {
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
+    // Derived: the drag is rewritten every frame, its snapped start once a slot.
+    val dragStartMin by remember(dragController) {
+        derivedStateOf { dragController.drag?.startMin }
+    }
+    val hourAlpha by animateFloatAsState(
+        targetValue = if (dragStartMin != null) DIMMED_HOUR_ALPHA else 1f,
+        label = "hourLabelAlpha",
+    )
+
+    Box(
+        modifier = modifier
+            .width(GUTTER_WIDTH)
+            .padding(start = GUTTER_CONTENT_START_INSET)
+            .fillMaxHeight()
+            .verticalScroll(scrollState),
+    ) {
+        Column {
+            (0 until 24).forEach { h ->
+                Box(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .height(hourHeight),
+                ) {
+                    if (h > 0) {
+                        Text(
+                            text = formatHourLabel(h, use24Hour, locale),
+                            style = MaterialTheme.typography.labelSmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                                .copy(alpha = hourAlpha),
+                            modifier = Modifier
+                                .align(Alignment.TopCenter)
+                                .offset(y = (-6).dp),
+                        )
+                    }
+                }
+            }
+        }
+        dragStartMin?.let { startMin ->
+            val top = (hourHeight * (startMin / 60f) - BADGE_HEIGHT / 2).coerceAtLeast(0.dp)
+            Box(
+                modifier = Modifier
+                    .align(Alignment.TopCenter)
+                    .offset(y = top)
+                    .height(BADGE_HEIGHT)
+                    .background(MaterialTheme.colorScheme.primary, CircleShape)
+                    .padding(horizontal = 4.dp)
+                    // The dragged block already announces this time.
+                    .clearAndSetSemantics { },
+                contentAlignment = Alignment.Center,
+            ) {
+                Text(
+                    text = formatGutterTime(startMin, use24Hour, locale),
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onPrimary,
+                    maxLines = 1,
+                    softWrap = false,
+                )
+            }
+        }
+    }
+}

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

@@ -0,0 +1,169 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atTime
+import kotlinx.datetime.plus
+import kotlinx.datetime.toInstant
+import kotlin.time.Duration.Companion.minutes
+import kotlin.time.Instant
+
+/**
+ * Stand-in events for the view previews. A preview has no business querying the
+ * provider for a thumbnail, so every chooser renders the same invented week.
+ *
+ * Colours are raw ARGB on purpose: that is what the provider hands out for an
+ * event, so a theme token here would misrepresent what the views actually draw.
+ */
+private val SAMPLE_COLORS = listOf(
+    0xFF3F7BD4.toInt(),
+    0xFFCE5B4C.toInt(),
+    0xFF4E9A6A.toInt(),
+    0xFF8A63C7.toInt(),
+)
+
+private val SAMPLE_TITLES = listOf(
+    "Standup",
+    "Lunch",
+    "Review",
+    "Gym",
+    "Call",
+    "Workshop",
+    "Dentist",
+    "Trip",
+)
+
+/** Hands out [EventInstance]s with running ids and cycling sample titles/colours. */
+private class SampleEvents(private val zone: TimeZone) {
+    private var id = 0L
+
+    fun timed(
+        day: LocalDate,
+        hour: Int,
+        minute: Int = 0,
+        lengthMinutes: Int,
+        colorIndex: Int,
+    ): EventInstance {
+        val start = day.atTime(hour, minute).toInstant(zone)
+        return build(
+            start = start,
+            end = start + lengthMinutes.minutes,
+            isAllDay = false,
+            colorIndex = colorIndex,
+        )
+    }
+
+    fun allDay(from: LocalDate, days: Int, colorIndex: Int): EventInstance = build(
+        // All-day events sit at UTC midnights with an exclusive end.
+        start = from.atTime(0, 0).toInstant(TimeZone.UTC),
+        end = from.plus(days, DateTimeUnit.DAY).atTime(0, 0).toInstant(TimeZone.UTC),
+        isAllDay = true,
+        colorIndex = colorIndex,
+    )
+
+    private fun build(
+        start: Instant,
+        end: Instant,
+        isAllDay: Boolean,
+        colorIndex: Int,
+    ): EventInstance {
+        val next = ++id
+        return EventInstance(
+            instanceId = next,
+            eventId = next,
+            calendarId = 1L,
+            title = SAMPLE_TITLES[(next.toInt() - 1) % SAMPLE_TITLES.size],
+            start = start,
+            end = end,
+            isAllDay = isAllDay,
+            color = SAMPLE_COLORS[colorIndex % SAMPLE_COLORS.size],
+            location = null,
+        )
+    }
+}
+
+/**
+ * A month's worth of stand-ins, spread so most weeks carry something, with one
+ * multi-day bar bridging cells and a busy today for the split pane.
+ */
+internal fun sampleMonthEvents(
+    firstOfMonth: LocalDate,
+    today: LocalDate,
+    zone: TimeZone,
+): List<EventInstance> {
+    val sample = SampleEvents(zone)
+    return buildList {
+        add(sample.allDay(firstOfMonth.plus(9, DateTimeUnit.DAY), days = 3, colorIndex = 2))
+        add(sample.timed(firstOfMonth.plus(1, DateTimeUnit.DAY), 9, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(firstOfMonth.plus(4, DateTimeUnit.DAY), 14, lengthMinutes = 120, colorIndex = 1))
+        add(sample.timed(firstOfMonth.plus(7, DateTimeUnit.DAY), 11, lengthMinutes = 60, colorIndex = 3))
+        add(sample.timed(firstOfMonth.plus(15, DateTimeUnit.DAY), 10, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(firstOfMonth.plus(18, DateTimeUnit.DAY), 16, lengthMinutes = 60, colorIndex = 2))
+        add(sample.timed(firstOfMonth.plus(22, DateTimeUnit.DAY), 8, lengthMinutes = 120, colorIndex = 1))
+        add(sample.timed(firstOfMonth.plus(25, DateTimeUnit.DAY), 13, lengthMinutes = 60, colorIndex = 3))
+        // Today, so the split pane's list and the grid's dots both have content.
+        add(sample.timed(today, 9, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(today, 12, lengthMinutes = 60, colorIndex = 1))
+        add(sample.timed(today, 15, lengthMinutes = 120, colorIndex = 3))
+    }
+}
+
+/**
+ * Stand-ins for a timeline preview over [days]. [anchor] — the day the preview
+ * is centred on — gets the busy set, including one overlapping pair so the
+ * side-by-side lane layout shows; the rest of the week is sparser. A multi-day
+ * all-day bar is only added when there is more than one column to span.
+ */
+internal fun sampleTimelineEvents(
+    days: List<LocalDate>,
+    anchor: LocalDate,
+    zone: TimeZone,
+): List<EventInstance> {
+    val sample = SampleEvents(zone)
+    return buildList {
+        if (days.size > 1) {
+            add(sample.allDay(days[days.size / 2], days = 2, colorIndex = 2))
+        } else {
+            add(sample.allDay(anchor, days = 1, colorIndex = 2))
+        }
+        // The anchor day: enough to fill the column, with 09:30–11:00 running
+        // under 09:00–10:00 so the overlap resolves into two lanes.
+        add(sample.timed(anchor, 9, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(anchor, 9, minute = 30, lengthMinutes = 90, colorIndex = 1))
+        add(sample.timed(anchor, 13, lengthMinutes = 120, colorIndex = 3))
+        days.filterNot { it == anchor }.forEachIndexed { index, day ->
+            // Skip every third day so the week doesn't read as a solid block.
+            if (index % 3 == 2) return@forEachIndexed
+            add(
+                sample.timed(
+                    day = day,
+                    hour = 8 + (index * 3) % 9,
+                    lengthMinutes = if (index % 2 == 0) 60 else 90,
+                    colorIndex = index,
+                ),
+            )
+        }
+    }
+}
+
+/**
+ * Stand-ins for the agenda preview: a forward-looking fortnight where the first
+ * days are busy and later ones thin out, so the grouped-by-day list shows both
+ * a full day and the gaps between days.
+ */
+internal fun sampleAgendaEvents(today: LocalDate, zone: TimeZone): List<EventInstance> {
+    val sample = SampleEvents(zone)
+    return buildList {
+        add(sample.timed(today, 9, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(today, 12, minute = 30, lengthMinutes = 60, colorIndex = 1))
+        add(sample.timed(today, 16, lengthMinutes = 90, colorIndex = 3))
+        val tomorrow = today.plus(1, DateTimeUnit.DAY)
+        add(sample.allDay(tomorrow, days = 2, colorIndex = 2))
+        add(sample.timed(tomorrow, 10, lengthMinutes = 120, colorIndex = 1))
+        add(sample.timed(today.plus(3, DateTimeUnit.DAY), 14, lengthMinutes = 60, colorIndex = 0))
+        add(sample.timed(today.plus(6, DateTimeUnit.DAY), 11, lengthMinutes = 60, colorIndex = 3))
+        add(sample.timed(today.plus(10, DateTimeUnit.DAY), 18, lengthMinutes = 120, colorIndex = 2))
+    }
+}

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

@@ -0,0 +1,69 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
+import de.jeanlucmakiola.floret.components.OptionCard
+
+/**
+ * How far a write to a recurring event should reach: this occurrence, it and
+ * everything after (a series split), or the whole series. Shared by the edit
+ * screen's save and a drag-and-drop reschedule; one of the two carve-outs from
+ * the full-screen picker rule.
+ *
+ * [allowOccurrence] drops "only this event" (an exception row can't carry its own
+ * rule); [allowSeries] drops the two wider options, for a rule whose days can't
+ * be recalculated from one moved occurrence — [reason] then says why.
+ */
+@Composable
+fun RecurringScopeDialog(
+    title: String,
+    onSelect: (RecurringWriteScope) -> Unit,
+    onDismiss: () -> Unit,
+    allowOccurrence: Boolean = true,
+    allowSeries: Boolean = true,
+    reason: String? = null,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(title) },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                if (reason != null) {
+                    Text(
+                        text = reason,
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+                if (allowOccurrence) {
+                    OptionCard(
+                        label = stringResource(R.string.event_delete_option_occurrence),
+                        onClick = { onSelect(RecurringWriteScope.ThisEvent) },
+                    )
+                }
+                if (allowSeries) {
+                    OptionCard(
+                        label = stringResource(R.string.event_delete_option_following),
+                        onClick = { onSelect(RecurringWriteScope.ThisAndFollowing) },
+                    )
+                    OptionCard(
+                        label = stringResource(R.string.event_delete_option_series),
+                        onClick = { onSelect(RecurringWriteScope.AllEvents) },
+                    )
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = onDismiss) { Text(stringResource(R.string.dialog_cancel)) }
+        },
+    )
+}

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

@@ -0,0 +1,463 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
+import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
+import de.jeanlucmakiola.calendula.data.di.IoDispatcher
+import de.jeanlucmakiola.calendula.domain.EventDetail
+import de.jeanlucmakiola.calendula.domain.EventForm
+import de.jeanlucmakiola.calendula.domain.EventFormProblem
+import de.jeanlucmakiola.calendula.domain.RecurrenceEnd
+import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
+import de.jeanlucmakiola.calendula.domain.allowsEventMove
+import de.jeanlucmakiola.calendula.domain.parseSimpleRecurrence
+import de.jeanlucmakiola.calendula.domain.problems
+import de.jeanlucmakiola.calendula.domain.realignRecurrence
+import de.jeanlucmakiola.calendula.domain.resolvedZone
+import de.jeanlucmakiola.calendula.domain.shiftedByDays
+import de.jeanlucmakiola.calendula.domain.shiftedTo
+import de.jeanlucmakiola.calendula.domain.toEditForm
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atStartOfDayIn
+import kotlinx.datetime.plus
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.coroutines.cancellation.CancellationException
+import kotlin.time.Instant
+import javax.inject.Inject
+
+private const val MILLIS_PER_MINUTE = 60_000
+private const val MINUTES_PER_DAY = 24 * 60
+
+/** Where a dragged event should land. */
+sealed interface MoveTarget {
+    /** A new start instant — a timeline drag, which moves time and day at once. */
+    data class Start(val instant: Instant) : MoveTarget
+
+    /**
+     * A whole-day shift, keeping the time of day — a month-grid or all-day drag.
+     * A delta rather than a target date, so the screen and this view model can't
+     * disagree by a day over which zone the event's first day is resolved in.
+     */
+    data class ByDays(val days: Int) : MoveTarget
+}
+
+/**
+ * One dropped event. [beginMillis]/[endMillis] are the dragged *occurrence's*
+ * own times (`Instances.BEGIN`/`END`), as the detail and edit screens pass them.
+ */
+data class MoveRequest(
+    val eventId: Long,
+    val beginMillis: Long,
+    val endMillis: Long,
+    val target: MoveTarget,
+)
+
+/**
+ * A recurring drop waiting for the user to pick how far it reaches.
+ * [occurrenceOnly] means a wider write would leave the rule and the series
+ * anchor disagreeing — either the rule names days one moved occurrence can't
+ * re-derive (`BYDAY=MO,WE`, `2TH`, …), or the shift wouldn't carry the anchor
+ * across the same midnights the occurrence crossed.
+ */
+data class MoveScopePrompt(val occurrenceOnly: Boolean)
+
+/** The inverse of a completed move, for the undo action. */
+data class MoveUndo(
+    val eventId: Long,
+    /** The form as it now stands (the moved state). */
+    val moved: EventForm,
+    /** The form as it stood before the move. */
+    val restored: EventForm,
+)
+
+sealed interface MoveOutcome {
+    /**
+     * Written. [startMillis] is where the dragged occurrence now begins, for the
+     * confirmation message; [undo] is null when the write has no clean inverse.
+     */
+    data class Moved(
+        val startMillis: Long,
+        val isAllDay: Boolean,
+        val undo: MoveUndo?,
+    ) : MoveOutcome
+
+    data object Undone : MoveOutcome
+
+    /** `WRITE_CALENDAR` was revoked between the drop and the provider call. */
+    data object WriteDenied : MoveOutcome
+
+    /** The event vanished (sync, another device) between the read and the write. */
+    data object Gone : MoveOutcome
+
+    /** The drop would push the series past its own `UNTIL`, generating nothing. */
+    data object BlockedSeriesEnd : MoveOutcome
+
+    data object Failed : MoveOutcome
+}
+
+/**
+ * Writes a drag-and-drop reschedule (#68) through the same repository calls the
+ * edit screen's save uses, so recurring writes, reminder reconciliation and
+ * attendee preservation behave identically. Hosted at `CalendarHost` so one
+ * instance serves every calendar view and survives view switches. The full
+ * prefilled form is carried through the write — a stripped one would wipe the
+ * reminders and attendees the occurrence-exception path reconciles.
+ */
+@HiltViewModel
+class RescheduleViewModel @Inject constructor(
+    private val repository: CalendarRepository,
+    @IoDispatcher private val io: CoroutineDispatcher,
+) : ViewModel() {
+
+    private val _scopePrompt = MutableStateFlow<MoveScopePrompt?>(null)
+    val scopePrompt: StateFlow<MoveScopePrompt?> = _scopePrompt.asStateFlow()
+
+    private val _outcome = MutableStateFlow<MoveOutcome?>(null)
+    val outcome: StateFlow<MoveOutcome?> = _outcome.asStateFlow()
+
+    private var pending: PreparedMove? = null
+
+    private val _inFlight = MutableStateFlow(false)
+
+    /**
+     * True from the moment a drop is accepted until its write settles — the
+     * window the dropped block holds its landing position for.
+     */
+    val inFlight: StateFlow<Boolean> = _inFlight.asStateFlow()
+
+    private val _undoStarted = MutableStateFlow(0)
+
+    /**
+     * Ticks the moment an undo write begins, before the provider has anything to
+     * re-read, so the view that drew the drop can carry its chip back rather than
+     * let it reappear on the old day.
+     */
+    val undoStarted: StateFlow<Int> = _undoStarted.asStateFlow()
+
+    /**
+     * Set from the moment a drop is accepted until its write settles. Two drops
+     * of the same recurring event inside that window would compute their shift
+     * from the same pre-move occurrence, and the shifts would compound.
+     */
+    private var busy = false
+        set(value) {
+            field = value
+            _inFlight.value = value
+        }
+
+    /**
+     * The calendars whose events may be dragged. Nothing below the UI guards
+     * this, so a block outside this set registers no drag gesture at all.
+     */
+    val movableCalendarIds: StateFlow<Set<Long>> = repository.calendars()
+        .map { calendars -> calendars.filter { it.allowsEventMove }.map { it.id }.toSet() }
+        .catch { emit(emptySet<Long>()) }
+        .flowOn(io)
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = emptySet(),
+        )
+
+    /** Everything a drop needs, resolved before anything is written. */
+    private data class PreparedMove(
+        val request: MoveRequest,
+        val original: EventForm,
+        val updated: EventForm,
+        /** True for a series master with a rule — an exception row is not one. */
+        val isRecurring: Boolean,
+        /** False when the rule names days this move can't re-derive. */
+        val canRealign: Boolean,
+        /** The series row's DTSTART date after the move — what its `UNTIL` must clear. */
+        val newAnchorDate: LocalDate,
+    )
+
+    /**
+     * Take a drop, unless one is already being written. False means nothing will
+     * be written and the caller must let its held copy go now — waiting on
+     * [inFlight] would strand it until the settle timeout instead.
+     */
+    fun move(request: MoveRequest): Boolean {
+        if (busy || _scopePrompt.value != null) return false
+        busy = true
+        viewModelScope.launch {
+            val prepared = prepare(request)
+            if (prepared == null) {
+                busy = false
+                return@launch
+            }
+            if (!prepared.isRecurring) {
+                write(prepared, RecurringWriteScope.AllEvents)
+                busy = false
+            } else {
+                // Still busy: the scope dialog is now the thing in flight.
+                pending = prepared
+                _scopePrompt.value = MoveScopePrompt(occurrenceOnly = !prepared.canRealign)
+            }
+        }
+        return true
+    }
+
+    /** Answer the scope dialog. */
+    fun moveWithScope(scope: RecurringWriteScope) {
+        val prepared = pending ?: return
+        // Guard against the dialog ever offering a scope the rule can't carry.
+        if (!prepared.canRealign && scope != RecurringWriteScope.ThisEvent) return
+        pending = null
+        _scopePrompt.value = null
+        viewModelScope.launch {
+            write(prepared, scope)
+            busy = false
+        }
+    }
+
+    /** Dismiss the scope dialog without writing. */
+    fun cancelScope() {
+        pending = null
+        busy = false
+        _scopePrompt.value = null
+    }
+
+    /**
+     * Put a completed move back where it came from. The outcome stands until the
+     * inverse write reports back, so the one chip changes what it says rather
+     * than closing and reopening. False when another write is already running —
+     * the chip hides its action for that window, so this is the backstop.
+     */
+    fun undo(undo: MoveUndo): Boolean {
+        if (busy) return false
+        busy = true
+        _undoStarted.value += 1
+        viewModelScope.launch {
+            _outcome.value = try {
+                repository.updateEvent(undo.eventId, undo.moved, undo.restored)
+                MoveOutcome.Undone
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: SecurityException) {
+                MoveOutcome.WriteDenied
+            } catch (e: NoSuchEventException) {
+                MoveOutcome.Gone
+            } catch (e: Exception) {
+                MoveOutcome.Failed
+            }
+            busy = false
+        }
+        return true
+    }
+
+    /** Clear the outcome once the screen has shown it. */
+    fun consumeOutcome() {
+        _outcome.value = null
+    }
+
+    private suspend fun prepare(request: MoveRequest): PreparedMove? {
+        val detail = try {
+            repository.eventDetail(request.eventId)
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: NoSuchEventException) {
+            _outcome.value = MoveOutcome.Gone
+            return null
+        } catch (e: Exception) {
+            _outcome.value = MoveOutcome.Failed
+            return null
+        }
+
+        val zone = TimeZone.currentSystemDefault()
+        val original = detail.toEditForm(request.beginMillis, request.endMillis, zone)
+        val shifted = when (val target = request.target) {
+            is MoveTarget.Start -> original.shiftedTo(target.instant, zone)
+            is MoveTarget.ByDays -> original.shiftedByDays(target.days, zone)
+        }
+        // A zero-distance drop is not a write.
+        if (shifted == original) return null
+
+        // The UNTIL check is deferred to the write, which knows how far the move
+        // reaches and so which date has to clear it.
+        if ((shifted.problems() - EventFormProblem.RecurrenceEndsBeforeStart).isNotEmpty()) {
+            _outcome.value = MoveOutcome.Failed
+            return null
+        }
+
+        // An exception row stands alone whatever rule a sync adapter left on it.
+        val isRecurring = original.rrule != null && !detail.isException
+        val movedDay = shifted.start.date != original.start.date
+        // The series anchor moves by the same *wall-clock* shift as the dragged
+        // occurrence, so only a whole-day shift carries it across the same number
+        // of midnights whatever time of day it sits at. A same-date drag has its
+        // own, narrower check — see anchorKeepsItsDay.
+        val wholeDayShift = original.isAllDay || shifted.start.time == original.start.time
+        val realigned = if (isRecurring && movedDay) {
+            if (wholeDayShift) {
+                realignRecurrence(
+                    requireNotNull(original.rrule),
+                    original.start.date,
+                    shifted.start.date,
+                )
+            } else {
+                null
+            }
+        } else {
+            original.rrule
+        }
+        return PreparedMove(
+            request = request,
+            original = original,
+            // A rule we can't re-derive stays verbatim: the only scope offered
+            // then is the single occurrence, whose exception row carries no rule.
+            updated = shifted.copy(rrule = realigned ?: original.rrule),
+            isRecurring = isRecurring,
+            canRealign = when {
+                !isRecurring -> true
+                movedDay -> realigned != null
+                else -> anchorKeepsItsDay(detail, original, shifted, zone)
+            },
+            // Where the series row's own DTSTART lands, given the anchor moves by
+            // the same shift. Only read under canRealign, which is what
+            // guarantees the anchor really does travel this many days.
+            newAnchorDate = anchorDate(detail, original, zone)
+                .plus(shifted.start.date.toEpochDays() - original.start.date.toEpochDays(), DateTimeUnit.DAY),
+        )
+    }
+
+    private suspend fun write(prepared: PreparedMove, scope: RecurringWriteScope) {
+        val request = prepared.request
+        if (endsBeforeItStarts(prepared, scope)) {
+            _outcome.value = MoveOutcome.BlockedSeriesEnd
+            return
+        }
+        _outcome.value = try {
+            when {
+                !prepared.isRecurring || scope == RecurringWriteScope.AllEvents ->
+                    repository.updateEvent(request.eventId, prepared.original, prepared.updated)
+
+                scope == RecurringWriteScope.ThisEvent ->
+                    repository.updateOccurrence(
+                        request.eventId,
+                        request.beginMillis,
+                        prepared.updated,
+                    )
+
+                else -> repository.updateEventFromOccurrence(
+                    eventId = request.eventId,
+                    beginMillis = request.beginMillis,
+                    original = prepared.original,
+                    updated = prepared.updated,
+                )
+            }
+            MoveOutcome.Moved(
+                startMillis = movedStartMillis(prepared),
+                isAllDay = prepared.updated.isAllDay,
+                undo = undoFor(prepared, scope),
+            )
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: SecurityException) {
+            MoveOutcome.WriteDenied
+        } catch (e: NoSuchEventException) {
+            MoveOutcome.Gone
+        } catch (e: Exception) {
+            MoveOutcome.Failed
+        }
+    }
+
+    /**
+     * Whether this write would leave a rule whose `UNTIL` precedes the first day
+     * it now applies to — the provider then generates nothing at all. Which date
+     * has to clear `UNTIL` depends on the scope: a whole-series move carries the
+     * series *anchor*, a split starts at the moved occurrence, and a single
+     * occurrence becomes an exception row that no `UNTIL` constrains.
+     */
+    private fun endsBeforeItStarts(prepared: PreparedMove, scope: RecurringWriteScope): Boolean {
+        if (!prepared.isRecurring || scope == RecurringWriteScope.ThisEvent) return false
+        val rule = prepared.updated.rrule ?: return false
+        val end = parseSimpleRecurrence(rule)?.end as? RecurrenceEnd.Until ?: return false
+        val firstDay = if (scope == RecurringWriteScope.AllEvents) {
+            prepared.newAnchorDate
+        } else {
+            prepared.updated.start.date
+        }
+        return end.date < firstDay
+    }
+
+    /**
+     * Whether a same-date drag leaves the series anchor on its own day too. The
+     * anchor moves by the same wall-clock delta as the occurrence, and normally
+     * shares its time of day — but a row with no `EVENT_TIMEZONE` resolves the
+     * two in zones that can sit a DST hour apart, so a near-midnight drag could
+     * carry the anchor across a midnight the occurrence never crossed and leave
+     * `BYDAY` naming the wrong weekday.
+     */
+    private fun anchorKeepsItsDay(
+        detail: EventDetail,
+        original: EventForm,
+        shifted: EventForm,
+        zone: TimeZone,
+    ): Boolean {
+        val anchorZone = if (original.isAllDay) TimeZone.UTC else original.resolvedZone(zone)
+        val anchorMinute = detail.instance.start.toLocalDateTime(anchorZone)
+            .time.toMillisecondOfDay() / MILLIS_PER_MINUTE
+        val delta = (
+            shifted.start.time.toMillisecondOfDay() - original.start.time.toMillisecondOfDay()
+            ) / MILLIS_PER_MINUTE
+        return anchorMinute + delta in 0 until MINUTES_PER_DAY
+    }
+
+    /**
+     * The series row's own start date — for a recurring master, `EventDetail`
+     * carries the row's DTSTART rather than the tapped occurrence's. Read in the
+     * same anchoring the write path uses: UTC for an all-day series.
+     */
+    private fun anchorDate(detail: EventDetail, original: EventForm, zone: TimeZone): LocalDate =
+        detail.instance.start
+            .toLocalDateTime(if (original.isAllDay) TimeZone.UTC else original.resolvedZone(zone))
+            .date
+
+    /**
+     * Undo is offered only where the inverse is one symmetric write: a
+     * non-recurring event, and a whole-series move. "This event" leaves an
+     * exception row behind and "this and following" splits the series with an
+     * UNTIL truncation — neither is undone by shifting back.
+     */
+    private fun undoFor(prepared: PreparedMove, scope: RecurringWriteScope): MoveUndo? =
+        if (!prepared.isRecurring || scope == RecurringWriteScope.AllEvents) {
+            MoveUndo(
+                eventId = prepared.request.eventId,
+                moved = prepared.updated,
+                restored = prepared.original,
+            )
+        } else {
+            null
+        }
+
+    /**
+     * Where the dragged occurrence now begins, in the same anchoring the views
+     * read dates back in: UTC midnight for an all-day event.
+     */
+    private fun movedStartMillis(prepared: PreparedMove): Long {
+        val form = prepared.updated
+        return if (form.isAllDay) {
+            form.start.date.atStartOfDayIn(TimeZone.UTC).toEpochMilliseconds()
+        } else {
+            form.start.toInstant(form.resolvedZone(TimeZone.currentSystemDefault()))
+                .toEpochMilliseconds()
+        }
+    }
+
+}

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

@@ -17,6 +17,7 @@ val LocalUse24HourFormat = staticCompositionLocalOf { true }
 private const val PATTERN_24 = "HH:mm"
 private const val PATTERN_12 = "h:mm a"
 private const val HOUR_PATTERN_12 = "h a"
+private const val HOUR_MINUTE_PATTERN_12 = "h:mm"
 
 /** A time-of-day [DateTimeFormatter] for the resolved convention and [locale]. */
 fun timeOfDayFormatter(is24Hour: Boolean, locale: Locale): DateTimeFormatter =
@@ -42,6 +43,18 @@ fun formatMinuteOfDay(minutes: Int, is24Hour: Boolean, locale: Locale): String =
     else -> formatTimeOfDay(minutes / 60, minutes % 60, is24Hour, locale)
 }
 
+/**
+ * The time shown in the timeline gutter while a block is dragged: 24h →
+ * "09:15", 12h → "9:15". The meridiem is dropped — the hour labels around it
+ * already carry it, and the gutter is too narrow.
+ */
+fun formatGutterTime(minutes: Int, is24Hour: Boolean, locale: Locale): String {
+    val clamped = minutes.coerceIn(0, MINUTES_PER_DAY - 1)
+    val pattern = if (is24Hour) PATTERN_24 else HOUR_MINUTE_PATTERN_12
+    return LocalTime.of(clamped / 60, clamped % 60)
+        .format(DateTimeFormatter.ofPattern(pattern, locale))
+}
+
 /**
  * The compact hour-only label for a timeline gutter: 24h → "13" (zero-padded,
  * the prior look); 12h → "1 PM".

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

@@ -0,0 +1,484 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.MutatePriority
+import androidx.compose.foundation.background
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.absoluteOffset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.withFrameNanos
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.layout.boundsInRoot
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.layout.positionInRoot
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.week.MINUTES_PER_DAY
+import de.jeanlucmakiola.calendula.ui.week.TimedBlock
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import de.jeanlucmakiola.floret.locale.currentLocale
+import kotlinx.coroutines.delay
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.LocalTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
+import kotlin.math.roundToInt
+import kotlin.time.Instant
+
+/** Start granularity a dragged block snaps to, matching the big calendar apps. */
+const val DRAG_SNAP_MINUTES: Int = 15
+
+/** How close to a timeline edge the finger must get before the view scrolls. */
+private val AUTO_SCROLL_EDGE = 64.dp
+
+/** Fastest auto-scroll step, per frame, right at the edge. */
+private val AUTO_SCROLL_STEP = 16.dp
+
+/** A block being dragged, in root coordinates so it can be drawn in an overlay. */
+data class TimelineDrag(
+    val event: EventInstance,
+    val date: LocalDate,
+    val startMin: Int,
+    val endMin: Int,
+    val topLeftInRoot: Offset,
+    val sizePx: IntSize,
+) {
+    /** What the snap haptics key off: one tick per changed slot, not per frame. */
+    val slot: Pair<LocalDate, Int> get() = date to startMin
+}
+
+/** Where a finished drag asks its event to go. */
+data class TimelineDrop(val event: EventInstance, val date: LocalDate, val startMin: Int)
+
+/**
+ * The timeline's live geometry, republished on every layout. Plain fields rather
+ * than snapshot state: it changes on every scroll frame, and the drag loop reads
+ * it per frame anyway.
+ */
+class TimelineGeometry {
+    /** The day-columns row — scrolling *content*, so its root position folds in the scroll. */
+    var grid: LayoutCoordinates? = null
+
+    /** The scroll viewport, for the edge that triggers auto-scrolling. */
+    var viewport: LayoutCoordinates? = null
+    var scroll: ScrollState? = null
+    var hourPx: Float = 0f
+
+    /** Column pitch — one column plus the gap after it. */
+    var columnWidthPx: Float = 0f
+    var columnGapPx: Float = 0f
+    var edgePx: Float = 0f
+    var stepPx: Float = 0f
+    var days: List<LocalDate> = emptyList()
+
+    /**
+     * Whether the columns are laid out right-to-left. Pointer coordinates are
+     * never mirrored but the grid is, so the mapping has to flip with it.
+     */
+    var isRtl: Boolean = false
+}
+
+/**
+ * Hoisted drag state for one timeline (#68). It lives above the per-page
+ * `AnimatedContent`, so a page change mid-drag can't strand a ghost, and the
+ * block it renders is drawn in an overlay, clear of the day column's clip.
+ */
+@Stable
+class TimelineDragController {
+    val geometry = TimelineGeometry()
+
+    var drag: TimelineDrag? by mutableStateOf(null)
+        private set
+
+    /**
+     * A dropped block, held at the slot it landed on while the write runs — the
+     * grid behind it still shows the old time until the query re-reads.
+     */
+    var settling: TimelineDrag? by mutableStateOf(null)
+        private set
+
+    /**
+     * Which block is lifted, and whether anything is. Separate snapshot state
+     * from [drag], which changes every frame, so blocks that only need "am I the
+     * ghost" don't recompose that often. Stays set through [settling].
+     */
+    var liftedInstanceId: Long? by mutableStateOf(null)
+        private set
+
+    /**
+     * Where the settled drop came from, and which event row it belongs to. The
+     * instance id alone can't identify the source block for the length of the
+     * write: the provider regenerates `Instances` rows, so a re-read carrying the
+     * *old* time can arrive under a new instance id.
+     */
+    private var settledOrigin: Triple<Long, LocalDate, Int>? by mutableStateOf(null)
+
+    /** Whether a finger is on a block right now — [settling] is not dragging. */
+    var isDragging: Boolean by mutableStateOf(false)
+        private set
+
+    /**
+     * Whether the grid itself now draws the settled drop at its landing slot.
+     * The copy may only be handed back once this is true, or the source ghost
+     * flashes back to full opacity in its old slot.
+     */
+    var settledOnGrid: Boolean by mutableStateOf(false)
+        private set
+
+    private var source: TimedBlock? = null
+    private var grab = Offset.Zero
+    private var pointer = Offset.Zero
+
+    /**
+     * The slot the block already occupied when it was picked up — not the same
+     * as its start, since the target snaps to the grid (09:07 lifts to 09:00).
+     */
+    private var originSlot: Pair<LocalDate, Int>? = null
+
+    fun begin(block: TimedBlock, pointerInRoot: Offset, blockInRoot: Offset) {
+        source = block
+        settling = null
+        isDragging = true
+        liftedInstanceId = block.event.instanceId
+        grab = pointerInRoot - blockInRoot
+        pointer = pointerInRoot
+        originSlot = null
+        recompute()
+        originSlot = drag?.slot
+    }
+
+    fun move(pointerInRoot: Offset) {
+        pointer = pointerInRoot
+        recompute()
+    }
+
+    fun cancel() {
+        source = null
+        isDragging = false
+        liftedInstanceId = null
+        originSlot = null
+        drag = null
+        settling = null
+        settledOnGrid = false
+        settledOrigin = null
+    }
+
+    /**
+     * Whether [block] is the one whose copy is in flight, and so must stay a
+     * ghost: the instance the finger picked up, or once dropped whatever now
+     * sits in the slot it left.
+     */
+    fun ghosts(block: TimedBlock, date: LocalDate): Boolean {
+        if (liftedInstanceId == null) return false
+        if (block.event.instanceId == liftedInstanceId) return true
+        val (eventId, originDate, originMin) = settledOrigin ?: return false
+        return block.event.eventId == eventId &&
+            date == originDate &&
+            block.startMin == originMin
+    }
+
+    /**
+     * What a day column now holds, so a settled drop can tell when the grid has
+     * caught up with it. Matched on the landing slot plus either the event row
+     * or its title, since a single-occurrence move writes a new `eventId`.
+     */
+    fun noteGrid(date: LocalDate, blocks: List<TimedBlock>) {
+        val landed = settling ?: return
+        if (settledOnGrid || landed.date != date) return
+        settledOnGrid = blocks.any { block ->
+            block.startMin == landed.startMin &&
+                (
+                    block.event.eventId == landed.event.eventId ||
+                        block.event.title == landed.event.title
+                    )
+        }
+    }
+
+    /**
+     * End the drag, handing back where it landed — null when it never resolved,
+     * or when it landed back on the slot it started from. A real drop keeps its
+     * copy on the target as [settling] until [release].
+     */
+    fun finish(): TimelineDrop? {
+        val landed = drag
+        val origin = originSlot
+        cancel()
+        if (landed == null || landed.slot == origin) return null
+        settling = landed
+        liftedInstanceId = landed.event.instanceId
+        settledOrigin = origin?.let { (date, min) -> Triple(landed.event.eventId, date, min) }
+        return TimelineDrop(landed.event, landed.date, landed.startMin)
+    }
+
+    /**
+     * Stop ghosting the source — the grid draws the drop itself by now — while
+     * the copy is still dissolving. Un-ghosting at [release] instead would leave
+     * the block dim under the fading copy and then brighten it: a visible dip.
+     */
+    fun handOver() {
+        liftedInstanceId = null
+        settledOrigin = null
+    }
+
+    /** Drop the copy, once it has faded into the grid's own block. */
+    fun release() {
+        settling = null
+        settledOnGrid = false
+        handOver()
+    }
+
+    /**
+     * Re-derive the target from the pointer's *root* position. Recomputed rather
+     * than accumulated from `positionChange()`, because a stationary finger emits
+     * no move events while auto-scroll walks the content underneath it.
+     */
+    fun recompute() {
+        val block = source ?: return
+        val grid = geometry.grid?.takeIf { it.isAttached } ?: return
+        val hourPx = geometry.hourPx
+        val columnPx = geometry.columnWidthPx
+        val days = geometry.days
+        if (hourPx <= 0f || columnPx <= 0f || days.isEmpty()) return
+
+        val origin = grid.positionInRoot()
+        val rawMinutes = (pointer.y - grab.y - origin.y) / hourPx * 60f
+        val snapped = (rawMinutes / DRAG_SNAP_MINUTES).roundToInt() * DRAG_SNAP_MINUTES
+        // Clamp the start into the target day; a tail past midnight is fine.
+        val startMin = snapped.coerceIn(0, MINUTES_PER_DAY - DRAG_SNAP_MINUTES)
+        // The event's own length, not the block's: TimedBlock.endMin is clipped
+        // at midnight, which would draw a 22:00–02:00 event as a two-hour copy.
+        val span = (block.event.end - block.event.start).inWholeMinutes.toInt().coerceAtLeast(0)
+        // The column the finger is over on screen, and the day that column shows.
+        val column = ((pointer.x - origin.x) / columnPx).toInt().coerceIn(0, days.lastIndex)
+        val dayIndex = if (geometry.isRtl) days.lastIndex - column else column
+        val height = maxOf(span / 60f * hourPx, MIN_EVENT_FRACTION * hourPx)
+        drag = TimelineDrag(
+            event = block.event,
+            date = days[dayIndex],
+            startMin = startMin,
+            endMin = startMin + span,
+            topLeftInRoot = Offset(
+                x = origin.x + column * columnPx,
+                y = origin.y + startMin / 60f * hourPx,
+            ),
+            sizePx = IntSize(
+                (columnPx - geometry.columnGapPx).roundToInt(),
+                height.roundToInt(),
+            ),
+        )
+    }
+
+    /**
+     * Hold the scroll for the whole drag and nudge it once per frame while the
+     * finger sits near an edge. One `scroll` call, since a loop of
+     * `animateScrollBy` would re-acquire the mutex and cancel the last.
+     */
+    suspend fun autoScroll() {
+        val scroll = geometry.scroll ?: return
+        scroll.scroll(MutatePriority.UserInput) {
+            while (true) {
+                withFrameNanos { }
+                recompute()
+                val step = edgeStep()
+                if (step != 0f) scrollBy(step)
+            }
+        }
+    }
+
+    private fun edgeStep(): Float {
+        val viewport = geometry.viewport?.takeIf { it.isAttached } ?: return 0f
+        val edge = geometry.edgePx
+        if (edge <= 0f) return 0f
+        val bounds = viewport.boundsInRoot()
+        val fromTop = pointer.y - bounds.top
+        val fromBottom = bounds.bottom - pointer.y
+        return when {
+            fromTop < edge -> -(edge - fromTop) / edge * geometry.stepPx
+            fromBottom < edge -> (edge - fromBottom) / edge * geometry.stepPx
+            else -> 0f
+        }
+    }
+}
+
+@Composable
+fun rememberTimelineDragController(): TimelineDragController {
+    val controller = remember { TimelineDragController() }
+    val density = LocalDensity.current
+    controller.geometry.edgePx = with(density) { AUTO_SCROLL_EDGE.toPx() }
+    controller.geometry.stepPx = with(density) { AUTO_SCROLL_STEP.toPx() }
+    return controller
+}
+
+/**
+ * True when [block] actually begins on [day] rather than being the tail of an
+ * event that started earlier. A clipped block's top edge is midnight, not the
+ * event's start, so dragging it would move the event to a time it never had.
+ */
+fun TimedBlock.beginsOn(day: LocalDate, zone: TimeZone): Boolean =
+    event.start.toLocalDateTime(zone).date == day
+
+/**
+ * The instant a drop asks for, read in the zone the timeline is drawn in. A drop
+ * into a spring-forward gap has no instant of its own; `toInstant` resolves it
+ * forward by the missing hour, and the block visibly settles there.
+ */
+fun TimelineDrop.startInstant(zone: TimeZone): Instant =
+    LocalDateTime(date, LocalTime(startMin / 60, startMin % 60)).toInstant(zone)
+
+/**
+ * A beat after the grid draws the drop, so its own block is under way before the
+ * copy starts dissolving.
+ */
+const val SETTLE_GRACE_MILLIS: Long = 60L
+
+/**
+ * How long to wait for a grid that never confirms the drop — it landed on a day
+ * this timeline doesn't show, or the write failed. The copy has to go either way.
+ */
+private const val SETTLE_TIMEOUT_MILLIS = 900L
+
+/**
+ * The hand-over: the copy dissolves over this while the grid's own block slides
+ * in under it. Kept short, because a full-width copy sits over any neighbour it
+ * now shares a lane with until it is gone.
+ */
+const val SETTLE_FADE_MILLIS: Int = 250
+
+/**
+ * The floating block, drawn over the whole calendar so it is free of the day
+ * column's clip and of the scroll viewport's rounded corners.
+ */
+@Composable
+fun TimelineDragOverlay(controller: TimelineDragController, modifier: Modifier = Modifier) {
+    var origin by remember { mutableStateOf(Offset.Zero) }
+    val dark = isSystemInDarkTheme()
+    val soften = LocalSoftenColors.current
+    val use24Hour = LocalUse24HourFormat.current
+    val locale = currentLocale()
+    val reduceMotion = rememberReduceMotion()
+    val density = LocalDensity.current
+    val moveInFlight = moveInFlight()
+
+    // Both live here rather than beside the controller: they read [drag], which
+    // changes every frame, and this composable is the one that is meant to.
+    DragSnapHaptics(controller.drag?.slot)
+    LaunchedEffect(controller.isDragging) {
+        if (controller.isDragging) controller.autoScroll()
+    }
+    // Hold the landed copy until the write is done — including the time a
+    // recurring drop's scope dialog is up — and then until the grid draws the
+    // drop itself.
+    var handingOver by remember(controller.settling) { mutableStateOf(false) }
+    LaunchedEffect(controller.settling, moveInFlight, controller.settledOnGrid) {
+        if (controller.settling == null || moveInFlight) return@LaunchedEffect
+        delay(if (controller.settledOnGrid) SETTLE_GRACE_MILLIS else SETTLE_TIMEOUT_MILLIS)
+        handingOver = true
+        controller.handOver()
+        delay(SETTLE_FADE_MILLIS.toLong())
+        controller.release()
+    }
+
+    Box(
+        modifier = modifier
+            .fillMaxSize()
+            // A copy of a block still in the tree behind it; announcing it again
+            // would duplicate the event for the drag's duration.
+            .clearAndSetSemantics { }
+            .onGloballyPositioned { origin = it.positionInRoot() },
+    ) {
+        val drag = controller.drag ?: controller.settling ?: return@Box
+        // Landed: the copy sinks back to the grid's own plane while the write runs.
+        val landed = controller.drag == null
+        val lift by animateFloatAsState(
+            targetValue = if (landed || reduceMotion) 0f else 1f,
+            label = "drag-lift",
+        )
+        val copyAlpha by animateFloatAsState(
+            targetValue = if (handingOver) 0f else 1f,
+            animationSpec = tween(SETTLE_FADE_MILLIS),
+            label = "drag-handover",
+        )
+        val fill = eventFill(drag.event.color, dark, soften)
+        val title = drag.event.title.ifBlank { stringResource(R.string.event_untitled) }
+        // An end past midnight wraps rather than saturating, so a four-hour
+        // event dragged to 22:00 reads "22:00–02:00" and not "22:00–24:00".
+        val endMin = if (drag.endMin > MINUTES_PER_DAY) {
+            drag.endMin % MINUTES_PER_DAY
+        } else {
+            drag.endMin
+        }
+        val label = "${formatMinuteOfDay(drag.startMin, use24Hour, locale)}–" +
+            formatMinuteOfDay(endMin, use24Hour, locale)
+        Box(
+            modifier = Modifier
+                // Absolute: these are root coordinates, and the direction-aware
+                // offset would mirror them across the screen in an RTL layout.
+                .absoluteOffset {
+                    IntOffset(
+                        (drag.topLeftInRoot.x - origin.x).roundToInt(),
+                        (drag.topLeftInRoot.y - origin.y).roundToInt(),
+                    )
+                }
+                .size(
+                    width = with(density) { drag.sizePx.width.toDp() },
+                    height = with(density) { drag.sizePx.height.toDp() },
+                )
+                .padding(horizontal = 1.dp)
+                .graphicsLayer {
+                    scaleX = 1f + 0.02f * lift
+                    scaleY = 1f + 0.02f * lift
+                    shadowElevation = 8.dp.toPx() * lift
+                    alpha = copyAlpha
+                    shape = RoundedCornerShape(4.dp)
+                    clip = false
+                }
+                .background(fill, RoundedCornerShape(4.dp))
+                .padding(horizontal = 4.dp, vertical = 2.dp),
+        ) {
+            Column {
+                Text(
+                    text = title,
+                    style = MaterialTheme.typography.labelMedium,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    color = eventInk(fill, alpha = 0.85f),
+                )
+                Text(
+                    text = label,
+                    style = MaterialTheme.typography.labelSmall,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    color = eventInk(fill, alpha = SECONDARY_INK_ALPHA),
+                )
+            }
+        }
+    }
+}

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

@@ -41,7 +41,14 @@ class TimelineZoom(
     var scale: TimelineScale by mutableStateOf(initial)
         private set
 
-    private var pinching = false
+    /**
+     * Whether fingers are rescaling the timeline right now. Snapshot state, so
+     * anything that tweens off [scale] can stand down for the gesture: the
+     * height changes every pointer frame, and a spring would spend the whole
+     * pinch chasing a target that has already moved.
+     */
+    var isPinching: Boolean by mutableStateOf(false)
+        private set
 
     /**
      * Take a value that came from the preference. Ignored mid-pinch: the stored
@@ -49,11 +56,11 @@ class TimelineZoom(
      * snap the timeline back while the user is still pinching.
      */
     fun adopt(stored: TimelineScale) {
-        if (!pinching) scale = stored
+        if (!isPinching) scale = stored
     }
 
     fun beginPinch() {
-        pinching = true
+        isPinching = true
     }
 
     fun pinchTo(hourHeight: Dp) {
@@ -61,7 +68,7 @@ class TimelineZoom(
     }
 
     fun endPinch() {
-        pinching = false
+        isPinching = false
         persist(scale)
     }
 }

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

@@ -0,0 +1,145 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.Crossfade
+import androidx.compose.animation.core.snap
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.clipToBounds
+import androidx.compose.ui.graphics.TransformOrigin
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.layout
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.unit.Constraints
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import kotlin.math.roundToInt
+
+/**
+ * The viewport a view preview pretends to be: a phone's width by the height a
+ * calendar view gets under the top bar. Scaling every preview from one fixed
+ * height keeps them comparable — each shows the same slice of screen.
+ */
+internal val PREVIEW_VIEWPORT_HEIGHT = 440.dp
+
+/**
+ * Renders [content] at a full phone viewport and shrinks the finished layout
+ * into a box [height] tall, for the settings and onboarding choosers. Callers
+ * pass the *real* view composables, so a preview cannot drift from what it
+ * depicts.
+ *
+ * The [layout] below ignores the incoming constraints so the view measures at a
+ * phone viewport, and a [graphicsLayer] scale shrinks the result.
+ * `Modifier.requiredSize` is the obvious alternative but *centres* content that
+ * overflows its constraints, leaving only the bottom-right corner in the clip.
+ */
+@Composable
+internal fun ScaledViewPreview(
+    height: Dp,
+    modifier: Modifier = Modifier,
+    content: @Composable () -> Unit,
+) {
+    val screenWidth = LocalConfiguration.current.screenWidthDp.dp
+    val scale = height.value / PREVIEW_VIEWPORT_HEIGHT.value
+
+    Box(
+        modifier = modifier
+            .clipToBounds()
+            .background(MaterialTheme.colorScheme.surface)
+            // A preview is a picture, not a control: swallow touches before the
+            // view's own clickables see them, and give screen readers one label
+            // instead of six weeks of day cells.
+            .pointerInput(Unit) {
+                awaitPointerEventScope {
+                    while (true) {
+                        awaitPointerEvent(PointerEventPass.Initial).changes
+                            .forEach { it.consume() }
+                    }
+                }
+            }
+            .clearAndSetSemantics { }
+            // Measure at a full phone viewport but report the scaled size, so the
+            // node occupies exactly what it draws.
+            .layout { measurable, _ ->
+                val fullWidth = screenWidth.roundToPx()
+                val fullHeight = PREVIEW_VIEWPORT_HEIGHT.roundToPx()
+                val placeable = measurable.measure(Constraints.fixed(fullWidth, fullHeight))
+                layout((fullWidth * scale).roundToInt(), (fullHeight * scale).roundToInt()) {
+                    placeable.place(0, 0)
+                }
+            }
+            .graphicsLayer {
+                scaleX = scale
+                scaleY = scale
+                transformOrigin = TransformOrigin(0f, 0f)
+            },
+    ) {
+        Column(Modifier.fillMaxSize()) { content() }
+    }
+}
+
+/**
+ * The stage every preview picker sets its preview on, cross-fading as [selected]
+ * changes. A preview draws the app's own surface, so a tonal plate gives it the
+ * edge it would otherwise lack on a chooser screen; the plate takes the width
+ * and outer radius of the grouped rows underneath so the two read as one stack.
+ *
+ * Only vertical spacing is the caller's to pass — the horizontal inset is the
+ * rows' own, and the alignment is the point.
+ */
+@Composable
+internal fun <T> ViewPreviewFrame(
+    selected: T,
+    label: String,
+    modifier: Modifier = Modifier,
+    content: @Composable (T) -> Unit,
+) {
+    val reduceMotion = rememberReduceMotion()
+    Box(
+        modifier = modifier
+            .fillMaxWidth()
+            .padding(horizontal = GroupedListInset)
+            .clip(FRAME_SHAPE)
+            .background(MaterialTheme.colorScheme.surfaceContainerHigh)
+            .padding(FRAME_INSET),
+        contentAlignment = Alignment.Center,
+    ) {
+        Crossfade(
+            targetState = selected,
+            animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
+            label = label,
+        ) { shown ->
+            // Each preview renders the real view at phone size and scales it
+            // down, so its own corners are square — the plate rounds them.
+            Box(
+                modifier = Modifier
+                    .clip(PREVIEW_SHAPE)
+                    .background(MaterialTheme.colorScheme.surface)
+                    .clipToBounds(),
+            ) {
+                content(shown)
+            }
+        }
+    }
+}
+
+private val FRAME_INSET = 8.dp
+
+/** The grouped rows' own outer radius, so the stack shares one silhouette. */
+private val FRAME_SHAPE = RoundedCornerShape(22.dp)
+private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

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

@@ -42,6 +42,7 @@ import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -54,14 +55,19 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.RectangleShape
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.customActions
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
@@ -75,7 +81,21 @@ import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.BlockTimeLabel
+import de.jeanlucmakiola.calendula.ui.common.animatedBlockPlacement
+import de.jeanlucmakiola.calendula.ui.common.ghostAlpha
+import de.jeanlucmakiola.calendula.ui.common.LocalEventMove
+import de.jeanlucmakiola.calendula.ui.common.MoveRequest
+import de.jeanlucmakiola.calendula.ui.common.MoveTarget
 import de.jeanlucmakiola.calendula.ui.common.NowLine
+import de.jeanlucmakiola.calendula.ui.common.TimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.TimelineDragOverlay
+import de.jeanlucmakiola.calendula.ui.common.TimelineDrop
+import de.jeanlucmakiola.calendula.ui.common.beginsOn
+import de.jeanlucmakiola.calendula.ui.common.eventMoveAction
+import de.jeanlucmakiola.calendula.ui.common.rememberEventDragSource
+import de.jeanlucmakiola.calendula.ui.common.rememberTimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.startInstant
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.calendarSlideTransition
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
@@ -94,8 +114,9 @@ import de.jeanlucmakiola.calendula.ui.common.MIN_EVENT_FRACTION
 import de.jeanlucmakiola.calendula.ui.common.SECONDARY_INK_ALPHA
 import de.jeanlucmakiola.calendula.ui.common.hourHeight
 import de.jeanlucmakiola.calendula.ui.common.rememberTimelinePinchZoom
-import de.jeanlucmakiola.calendula.ui.common.formatHourLabel
 import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
+import de.jeanlucmakiola.calendula.ui.common.GUTTER_WIDTH
+import de.jeanlucmakiola.calendula.ui.common.HourGutter
 import de.jeanlucmakiola.calendula.ui.common.hourSeparatorLines
 import de.jeanlucmakiola.calendula.ui.common.tappedMinuteOfDay
 import de.jeanlucmakiola.calendula.ui.week.TimedBlock
@@ -108,16 +129,11 @@ import kotlin.time.Clock
 import java.util.Locale
 import kotlin.math.roundToInt
 
-private val GUTTER_WIDTH = 48.dp
-/** Start inset for the gutter's hour labels so they centre on the top bar's
- *  hamburger: with a 48dp gutter, 8dp lands the centre at 28dp (the app bar's
- *  4dp inset + 24dp half icon button), matching the week view. */
-private val GUTTER_CONTENT_START_INSET = 8.dp
 private val ALL_DAY_ROW_HEIGHT = 24.dp
 private val ALL_DAY_VERTICAL_PADDING = 6.dp
 
 /** Total all-day strip height for the day (0 when there are no all-day events). */
-private fun DayUiState.Success.allDayStripHeight(): Dp {
+internal fun DayUiState.Success.allDayStripHeight(): Dp {
     if (allDay.isEmpty()) return 0.dp
     val lanes = allDay.maxOf { it.lane } + 1
     return ALL_DAY_ROW_HEIGHT * lanes + ALL_DAY_VERTICAL_PADDING * 2
@@ -300,42 +316,67 @@ private fun DayContent(
     // drag is consumed by the inner scroll first — the two gestures coexist.
     val swipeModifier = rememberCalendarPageSwipe(onSwipeNext, onSwipePrev)
 
-    AnimatedContent(
-        targetState = state,
-        modifier = modifier.then(swipeModifier),
-        contentKey = { s ->
+    // Above the AnimatedContent: a page change mid-drag would strand the
+    // floating block inside the outgoing page.
+    val dragController = rememberTimelineDragController()
+    val move = LocalEventMove.current
+    val zone = remember { TimeZone.currentSystemDefault() }
+
+    Box(modifier = modifier) {
+        AnimatedContent(
+            targetState = state,
+            modifier = Modifier.fillMaxSize().then(swipeModifier),
+            contentKey = { s ->
+                when (s) {
+                    is DayUiState.Success -> "success-${s.date}"
+                    is DayUiState.Failure -> "failure-${s.reason}"
+                    DayUiState.Loading -> "loading"
+                }
+            },
+            transitionSpec = { calendarSlideTransition(slideDir, slideSpec, fadeSpec, reduceMotion) },
+            label = "day-transition",
+        ) { s ->
             when (s) {
-                is DayUiState.Success -> "success-${s.date}"
-                is DayUiState.Failure -> "failure-${s.reason}"
-                DayUiState.Loading -> "loading"
+                DayUiState.Loading -> DayLoading()
+                is DayUiState.Failure -> CalendarFailure(reason = s.reason, onRetry = onRetry)
+                is DayUiState.Success -> DaySuccess(
+                    state = s,
+                    topSectionColor = topSectionColor,
+                    scrollState = scrollState,
+                    allDayHeight = allDayHeight,
+                    dragController = dragController,
+                    onEventClick = onEventClick,
+                    onCreateAt = onCreateAt,
+                    onDrop = { drop ->
+                        val took = move?.move(
+                            MoveRequest(
+                                eventId = drop.event.eventId,
+                                beginMillis = drop.event.start.toEpochMilliseconds(),
+                                endMillis = drop.event.end.toEpochMilliseconds(),
+                                target = MoveTarget.Start(drop.startInstant(zone)),
+                            ),
+                        )
+                        // Refused, so nothing will land: let the copy go now
+                        // rather than hold it out for a settle that never comes.
+                        if (took != true) dragController.release()
+                    },
+                )
             }
-        },
-        transitionSpec = { calendarSlideTransition(slideDir, slideSpec, fadeSpec, reduceMotion) },
-        label = "day-transition",
-    ) { s ->
-        when (s) {
-            DayUiState.Loading -> DayLoading()
-            is DayUiState.Failure -> CalendarFailure(reason = s.reason, onRetry = onRetry)
-            is DayUiState.Success -> DaySuccess(
-                state = s,
-                topSectionColor = topSectionColor,
-                scrollState = scrollState,
-                allDayHeight = allDayHeight,
-                onEventClick = onEventClick,
-                onCreateAt = onCreateAt,
-            )
         }
+        TimelineDragOverlay(dragController)
     }
 }
 
 @Composable
-private fun DaySuccess(
+internal fun DaySuccess(
     state: DayUiState.Success,
     topSectionColor: Color,
     scrollState: ScrollState,
     allDayHeight: Dp,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
 ) {
     Column(modifier = Modifier.fillMaxSize()) {
         // All-day strip collapses to nothing when the day has no all-day events,
@@ -354,8 +395,10 @@ private fun DaySuccess(
         Timeline(
             state = state,
             scrollState = scrollState,
+            dragController = dragController,
             onEventClick = onEventClick,
             onCreateAt = onCreateAt,
+            onDrop = onDrop,
         )
     }
 }
@@ -489,13 +532,15 @@ private fun AllDayBar(
 private fun Timeline(
     state: DayUiState.Success,
     scrollState: ScrollState,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
 ) {
     val dark = isSystemInDarkTheme()
-    val use24Hour = LocalUse24HourFormat.current
-    val locale = currentLocale()
     val zoom = LocalTimelineZoom.current
+    val density = LocalDensity.current
+    val isRtl = LocalLayoutDirection.current == LayoutDirection.Rtl
 
     // BoxWithConstraints rather than Box: the fit-the-whole-day scale needs the
     // timeline's own viewport height, which is only known here — below the top
@@ -514,39 +559,19 @@ private fun Timeline(
         Row(modifier = Modifier.fillMaxSize().then(pinch)) {
             // Hour gutter (scrolls in sync with the day column). Start inset so the
             // labels centre on the top bar hamburger, matching the week view.
-            Column(
-                modifier = Modifier
-                    .width(GUTTER_WIDTH)
-                    .padding(start = GUTTER_CONTENT_START_INSET)
-                    .fillMaxHeight()
-                    .verticalScroll(scrollState),
-            ) {
-                (0 until 24).forEach { h ->
-                    Box(
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .height(hourHeight),
-                    ) {
-                        if (h > 0) {
-                            Text(
-                                text = formatHourLabel(h, use24Hour, locale),
-                                style = MaterialTheme.typography.labelSmall,
-                                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                                modifier = Modifier
-                                    .align(Alignment.TopCenter)
-                                    .offset(y = (-6).dp),
-                            )
-                        }
-                    }
-                }
-            }
+            HourGutter(
+                scrollState = scrollState,
+                hourHeight = hourHeight,
+                dragController = dragController,
+            )
             // Day column: rounded, clipped scroll viewport (permanent corners).
             Box(
                 modifier = Modifier
                     .weight(1f)
                     .fillMaxHeight()
                     .clip(RoundedCornerShape(16.dp))
-                    .verticalScroll(scrollState),
+                    .verticalScroll(scrollState)
+                    .onGloballyPositioned { dragController.geometry.viewport = it },
             ) {
                 DayColumnCard(
                     blocks = state.timed,
@@ -554,11 +579,26 @@ private fun Timeline(
                     date = state.date,
                     today = state.today,
                     hourHeight = hourHeight,
+                    dragController = dragController,
                     onEventClick = onEventClick,
                     onCreateAt = onCreateAt,
+                    onDrop = onDrop,
                     modifier = Modifier
                         .fillMaxWidth()
-                        .height(totalHeight),
+                        .height(totalHeight)
+                        // The scrolling content itself, so its root position
+                        // already folds in the scroll offset.
+                        .onGloballyPositioned { coords ->
+                            dragController.geometry.let {
+                                it.grid = coords
+                                it.scroll = scrollState
+                                it.hourPx = with(density) { hourHeight.toPx() }
+                                it.columnGapPx = 0f
+                                it.columnWidthPx = coords.size.width.toFloat()
+                                it.days = listOf(state.date)
+                                it.isRtl = isRtl
+                            }
+                        },
                 )
             }
         }
@@ -572,13 +612,19 @@ private fun DayColumnCard(
     date: LocalDate,
     today: LocalDate,
     hourHeight: Dp,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     val hourPx = with(LocalDensity.current) { hourHeight.toPx() }
     val showHourLines = LocalShowHourLines.current
     val hourLineColor = MaterialTheme.colorScheme.outlineVariant
+    // Tells a settled drop when this column has caught up with it.
+    LaunchedEffect(blocks, dragController.settling) {
+        dragController.noteGrid(date, blocks)
+    }
     // The tap detector outlives the composition that installed it — a pinch or a
     // Settings change moves the hour height without restarting it — so it reads
     // the height and the callback through state handles instead of capturing
@@ -614,22 +660,38 @@ private fun DayColumnCard(
         ) {
             val colWidth = maxWidth
             val minEventHeight = hourHeight * MIN_EVENT_FRACTION
+            // Keyed by event, so a block that changes time or lane is the *same*
+            // composable afterwards and tweens there. The ordinal disambiguates
+            // a column holding two occurrences of one series.
+            val ordinals = mutableMapOf<Long, Int>()
             blocks.forEach { block ->
-                val laneWidth = colWidth / block.laneCount
-                val top = hourHeight * (block.startMin / 60f)
-                val rawHeight = hourHeight * ((block.endMin - block.startMin) / 60f)
-                val height = if (rawHeight < minEventHeight) minEventHeight else rawHeight
-                EventBlock(
-                    block = block,
-                    dark = dark,
-                    height = height,
-                    onClick = { onEventClick(block.event) },
-                    modifier = Modifier
-                        .offset(x = laneWidth * block.lane, y = top)
-                        .width(laneWidth)
-                        .height(height)
-                        .padding(horizontal = 1.dp),
-                )
+                val ordinal = ordinals.merge(block.event.eventId, 1, Int::plus)!! - 1
+                key(block.event.eventId, ordinal) {
+                    val laneWidth = colWidth / block.laneCount
+                    val top = hourHeight * (block.startMin / 60f)
+                    val rawHeight = hourHeight * ((block.endMin - block.startMin) / 60f)
+                    val height = if (rawHeight < minEventHeight) minEventHeight else rawHeight
+                    val place = animatedBlockPlacement(
+                        x = laneWidth * block.lane,
+                        y = top,
+                        width = laneWidth,
+                        height = height,
+                    )
+                    EventBlock(
+                        block = block,
+                        dark = dark,
+                        height = place.height,
+                        date = date,
+                        dragController = dragController,
+                        onClick = { onEventClick(block.event) },
+                        onDrop = onDrop,
+                        modifier = Modifier
+                            .offset(x = place.x, y = place.y)
+                            .width(place.width)
+                            .height(place.height)
+                            .padding(horizontal = 1.dp),
+                    )
+                }
             }
             // Current-time line, on top of the events, only on today's column.
             if (date == today) {
@@ -644,7 +706,10 @@ private fun EventBlock(
     block: TimedBlock,
     dark: Boolean,
     height: Dp,
+    date: LocalDate,
+    dragController: TimelineDragController,
     onClick: () -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     val title = block.event.title.ifBlank { stringResource(R.string.event_untitled) }
@@ -668,12 +733,35 @@ private fun EventBlock(
     val showTitle = available >= titleLineHeight
     val soften = LocalSoftenColors.current
     val fill = eventFill(block.event.color, dark, soften)
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val moveAction = eventMoveAction(block.event)
+    // A block clipped at the top continues from the previous day: its top edge
+    // is midnight, not the event's start, so dragging it would invent a time.
+    val draggable = moveAction != null && block.beginsOn(date, zone)
+    val dragModifier = rememberEventDragSource(
+        enabled = draggable,
+        key = block.event.instanceId,
+        onPickUp = { pointer, blockRoot, _ -> dragController.begin(block, pointer, blockRoot) },
+        onMove = dragController::move,
+        onDrop = { dragController.finish()?.let(onDrop) },
+        onCancel = dragController::cancel,
+    )
+    val lifted = draggable && dragController.ghosts(block, date)
+    val ghost = ghostAlpha(lifted)
     Box(
         modifier = modifier
+            // The source stays put as a ghost while its floating copy travels.
+            .then(if (ghost < 1f) Modifier.alpha(ghost) else Modifier)
             .background(fill, RoundedCornerShape(4.dp))
             .clickable(onClick = onClick)
+            // After clickable, so it is the inner node and wins the main pass;
+            // the tap still works, since a drag consumes the up.
+            .then(dragModifier)
             .padding(horizontal = 4.dp, vertical = 2.dp)
-            .semantics { contentDescription = "$title, $timeLabel" },
+            .semantics {
+                contentDescription = "$title, $timeLabel"
+                if (moveAction != null) customActions = listOf(moveAction)
+            },
     ) {
         Column {
             if (showTitle) {
@@ -686,11 +774,8 @@ private fun EventBlock(
                 )
             }
             if (showTime) {
-                Text(
-                    text = timeLabel,
-                    style = MaterialTheme.typography.labelSmall,
-                    maxLines = 1,
-                    overflow = TextOverflow.Ellipsis,
+                BlockTimeLabel(
+                    label = timeLabel,
                     color = eventInk(fill, alpha = SECONDARY_INK_ALPHA),
                 )
             }

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

@@ -0,0 +1,65 @@
+package de.jeanlucmakiola.calendula.ui.day
+
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
+import de.jeanlucmakiola.calendula.ui.common.rememberTimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.sampleTimelineEvents
+import de.jeanlucmakiola.calendula.ui.week.layoutAllDay
+import de.jeanlucmakiola.calendula.ui.week.layoutDay
+import kotlinx.coroutines.flow.first
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+
+/**
+ * A live, scaled-down Day view for the onboarding view chooser. Today's date is
+ * real; only the events are stand-ins.
+ */
+@Composable
+internal fun DayViewPreview(
+    height: Dp,
+    modifier: Modifier = Modifier,
+) {
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    val state = remember(today, zone) { sampleDayState(today, zone) }
+    val scrollState = rememberScrollState()
+    LaunchedEffect(Unit) {
+        snapshotFlow { scrollState.maxValue }.first { it > 0 }
+        // Half the scroll range is noon — the same centring the live view does.
+        scrollState.scrollTo(scrollState.maxValue / 2)
+    }
+
+    ScaledViewPreview(height = height, modifier = modifier) {
+        DaySuccess(
+            state = state,
+            topSectionColor = MaterialTheme.colorScheme.surface,
+            scrollState = scrollState,
+            allDayHeight = state.allDayStripHeight(),
+            dragController = rememberTimelineDragController(),
+            onEventClick = {},
+            onCreateAt = { _, _ -> },
+            onDrop = {},
+        )
+    }
+}
+
+/** Sample day state, laid out through the same helpers the live view uses. */
+private fun sampleDayState(today: LocalDate, zone: TimeZone): DayUiState.Success {
+    val days = listOf(today)
+    val events = sampleTimelineEvents(days, today, zone)
+    return DayUiState.Success(
+        date = today,
+        today = today,
+        allDay = layoutAllDay(events.filter { it.isAllDay }, days, zone),
+        timed = layoutDay(events, today, zone),
+    )
+}

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

@@ -127,6 +127,7 @@ import de.jeanlucmakiola.floret.identity.collapseExit
 import de.jeanlucmakiola.floret.identity.expandEnter
 import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
+import de.jeanlucmakiola.calendula.ui.common.RecurringScopeDialog
 import de.jeanlucmakiola.calendula.ui.common.CalendarPickerGroups
 import de.jeanlucmakiola.calendula.ui.common.CalendarDatePickerDialog
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
@@ -452,30 +453,11 @@ private fun SaveScopeDialog(
     onSelect: (RecurringWriteScope) -> Unit,
     onDismiss: () -> Unit,
 ) {
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        title = { Text(stringResource(R.string.event_edit_recurring_title)) },
-        text = {
-            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-                if (!recurrenceChanged) {
-                    OptionCard(
-                        label = stringResource(R.string.event_delete_option_occurrence),
-                        onClick = { onSelect(RecurringWriteScope.ThisEvent) },
-                    )
-                }
-                OptionCard(
-                    label = stringResource(R.string.event_delete_option_following),
-                    onClick = { onSelect(RecurringWriteScope.ThisAndFollowing) },
-                )
-                OptionCard(
-                    label = stringResource(R.string.event_delete_option_series),
-                    onClick = { onSelect(RecurringWriteScope.AllEvents) },
-                )
-            }
-        },
-        confirmButton = {
-            TextButton(onClick = onDismiss) { Text(stringResource(R.string.dialog_cancel)) }
-        },
+    RecurringScopeDialog(
+        title = stringResource(R.string.event_edit_recurring_title),
+        onSelect = onSelect,
+        onDismiss = onDismiss,
+        allowOccurrence = !recurrenceChanged,
     )
 }
 

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

@@ -0,0 +1,303 @@
+package de.jeanlucmakiola.calendula.ui.month
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.layout.boundsInRoot
+import androidx.compose.ui.layout.positionInRoot
+import androidx.compose.ui.unit.IntSize
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+import kotlin.math.abs
+
+/** One week row's live geometry, republished on every layout while it is on screen. */
+class MonthRowGeometry(
+    val days: List<LocalDate>,
+    /** The row's day-column box — the space chip offsets are measured in. */
+    val cell: LayoutCoordinates,
+    /** The lane band inside that box, where the chips themselves are seated. */
+    val band: LayoutCoordinates?,
+    val columnWidthPx: Float,
+    val laneHeightPx: Float,
+    val laneCount: Int,
+    /**
+     * Whether the columns are laid out right-to-left. Pointer coordinates are
+     * never mirrored but the grid is, so the mapping has to flip with it.
+     */
+    val isRtl: Boolean,
+    /** What this row currently draws in [lane] of column `col`, or null. */
+    val chipAt: (col: Int, lane: Int) -> EventInstance?,
+) {
+    /** Root top-left of the chip seated in [lane] of column [col]. */
+    fun seat(col: Int, lane: Int): Offset? {
+        val band = band?.takeIf { it.isAttached } ?: return null
+        val origin = band.positionInRoot()
+        val column = if (isRtl) days.lastIndex - col else col
+        return Offset(origin.x + column * columnWidthPx, origin.y + lane * laneHeightPx)
+    }
+
+    /**
+     * Where this row seats [event] on [date], or null when it doesn't hold it —
+     * the day isn't in this week, or the chip went into the day's "+N" overflow.
+     */
+    fun seatOf(event: EventInstance, date: LocalDate): Offset? {
+        val col = days.indexOf(date).takeIf { it >= 0 } ?: return null
+        val lane = (0 until laneCount).firstOrNull { lane ->
+            chipAt(col, lane)?.let { isSameEvent(it, event) } == true
+        } ?: return null
+        return seat(col, lane)
+    }
+}
+
+/**
+ * Whether [chip] is the moved event [moved] as the grid now holds it. Neither id
+ * alone will do: re-read instances get new instance ids, and a single-occurrence
+ * move writes a new event id — the title survives both.
+ */
+private fun isSameEvent(chip: EventInstance, moved: EventInstance): Boolean =
+    chip.eventId == moved.eventId || chip.title == moved.title
+
+/** A chip in flight, in root coordinates so it can be drawn in an overlay. */
+data class MonthChipDrag(
+    val event: EventInstance,
+    /** The day whose column the chip was grabbed in — the drag is a delta from it. */
+    val grabDate: LocalDate,
+    val targetDate: LocalDate?,
+    val topLeftInRoot: Offset,
+    val sizePx: IntSize,
+)
+
+/** Where a finished chip drag asks its event to go, as a whole-day shift. */
+data class MonthChipDrop(
+    val event: EventInstance,
+    val grabDate: LocalDate,
+    val targetDate: LocalDate,
+)
+
+/**
+ * Hoisted drag state for the month grid (#68). Every visible week row registers
+ * itself so a chip can be carried across rows, the target resolved against
+ * whichever registered row the finger is over. Rows are keyed by an identity
+ * token rather than a date: the continuous style can show the same week twice.
+ */
+@Stable
+class MonthDragController {
+    private val rows = LinkedHashMap<Any, MonthRowGeometry>()
+
+    var drag: MonthChipDrag? by mutableStateOf(null)
+        private set
+
+    /**
+     * A dropped chip, held on the day it landed on while the write runs — the
+     * grid behind it still shows the old day until the query re-reads.
+     */
+    var settling: MonthChipDrag? by mutableStateOf(null)
+        private set
+
+    /**
+     * Which chip is lifted, and whether anything is. Separate snapshot state from
+     * [drag], which changes every frame, so the chips and rows that only need
+     * "am I the ghost" don't recompose that often. Stays set through [settling].
+     */
+    var liftedInstanceId: Long? by mutableStateOf(null)
+        private set
+
+    /**
+     * Where the grid itself now draws the drop, in root coordinates — published
+     * by whichever week row ends up holding it. The copy is dropped wherever the
+     * finger was while the grid seats it in a lane, so without this it would
+     * cross-fade across the gap instead of gliding onto its seat.
+     */
+    var settledInRoot: Offset? by mutableStateOf(null)
+        private set
+
+    /**
+     * Whether the drop's own chip is still standing in for the copy. Cleared at
+     * [handOver] rather than [release], or the chip stays dim under a copy that
+     * has already faded and brightens afterwards: a visible dip.
+     */
+    private var settledGhost: Boolean by mutableStateOf(false)
+
+    /** Whether a finger is on a chip right now — [settling] is not dragging. */
+    var isDragging: Boolean by mutableStateOf(false)
+        private set
+
+    /**
+     * The last drop this controller made, kept past [release] for [beginUndo] —
+     * the confirmation chip carries Undo long after the copy is gone.
+     */
+    private var undoable: MonthChipDrag? = null
+
+    private var event: EventInstance? = null
+    private var grabDate: LocalDate? = null
+    private var grab = Offset.Zero
+    private var pointer = Offset.Zero
+    private var sizePx = IntSize.Zero
+
+    fun putRow(token: Any, geometry: MonthRowGeometry) {
+        rows[token] = geometry
+    }
+
+    fun removeRow(token: Any) {
+        rows.remove(token)
+    }
+
+    fun begin(
+        event: EventInstance,
+        grabDate: LocalDate,
+        pointerInRoot: Offset,
+        chipInRoot: Offset,
+        size: IntSize,
+    ) {
+        this.event = event
+        this.grabDate = grabDate
+        settling = null
+        isDragging = true
+        liftedInstanceId = event.instanceId
+        grab = pointerInRoot - chipInRoot
+        pointer = pointerInRoot
+        sizePx = size
+        recompute()
+    }
+
+    fun move(pointerInRoot: Offset) {
+        pointer = pointerInRoot
+        recompute()
+    }
+
+    fun cancel() {
+        event = null
+        grabDate = null
+        isDragging = false
+        liftedInstanceId = null
+        drag = null
+        settling = null
+        settledInRoot = null
+        settledGhost = false
+    }
+
+    /**
+     * Whether [days] holds the chip the grid has drawn for the settled drop —
+     * the seat the copy is on its way to, which must ghost until it gets there.
+     */
+    fun isSettledChip(event: EventInstance, days: List<LocalDate>?): Boolean {
+        val landed = settling?.takeIf { settledGhost } ?: return false
+        if (days == null || landed.targetDate !in days) return false
+        return isSameEvent(event, landed.event)
+    }
+
+    /**
+     * Ask the row keyed [token] whether it now seats the settled chip. Both
+     * copies of a week the continuous style shows twice will answer; the seat
+     * nearest where the chip was let go is the one the finger was over.
+     */
+    fun noteSettled(token: Any) {
+        val landed = settling ?: return
+        val target = landed.targetDate ?: return
+        val at = rows[token]?.seatOf(landed.event, target) ?: return
+        val current = settledInRoot
+        val closer = current == null ||
+            abs(at.y - landed.topLeftInRoot.y) < abs(current.y - landed.topLeftInRoot.y)
+        if (closer) settledInRoot = at
+    }
+
+    /**
+     * Put a chip on the journey an undo's inverse write is about to make, so it
+     * travels back rather than teleporting. Writes nothing itself. False when
+     * there is no drop of this controller's left to undo, or the grid doesn't
+     * seat the moved event where the chip would have to start from.
+     */
+    fun beginUndo(): Boolean {
+        val last = undoable ?: return false
+        undoable = null
+        val from = last.targetDate ?: return false
+        val at = rows.values.firstNotNullOfOrNull { it.seatOf(last.event, from) } ?: return false
+        settling = last.copy(grabDate = from, targetDate = last.grabDate, topLeftInRoot = at)
+        liftedInstanceId = last.event.instanceId
+        settledGhost = true
+        settledInRoot = null
+        return true
+    }
+
+    /**
+     * End the drag, handing back where it landed — null when it never resolved,
+     * or when it landed back on the day it came from. A real drop keeps its chip
+     * on the target day as [settling] until [release], slid over to that day's
+     * column so it lands where the grid is about to draw it.
+     */
+    fun finish(): MonthChipDrop? {
+        val landed = drag
+        val left = landed?.targetDate?.let(::columnLeft)
+        cancel()
+        val target = landed?.targetDate?.takeIf { it != landed.grabDate } ?: return null
+        settling = landed.copy(
+            topLeftInRoot = Offset(left ?: landed.topLeftInRoot.x, landed.topLeftInRoot.y),
+        )
+        liftedInstanceId = landed.event.instanceId
+        settledGhost = true
+        undoable = settling
+        return MonthChipDrop(landed.event, landed.grabDate, target)
+    }
+
+    /**
+     * Stop ghosting the source while the copy is still dissolving — un-ghosting
+     * at [release] instead leaves the chip dim and then brightens it.
+     */
+    fun handOver() {
+        liftedInstanceId = null
+        settledGhost = false
+    }
+
+    /** Drop the copy, once it has faded into the grid's own chip. */
+    fun release() {
+        settling = null
+        settledInRoot = null
+        handOver()
+    }
+
+    /** Root x of [date]'s column, in whichever visible row shows that day. */
+    private fun columnLeft(date: LocalDate): Float? = rows.values.firstNotNullOfOrNull { row ->
+        val index = row.days.indexOf(date).takeIf { it >= 0 } ?: return@firstNotNullOfOrNull null
+        val bounds = row.cell.takeIf { it.isAttached }?.boundsInRoot()
+            ?: return@firstNotNullOfOrNull null
+        val column = if (row.isRtl) row.days.lastIndex - index else index
+        bounds.left + column * row.columnWidthPx
+    }
+
+    private fun recompute() {
+        val event = event ?: return
+        val grabbed = grabDate ?: return
+        val resolved = rows.values.firstNotNullOfOrNull { row ->
+            val bounds = row.cell.takeIf { it.isAttached }?.boundsInRoot()
+                ?: return@firstNotNullOfOrNull null
+            if (!bounds.contains(pointer) || row.columnWidthPx <= 0f) {
+                null
+            } else {
+                val column = ((pointer.x - bounds.left) / row.columnWidthPx)
+                    .toInt()
+                    .coerceIn(0, row.days.lastIndex)
+                row.days[if (row.isRtl) row.days.lastIndex - column else column]
+            }
+        }
+        drag = MonthChipDrag(
+            event = event,
+            grabDate = grabbed,
+            // Off the grid entirely: keep the last cell it was over, so a
+            // wobble past the edge doesn't drop the target.
+            targetDate = resolved ?: drag?.targetDate,
+            topLeftInRoot = pointer - grab,
+            sizePx = sizePx,
+        )
+    }
+}
+
+@Composable
+fun rememberMonthDragController(): MonthDragController = remember { MonthDragController() }
+
+val LocalMonthDrag = compositionLocalOf<MonthDragController?> { null }

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

@@ -4,7 +4,9 @@ import androidx.activity.compose.BackHandler
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.animation.SharedTransitionLayout
+import androidx.compose.animation.core.Animatable
 import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.VectorConverter
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.snap
 import androidx.compose.animation.core.animateFloat
@@ -59,9 +61,11 @@ import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.key
 import androidx.compose.runtime.snapshotFlow
 import androidx.compose.runtime.mutableIntStateOf
@@ -77,7 +81,32 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.draw.drawBehind
 import androidx.compose.ui.geometry.CornerRadius
+import androidx.compose.foundation.layout.absoluteOffset
+import androidx.compose.ui.platform.LocalLayoutDirection
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.geometry.Offset
+import kotlin.math.roundToInt
+import de.jeanlucmakiola.calendula.ui.common.rememberDragSurface
+import de.jeanlucmakiola.calendula.ui.common.eventMoveAction
+import de.jeanlucmakiola.calendula.ui.common.MoveTarget
+import de.jeanlucmakiola.calendula.ui.common.MoveRequest
+import de.jeanlucmakiola.calendula.ui.common.LocalEventMove
+import de.jeanlucmakiola.calendula.ui.common.moveInFlight
+import de.jeanlucmakiola.calendula.ui.common.OnUndoStarted
+import de.jeanlucmakiola.calendula.ui.common.ghostAlpha
+import de.jeanlucmakiola.calendula.ui.common.DragSnapHaptics
+import de.jeanlucmakiola.calendula.ui.common.SETTLE_FADE_MILLIS
+import de.jeanlucmakiola.calendula.ui.common.SETTLE_GRACE_MILLIS
+import de.jeanlucmakiola.calendula.ui.common.EventMoveScope
+import de.jeanlucmakiola.calendula.domain.spanFirstDay
+import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.semantics.customActions
+import androidx.compose.ui.layout.positionInRoot
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.drawscope.Stroke
@@ -126,6 +155,7 @@ import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.floret.time.isoWeekNumber
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.launch
@@ -384,13 +414,23 @@ fun MonthScreen(
                 )
             },
         ) { innerPadding ->
-            Column(
+            // Hoisted above every style's grid: a dragged chip is drawn in an
+            // overlay, clear of the week row's and the list viewport's clips.
+            val chipDrag = rememberMonthDragController()
+            // Undo moves the event back, so the chip travels back too. The
+            // signal comes from the write, not from the chip that offers it.
+            OnUndoStarted { chipDrag.beginUndo() }
+            Box(
                 modifier = Modifier
                     .padding(innerPadding)
                     .fillMaxSize(),
             ) {
+            Column(modifier = Modifier.fillMaxSize()) {
                 WeekdayHeader(weekStart = weekStart, showWeekNumbers = showWeekNumbers)
-                CompositionLocalProvider(LocalDimCutoff provides dimCutoff) {
+                CompositionLocalProvider(
+                    LocalDimCutoff provides dimCutoff,
+                    LocalMonthDrag provides chipDrag,
+                ) {
                     if (scrolling) {
                         ContinuousMonthContent(
                             state = continuousState,
@@ -427,10 +467,103 @@ fun MonthScreen(
                     }
                 }
             }
+            MonthDragOverlay(chipDrag)
+            }
         }
     }
 }
 
+/**
+ * How long to wait for a grid that never seats the drop — it landed in a day's
+ * "+N" overflow or on a day this month doesn't show, or the write failed.
+ */
+private const val MONTH_SETTLE_TIMEOUT_MILLIS = 450L
+
+/** The chip in flight, drawn over the grid and following the finger. */
+@Composable
+private fun MonthDragOverlay(controller: MonthDragController) {
+    var origin by remember { mutableStateOf(Offset.Zero) }
+    val dark = isSystemInDarkTheme()
+    val density = LocalDensity.current
+    val reduceMotion = rememberReduceMotion()
+    val moveInFlight = moveInFlight()
+    // Here rather than beside the controller: this reads [drag], which changes
+    // every frame, and this composable is the one that is meant to.
+    DragSnapHaptics(controller.drag?.targetDate)
+    // Hold the landed chip until the write is done — including the time a
+    // recurring drop's scope dialog is up — and then, unlike the timeline, carry
+    // it to its seat: it was dropped at whatever height the finger was at, while
+    // the grid seats it in a lane.
+    var handingOver by remember(controller.settling) { mutableStateOf(false) }
+    var gliding by remember(controller.settling) { mutableStateOf(false) }
+    val glide = remember { Animatable(Offset.Zero, Offset.VectorConverter) }
+    val glideSpec = MaterialTheme.motionScheme.fastSpatialSpec<Offset>()
+    val seat = controller.settledInRoot
+    LaunchedEffect(controller.settling, moveInFlight, seat) {
+        val landed = controller.settling
+        if (landed == null || moveInFlight) return@LaunchedEffect
+        if (seat == null) {
+            delay(MONTH_SETTLE_TIMEOUT_MILLIS)
+        } else {
+            if (!gliding) glide.snapTo(landed.topLeftInRoot)
+            gliding = true
+            if (reduceMotion) glide.snapTo(seat) else glide.animateTo(seat, glideSpec)
+            delay(SETTLE_GRACE_MILLIS)
+        }
+        handingOver = true
+        controller.handOver()
+        delay(SETTLE_FADE_MILLIS.toLong())
+        controller.release()
+    }
+    Box(
+        modifier = Modifier
+            .fillMaxSize()
+            // A copy of a chip still in the tree behind it; announcing it again
+            // would duplicate the event for the drag's duration.
+            .clearAndSetSemantics { }
+            .onGloballyPositioned { origin = it.positionInRoot() },
+    ) {
+        val drag = controller.drag ?: controller.settling ?: return@Box
+        // Landed: the copy sinks back to the grid's own plane while the write runs.
+        val lift by animateFloatAsState(
+            targetValue = if (controller.drag == null || reduceMotion) 0f else 1f,
+            label = "chip-lift",
+        )
+        val copyAlpha by animateFloatAsState(
+            targetValue = if (handingOver) 0f else 1f,
+            animationSpec = tween(SETTLE_FADE_MILLIS),
+            label = "chip-handover",
+        )
+        MonthBar(
+            event = drag.event,
+            dark = dark,
+            continuesLeft = false,
+            continuesRight = false,
+            modifier = Modifier
+                // Absolute: these are root coordinates, and the direction-aware
+                // offset would mirror them across the screen in an RTL layout.
+                .absoluteOffset {
+                    val at = if (gliding) glide.value else drag.topLeftInRoot
+                    IntOffset(
+                        (at.x - origin.x).roundToInt(),
+                        (at.y - origin.y).roundToInt(),
+                    )
+                }
+                .width(with(density) { drag.sizePx.width.toDp() })
+                .height(with(density) { drag.sizePx.height.toDp() })
+                .padding(horizontal = CELL_GAP + 1.dp, vertical = 1.dp)
+                .graphicsLayer {
+                    scaleX = 1f + 0.04f * lift
+                    scaleY = 1f + 0.04f * lift
+                    shadowElevation = 8.dp.toPx() * lift
+                    alpha = copyAlpha
+                    shape = RoundedCornerShape(4.dp)
+                    clip = false
+                },
+        )
+    }
+}
+
 @Composable
 private fun MonthContent(
     state: MonthUiState,
@@ -1720,6 +1853,50 @@ private fun MonthWeekRow(
     val shownLanes = laneCount.coerceAtMost(MAX_EVENT_ROWS)
     val morphing = morphInFlight()
 
+    // Drag to reschedule (#68). The chips can take no pointer input of their own
+    // — the full-bleed tap layer sits on top of them — so one detector on the
+    // row's day-column box hit-tests them geometrically instead.
+    val moveScope = LocalEventMove.current
+    val dragController = LocalMonthDrag.current
+    val rowToken = remember { Any() }
+    val bandCoordinates = remember { arrayOfNulls<LayoutCoordinates>(1) }
+    val cellCoordinates = remember { arrayOfNulls<LayoutCoordinates>(1) }
+    val density = LocalDensity.current
+    val rowHeightPx = with(density) { EVENT_ROW_HEIGHT.toPx() }
+    val isRtl = LocalLayoutDirection.current == LayoutDirection.Rtl
+    val dragging = dragController?.isDragging == true
+    DisposableEffect(rowToken, dragController) {
+        onDispose { dragController?.removeRow(rowToken) }
+    }
+    // Republished on layout *and* on every recomposition: the coordinates change
+    // only on the former, but what the row draws — which the controller reads to
+    // find a moved chip's seat — changes on the latter.
+    val publish = {
+        val cell = cellCoordinates[0]?.takeIf { it.isAttached }
+        if (dragController != null && cell != null) {
+            dragController.putRow(
+                rowToken,
+                MonthRowGeometry(
+                    days = week.days,
+                    cell = cell,
+                    band = bandCoordinates[0],
+                    columnWidthPx = cell.size.width / 7f,
+                    laneHeightPx = rowHeightPx,
+                    laneCount = MAX_EVENT_ROWS,
+                    isRtl = isRtl,
+                    chipAt = { col, lane -> week.chipAt(col, lane, MAX_EVENT_ROWS) },
+                ),
+            )
+        }
+    }
+    SideEffect { publish() }
+    // Once the grid holds the settled chip, tell the controller where this row
+    // has seated it, so the copy in flight can glide onto it. Keyed on the week,
+    // which is what changes when the re-read lands.
+    LaunchedEffect(week, dragController?.settling) {
+        dragController?.noteSettled(rowToken)
+    }
+
     Row(modifier) {
         // Optional calendar-week gutter, sized so the seven day columns below
         // divide the remaining width — the absolute bar offsets stay correct
@@ -1735,7 +1912,21 @@ private fun MonthWeekRow(
         BoxWithConstraints(
             Modifier
                 .weight(1f)
-                .fillMaxHeight(),
+                .fillMaxHeight()
+                .onGloballyPositioned { coords ->
+                    cellCoordinates[0] = coords
+                    publish()
+                }
+                .then(
+                    monthChipDragModifier(
+                        week = week,
+                        moveScope = moveScope,
+                        controller = dragController,
+                        band = bandCoordinates,
+                        rowHeightPx = rowHeightPx,
+                        isRtl = isRtl,
+                    ),
+                ),
         ) {
             val colW = maxWidth / 7
 
@@ -1800,7 +1991,13 @@ private fun MonthWeekRow(
                     modifier = Modifier
                         .fillMaxWidth()
                         .weight(1f)
-                        .then(if (morphing) Modifier else Modifier.clipToBounds()),
+                        .onGloballyPositioned {
+                            bandCoordinates[0] = it
+                            publish()
+                        }
+                        // A dragged chip travels to another row, so the clip
+                        // yields for it as it does for a morph.
+                        .then(if (morphing || dragging) Modifier else Modifier.clipToBounds()),
                 ) {
                     // Spanning bars on their shared lanes.
                     week.spans.filter { it.lane < shownLanes }.forEach { span ->
@@ -1810,6 +2007,7 @@ private fun MonthWeekRow(
                             dark = dark,
                             continuesLeft = span.continuesLeft,
                             continuesRight = span.continuesRight,
+                            days = week.days.subList(span.startCol, span.endCol + 1),
                             modifier = Modifier
                                 .offset(
                                     x = colW * span.startCol,
@@ -1879,6 +2077,7 @@ private fun MonthWeekRow(
                                 dark = dark,
                                 continuesLeft = false,
                                 continuesRight = false,
+                                days = listOf(d),
                                 modifier = Modifier
                                     .offset(
                                         x = colW * col,
@@ -1959,6 +2158,73 @@ private fun MonthWeekRow(
     }
 }
 
+/**
+ * The row-level pickup for month chips: resolves which chip the press landed on
+ * from the geometry the row just laid out, and abandons the gesture on empty
+ * space (or an unmovable calendar) so tapping a day still opens it.
+ */
+@Composable
+private fun monthChipDragModifier(
+    week: MonthWeek,
+    moveScope: EventMoveScope?,
+    controller: MonthDragController?,
+    band: Array<LayoutCoordinates?>,
+    rowHeightPx: Float,
+    isRtl: Boolean,
+): Modifier = rememberDragSurface(
+    enabled = moveScope != null && controller != null,
+    key = week.days.first(),
+    onPickUp = { local, pointerInRoot, nodeInRoot, size ->
+        val bandTop = band[0]?.takeIf { it.isAttached }?.positionInRoot()?.y
+        val columnPx = size.width / 7f
+        val bandY = if (bandTop == null) -1f else local.y - (bandTop - nodeInRoot.y)
+        val lane = (bandY / rowHeightPx).toInt()
+        // The column under the finger on screen, and the day that column shows.
+        val column = (local.x / columnPx).toInt()
+        val dayIndex = if (isRtl) week.days.lastIndex - column else column
+        val event = if (bandY < 0f || columnPx <= 0f) {
+            null
+        } else {
+            week.chipAt(dayIndex, lane, MAX_EVENT_ROWS)
+        }
+        if (event == null || moveScope?.allows(event) != true) {
+            false
+        } else {
+            controller?.begin(
+                event = event,
+                grabDate = week.days[dayIndex],
+                pointerInRoot = pointerInRoot,
+                chipInRoot = Offset(
+                    x = nodeInRoot.x + column * columnPx,
+                    y = requireNotNull(bandTop) + lane * rowHeightPx,
+                ),
+                size = IntSize(columnPx.toInt(), rowHeightPx.toInt()),
+            )
+            true
+        }
+    },
+    onMove = { controller?.move(it) },
+    onDrop = {
+        controller?.finish()?.let { drop ->
+            // How many columns the finger crossed — grabbing the middle of a
+            // multi-day bar shifts by what it travelled, not to where it landed.
+            val delta = (drop.targetDate.toEpochDays() - drop.grabDate.toEpochDays()).toInt()
+            val took = moveScope?.move(
+                MoveRequest(
+                    eventId = drop.event.eventId,
+                    beginMillis = drop.event.start.toEpochMilliseconds(),
+                    endMillis = drop.event.end.toEpochMilliseconds(),
+                    target = MoveTarget.ByDays(delta),
+                ),
+            )
+            // Refused, so nothing will land: let the copy go now rather than
+            // hold the chip out for a settle that can never arrive.
+            if (took != true) controller?.release()
+        }
+    },
+    onCancel = { controller?.cancel() },
+)
+
 /**
  * Left-gutter calendar-week cell (#25): a full-height tonal pill mirroring the
  * day cells' geometry, set apart by the secondaryContainer tint (matching the
@@ -2051,12 +2317,24 @@ private fun MonthBar(
     continuesLeft: Boolean,
     continuesRight: Boolean,
     modifier: Modifier = Modifier,
+    /**
+     * The days this chip covers in its row, for the drag (#68). A drop's own chip
+     * has to ghost until the copy lands on it, and the instance id can't find it:
+     * the provider hands the re-read instance a new one.
+     */
+    days: List<LocalDate>? = null,
 ) {
     val title = event.title.ifBlank { stringResource(R.string.event_untitled) }
     val dimCutoff = LocalDimCutoff.current
     val dimmed = dimCutoff != null && event.hasEnded(dimCutoff)
     val soften = LocalSoftenColors.current
     val fill = eventFill(event.color, dark, soften)
+    val moveAction = eventMoveAction(event)
+    // The source stays put as a ghost while its floating copy travels.
+    val monthDrag = LocalMonthDrag.current
+    val lifted = monthDrag?.liftedInstanceId == event.instanceId ||
+        monthDrag?.isSettledChip(event, days) == true
+    val ghost = ghostAlpha(lifted)
     val shape = RoundedCornerShape(
         topStart = if (continuesLeft) 0.dp else 4.dp,
         bottomStart = if (continuesLeft) 0.dp else 4.dp,
@@ -2065,9 +2343,13 @@ private fun MonthBar(
     )
     Box(
         modifier = (if (dimmed) modifier.alpha(EventDimAlpha) else modifier)
+            .then(if (ghost < 1f) Modifier.alpha(ghost) else Modifier)
             .background(fill, shape)
             .padding(horizontal = 4.dp)
-            .semantics { contentDescription = title },
+            .semantics {
+                contentDescription = title
+                if (moveAction != null) customActions = listOf(moveAction)
+            },
         contentAlignment = Alignment.CenterStart,
     ) {
         Text(

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

@@ -1,54 +1,31 @@
 package de.jeanlucmakiola.calendula.ui.month
 
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.lazy.rememberLazyListState
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clipToBounds
-import androidx.compose.ui.layout.layout
-import androidx.compose.ui.unit.Constraints
-import androidx.compose.ui.graphics.TransformOrigin
-import androidx.compose.ui.graphics.graphicsLayer
-import androidx.compose.ui.input.pointer.PointerEventPass
-import androidx.compose.ui.input.pointer.pointerInput
-import androidx.compose.ui.platform.LocalConfiguration
-import androidx.compose.ui.semantics.clearAndSetSemantics
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
-import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
+import de.jeanlucmakiola.calendula.ui.common.sampleMonthEvents
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.YearMonth
-import kotlinx.datetime.atTime
 import kotlinx.datetime.plus
-import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Clock
-import kotlin.math.roundToInt
 
 /**
  * A live, scaled-down Month view in a given [MonthViewStyle], for the settings
- * chooser.
- *
- * It renders the *real* grid composables rather than a drawing of them, so the
- * preview cannot drift from the thing it depicts: change a cell's shape or an
- * event bar's colour and every preview follows automatically. The trick is
- * [requiredSize] — it ignores the incoming constraints, so the grid lays itself
- * out at a full phone width and a plausible viewport height, and a
- * [graphicsLayer] scale shrinks the finished layout into the card.
+ * and onboarding choosers.
  *
  * The month, today's position and the week start are all real; only the events
- * are stand-ins, since the settings screen has no business querying the
- * provider for a thumbnail.
+ * are stand-ins. See [ScaledViewPreview] for how the real grid composables get
+ * measured at phone size and shrunk into the card.
  */
 @Composable
 internal fun MonthStylePreview(
@@ -57,108 +34,61 @@ internal fun MonthStylePreview(
     height: Dp,
     modifier: Modifier = Modifier,
 ) {
-    val screenWidth = LocalConfiguration.current.screenWidthDp.dp
-    val scale = height.value / VIRTUAL_HEIGHT.value
     val zone = remember { TimeZone.currentSystemDefault() }
     val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
     val sample = remember(today, weekStart, zone) { sampleMonthState(today, weekStart, zone) }
 
-    Box(
-        modifier = modifier
-            .clipToBounds()
-            .background(MaterialTheme.colorScheme.surface)
-            // A preview is a picture, not a control: swallow touches before the
-            // grid's own clickables see them, and give screen readers one label
-            // instead of six weeks of day cells.
-            .pointerInput(Unit) {
-                awaitPointerEventScope {
-                    while (true) {
-                        awaitPointerEvent(PointerEventPass.Initial).changes
-                            .forEach { it.consume() }
-                    }
-                }
-            }
-            .clearAndSetSemantics { }
-            // Measure the grid at a full phone viewport but report the scaled
-            // size, so the node occupies exactly what it draws.
-            //
-            // Modifier.requiredSize would be the obvious way to force the larger
-            // measurement, but it *centres* content that overflows the incoming
-            // constraints — which pushed the grid to a negative offset and left
-            // only its bottom-right corner inside the clip.
-            .layout { measurable, _ ->
-                val fullWidth = screenWidth.roundToPx()
-                val fullHeight = VIRTUAL_HEIGHT.roundToPx()
-                val placeable = measurable.measure(Constraints.fixed(fullWidth, fullHeight))
-                layout((fullWidth * scale).roundToInt(), (fullHeight * scale).roundToInt()) {
-                    placeable.place(0, 0)
-                }
-            }
-            .graphicsLayer {
-                scaleX = scale
-                scaleY = scale
-                transformOrigin = TransformOrigin(0f, 0f)
-            },
-    ) {
-        Column(Modifier.fillMaxSize()) {
-            WeekdayHeader(weekStart = weekStart, showWeekNumbers = false)
-                when (style) {
-                    MonthViewStyle.Paged -> MonthGrid(
-                        state = sample.month,
-                        showWeekNumbers = false,
-                        onOpenDay = {},
-                    )
-                    MonthViewStyle.Continuous -> ContinuousMonthGrid(
-                        state = sample.continuous,
-                        listState = rememberLazyListState(
-                            initialFirstVisibleItemIndex = itemIndexForMonth(
-                                monthIndexOf(YearMonth(today.year, today.month)),
-                            ),
-                        ),
-                        showWeekNumbers = false,
-                        onOpenDay = {},
-                    )
-                    MonthViewStyle.Dense -> DenseMonthGrid(
-                        state = sample.continuous,
-                        listState = rememberLazyListState(
-                            // Start a week above today's, so the preview shows a
-                            // stream running past the viewport rather than one
-                            // beginning at its top edge.
-                            initialFirstVisibleItemIndex =
-                                weekIndexOf(today, weekStart) - 1,
-                        ),
-                        showWeekNumbers = false,
-                        onOpenDay = {},
-                    )
-                    MonthViewStyle.Split -> {
-                        SplitMonthGrid(
-                            state = sample.month,
-                            selected = today,
-                            showWeekNumbers = false,
-                            onSelectDay = {},
-                        )
-                        SplitDayPane(
-                            date = today,
-                            today = today,
-                            events = sample.month.instancesByDay[today].orEmpty(),
-                            zone = zone,
-                            onOpenDay = {},
-                            onEventClick = {},
-                            onCreateEvent = {},
-                            modifier = Modifier.fillMaxWidth().height(SPLIT_PANE_HEIGHT),
-                        )
-                    }
-                }
+    ScaledViewPreview(height = height, modifier = modifier) {
+        WeekdayHeader(weekStart = weekStart, showWeekNumbers = false)
+        when (style) {
+            MonthViewStyle.Paged -> MonthGrid(
+                state = sample.month,
+                showWeekNumbers = false,
+                onOpenDay = {},
+            )
+            MonthViewStyle.Continuous -> ContinuousMonthGrid(
+                state = sample.continuous,
+                listState = rememberLazyListState(
+                    initialFirstVisibleItemIndex = itemIndexForMonth(
+                        monthIndexOf(YearMonth(today.year, today.month)),
+                    ),
+                ),
+                showWeekNumbers = false,
+                onOpenDay = {},
+            )
+            MonthViewStyle.Dense -> DenseMonthGrid(
+                state = sample.continuous,
+                listState = rememberLazyListState(
+                    // Start a week above today's, so the preview shows a stream
+                    // running past the viewport rather than one beginning at its
+                    // top edge.
+                    initialFirstVisibleItemIndex = weekIndexOf(today, weekStart) - 1,
+                ),
+                showWeekNumbers = false,
+                onOpenDay = {},
+            )
+            MonthViewStyle.Split -> {
+                SplitMonthGrid(
+                    state = sample.month,
+                    selected = today,
+                    showWeekNumbers = false,
+                    onSelectDay = {},
+                )
+                SplitDayPane(
+                    date = today,
+                    today = today,
+                    events = sample.month.instancesByDay[today].orEmpty(),
+                    zone = zone,
+                    onOpenDay = {},
+                    onEventClick = {},
+                    onCreateEvent = {},
+                    modifier = Modifier.fillMaxWidth().height(SPLIT_PANE_HEIGHT),
+                )
             }
+        }
     }
 }
 
-/**
- * The viewport the preview pretends to be: a phone's width by the height a
- * calendar view gets under the top bar. Scaling from a fixed height keeps the
- * three styles comparable — each shows the same slice of screen.
- */
-private val VIRTUAL_HEIGHT = 440.dp
 private val SPLIT_PANE_HEIGHT = 170.dp
 
 private class SampleMonth(
@@ -170,9 +100,6 @@ private class SampleMonth(
  * A month's worth of stand-in events, laid out through the same
  * [layoutMonthWeeks] / [clipWeekToMonth] the live views use — so the preview
  * exercises the real span, lane and overflow logic rather than approximating it.
- *
- * Colours are raw ARGB on purpose: that is what the provider hands out for an
- * event, so a token here would misrepresent what the grid actually renders.
  */
 private fun sampleMonthState(
     today: LocalDate,
@@ -181,7 +108,7 @@ private fun sampleMonthState(
 ): SampleMonth {
     val ym = YearMonth(today.year, today.month)
     val first = LocalDate(ym.year, ym.month, 1)
-    val events = sampleEvents(first, today, zone)
+    val events = sampleMonthEvents(first, today, zone)
 
     val weeks = layoutMonthWeeks(ym, weekStart, events, zone)
     val month = MonthUiState.Success(
@@ -213,72 +140,3 @@ private fun sampleMonthState(
     )
     return SampleMonth(month, continuous)
 }
-
-private val SAMPLE_COLORS = listOf(
-    0xFF3F7BD4.toInt(),
-    0xFFCE5B4C.toInt(),
-    0xFF4E9A6A.toInt(),
-    0xFF8A63C7.toInt(),
-)
-
-private fun sampleEvents(
-    firstOfMonth: LocalDate,
-    today: LocalDate,
-    zone: TimeZone,
-): List<EventInstance> {
-    var id = 0L
-    fun next() = ++id
-
-    fun timed(day: LocalDate, hour: Int, length: Int, colorIndex: Int) = EventInstance(
-        instanceId = next(),
-        eventId = id,
-        calendarId = 1L,
-        title = SAMPLE_TITLES[(id.toInt() - 1) % SAMPLE_TITLES.size],
-        start = day.atTime(hour, 0).toInstant(zone),
-        end = day.atTime(hour + length, 0).toInstant(zone),
-        isAllDay = false,
-        color = SAMPLE_COLORS[colorIndex % SAMPLE_COLORS.size],
-        location = null,
-    )
-
-    fun allDay(from: LocalDate, days: Int, colorIndex: Int) = EventInstance(
-        instanceId = next(),
-        eventId = id,
-        calendarId = 1L,
-        title = SAMPLE_TITLES[(id.toInt() - 1) % SAMPLE_TITLES.size],
-        // All-day events sit at UTC midnights with an exclusive end.
-        start = from.atTime(0, 0).toInstant(TimeZone.UTC),
-        end = from.plus(days, DateTimeUnit.DAY).atTime(0, 0).toInstant(TimeZone.UTC),
-        isAllDay = true,
-        color = SAMPLE_COLORS[colorIndex % SAMPLE_COLORS.size],
-        location = null,
-    )
-
-    // Spread across the month so most weeks carry something, with one multi-day
-    // bar to show a span bridging cells and a busy today for the split pane.
-    return buildList {
-        add(allDay(firstOfMonth.plus(9, DateTimeUnit.DAY), days = 3, colorIndex = 2))
-        add(timed(firstOfMonth.plus(1, DateTimeUnit.DAY), 9, 1, 0))
-        add(timed(firstOfMonth.plus(4, DateTimeUnit.DAY), 14, 2, 1))
-        add(timed(firstOfMonth.plus(7, DateTimeUnit.DAY), 11, 1, 3))
-        add(timed(firstOfMonth.plus(15, DateTimeUnit.DAY), 10, 1, 0))
-        add(timed(firstOfMonth.plus(18, DateTimeUnit.DAY), 16, 1, 2))
-        add(timed(firstOfMonth.plus(22, DateTimeUnit.DAY), 8, 2, 1))
-        add(timed(firstOfMonth.plus(25, DateTimeUnit.DAY), 13, 1, 3))
-        // Today, so the split pane's list and the grid's dots both have content.
-        add(timed(today, 9, 1, 0))
-        add(timed(today, 12, 1, 1))
-        add(timed(today, 15, 2, 3))
-    }
-}
-
-private val SAMPLE_TITLES = listOf(
-    "Standup",
-    "Lunch",
-    "Review",
-    "Gym",
-    "Call",
-    "Workshop",
-    "Dentist",
-    "Trip",
-)

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

@@ -67,6 +67,23 @@ fun MonthWeek.laneEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInst
     return byLane.filterNotNull()
 }
 
+/**
+ * The event drawn in lane [lane] of column [col], or null for an empty slot.
+ * Unlike [laneEvents] the lanes are *not* compacted — this answers "what is under
+ * this point", so an empty lane above a seated bar has to stay empty (#68).
+ */
+fun MonthWeek.chipAt(col: Int, lane: Int, laneCap: Int): EventInstance? {
+    if (col !in days.indices || lane !in 0 until laneCap) return null
+    spans.firstOrNull { it.lane == lane && col in it.startCol..it.endCol }?.let { return it.event }
+    val occupied = spans
+        .filter { it.lane < laneCap && col in it.startCol..it.endCol }
+        .map { it.lane }
+        .toSet()
+    val free = (0 until laneCap).filter { it !in occupied }
+    val index = free.indexOf(lane).takeIf { it >= 0 } ?: return null
+    return timedByDay[days[col]].orEmpty().take(free.size).getOrNull(index)
+}
+
 /**
  * The events on [day] that [laneEvents] had no lane left for — its exact
  * complement, in the same bars-then-pills order. Returned as events rather than

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/BackupStep.kt

@@ -0,0 +1,100 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import android.net.Uri
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.CloudOff
+import androidx.compose.material.icons.filled.FolderOpen
+import androidx.compose.material.icons.filled.Schedule
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.BenefitRow
+import de.jeanlucmakiola.floret.components.OnboardingScaffold
+import de.jeanlucmakiola.floret.components.OnboardingSpace
+
+/**
+ * Wizard step shown only when everything you write to is a device-only calendar
+ * (#163): the events exist nowhere but this phone, so losing it loses them.
+ *
+ * The primary action picks a folder and switches automatic backup on in one go.
+ * Everything it sets is a normal Backup setting, adjustable afterwards.
+ */
+@Composable
+internal fun BackupStep(
+    onEnable: (Uri) -> Unit,
+    onSkip: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+) {
+    val pickFolder = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocumentTree(),
+    ) { uri ->
+        // Cancelling the picker decides nothing and leaves the step open.
+        uri?.let(onEnable)
+    }
+
+    OnboardingScaffold(
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+        topSpacing = OnboardingSpace.lg,
+        hero = { IconHero(Icons.Filled.CloudOff) },
+        actions = {
+            Button(
+                onClick = { runCatching { pickFolder.launch(null) } },
+                modifier = Modifier.fillMaxWidth().height(56.dp),
+            ) {
+                Text(
+                    text = stringResource(R.string.onboarding_backup_enable_button),
+                    style = MaterialTheme.typography.titleMedium,
+                )
+            }
+            TextButton(
+                onClick = onSkip,
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Text(stringResource(R.string.onboarding_backup_skip_button))
+            }
+        },
+    ) {
+        Text(
+            text = stringResource(R.string.onboarding_backup_title),
+            style = MaterialTheme.typography.headlineMedium,
+            textAlign = TextAlign.Center,
+        )
+        Spacer(Modifier.height(12.dp))
+        Text(
+            text = stringResource(R.string.onboarding_backup_body),
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+
+        Spacer(Modifier.height(OnboardingSpace.lg))
+
+        BenefitRow(
+            icon = Icons.Filled.FolderOpen,
+            title = stringResource(R.string.onboarding_backup_benefit_folder_title),
+            body = stringResource(R.string.onboarding_backup_benefit_folder_body),
+        )
+        Spacer(Modifier.height(OnboardingSpace.sm))
+        BenefitRow(
+            icon = Icons.Filled.Schedule,
+            title = stringResource(R.string.onboarding_backup_benefit_daily_title),
+            body = stringResource(R.string.onboarding_backup_benefit_daily_body),
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/BrandHero.kt

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.calendula.ui.permission
+package de.jeanlucmakiola.calendula.ui.onboarding
 
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
@@ -9,6 +9,7 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Lock
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -16,20 +17,25 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.res.colorResource
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 
+/** What, if anything, the brand mark is wearing in its corner. */
+internal enum class HeroBadge { Denied, Done }
+
 /**
  * The app's adaptive launcher mark, reconstructed as a large branded squircle —
  * the hero of the onboarding screens (floret-kit's OnboardingScaffold supplies
  * the shell; the mark stays app-local so each sibling keeps its own identity).
- * A lock badge overlays the corner when permission has been [denied].
+ * A [badge] overlays the corner where the screen has a verdict to give: blocked,
+ * or finished.
  */
 @Composable
-internal fun BrandHero(denied: Boolean) {
+internal fun BrandHero(badge: HeroBadge? = null) {
     Box(contentAlignment = Alignment.Center) {
         Box(
             modifier = Modifier
@@ -43,24 +49,56 @@ internal fun BrandHero(denied: Boolean) {
                 modifier = Modifier.fillMaxSize(),
             )
         }
-        if (denied) {
-            // A small lock badge sits over the corner to signal "blocked".
+        if (badge != null) {
+            val container = when (badge) {
+                HeroBadge.Denied -> MaterialTheme.colorScheme.errorContainer
+                HeroBadge.Done -> MaterialTheme.colorScheme.primaryContainer
+            }
+            val onContainer = when (badge) {
+                HeroBadge.Denied -> MaterialTheme.colorScheme.onErrorContainer
+                HeroBadge.Done -> MaterialTheme.colorScheme.onPrimaryContainer
+            }
             Box(
                 modifier = Modifier
                     .align(Alignment.BottomEnd)
                     .offset(x = 10.dp, y = 10.dp)
                     .size(44.dp)
                     .clip(CircleShape)
-                    .background(MaterialTheme.colorScheme.errorContainer),
+                    .background(container),
                 contentAlignment = Alignment.Center,
             ) {
                 Icon(
-                    imageVector = Icons.Filled.Lock,
+                    imageVector = when (badge) {
+                        HeroBadge.Denied -> Icons.Filled.Lock
+                        HeroBadge.Done -> Icons.Filled.Check
+                    },
                     contentDescription = null,
-                    tint = MaterialTheme.colorScheme.onErrorContainer,
+                    tint = onContainer,
                     modifier = Modifier.size(24.dp),
                 )
             }
         }
     }
 }
+
+/**
+ * A single [icon] in the brand squircle — the same silhouette as [BrandHero],
+ * for the wizard steps that stand for a feature rather than for the app itself.
+ */
+@Composable
+internal fun IconHero(icon: ImageVector) {
+    Box(
+        modifier = Modifier
+            .size(128.dp)
+            .clip(RoundedCornerShape(34.dp))
+            .background(MaterialTheme.colorScheme.primaryContainer),
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            imageVector = icon,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.onPrimaryContainer,
+            modifier = Modifier.size(56.dp),
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/DoneStep.kt

@@ -0,0 +1,61 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.OnboardingScaffold
+import de.jeanlucmakiola.floret.components.OnboardingSpace
+
+/**
+ * The wizard's closing screen (#163): the flow ends on a full screen saying so
+ * rather than dropping into the calendar mid-gesture, and the brand mark wears
+ * the check that the last step earned.
+ */
+@Composable
+internal fun DoneStep(
+    onFinished: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+) {
+    OnboardingScaffold(
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+        topSpacing = OnboardingSpace.lg,
+        hero = { BrandHero(HeroBadge.Done) },
+        actions = {
+            Button(
+                onClick = onFinished,
+                modifier = Modifier.fillMaxWidth().height(56.dp),
+            ) {
+                Text(
+                    text = stringResource(R.string.onboarding_done_button),
+                    style = MaterialTheme.typography.titleMedium,
+                )
+            }
+        },
+    ) {
+        Text(
+            text = stringResource(R.string.onboarding_done_title),
+            style = MaterialTheme.typography.headlineMedium,
+            textAlign = TextAlign.Center,
+        )
+        Spacer(Modifier.height(12.dp))
+        Text(
+            text = stringResource(R.string.onboarding_done_body),
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/OnboardingMotion.kt

@@ -0,0 +1,58 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import androidx.compose.animation.ContentTransform
+import androidx.compose.animation.SizeTransform
+import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideInHorizontally
+import androidx.compose.animation.slideOutHorizontally
+import androidx.compose.animation.togetherWith
+import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.unit.IntOffset
+
+/**
+ * The M3 Expressive spatial spring the wizard's steps travel on. Read in
+ * composable scope so it can be captured by `AnimatedContent`'s non-composable
+ * transitionSpec lambda.
+ */
+@OptIn(ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+internal fun rememberOnboardingSlideSpec(): FiniteAnimationSpec<IntOffset> =
+    MaterialTheme.motionScheme.defaultSpatialSpec()
+
+/**
+ * Moving between wizard steps (#163): the steps sit side by side and the whole
+ * width swipes across, position on a spring so the arriving step settles with a
+ * little give rather than stopping dead.
+ *
+ * No cross-fade, unlike the calendar's shared-axis paging: two steps have
+ * nothing in common, so fading one through the other smears. Both are opaque and
+ * travel in lockstep, showing one screen pushing the other off.
+ *
+ * @param slideDir     +1 = forward (incoming from the right), -1 = back.
+ * @param spec         spatial spec, typically [rememberOnboardingSlideSpec].
+ * @param fadeSpec     effects spec used for the whole transition under reduced
+ *                     motion.
+ * @param reduceMotion when true, drop the movement and cross-fade alone.
+ */
+internal fun onboardingSlideTransition(
+    slideDir: Int,
+    spec: FiniteAnimationSpec<IntOffset>,
+    fadeSpec: FiniteAnimationSpec<Float>,
+    reduceMotion: Boolean,
+): ContentTransform {
+    if (reduceMotion) {
+        return fadeIn(fadeSpec).togetherWith(fadeOut(fadeSpec))
+    }
+    val dir = if (slideDir == 0) 1 else slideDir
+    return ContentTransform(
+        targetContentEnter = slideInHorizontally(spec) { w -> dir * w },
+        initialContentExit = slideOutHorizontally(spec) { w -> -dir * w },
+        // Clipping to the animating container would shear both steps against the
+        // viewport edge as they pass; there is no size change here to contain.
+        sizeTransform = SizeTransform(clip = false),
+    )
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/OnboardingPlan.kt

@@ -0,0 +1,116 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+/** One screen of the first-launch wizard (#163), in the order they are shown. */
+enum class OnboardingStep {
+    /** Required: nothing works without the calendar grant. */
+    Permission,
+
+    /** Whether Calendula delivers reminder notifications itself. */
+    Reminders,
+
+    /** Only when nothing you write to is synced anywhere — offers a backup. */
+    Backup,
+
+    /** Which view the app opens on, chosen from a live preview. */
+    View,
+
+    /** How the Month view lays itself out, chosen from a live preview. */
+    MonthStyle,
+
+    /** Only on an install that has calendars the device is hiding (#75). */
+    Visibility,
+
+    /** The closing screen: everything is answered and the app is ready. */
+    Done,
+}
+
+/**
+ * Which steps this install owes and where it has got to. [steps] is the whole
+ * flow — completed steps included — so the counter doesn't renumber as steps
+ * are finished; [current] is null once nothing is left and the app opens.
+ */
+data class OnboardingPlan(
+    val steps: List<OnboardingStep>,
+    val current: OnboardingStep?,
+) {
+    /** 1-based position of [current] in [steps], or 0 when the flow is done. */
+    val index: Int get() = steps.indexOf(current) + 1
+
+    val total: Int get() = steps.size
+
+    /** A one-step flow is not a wizard: there is nothing to count down. */
+    val showsProgress: Boolean get() = total > 1
+
+    /** The step before [current], or null at the start (and once finished). */
+    val previous: OnboardingStep? get() = steps.getOrNull(index - 2).takeIf { current != null }
+
+    /**
+     * Whether the wizard can step back. Everything is re-askable except the
+     * calendar grant, which belongs to the system — once given there is nothing
+     * for a back press to return to.
+     */
+    val canGoBack: Boolean get() = previous != null && previous != OnboardingStep.Permission
+}
+
+/**
+ * Work out the flow from what is stored.
+ *
+ * The optional steps belong to installs still working through their first run.
+ * Before the grant that can only be guessed, so one that has not answered the
+ * reminder step either counts as fresh — the same condition
+ * [de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs.armOnboardingWizard]
+ * commits to storage a moment later, and clears again on the closing screen so
+ * a later re-grant is only the permission step.
+ *
+ * [backupApplies] is null until the calendar list can be read, i.e. for the
+ * whole permission step; the backup step is assumed to apply until proven
+ * otherwise, so the flow can only ever get shorter — never sprout a step the
+ * counter had not accounted for.
+ *
+ * The month-style step is *not* conditional on Month being the chosen view:
+ * Month is reachable from the drawer whatever opens first, and a step that came
+ * and went as the view is picked would move the counter under the user on the
+ * step right before it.
+ *
+ * [visibilityArmed] carries the one-time notice that the device is hiding some
+ * calendars (#75) — the only optional step an *existing* install can be given,
+ * which is why it is not gated on `fresh`, and on its own it earns no closing
+ * screen.
+ */
+fun onboardingPlan(
+    hasPermission: Boolean,
+    remindersDone: Boolean,
+    wizardArmed: Boolean,
+    backupDone: Boolean,
+    viewDone: Boolean,
+    monthStyleDone: Boolean,
+    backupApplies: Boolean?,
+    visibilityArmed: Boolean = false,
+    visibilityDone: Boolean = false,
+    doneShown: Boolean = false,
+): OnboardingPlan {
+    val fresh = wizardArmed || (!hasPermission && !remindersDone)
+    val steps = buildList {
+        if (!hasPermission || fresh) add(OnboardingStep.Permission)
+        if (!remindersDone || fresh) add(OnboardingStep.Reminders)
+        if (fresh && backupApplies != false) add(OnboardingStep.Backup)
+        if (fresh) {
+            add(OnboardingStep.View)
+            add(OnboardingStep.MonthStyle)
+        }
+        if (visibilityArmed) add(OnboardingStep.Visibility)
+        if (fresh) add(OnboardingStep.Done)
+    }
+    val current = steps.firstOrNull { step ->
+        when (step) {
+            OnboardingStep.Permission -> !hasPermission
+            OnboardingStep.Reminders -> !remindersDone
+            OnboardingStep.Backup -> !backupDone
+            OnboardingStep.View -> !viewDone
+            OnboardingStep.MonthStyle -> !monthStyleDone
+            OnboardingStep.Visibility -> !visibilityDone
+            OnboardingStep.Done -> !doneShown
+        }
+    }
+    return OnboardingPlan(steps, current)
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/OnboardingSteps.kt

@@ -0,0 +1,118 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import androidx.activity.compose.BackHandler
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.OnboardingProgress
+
+/**
+ * Renders the wizard's current [step] (#163). Each step commits its own answer
+ * through [viewModel], which then hands the host the next one.
+ */
+@Composable
+fun OnboardingSteps(
+    step: OnboardingStep,
+    plan: OnboardingPlan,
+    viewModel: OnboardingViewModel,
+    onPermissionGranted: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    // Collected for every step, not just the two that draw a preview: starting
+    // it when the picker composes would leave that step blank as it slides in.
+    val choice by viewModel.viewChoice.collectAsStateWithLifecycle()
+
+    // Coerced because the outgoing half of a transition may be a step the live
+    // plan has since dropped — the backup step goes once the calendars say it
+    // does not apply — and a "Step 0 of 3" flash is worse than a stale number.
+    val index = (plan.steps.indexOf(step) + 1).coerceAtLeast(1)
+    val progress: (@Composable () -> Unit)? = if (!plan.showsProgress) {
+        null
+    } else {
+        {
+            OnboardingProgress(
+                step = index,
+                total = plan.total,
+                label = stringResource(R.string.onboarding_step_counter, index, plan.total),
+            )
+        }
+    }
+
+    // The system back gesture does the same thing as the button, and stays off
+    // on the first step so back still leaves the app.
+    BackHandler(enabled = plan.canGoBack) { viewModel.goBack() }
+    val navigationIcon: (@Composable () -> Unit)? = if (!plan.canGoBack) {
+        null
+    } else {
+        {
+            IconButton(onClick = viewModel::goBack) {
+                Icon(
+                    imageVector = Icons.AutoMirrored.Filled.ArrowBack,
+                    contentDescription = stringResource(R.string.onboarding_back),
+                )
+            }
+        }
+    }
+
+    when (step) {
+        OnboardingStep.Permission -> PermissionScreen(
+            onGranted = onPermissionGranted,
+            modifier = modifier,
+            progress = progress,
+        )
+        OnboardingStep.Reminders -> ReminderStep(
+            onFinished = viewModel::finishReminders,
+            modifier = modifier,
+            progress = progress,
+            navigationIcon = navigationIcon,
+        )
+        OnboardingStep.Backup -> BackupStep(
+            onEnable = viewModel::enableAutoBackup,
+            onSkip = viewModel::skipBackup,
+            modifier = modifier,
+            progress = progress,
+            navigationIcon = navigationIcon,
+        )
+        // The choice is null only until DataStore's first emission; rendering
+        // nothing for that frame beats a preview built on the wrong defaults.
+        OnboardingStep.View -> choice?.let {
+            ViewStep(
+                choice = it,
+                onSelect = viewModel::setDefaultView,
+                onFinished = viewModel::finishView,
+                modifier = modifier,
+                progress = progress,
+                navigationIcon = navigationIcon,
+            )
+        }
+        OnboardingStep.MonthStyle -> choice?.let {
+            MonthStyleStep(
+                choice = it,
+                onSelect = viewModel::setMonthViewStyle,
+                onFinished = viewModel::finishMonthStyle,
+                modifier = modifier,
+                progress = progress,
+                navigationIcon = navigationIcon,
+            )
+        }
+        OnboardingStep.Visibility -> VisibilityStep(
+            onFinished = viewModel::finishVisibility,
+            modifier = modifier,
+            progress = progress,
+            navigationIcon = navigationIcon,
+        )
+        OnboardingStep.Done -> DoneStep(
+            onFinished = viewModel::finishOnboarding,
+            modifier = modifier,
+            progress = progress,
+            navigationIcon = navigationIcon,
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/OnboardingViewModel.kt

@@ -0,0 +1,321 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+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.calendar.CalendarVisibilityReconciler
+import de.jeanlucmakiola.calendula.data.di.IoDispatcher
+import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
+import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.data.prefs.WeekStartPref
+import de.jeanlucmakiola.calendula.data.reminders.ReminderScanner
+import de.jeanlucmakiola.calendula.domain.CalendarSource
+import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.mapLatest
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+/**
+ * Drives the first-launch wizard (#163): decides which steps this install owes
+ * (see [onboardingPlan]) and commits each answer.
+ *
+ * [plan] is null until the first stored emission, so the host renders nothing
+ * for that frame rather than flashing a step the user has already answered.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+@HiltViewModel
+class OnboardingViewModel @Inject constructor(
+    @ApplicationContext private val context: Context,
+    private val prefs: SettingsPrefs,
+    private val calendarPrefs: CalendarPrefs,
+    private val repository: CalendarRepository,
+    private val scanner: ReminderScanner,
+    private val visibilityReconciler: CalendarVisibilityReconciler,
+    @IoDispatcher private val io: CoroutineDispatcher,
+) : ViewModel() {
+
+    /** Null until the host reports it — assuming either way would flash a screen. */
+    private val permissionReported = MutableStateFlow<Boolean?>(null)
+
+    /**
+     * The grant as the rest of the flow sees it: published only once the wizard
+     * has been armed for it, since arming is a stored write and the frames
+     * before it lands would collapse the plan to its one-step form.
+     */
+    private val hasPermission: StateFlow<Boolean?> = permissionReported
+        .mapLatest { granted ->
+            if (granted == true) armWizardIfFresh()
+            granted
+        }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.Eagerly,
+            initialValue = null,
+        )
+
+    /**
+     * Whether the backup step applies: something of yours is worth exporting and
+     * nothing you write to is synced anywhere. Null while the calendar list
+     * cannot be read: every frame before the grant, and any read that fails —
+     * an empty list is also how a null cursor arrives, and guessing false there
+     * would drop the step for the whole session.
+     */
+    private val backupApplies: Flow<Boolean?> = hasPermission.flatMapLatest { granted ->
+        if (granted != true) {
+            flowOf(null)
+        } else {
+            repository.calendars()
+                .map { calendars -> if (calendars.isEmpty()) null else calendars.backupApplies() }
+                .catch { emit(null) }
+                .flowOn(io)
+        }
+    }
+
+    private val flags: Flow<OnboardingFlags> = combine(
+        prefs.reminderOnboardingDone,
+        prefs.onboardingWizardArmed,
+        prefs.onboardingBackupDone,
+        prefs.onboardingViewDone,
+        prefs.onboardingMonthStyleDone,
+        ::OnboardingFlags,
+    )
+
+    /** The closing steps' own flags, and whether the notice applies at all. */
+    private val closingFlags: Flow<ClosingFlags> = combine(
+        calendarPrefs.visibilityNoticePending.map { it == true },
+        prefs.onboardingVisibilityDone,
+        prefs.onboardingDoneShown,
+        ::ClosingFlags,
+    )
+
+    val plan: StateFlow<OnboardingPlan?> =
+        combine(hasPermission, flags, closingFlags, backupApplies) { granted, stored, closing, backup ->
+            granted?.let {
+                onboardingPlan(
+                    hasPermission = it,
+                    remindersDone = stored.remindersDone,
+                    wizardArmed = stored.wizardArmed,
+                    backupDone = stored.backupDone,
+                    viewDone = stored.viewDone,
+                    monthStyleDone = stored.monthStyleDone,
+                    backupApplies = backup,
+                    visibilityArmed = closing.visibilityArmed,
+                    visibilityDone = closing.visibilityDone,
+                    doneShown = closing.doneShown,
+                )
+            }
+        }.stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = null,
+        )
+
+    /** The current view preferences, for the view step's initial selection. */
+    val viewChoice: StateFlow<ViewChoice?> = combine(
+        prefs.defaultView,
+        prefs.monthViewStyle,
+        prefs.weekStart,
+        ::ViewChoice,
+    ).stateIn(
+        scope = viewModelScope,
+        started = SharingStarted.WhileSubscribed(5_000L),
+        initialValue = null,
+    )
+
+    fun setHasPermission(granted: Boolean) {
+        permissionReported.value = granted
+    }
+
+    /**
+     * Arm the wizard for an install that has yet to answer the reminder step,
+     * whatever route the grant took. Gating this on the in-app grant would
+     * strand anyone who granted on Android's own settings screen and came back
+     * to a restarted process, leaving them the reminder step alone.
+     */
+    private suspend fun armWizardIfFresh() {
+        if (!prefs.reminderOnboardingDone.first()) prefs.armOnboardingWizard()
+    }
+
+    /**
+     * Record the in-app grant. The launch scan ran before it and bailed out
+     * without arming anything, so the first alarm would otherwise wait on the
+     * daily worker.
+     */
+    fun onPermissionGranted() {
+        scanner.scanInBackground()
+    }
+
+    /** Close the reminder step, recording whether notifications stay on. */
+    fun finishReminders(remindersEnabled: Boolean) {
+        viewModelScope.launch {
+            prefs.setRemindersEnabled(remindersEnabled)
+            prefs.setReminderOnboardingDone()
+            // Nothing else re-arms the scan: turning reminders off cancels the
+            // alarm (#75).
+            scanner.scan()
+        }
+    }
+
+    /**
+     * Re-ask the step before the current one, by clearing its answer. The plan
+     * derives the position from those answers, so un-setting one *is* the back
+     * navigation. The calendar grant belongs to the system and cannot be
+     * returned to, which [OnboardingPlan.canGoBack] already refuses.
+     */
+    fun goBack() {
+        viewModelScope.launch {
+            when (plan.value?.previous) {
+                OnboardingStep.Reminders -> prefs.setReminderOnboardingDone(false)
+                OnboardingStep.Backup -> prefs.setOnboardingBackupDone(false)
+                OnboardingStep.View -> prefs.setOnboardingViewDone(false)
+                OnboardingStep.MonthStyle -> prefs.setOnboardingMonthStyleDone(false)
+                OnboardingStep.Visibility -> prefs.setOnboardingVisibilityDone(false)
+                OnboardingStep.Done -> prefs.setOnboardingDoneShown(false)
+                OnboardingStep.Permission, null -> Unit
+            }
+        }
+    }
+
+    /** Close the backup step without setting anything up. */
+    fun skipBackup() {
+        viewModelScope.launch { prefs.setOnboardingBackupDone() }
+    }
+
+    /**
+     * Turn automatic backup on, writing to the folder the user just picked
+     * (taking a durable write grant so background runs can keep writing), and
+     * close the step.
+     */
+    fun enableAutoBackup(folder: Uri) {
+        viewModelScope.launch {
+            runCatching {
+                context.contentResolver.takePersistableUriPermission(
+                    folder,
+                    Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION,
+                )
+            }
+            prefs.setAutoBackupFolderUri(folder.toString())
+            prefs.setAutoBackupEnabled(true)
+            BackupScheduler.apply(
+                context = context,
+                enabled = true,
+                intervalMinutes = prefs.autoBackupIntervalMinutes.first(),
+                hasFolder = true,
+            )
+            // Immediate feedback: the first backup lands while onboarding runs.
+            BackupScheduler.runNow(context)
+            prefs.setOnboardingBackupDone()
+        }
+    }
+
+    fun setDefaultView(view: CalendarView) {
+        viewModelScope.launch { prefs.setDefaultView(view) }
+    }
+
+    fun setMonthViewStyle(style: MonthViewStyle) {
+        viewModelScope.launch { prefs.setMonthViewStyle(style) }
+    }
+
+    /** Close a picker step — the choice itself is saved as it is made. */
+    fun finishView() {
+        viewModelScope.launch { prefs.setOnboardingViewDone() }
+    }
+
+    fun finishMonthStyle() {
+        viewModelScope.launch { prefs.setOnboardingMonthStyleDone() }
+    }
+
+    /** Acknowledge the calendar-visibility notice (#75). */
+    fun finishVisibility() {
+        viewModelScope.launch {
+            prefs.setOnboardingVisibilityDone()
+            // Retiring the notice drops its step, so it waits until nothing
+            // follows — the count must not fall on the way to a later screen.
+            if (plan.value?.steps?.last() == OnboardingStep.Visibility) retireVisibilityNotice()
+        }
+    }
+
+    /** Close the wizard from its last screen. */
+    fun finishOnboarding() {
+        viewModelScope.launch {
+            prefs.finishOnboardingWizard()
+            retireVisibilityNotice()
+        }
+    }
+
+    /**
+     * Put the one-time visibility notice away for good — nothing else clears it
+     * now that the wizard owns it, and left standing it would keep its step in
+     * every later plan.
+     */
+    private suspend fun retireVisibilityNotice() {
+        if (calendarPrefs.visibilityNoticePending.first() == true) {
+            calendarPrefs.setVisibilityNoticePending(false)
+        }
+    }
+
+    /**
+     * Fold the retired app-local calendar visibility into the device's own, and
+     * arm the notice if this install has anything to announce. Runs whenever the
+     * app comes up holding the permission, however it was granted — one taken on
+     * Android's app-settings screen never reaches the permission step's callback.
+     */
+    fun reconcileCalendarVisibility() {
+        viewModelScope.launch { visibilityReconciler.run() }
+    }
+}
+
+/** The stored answers the plan is derived from. */
+private data class OnboardingFlags(
+    val remindersDone: Boolean,
+    val wizardArmed: Boolean,
+    val backupDone: Boolean,
+    val viewDone: Boolean,
+    val monthStyleDone: Boolean,
+)
+
+/** The tail of the flow: the visibility notice and the closing screen. */
+private data class ClosingFlags(
+    val visibilityArmed: Boolean,
+    val visibilityDone: Boolean,
+    val doneShown: Boolean,
+)
+
+/** What the view step starts from, and renders its previews with. */
+data class ViewChoice(
+    val defaultView: CalendarView,
+    val monthViewStyle: MonthViewStyle,
+    val weekStart: WeekStartPref,
+)
+
+/**
+ * True when this device holds events that live nowhere else: at least one local
+ * calendar worth exporting, and no writable synced calendar to carry them.
+ * A read-only subscription is not a backup, so it does not count.
+ */
+private fun List<CalendarSource>.backupApplies(): Boolean {
+    val exportable = any { it.isLocal && it.canModifyContents && !it.isManaged }
+    val syncedTarget = any { !it.isLocal && it.canModifyContents }
+    return exportable && !syncedTarget
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/PermissionScreen.kt

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.calendula.ui.permission
+package de.jeanlucmakiola.calendula.ui.onboarding
 
 import de.jeanlucmakiola.floret.components.BenefitRow
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
@@ -10,19 +10,15 @@ import android.net.Uri
 import android.provider.Settings
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowForward
 import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material.icons.filled.Lock
-import androidx.compose.material.icons.filled.VisibilityOff
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Icon
@@ -32,13 +28,11 @@ import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
@@ -52,6 +46,7 @@ private val CALENDAR_PERMISSIONS = arrayOf(
 fun PermissionScreen(
     onGranted: () -> Unit,
     modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
     viewModel: PermissionViewModel = hiltViewModel(),
 ) {
     val state by viewModel.state.collectAsStateWithLifecycle()
@@ -76,6 +71,7 @@ fun PermissionScreen(
     when (state) {
         is PermissionUiState.Rationale -> RationaleContent(
             onRequest = { launcher.launch(CALENDAR_PERMISSIONS) },
+            progress = progress,
             modifier = modifier,
         )
         is PermissionUiState.Denied -> DeniedContent(
@@ -83,6 +79,7 @@ fun PermissionScreen(
                 viewModel.onRetry()
                 launcher.launch(CALENDAR_PERMISSIONS)
             },
+            progress = progress,
             modifier = modifier,
         )
         is PermissionUiState.Granted -> {
@@ -94,11 +91,14 @@ fun PermissionScreen(
 @Composable
 private fun RationaleContent(
     onRequest: () -> Unit,
+    progress: (@Composable () -> Unit)?,
     modifier: Modifier = Modifier,
 ) {
     OnboardingScaffold(
         modifier = modifier,
-        hero = { BrandHero(denied = false) },
+        progress = progress,
+        topSpacing = OnboardingSpace.lg,
+        hero = { BrandHero() },
         actions = {
             Button(
                 onClick = onRequest,
@@ -116,16 +116,8 @@ private fun RationaleContent(
                     modifier = Modifier.size(20.dp),
                 )
             }
-            PrivacyFootnote()
         },
     ) {
-        Text(
-            text = stringResource(R.string.app_name).uppercase(),
-            style = MaterialTheme.typography.labelLarge,
-            color = MaterialTheme.colorScheme.primary,
-            letterSpacing = 2.sp,
-        )
-        Spacer(Modifier.height(OnboardingSpace.xs))
         Text(
             text = stringResource(R.string.permission_rationale_title),
             style = MaterialTheme.typography.headlineMedium,
@@ -139,14 +131,8 @@ private fun RationaleContent(
             textAlign = TextAlign.Center,
         )
 
-        Spacer(Modifier.height(OnboardingSpace.xl))
+        Spacer(Modifier.height(OnboardingSpace.lg))
 
-        BenefitRow(
-            icon = Icons.Filled.Lock,
-            title = stringResource(R.string.permission_benefit_private_title),
-            body = stringResource(R.string.permission_benefit_private_body),
-        )
-        Spacer(Modifier.height(OnboardingSpace.sm))
         BenefitRow(
             icon = Icons.Filled.CalendarMonth,
             title = stringResource(R.string.permission_benefit_sync_title),
@@ -154,9 +140,9 @@ private fun RationaleContent(
         )
         Spacer(Modifier.height(OnboardingSpace.sm))
         BenefitRow(
-            icon = Icons.Filled.VisibilityOff,
-            title = stringResource(R.string.permission_benefit_privacy_title),
-            body = stringResource(R.string.permission_benefit_privacy_body),
+            icon = Icons.Filled.Lock,
+            title = stringResource(R.string.permission_benefit_private_title),
+            body = stringResource(R.string.permission_benefit_private_body),
         )
     }
 }
@@ -164,12 +150,14 @@ private fun RationaleContent(
 @Composable
 private fun DeniedContent(
     onRetry: () -> Unit,
+    progress: (@Composable () -> Unit)?,
     modifier: Modifier = Modifier,
 ) {
     val context = LocalContext.current
     OnboardingScaffold(
         modifier = modifier,
-        hero = { BrandHero(denied = true) },
+        progress = progress,
+        hero = { BrandHero(HeroBadge.Denied) },
         actions = {
             Button(
                 onClick = {
@@ -208,25 +196,3 @@ private fun DeniedContent(
         )
     }
 }
-
-@Composable
-private fun PrivacyFootnote() {
-    Row(
-        modifier = Modifier.fillMaxWidth().padding(top = 4.dp),
-        horizontalArrangement = Arrangement.Center,
-        verticalAlignment = Alignment.CenterVertically,
-    ) {
-        Icon(
-            imageVector = Icons.Filled.Lock,
-            contentDescription = null,
-            tint = MaterialTheme.colorScheme.onSurfaceVariant,
-            modifier = Modifier.size(14.dp),
-        )
-        Spacer(Modifier.width(6.dp))
-        Text(
-            text = stringResource(R.string.permission_privacy_footnote),
-            style = MaterialTheme.typography.labelMedium,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-        )
-    }
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/PermissionUiState.kt

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.calendula.ui.permission
+package de.jeanlucmakiola.calendula.ui.onboarding
 
 sealed interface PermissionUiState {
     data object Rationale : PermissionUiState

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

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.calendula.ui.permission
+package de.jeanlucmakiola.calendula.ui.onboarding
 
 import androidx.lifecycle.ViewModel
 import dagger.hilt.android.lifecycle.HiltViewModel

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/ReminderStep.kt

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.calendula.ui.permission
+package de.jeanlucmakiola.calendula.ui.onboarding
 
 import de.jeanlucmakiola.floret.components.BenefitRow
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
@@ -8,34 +8,25 @@ import android.Manifest
 import android.os.Build
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.NotificationsActive
 import androidx.compose.material.icons.filled.ContentCopy
-import androidx.compose.material.icons.filled.Tune
 import androidx.compose.material3.Button
-import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
 import de.jeanlucmakiola.calendula.R
 
 /**
- * One-time onboarding step after the calendar grant (v1.4): explains that
+ * Wizard step after the calendar grant (v1.4): explains that
  * Calendula delivers reminder notifications itself, warns about duplicates
  * when a second calendar app has notifications on, and requests
  * `POST_NOTIFICATIONS` (a system dialog on API 33+ only; minSdk is 29).
@@ -45,9 +36,11 @@ import de.jeanlucmakiola.calendula.R
  * the Settings toggle re-requests it. "Not now" turns the in-app toggle off.
  */
 @Composable
-fun ReminderOnboardingScreen(
+fun ReminderStep(
     onFinished: (remindersEnabled: Boolean) -> Unit,
     modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
 ) {
     val launcher = rememberLauncherForActivityResult(
         contract = ActivityResultContracts.RequestPermission(),
@@ -55,7 +48,10 @@ fun ReminderOnboardingScreen(
 
     OnboardingScaffold(
         modifier = modifier,
-        hero = { BellHero() },
+        progress = progress,
+        navigationIcon = navigationIcon,
+        topSpacing = OnboardingSpace.lg,
+        hero = { IconHero(Icons.Filled.NotificationsActive) },
         actions = {
             Button(
                 onClick = {
@@ -80,13 +76,6 @@ fun ReminderOnboardingScreen(
             }
         },
     ) {
-        Text(
-            text = stringResource(R.string.app_name).uppercase(),
-            style = MaterialTheme.typography.labelLarge,
-            color = MaterialTheme.colorScheme.primary,
-            letterSpacing = 2.sp,
-        )
-        Spacer(Modifier.height(OnboardingSpace.xs))
         Text(
             text = stringResource(R.string.reminder_onboarding_title),
             style = MaterialTheme.typography.headlineMedium,
@@ -100,7 +89,7 @@ fun ReminderOnboardingScreen(
             textAlign = TextAlign.Center,
         )
 
-        Spacer(Modifier.height(OnboardingSpace.xl))
+        Spacer(Modifier.height(OnboardingSpace.lg))
 
         BenefitRow(
             icon = Icons.Filled.NotificationsActive,
@@ -113,30 +102,5 @@ fun ReminderOnboardingScreen(
             title = stringResource(R.string.reminder_benefit_duplicates_title),
             body = stringResource(R.string.reminder_benefit_duplicates_body),
         )
-        Spacer(Modifier.height(OnboardingSpace.sm))
-        BenefitRow(
-            icon = Icons.Filled.Tune,
-            title = stringResource(R.string.reminder_benefit_reversible_title),
-            body = stringResource(R.string.reminder_benefit_reversible_body),
-        )
-    }
-}
-
-/** A bell in the brand squircle — same silhouette as the permission hero. */
-@Composable
-private fun BellHero() {
-    Box(
-        modifier = Modifier
-            .size(128.dp)
-            .clip(RoundedCornerShape(34.dp))
-            .background(MaterialTheme.colorScheme.primaryContainer),
-        contentAlignment = Alignment.Center,
-    ) {
-        Icon(
-            imageVector = Icons.Filled.NotificationsActive,
-            contentDescription = null,
-            tint = MaterialTheme.colorScheme.onPrimaryContainer,
-            modifier = Modifier.size(56.dp),
-        )
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/ViewStep.kt

@@ -0,0 +1,209 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaViewPreview
+import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.common.ViewPreviewFrame
+import de.jeanlucmakiola.calendula.ui.common.icon
+import de.jeanlucmakiola.calendula.ui.common.labelRes
+import de.jeanlucmakiola.calendula.ui.day.DayViewPreview
+import de.jeanlucmakiola.calendula.ui.month.MonthStylePreview
+import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
+import de.jeanlucmakiola.calendula.ui.month.descriptionRes
+import de.jeanlucmakiola.calendula.ui.month.labelRes
+import de.jeanlucmakiola.calendula.ui.week.WeekViewPreview
+import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.OnboardingScaffold
+import de.jeanlucmakiola.floret.components.OnboardingSpace
+import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.locale.currentLocale
+
+/**
+ * Wizard step: which view the app opens on (#163). Built like the Settings
+ * picker it mirrors — a live preview over connected grouped rows. Selecting
+ * applies immediately and leaves the step open; the preview is the confirmation.
+ */
+@Composable
+internal fun ViewStep(
+    choice: ViewChoice,
+    onSelect: (CalendarView) -> Unit,
+    onFinished: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+) {
+    val weekStart = choice.weekStart.resolveFirstDay(currentLocale())
+
+    StepPickerScaffold(
+        title = stringResource(R.string.onboarding_view_title),
+        onFinished = onFinished,
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+    ) {
+        StepPreview(selected = choice.defaultView) { view ->
+            when (view) {
+                CalendarView.Month -> MonthStylePreview(
+                    style = choice.monthViewStyle,
+                    weekStart = weekStart,
+                    height = PREVIEW_HEIGHT,
+                )
+                CalendarView.Week -> WeekViewPreview(weekStart = weekStart, height = PREVIEW_HEIGHT)
+                CalendarView.Day -> DayViewPreview(height = PREVIEW_HEIGHT)
+                CalendarView.Agenda -> AgendaViewPreview(height = PREVIEW_HEIGHT)
+            }
+        }
+        IMPLEMENTED_VIEWS.forEachIndexed { index, view ->
+            val isSelected = view == choice.defaultView
+            GroupedRow(
+                title = stringResource(view.labelRes),
+                position = positionOf(index, IMPLEMENTED_VIEWS.size),
+                selected = isSelected,
+                leading = {
+                    Icon(
+                        imageVector = view.icon,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                },
+                trailing = if (isSelected) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
+                onClick = { onSelect(view) },
+            )
+        }
+    }
+}
+
+/**
+ * Wizard step: how the Month view lays itself out (#163). The same shape as
+ * [ViewStep] and as the Settings chooser this duplicates, down to the selected
+ * style's own blurb sitting under its preview rather than on every row.
+ */
+@Composable
+internal fun MonthStyleStep(
+    choice: ViewChoice,
+    onSelect: (MonthViewStyle) -> Unit,
+    onFinished: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+) {
+    val weekStart = choice.weekStart.resolveFirstDay(currentLocale())
+    val options = MonthViewStyle.entries
+
+    StepPickerScaffold(
+        title = stringResource(R.string.onboarding_month_style_title),
+        onFinished = onFinished,
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+    ) {
+        StepPreview(selected = choice.monthViewStyle) { style ->
+            MonthStylePreview(style = style, weekStart = weekStart, height = PREVIEW_HEIGHT)
+        }
+        PickerDescription(stringResource(choice.monthViewStyle.descriptionRes))
+        options.forEachIndexed { index, style ->
+            val isSelected = style == choice.monthViewStyle
+            GroupedRow(
+                title = stringResource(style.labelRes),
+                position = positionOf(index, options.size),
+                selected = isSelected,
+                trailing = if (isSelected) {
+                    { SelectedCheck() }
+                } else {
+                    null
+                },
+                onClick = { onSelect(style) },
+            )
+        }
+    }
+}
+
+/**
+ * The shell both picker steps share: the wizard chrome around a title and a
+ * full-bleed column, since grouped rows carry their own inset.
+ */
+@Composable
+private fun StepPickerScaffold(
+    title: String,
+    onFinished: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+    body: @Composable ColumnScope.() -> Unit,
+) {
+    OnboardingScaffold(
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+        topSpacing = OnboardingSpace.xs,
+        contentPadding = 0.dp,
+        // The preview gets the room it needs; Continue scrolls in under the
+        // options rather than pinning to the bottom.
+        scrollingActions = true,
+        hero = {
+            Text(
+                text = title,
+                style = MaterialTheme.typography.headlineSmall,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = GroupedListInset),
+            )
+        },
+        actions = {
+            Button(
+                onClick = onFinished,
+                // Full-bleed step: the button takes the grouped rows' own inset
+                // and ends up as wide as the options above it.
+                modifier = Modifier
+                    .padding(horizontal = GroupedListInset)
+                    .fillMaxWidth()
+                    .height(56.dp),
+            ) {
+                Text(
+                    text = stringResource(R.string.onboarding_view_continue_button),
+                    style = MaterialTheme.typography.titleMedium,
+                )
+            }
+        },
+        body = body,
+    )
+}
+
+/**
+ * The live preview, framed like the picker's. The wider gap below keeps the rows
+ * reading as a group of their own rather than as the preview's caption.
+ */
+@Composable
+private fun <T> StepPreview(selected: T, content: @Composable (T) -> Unit) {
+    ViewPreviewFrame(
+        selected = selected,
+        label = "step-preview",
+        modifier = Modifier.padding(top = OnboardingSpace.xs, bottom = OnboardingSpace.md),
+        content = content,
+    )
+}
+
+/** The same size the Settings chooser gives it. */
+private val PREVIEW_HEIGHT: Dp = 280.dp

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/VisibilityStep.kt

@@ -0,0 +1,65 @@
+package de.jeanlucmakiola.calendula.ui.onboarding
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.OnboardingScaffold
+import de.jeanlucmakiola.floret.components.OnboardingSpace
+
+/**
+ * Wizard step for the one-time notice that Calendula now follows the device's
+ * own per-calendar visibility and some of yours are switched off (#75, #163).
+ *
+ * Nothing to decide here — the app does not switch those calendars back on,
+ * since that would un-hide them everywhere else too.
+ */
+@Composable
+internal fun VisibilityStep(
+    onFinished: () -> Unit,
+    modifier: Modifier = Modifier,
+    progress: (@Composable () -> Unit)? = null,
+    navigationIcon: (@Composable () -> Unit)? = null,
+) {
+    OnboardingScaffold(
+        modifier = modifier,
+        progress = progress,
+        navigationIcon = navigationIcon,
+        topSpacing = OnboardingSpace.lg,
+        hero = { IconHero(Icons.Filled.VisibilityOff) },
+        actions = {
+            Button(
+                onClick = onFinished,
+                modifier = Modifier.fillMaxWidth().height(56.dp),
+            ) {
+                Text(
+                    text = stringResource(R.string.onboarding_visibility_button),
+                    style = MaterialTheme.typography.titleMedium,
+                )
+            }
+        },
+    ) {
+        Text(
+            text = stringResource(R.string.calendars_visibility_notice_title),
+            style = MaterialTheme.typography.headlineMedium,
+            textAlign = TextAlign.Center,
+        )
+        Spacer(Modifier.height(12.dp))
+        Text(
+            text = stringResource(R.string.calendars_visibility_notice_message),
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+        )
+    }
+}

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

@@ -1,53 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.permission
-
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
-import dagger.hilt.android.lifecycle.HiltViewModel
-import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
-import de.jeanlucmakiola.calendula.data.reminders.ReminderScanner
-import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
-import kotlinx.coroutines.launch
-import javax.inject.Inject
-
-/**
- * Gates the one-time reminder onboarding step (v1.4) shown after the calendar
- * grant. [onboardingDone] is null until DataStore's first emission so the
- * step neither flashes for users who completed it nor gets skipped.
- */
-@HiltViewModel
-class ReminderOnboardingViewModel @Inject constructor(
-    private val prefs: SettingsPrefs,
-    private val scanner: ReminderScanner,
-) : ViewModel() {
-
-    val onboardingDone: StateFlow<Boolean?> = prefs.reminderOnboardingDone
-        .map { done -> done as Boolean? }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = null,
-        )
-
-    /** Close the step, recording whether reminder notifications stay on. */
-    fun finish(remindersEnabled: Boolean) {
-        viewModelScope.launch {
-            prefs.setRemindersEnabled(remindersEnabled)
-            prefs.setReminderOnboardingDone()
-            // Nothing else re-arms the scan: turning reminders off cancels the
-            // alarm (#75).
-            scanner.scan()
-        }
-    }
-
-    /**
-     * Re-scan after the calendar permission is granted. The launch scan runs
-     * before the grant and bails out without arming anything, so without this
-     * the first alarm waits on the daily worker.
-     */
-    fun rearmAfterGrant() {
-        scanner.scanInBackground()
-    }
-}

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

@@ -1,67 +1,108 @@
 package de.jeanlucmakiola.calendula.ui.search
 
+import android.Manifest
+import android.content.pm.PackageManager
+import androidx.activity.compose.BackHandler
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.animateColorAsState
 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.PaddingValues
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.Close
+import androidx.compose.material.icons.filled.Delete
 import androidx.compose.material.icons.filled.SearchOff
+import androidx.compose.material.icons.filled.SelectAll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Checkbox
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalSoftwareKeyboardController
+import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardCapitalization
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
+import androidx.core.content.ContextCompat
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.MatchSpan
+import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
+import de.jeanlucmakiola.calendula.domain.SearchHit
+import de.jeanlucmakiola.calendula.domain.SearchMonth
 import de.jeanlucmakiola.floret.identity.animateItemMotion
+import de.jeanlucmakiola.floret.identity.fadeThrough
 import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.InlineTextField
 import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.SnackChip
+import de.jeanlucmakiola.floret.components.SnackChipHeight
+import de.jeanlucmakiola.floret.components.SnackChipMargin
 import de.jeanlucmakiola.floret.locale.currentLocale
+import de.jeanlucmakiola.floret.locale.localizedDateFormatter
+import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
+import de.jeanlucmakiola.calendula.ui.common.RecurringScopeDialog
 import de.jeanlucmakiola.calendula.ui.common.eventAccent
 import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.calendula.domain.spanFirstDay
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
 import de.jeanlucmakiola.floret.components.positionOf
+import kotlinx.coroutines.delay
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toJavaLocalDate
 import java.time.Instant as JavaInstant
@@ -69,11 +110,13 @@ import java.time.ZoneId
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
 
+/** How long the delete confirmation chip stays up, matching a short snackbar. */
+private const val CHIP_MILLIS = 4_000L
+
 /**
- * Full-text event search (top-bar entry). Type a query → matching events
- * (title / location / description) across the whole calendar, newest-relevant
- * first; tap a result to open its detail. A full-screen overlay hosted by
- * [de.jeanlucmakiola.calendula.ui.CalendarHost].
+ * Full-text event search over title / location / description: tap a result to
+ * open its detail, long-press to select several and delete them at once (#80).
+ * A full-screen overlay hosted by [de.jeanlucmakiola.calendula.ui.CalendarHost].
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -85,63 +128,79 @@ fun SearchScreen(
 ) {
     val query by viewModel.query.collectAsStateWithLifecycle()
     val state by viewModel.state.collectAsStateWithLifecycle()
+    val selection by viewModel.selection.collectAsStateWithLifecycle()
+    val deleteState by viewModel.deleteState.collectAsStateWithLifecycle()
     val focusRequester = remember { FocusRequester() }
     val keyboard = LocalSoftwareKeyboardController.current
+    val context = LocalContext.current
+    val inSelection = selection.isNotEmpty()
+    var showDeleteDialog by remember { mutableStateOf(false) }
 
-    // Each fresh open starts blank and straight into typing. The ViewModel is
-    // activity-scoped so it outlives the overlay; clearing on (re)enter is what
-    // resets a previous search. Peeking a result doesn't re-run this (the screen
-    // stays composed under the detail), so backing out keeps the query.
+    // The ViewModel is activity-scoped, so a re-enter is what resets the last
+    // search, its selection and any delete receipt still up. Peeking a result
+    // doesn't re-run this — the screen stays composed under the detail.
     LaunchedEffect(Unit) {
         viewModel.setQuery("")
+        viewModel.clearSelection()
+        viewModel.consumeDeleteResult()
+    }
+    // The field only exists out of selection mode, so a recreation that lands
+    // mid-selection has to wait for the clear above before it can be focused.
+    var focusPending by remember { mutableStateOf(true) }
+    LaunchedEffect(inSelection) {
+        if (inSelection || !focusPending) return@LaunchedEffect
+        focusPending = false
         focusRequester.requestFocus()
         keyboard?.show()
     }
+
+    // Same in-place WRITE_CALENDAR upgrade the detail screen does: a v1.0 install
+    // holds only READ_CALENDAR, and granting continues into the held delete.
+    var pendingWrite by remember { mutableStateOf<(() -> Unit)?>(null) }
+    val writePermissionLauncher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+    ) { granted ->
+        if (granted) pendingWrite?.invoke()
+        pendingWrite = null
+    }
+    val requireWrite: (() -> Unit) -> Unit = { action ->
+        val granted = ContextCompat.checkSelfPermission(
+            context,
+            Manifest.permission.WRITE_CALENDAR,
+        ) == PackageManager.PERMISSION_GRANTED
+        if (granted) {
+            action()
+        } else {
+            pendingWrite = action
+            writePermissionLauncher.launch(Manifest.permission.WRITE_CALENDAR)
+        }
+    }
+
+    // Back leaves selection mode before it leaves the screen, and without the
+    // predictive-back scale-out — that would read as search closing and snapping
+    // back. The two handlers are mutually exclusive on [inSelection].
+    BackHandler(enabled = inSelection) { viewModel.clearSelection() }
+
     Scaffold(
-        modifier = modifier.predictiveBack(onBack = onBack),
+        modifier = modifier.predictiveBack(onBack = onBack, enabled = !inSelection),
         containerColor = MaterialTheme.colorScheme.surface,
         topBar = {
-            TopAppBar(
-                title = {
-                    InlineTextField(
-                        value = query,
-                        onValueChange = viewModel::setQuery,
-                        placeholder = stringResource(R.string.search_hint),
-                        capitalization = KeyboardCapitalization.None,
-                        imeAction = ImeAction.Search,
-                        onImeAction = { keyboard?.hide() },
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .focusRequester(focusRequester),
-                    )
-                },
-                navigationIcon = {
-                    IconButton(onClick = onBack) {
-                        Icon(
-                            imageVector = Icons.AutoMirrored.Filled.ArrowBack,
-                            contentDescription = stringResource(R.string.search_back),
-                        )
-                    }
-                },
-                actions = {
-                    if (query.isNotEmpty()) {
-                        IconButton(onClick = { viewModel.setQuery("") }) {
-                            Icon(
-                                imageVector = Icons.Default.Close,
-                                contentDescription = stringResource(R.string.search_clear),
-                            )
-                        }
-                    }
-                },
-                colors = TopAppBarDefaults.topAppBarColors(
-                    containerColor = MaterialTheme.colorScheme.surface,
-                ),
+            SearchTopBar(
+                inSelection = inSelection,
+                query = query,
+                selectedCount = selection.size,
+                focusRequester = focusRequester,
+                onQueryChange = viewModel::setQuery,
+                onImeAction = { keyboard?.hide() },
+                onBack = onBack,
+                onCloseSelection = viewModel::clearSelection,
+                onSelectAll = viewModel::selectAll,
+                onDelete = { requireWrite { showDeleteDialog = true } },
             )
         },
     ) { padding ->
-        // imePadding shrinks the content by the keyboard, so the centered
-        // idle/empty message re-centres in the space above it (and the results
-        // list lifts clear of the keyboard too).
+        // imePadding so the idle/empty message re-centres above the keyboard and
+        // the results list lifts clear of it.
         Box(
             modifier = Modifier
                 .fillMaxSize()
@@ -158,52 +217,314 @@ fun SearchScreen(
                     text = stringResource(R.string.search_empty, s.query),
                 )
                 is SearchUiState.Results -> SearchResults(
-                    events = s.events,
+                    results = s,
+                    selection = selection,
+                    inSelection = inSelection,
                     onEventClick = onEventClick,
+                    onToggle = viewModel::toggleSelection,
                 )
             }
+            DeleteOutcomeChip(
+                deleteState = deleteState,
+                onConsume = viewModel::consumeDeleteResult,
+                modifier = Modifier.align(Alignment.BottomStart),
+            )
         }
     }
-}
 
-@Composable
-private fun SearchResults(
-    events: List<EventInstance>,
-    onEventClick: (EventInstance) -> Unit,
-) {
-    LazyColumn(
-        modifier = Modifier.fillMaxSize(),
-        contentPadding = PaddingValues(start = 16.dp, end = 16.dp, top = 8.dp, bottom = 96.dp),
-    ) {
-        itemsIndexed(
-            items = events,
-            key = { _, event -> event.eventId },
-        ) { index, event ->
-            SearchResultRow(
-                event = event,
-                position = positionOf(index, events.size),
-                modifier = animateItemMotion(),
-                onClick = { onEventClick(event) },
+    if (showDeleteDialog) {
+        val count = selection.size
+        // One decision for the whole batch: the scope question is only asked when
+        // a recurring event is in it, and one-offs ignore whatever comes back.
+        if (viewModel.selectionHasRecurring()) {
+            RecurringScopeDialog(
+                title = stringResource(R.string.event_delete_recurring_title),
+                onSelect = { scope ->
+                    showDeleteDialog = false
+                    viewModel.deleteSelected(scope)
+                },
+                onDismiss = { showDeleteDialog = false },
+            )
+        } else {
+            AlertDialog(
+                onDismissRequest = { showDeleteDialog = false },
+                title = {
+                    Text(pluralStringResource(R.plurals.search_delete_title, count, count))
+                },
+                text = { Text(stringResource(R.string.event_delete_body)) },
+                confirmButton = {
+                    TextButton(
+                        onClick = {
+                            showDeleteDialog = false
+                            viewModel.deleteSelected(RecurringWriteScope.AllEvents)
+                        },
+                    ) {
+                        Text(
+                            text = stringResource(R.string.event_detail_delete),
+                            color = MaterialTheme.colorScheme.error,
+                        )
+                    }
+                },
+                dismissButton = {
+                    TextButton(onClick = { showDeleteDialog = false }) {
+                        Text(stringResource(R.string.dialog_cancel))
+                    }
+                },
             )
         }
     }
 }
 
+/**
+ * The search field and the contextual selection bar as one bar: the bar stays
+ * in place across the swap, easing its colour and fading its slots through.
+ */
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+private fun SearchTopBar(
+    inSelection: Boolean,
+    query: String,
+    selectedCount: Int,
+    focusRequester: FocusRequester,
+    onQueryChange: (String) -> Unit,
+    onImeAction: () -> Unit,
+    onBack: () -> Unit,
+    onCloseSelection: () -> Unit,
+    onSelectAll: () -> Unit,
+    onDelete: () -> Unit,
+) {
+    val container by animateColorAsState(
+        targetValue = if (inSelection) {
+            MaterialTheme.colorScheme.surfaceContainerHigh
+        } else {
+            MaterialTheme.colorScheme.surface
+        },
+        animationSpec = MaterialTheme.motionScheme.fastEffectsSpec(),
+        label = "search-top-bar-color",
+    )
+    // Held past the selection emptying, so the count has something to draw while
+    // it fades out.
+    var lastCount by remember { mutableIntStateOf(0) }
+    if (selectedCount > 0) lastCount = selectedCount
+
+    // Read here so the non-composable transitionSpec lambdas can capture it.
+    val slotSwap = fadeThrough()
+
+    TopAppBar(
+        title = {
+            AnimatedContent(
+                targetState = inSelection,
+                transitionSpec = { slotSwap },
+                label = "search-top-bar-title",
+            ) { selecting ->
+                if (selecting) {
+                    Text(
+                        pluralStringResource(
+                            R.plurals.search_selected_count,
+                            lastCount,
+                            lastCount,
+                        ),
+                    )
+                } else {
+                    InlineTextField(
+                        value = query,
+                        onValueChange = onQueryChange,
+                        placeholder = stringResource(R.string.search_hint),
+                        capitalization = KeyboardCapitalization.None,
+                        imeAction = ImeAction.Search,
+                        onImeAction = onImeAction,
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .focusRequester(focusRequester),
+                    )
+                }
+            }
+        },
+        navigationIcon = {
+            AnimatedContent(
+                targetState = inSelection,
+                transitionSpec = { slotSwap },
+                label = "search-top-bar-navigation",
+            ) { selecting ->
+                if (selecting) {
+                    IconButton(onClick = onCloseSelection) {
+                        Icon(
+                            imageVector = Icons.Default.Close,
+                            contentDescription = stringResource(R.string.search_selection_close),
+                        )
+                    }
+                } else {
+                    IconButton(onClick = onBack) {
+                        Icon(
+                            imageVector = Icons.AutoMirrored.Filled.ArrowBack,
+                            contentDescription = stringResource(R.string.search_back),
+                        )
+                    }
+                }
+            }
+        },
+        actions = {
+            AnimatedContent(
+                targetState = inSelection,
+                transitionSpec = { slotSwap },
+                label = "search-top-bar-actions",
+            ) { selecting ->
+                Row {
+                    if (selecting) {
+                        IconButton(onClick = onSelectAll) {
+                            Icon(
+                                imageVector = Icons.Default.SelectAll,
+                                contentDescription = stringResource(R.string.search_select_all),
+                            )
+                        }
+                        IconButton(onClick = onDelete) {
+                            Icon(
+                                imageVector = Icons.Default.Delete,
+                                contentDescription = stringResource(
+                                    R.string.search_delete_selected,
+                                ),
+                                tint = MaterialTheme.colorScheme.error,
+                            )
+                        }
+                    } else if (query.isNotEmpty()) {
+                        IconButton(onClick = { onQueryChange("") }) {
+                            Icon(
+                                imageVector = Icons.Default.Close,
+                                contentDescription = stringResource(R.string.search_clear),
+                            )
+                        }
+                    }
+                }
+            }
+        },
+        colors = TopAppBarDefaults.topAppBarColors(containerColor = container),
+    )
+}
+
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+private fun SearchResults(
+    results: SearchUiState.Results,
+    selection: Set<Long>,
+    inSelection: Boolean,
+    onEventClick: (EventInstance) -> Unit,
+    onToggle: (Long) -> Unit,
+) {
+    LazyColumn(
+        modifier = Modifier.fillMaxSize(),
+        // No horizontal inset: GroupedRow already insets itself.
+        contentPadding = PaddingValues(top = 8.dp, bottom = 96.dp),
+    ) {
+        results.results.months.forEach { month ->
+            stickyHeader(key = "month-${month.year}-${month.monthNumber}") {
+                SearchSectionHeader(text = monthLabel(month))
+            }
+            hitRows(month.hits, results, selection, inSelection, onEventClick, onToggle)
+        }
+        // Held back from the calendar above: matched only in the notes.
+        if (results.results.inDescriptions.isNotEmpty()) {
+            stickyHeader(key = "in-descriptions") {
+                SearchSectionHeader(text = stringResource(R.string.search_in_descriptions))
+            }
+            hitRows(
+                results.results.inDescriptions,
+                results,
+                selection,
+                inSelection,
+                onEventClick,
+                onToggle,
+            )
+        }
+    }
+}
+
+/** One section's rows, sharing a grouped-card run. */
+private fun LazyListScope.hitRows(
+    hits: List<SearchHit>,
+    results: SearchUiState.Results,
+    selection: Set<Long>,
+    inSelection: Boolean,
+    onEventClick: (EventInstance) -> Unit,
+    onToggle: (Long) -> Unit,
+) {
+    itemsIndexed(
+        items = hits,
+        key = { _, hit -> hit.event.eventId },
+    ) { index, hit ->
+        val event = hit.event
+        val deletable = results.isDeletable(event)
+        SearchResultRow(
+            hit = hit,
+            position = positionOf(index, hits.size),
+            modifier = animateItemMotion(),
+            selected = event.eventId in selection,
+            // A read-only calendar's row can't join a batch, so in selection
+            // mode it goes quiet rather than offering a checkbox that fails.
+            inSelection = inSelection,
+            selectable = deletable,
+            onClick = when {
+                inSelection && deletable -> ({ onToggle(event.eventId) })
+                inSelection -> null
+                else -> ({ onEventClick(event) })
+            },
+            onLongClick = { onToggle(event.eventId) }.takeIf { deletable && !inSelection },
+        )
+    }
+}
+
+/** Pinned section label, styled like the agenda's day headers. */
+@Composable
+private fun SearchSectionHeader(text: String) {
+    Surface(color = MaterialTheme.colorScheme.surface, modifier = Modifier.fillMaxWidth()) {
+        Text(
+            text = text,
+            style = MaterialTheme.typography.titleSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(start = 28.dp, end = 28.dp, top = 16.dp, bottom = 8.dp),
+        )
+    }
+}
+
+/** "August 2026" in the locale's own field order. */
+@Composable
+private fun monthLabel(month: SearchMonth): String {
+    val locale = currentLocale()
+    return remember(month.year, month.monthNumber, locale) {
+        localizedDateFormatter(locale, "LLLLy")
+            .format(java.time.LocalDate.of(month.year, month.monthNumber, 1))
+    }
+}
+
 @Composable
 private fun SearchResultRow(
-    event: EventInstance,
+    hit: SearchHit,
     position: Position,
     modifier: Modifier = Modifier,
-    onClick: () -> Unit,
+    selected: Boolean = false,
+    inSelection: Boolean = false,
+    selectable: Boolean = true,
+    onClick: (() -> Unit)?,
+    onLongClick: (() -> Unit)? = null,
 ) {
+    val event = hit.event
     val dark = isSystemInDarkTheme()
     val soften = LocalSoftenColors.current
+    // On a picked row the headline is already recoloured for the secondary
+    // container, so the match is carried by weight alone there.
+    val highlight = SpanStyle(
+        fontWeight = FontWeight.Bold,
+        color = if (selected) Color.Unspecified else MaterialTheme.colorScheme.primary,
+    )
     GroupedRow(
-        modifier = modifier,
-        title = event.title,
-        summary = searchSummary(event),
+        // Faded like a past event anywhere else in the app — search reaches back
+        // through the whole history.
+        modifier = if (hit.isPast) modifier.alpha(EventDimAlpha) else modifier,
+        title = marked(event.title, hit.titleSpans, highlight),
+        summary = searchSummary(hit, highlight),
         position = position,
         minHeight = 64.dp,
+        selected = selected,
+        dimmed = inSelection && !selectable,
         leading = {
             Box(
                 modifier = Modifier
@@ -212,21 +533,97 @@ private fun SearchResultRow(
                     .background(eventAccent(event.color, dark, soften)),
             )
         },
+        trailing = if (inSelection && selectable) {
+            {
+                Checkbox(
+                    checked = selected,
+                    onCheckedChange = null,
+                )
+            }
+        } else {
+            null
+        },
         onClick = onClick,
+        onLongClick = onLongClick,
     )
 }
 
-/** "Wed, 17 Jun 2026 · 09:00 · Office" — date, then time (or All day), then location. */
+/**
+ * The batch's receipt: how many went, and whether any refused. No Undo — the
+ * provider can't put a deleted event back.
+ */
 @Composable
-private fun searchSummary(event: EventInstance): String {
+private fun DeleteOutcomeChip(
+    deleteState: BulkDeleteUiState,
+    onConsume: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val message = when (deleteState) {
+        is BulkDeleteUiState.Done -> when {
+            deleteState.failed > 0 -> stringResource(
+                R.string.search_delete_partial,
+                deleteState.deleted,
+                deleteState.failed,
+            )
+            else -> pluralStringResource(
+                R.plurals.search_delete_done,
+                deleteState.deleted,
+                deleteState.deleted,
+            )
+        }
+        is BulkDeleteUiState.NeedsPermission -> if (deleteState.deleted > 0) {
+            stringResource(R.string.search_delete_denied_partial, deleteState.deleted)
+        } else {
+            stringResource(R.string.event_delete_write_denied)
+        }
+        else -> null
+    }
+    // Held past the state being consumed so the chip has something to draw while
+    // it springs back out.
+    val shown = remember { mutableStateOf("") }
+    if (message != null && shown.value != message) shown.value = message
+
+    LaunchedEffect(deleteState) {
+        if (message == null) return@LaunchedEffect
+        delay(CHIP_MILLIS)
+        onConsume()
+    }
+    Box(
+        modifier = modifier
+            .navigationBarsPadding()
+            .padding(start = SnackChipMargin, bottom = SnackChipMargin)
+            .height(SnackChipHeight),
+        contentAlignment = Alignment.CenterStart,
+    ) {
+        SnackChip(visible = message != null, message = shown.value)
+    }
+}
+
+/** [text] with every matched run emphasised. */
+private fun marked(text: String, spans: List<MatchSpan>, style: SpanStyle): AnnotatedString =
+    if (spans.isEmpty()) {
+        AnnotatedString(text)
+    } else {
+        buildAnnotatedString {
+            append(text)
+            spans.forEach { addStyle(style, it.start, it.end) }
+        }
+    }
+
+/**
+ * "Wed, 17 Jun 2026 · 09:00 · Office", with a second line excerpting the
+ * description when that is where the query matched.
+ */
+@Composable
+private fun searchSummary(hit: SearchHit, highlight: SpanStyle): AnnotatedString {
+    val event = hit.event
     val locale = currentLocale()
     val zone = remember { ZoneId.systemDefault() }
     val start = remember(event.start, zone) {
         JavaInstant.ofEpochMilli(event.start.toEpochMilliseconds()).atZone(zone)
     }
-    // From the shared span rule, not [start]: an all-day event sits at UTC
-    // midnight and would name the day before west of UTC (#82). The clock time
-    // below stays device-zone — it is only rendered for timed events.
+    // From the span rule, not [start]: an all-day event sits at UTC midnight and
+    // would name the day before west of UTC (#82).
     val dateText = remember(event.start, event.end, event.isAllDay, locale) {
         DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
             .format(event.spanFirstDay(TimeZone.currentSystemDefault()).toJavaLocalDate())
@@ -237,8 +634,23 @@ private fun searchSummary(event: EventInstance): String {
     } else {
         remember(locale, use24Hour) { timeOfDayFormatter(use24Hour, locale) }.format(start)
     }
-    val base = "$dateText · $timeText"
-    return event.location?.takeIf { it.isNotBlank() }?.let { "$base · $it" } ?: base
+    return buildAnnotatedString {
+        append("$dateText · $timeText")
+        event.location?.takeIf { it.isNotBlank() }?.let { location ->
+            append(" · ")
+            val offset = length
+            append(location)
+            hit.locationSpans.forEach {
+                addStyle(highlight, offset + it.start, offset + it.end)
+            }
+        }
+        hit.descriptionSnippet?.let { snippet ->
+            append("\n")
+            val offset = length
+            append(snippet.text)
+            snippet.spans.forEach { addStyle(highlight, offset + it.start, offset + it.end) }
+        }
+    }
 }
 
 @Composable

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

@@ -6,6 +6,10 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.EventSearch
+import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
+import de.jeanlucmakiola.calendula.domain.SearchResults
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.FlowPreview
@@ -14,12 +18,19 @@ 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.debounce
 import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.mapLatest
 import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atStartOfDayIn
+import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Clock
 import javax.inject.Inject
 
@@ -33,8 +44,30 @@ sealed interface SearchUiState {
     /** A query ran but matched nothing. */
     data class Empty(val query: String) : SearchUiState
 
-    /** Matches, ordered nearest-to-today first (upcoming ascending, then past descending). */
-    data class Results(val events: List<EventInstance>) : SearchUiState
+    /** Matches by month — see [de.jeanlucmakiola.calendula.domain.EventSearch]. */
+    data class Results(
+        val results: SearchResults,
+        /** Rows from these are kept out of selection rather than failing later. */
+        val readOnlyCalendarIds: Set<Long> = emptySet(),
+    ) : SearchUiState {
+        val events: List<EventInstance> get() = results.allHits.map { it.event }
+
+        fun isDeletable(event: EventInstance): Boolean =
+            event.calendarId !in readOnlyCalendarIds
+    }
+}
+
+/** Outcome of deleting the selected results (#80). */
+sealed interface BulkDeleteUiState {
+    data object Idle : BulkDeleteUiState
+
+    data object Deleting : BulkDeleteUiState
+
+    /** Terminal: [deleted] events went, [failed] wouldn't. */
+    data class Done(val deleted: Int, val failed: Int) : BulkDeleteUiState
+
+    /** WRITE_CALENDAR was revoked after [deleted] went; the rest wasn't tried. */
+    data class NeedsPermission(val deleted: Int) : BulkDeleteUiState
 }
 
 @OptIn(ExperimentalCoroutinesApi::class, FlowPreview::class)
@@ -47,17 +80,42 @@ class SearchViewModel @Inject constructor(
     private val _query = MutableStateFlow("")
     val query: StateFlow<String> = _query.asStateFlow()
 
-    val state: StateFlow<SearchUiState> = _query
-        .debounce(250L)
-        .map { it.trim() }
-        .distinctUntilChanged()
+    /** Bumped after a delete so the same query re-runs against the changed provider. */
+    private val _reload = MutableStateFlow(0)
+
+    private val _selection = MutableStateFlow<Set<Long>>(emptySet())
+
+    /** Event ids picked in selection mode; empty means the mode is off. */
+    val selection: StateFlow<Set<Long>> = _selection.asStateFlow()
+
+    private val _deleteState = MutableStateFlow<BulkDeleteUiState>(BulkDeleteUiState.Idle)
+    val deleteState: StateFlow<BulkDeleteUiState> = _deleteState.asStateFlow()
+
+    val state: StateFlow<SearchUiState> = combine(
+        _query.debounce(250L).map { it.trim() }.distinctUntilChanged(),
+        _reload,
+    ) { q, _ -> q }
         .mapLatest { q ->
             if (q.length < MIN_QUERY_LENGTH) {
                 SearchUiState.Idle
             } else {
-                val results = repository.searchEvents(q)
-                if (results.isEmpty()) SearchUiState.Empty(q)
-                else SearchUiState.Results(sortNearestFirst(results))
+                val now = Clock.System.now()
+                val zone = TimeZone.currentSystemDefault()
+                val results = EventSearch.search(
+                    candidates = repository.searchEvents(q),
+                    query = q,
+                    now = now,
+                    todayStart = now.toLocalDateTime(zone).date.atStartOfDayIn(zone),
+                    zone = zone,
+                )
+                if (results.isEmpty) {
+                    SearchUiState.Empty(q)
+                } else {
+                    SearchUiState.Results(
+                        results = results,
+                        readOnlyCalendarIds = readOnlyCalendarIds(),
+                    )
+                }
             }
         }
         .catch { emit(SearchUiState.Idle) }
@@ -65,13 +123,94 @@ class SearchViewModel @Inject constructor(
         .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000L), SearchUiState.Idle)
 
     fun setQuery(value: String) {
+        if (value != _query.value) _selection.value = emptySet()
         _query.value = value
     }
 
-    /** Soonest upcoming (and ongoing) first, then the most recent past. */
-    private fun sortNearestFirst(events: List<EventInstance>): List<EventInstance> {
-        val now = Clock.System.now()
-        val (upcoming, past) = events.partition { it.end >= now }
-        return upcoming.sortedBy { it.start } + past.sortedByDescending { it.start }
+    /** Toggle one result; the first pick is what turns selection mode on. */
+    fun toggleSelection(eventId: Long) {
+        val current = _selection.value
+        _selection.value = if (eventId in current) current - eventId else current + eventId
     }
+
+    /** Pick every result that lives in a writable calendar. */
+    fun selectAll() {
+        val results = state.value as? SearchUiState.Results ?: return
+        _selection.value = results.events.filter(results::isDeletable).map { it.eventId }.toSet()
+    }
+
+    /** Leave selection mode. */
+    fun clearSelection() {
+        _selection.value = emptySet()
+    }
+
+    /** Whether the batch needs a [RecurringWriteScope] decision before it runs. */
+    fun selectionHasRecurring(): Boolean {
+        val results = state.value as? SearchUiState.Results ?: return false
+        val picked = _selection.value
+        return results.events.any { it.eventId in picked && it.isRecurring }
+    }
+
+    /**
+     * Delete every selected event. [scope] reaches the recurring ones only; a
+     * one-off always goes whole. One at a time, so a single failure doesn't take
+     * the rest with it — the tally lands in [deleteState].
+     */
+    fun deleteSelected(scope: RecurringWriteScope) {
+        if (_deleteState.value == BulkDeleteUiState.Deleting) return
+        val results = state.value as? SearchUiState.Results ?: return
+        val picked = _selection.value
+        val targets = results.events.filter { it.eventId in picked && results.isDeletable(it) }
+        if (targets.isEmpty()) return
+
+        viewModelScope.launch {
+            _deleteState.value = BulkDeleteUiState.Deleting
+            var deleted = 0
+            var failed = 0
+            var denied = false
+            for (event in targets) {
+                try {
+                    withContext(io) { deleteOne(event, scope) }
+                    deleted++
+                } catch (e: CancellationException) {
+                    throw e
+                } catch (e: SecurityException) {
+                    denied = true
+                    break
+                } catch (e: Exception) {
+                    failed++
+                }
+            }
+            _selection.value = emptySet()
+            _reload.value += 1
+            _deleteState.value = if (denied) {
+                BulkDeleteUiState.NeedsPermission(deleted = deleted)
+            } else {
+                BulkDeleteUiState.Done(deleted = deleted, failed = failed)
+            }
+        }
+    }
+
+    /** Reset [deleteState] after the screen showed the outcome. */
+    fun consumeDeleteResult() {
+        _deleteState.value = BulkDeleteUiState.Idle
+    }
+
+    private suspend fun deleteOne(event: EventInstance, scope: RecurringWriteScope) {
+        val begin = event.start.toEpochMilliseconds()
+        when {
+            !event.isRecurring -> repository.deleteEvent(event.eventId)
+            scope == RecurringWriteScope.ThisEvent ->
+                repository.deleteOccurrence(event.eventId, begin)
+            scope == RecurringWriteScope.ThisAndFollowing ->
+                repository.deleteEventFromOccurrence(event.eventId, begin)
+            else -> repository.deleteEvent(event.eventId)
+        }
+    }
+
+    private suspend fun readOnlyCalendarIds(): Set<Long> =
+        repository.calendars().first()
+            .filterNot { it.canModifyContents }
+            .map { it.id }
+            .toSet()
 }

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

@@ -1,24 +1,13 @@
 package de.jeanlucmakiola.calendula.ui.settings
 
-import androidx.compose.animation.Crossfade
-import androidx.compose.animation.core.snap
-import androidx.compose.animation.core.tween
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.common.ViewPreviewFrame
 import de.jeanlucmakiola.calendula.ui.month.MonthStylePreview
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.calendula.ui.month.descriptionRes
@@ -27,7 +16,6 @@ import de.jeanlucmakiola.floret.components.FullScreenPicker
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.SelectedCheck
 import de.jeanlucmakiola.floret.components.positionOf
-import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 import kotlinx.datetime.DayOfWeek
 
 /**
@@ -51,39 +39,21 @@ internal fun MonthViewStylePicker(
     onDismiss: () -> Unit,
 ) {
     val options = MonthViewStyle.entries
-    val reduceMotion = rememberReduceMotion()
     FullScreenPicker(
         title = stringResource(R.string.settings_month_view_style),
         onDismiss = onDismiss,
         predictiveBack = true,
     ) {
-        Box(
-            modifier = Modifier
-                .fillMaxWidth()
-                .padding(horizontal = 12.dp, vertical = 8.dp)
-                .height(PREVIEW_HEIGHT),
-            contentAlignment = Alignment.Center,
-        ) {
-            Crossfade(
-                targetState = selected,
-                animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
-                label = "month-style-preview",
-            ) { shown ->
-                // The preview renders the real grid at phone size and scales it
-                // down, so its own corners are square — the frame rounds it.
-                Box(
-                    modifier = Modifier
-                        .clip(PREVIEW_SHAPE)
-                        .background(MaterialTheme.colorScheme.surface)
-                        .clipToBounds(),
-                ) {
-                    MonthStylePreview(
-                        style = shown,
-                        weekStart = weekStart,
-                        height = PREVIEW_HEIGHT,
-                    )
-                }
-            }
+        ViewPreviewFrame(
+            selected = selected,
+            label = "month-style-preview",
+            modifier = Modifier.padding(vertical = 8.dp),
+        ) { shown ->
+            MonthStylePreview(
+                style = shown,
+                weekStart = weekStart,
+                height = PREVIEW_HEIGHT,
+            )
         }
         // The selected style's own blurb lives here, under its preview, rather
         // than on every row — the rows stay single-line and dense, and the words
@@ -109,4 +79,3 @@ internal fun MonthViewStylePicker(
 }
 
 private val PREVIEW_HEIGHT = 280.dp
-private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

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

@@ -1,33 +1,21 @@
 package de.jeanlucmakiola.calendula.ui.settings
 
-import androidx.compose.animation.Crossfade
-import androidx.compose.animation.core.snap
-import androidx.compose.animation.core.tween
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.data.prefs.WeekStartPref
 import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
 import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.common.ViewPreviewFrame
 import de.jeanlucmakiola.calendula.ui.month.MonthStylePreview
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.floret.components.FullScreenPicker
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.SelectedCheck
 import de.jeanlucmakiola.floret.components.positionOf
-import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 import de.jeanlucmakiola.floret.locale.currentLocale
 
 /**
@@ -46,38 +34,22 @@ internal fun WeekStartPicker(
     onDismiss: () -> Unit,
 ) {
     val locale = currentLocale()
-    val reduceMotion = rememberReduceMotion()
     val resolved = selected.resolveFirstDay(locale)
     FullScreenPicker(
         title = stringResource(R.string.settings_week_start),
         onDismiss = onDismiss,
         predictiveBack = true,
     ) {
-        Box(
-            modifier = Modifier
-                .fillMaxWidth()
-                .padding(horizontal = 12.dp, vertical = 8.dp)
-                .height(PREVIEW_HEIGHT),
-            contentAlignment = Alignment.Center,
-        ) {
-            Crossfade(
-                targetState = resolved,
-                animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
-                label = "week-start-preview",
-            ) { day ->
-                Box(
-                    modifier = Modifier
-                        .clip(PREVIEW_SHAPE)
-                        .background(MaterialTheme.colorScheme.surface)
-                        .clipToBounds(),
-                ) {
-                    MonthStylePreview(
-                        style = monthStyle,
-                        weekStart = day,
-                        height = PREVIEW_HEIGHT,
-                    )
-                }
-            }
+        ViewPreviewFrame(
+            selected = resolved,
+            label = "week-start-preview",
+            modifier = Modifier.padding(vertical = 8.dp),
+        ) { day ->
+            MonthStylePreview(
+                style = monthStyle,
+                weekStart = day,
+                height = PREVIEW_HEIGHT,
+            )
         }
         PickerDescription(stringResource(R.string.settings_week_start_hint))
         options.forEachIndexed { index, option ->
@@ -107,4 +79,3 @@ internal fun WeekStartPicker(
 
 /** Short enough to leave the first options on screen under it. */
 private val PREVIEW_HEIGHT = 200.dp
-private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

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

@@ -47,6 +47,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.key
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.remember
@@ -63,13 +64,17 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.RectangleShape
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.customActions
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
@@ -85,6 +90,20 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
+import de.jeanlucmakiola.calendula.ui.common.BlockTimeLabel
+import de.jeanlucmakiola.calendula.ui.common.animatedBlockPlacement
+import de.jeanlucmakiola.calendula.ui.common.ghostAlpha
+import de.jeanlucmakiola.calendula.ui.common.LocalEventMove
+import de.jeanlucmakiola.calendula.ui.common.MoveRequest
+import de.jeanlucmakiola.calendula.ui.common.MoveTarget
+import de.jeanlucmakiola.calendula.ui.common.TimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.TimelineDragOverlay
+import de.jeanlucmakiola.calendula.ui.common.TimelineDrop
+import de.jeanlucmakiola.calendula.ui.common.beginsOn
+import de.jeanlucmakiola.calendula.ui.common.eventMoveAction
+import de.jeanlucmakiola.calendula.ui.common.rememberEventDragSource
+import de.jeanlucmakiola.calendula.ui.common.rememberTimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.startInstant
 import de.jeanlucmakiola.calendula.ui.common.LocalDimCutoff
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventFill
@@ -105,8 +124,10 @@ import de.jeanlucmakiola.calendula.ui.common.MIN_TITLE_WRAP_WIDTH
 import de.jeanlucmakiola.calendula.ui.common.SECONDARY_INK_ALPHA
 import de.jeanlucmakiola.calendula.ui.common.hourHeight
 import de.jeanlucmakiola.calendula.ui.common.rememberTimelinePinchZoom
-import de.jeanlucmakiola.calendula.ui.common.formatHourLabel
 import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
+import de.jeanlucmakiola.calendula.ui.common.GUTTER_CONTENT_START_INSET
+import de.jeanlucmakiola.calendula.ui.common.GUTTER_WIDTH
+import de.jeanlucmakiola.calendula.ui.common.HourGutter
 import de.jeanlucmakiola.calendula.ui.common.hourSeparatorLines
 import de.jeanlucmakiola.calendula.ui.common.tappedMinuteOfDay
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
@@ -123,16 +144,13 @@ import kotlin.time.Clock
 import java.time.format.TextStyle as JavaTextStyle
 import java.util.Locale
 
-private val GUTTER_WIDTH = 48.dp
-/** Start inset for the gutter's content (week badge + hour labels) so it centres
- *  on the top bar's hamburger: with a 48dp gutter, 8dp lands the centre at 28dp
- *  (the app bar's 4dp inset + 24dp half icon button). */
-private val GUTTER_CONTENT_START_INSET = 8.dp
 private val ALL_DAY_ROW_HEIGHT = 24.dp
 private val ALL_DAY_VERTICAL_PADDING = 6.dp
+/** Gap between day columns; part of the column pitch a drag maps positions through. */
+private val COLUMN_GAP = 2.dp
 
 /** Total all-day strip height for a week (0 when there are no all-day events). */
-private fun WeekUiState.Success.allDayStripHeight(): Dp {
+internal fun WeekUiState.Success.allDayStripHeight(): Dp {
     if (allDaySpans.isEmpty()) return 0.dp
     val lanes = allDaySpans.maxOf { it.lane } + 1
     return ALL_DAY_ROW_HEIGHT * lanes + ALL_DAY_VERTICAL_PADDING * 2
@@ -333,44 +351,69 @@ private fun WeekContent(
     // gestures coexist without fighting.
     val swipeModifier = rememberCalendarPageSwipe(onSwipeNext, onSwipePrev)
 
-    AnimatedContent(
-        targetState = state,
-        modifier = modifier.then(swipeModifier),
-        contentKey = { s ->
+    // Above the AnimatedContent: a page change mid-drag would strand the
+    // floating block inside the outgoing page.
+    val dragController = rememberTimelineDragController()
+    val move = LocalEventMove.current
+    val zone = remember { TimeZone.currentSystemDefault() }
+
+    Box(modifier = modifier) {
+        AnimatedContent(
+            targetState = state,
+            modifier = Modifier.fillMaxSize().then(swipeModifier),
+            contentKey = { s ->
+                when (s) {
+                    is WeekUiState.Success -> "success-${s.weekStart}"
+                    is WeekUiState.Failure -> "failure-${s.reason}"
+                    WeekUiState.Loading -> "loading"
+                }
+            },
+            transitionSpec = { calendarSlideTransition(slideDir, slideSpec, fadeSpec, reduceMotion) },
+            label = "week-transition",
+        ) { s ->
             when (s) {
-                is WeekUiState.Success -> "success-${s.weekStart}"
-                is WeekUiState.Failure -> "failure-${s.reason}"
-                WeekUiState.Loading -> "loading"
+                WeekUiState.Loading -> WeekLoading()
+                is WeekUiState.Failure -> CalendarFailure(reason = s.reason, onRetry = onRetry)
+                is WeekUiState.Success -> WeekSuccess(
+                    state = s,
+                    topSectionColor = topSectionColor,
+                    scrollState = scrollState,
+                    allDayHeight = allDayHeight,
+                    dragController = dragController,
+                    onEventClick = onEventClick,
+                    onOpenDay = onOpenDay,
+                    onCreateAt = onCreateAt,
+                    onDrop = { drop ->
+                        val took = move?.move(
+                            MoveRequest(
+                                eventId = drop.event.eventId,
+                                beginMillis = drop.event.start.toEpochMilliseconds(),
+                                endMillis = drop.event.end.toEpochMilliseconds(),
+                                target = MoveTarget.Start(drop.startInstant(zone)),
+                            ),
+                        )
+                        // Refused, so nothing will land: let the copy go now
+                        // rather than hold it out for a settle that never comes.
+                        if (took != true) dragController.release()
+                    },
+                )
             }
-        },
-        transitionSpec = { calendarSlideTransition(slideDir, slideSpec, fadeSpec, reduceMotion) },
-        label = "week-transition",
-    ) { s ->
-        when (s) {
-            WeekUiState.Loading -> WeekLoading()
-            is WeekUiState.Failure -> CalendarFailure(reason = s.reason, onRetry = onRetry)
-            is WeekUiState.Success -> WeekSuccess(
-                state = s,
-                topSectionColor = topSectionColor,
-                scrollState = scrollState,
-                allDayHeight = allDayHeight,
-                onEventClick = onEventClick,
-                onOpenDay = onOpenDay,
-                onCreateAt = onCreateAt,
-            )
         }
+        TimelineDragOverlay(dragController)
     }
 }
 
 @Composable
-private fun WeekSuccess(
+internal fun WeekSuccess(
     state: WeekUiState.Success,
     topSectionColor: Color,
     scrollState: ScrollState,
     allDayHeight: Dp,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onOpenDay: (LocalDate) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
 ) {
     Column(modifier = Modifier.fillMaxSize()) {
         Column(
@@ -387,8 +430,10 @@ private fun WeekSuccess(
         Timeline(
             state = state,
             scrollState = scrollState,
+            dragController = dragController,
             onEventClick = onEventClick,
             onCreateAt = onCreateAt,
+            onDrop = onDrop,
         )
     }
 }
@@ -624,13 +669,15 @@ private fun AllDayBar(
 private fun Timeline(
     state: WeekUiState.Success,
     scrollState: ScrollState,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
 ) {
     val dark = isSystemInDarkTheme()
-    val use24Hour = LocalUse24HourFormat.current
-    val locale = currentLocale()
     val zoom = LocalTimelineZoom.current
+    val density = LocalDensity.current
+    val isRtl = LocalLayoutDirection.current == LayoutDirection.Rtl
 
     // BoxWithConstraints rather than Box: the fit-the-whole-day scale needs the
     // timeline's own viewport height, which is only known here — below the top
@@ -650,45 +697,39 @@ private fun Timeline(
         Row(modifier = Modifier.fillMaxSize().then(pinch)) {
             // Hour gutter (scrolls in sync with the day columns). Same start inset
             // as the header badge so the labels sit under it and on the hamburger.
-            Column(
-                modifier = Modifier
-                    .width(GUTTER_WIDTH)
-                    .padding(start = GUTTER_CONTENT_START_INSET)
-                    .fillMaxHeight()
-                    .verticalScroll(scrollState),
-            ) {
-                (0 until 24).forEach { h ->
-                    Box(
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .height(hourHeight),
-                    ) {
-                        if (h > 0) {
-                            Text(
-                                text = formatHourLabel(h, use24Hour, locale),
-                                style = MaterialTheme.typography.labelSmall,
-                                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                                modifier = Modifier
-                                    .align(Alignment.TopCenter)
-                                    .offset(y = (-6).dp),
-                            )
-                        }
-                    }
-                }
-            }
+            HourGutter(
+                scrollState = scrollState,
+                hourHeight = hourHeight,
+                dragController = dragController,
+            )
             // Day columns: rounded, clipped scroll viewport (permanent corners).
             Box(
                 modifier = Modifier
                     .weight(1f)
                     .fillMaxHeight()
                     .clip(RoundedCornerShape(16.dp))
-                    .verticalScroll(scrollState),
+                    .verticalScroll(scrollState)
+                    .onGloballyPositioned { dragController.geometry.viewport = it },
             ) {
                 Row(
                     modifier = Modifier
                         .fillMaxWidth()
-                        .height(totalHeight),
-                    horizontalArrangement = Arrangement.spacedBy(2.dp),
+                        .height(totalHeight)
+                        // The scrolling content itself, so its root position
+                        // already folds in the scroll offset.
+                        .onGloballyPositioned { coords ->
+                            val gap = with(density) { COLUMN_GAP.toPx() }
+                            dragController.geometry.let {
+                                it.grid = coords
+                                it.scroll = scrollState
+                                it.hourPx = with(density) { hourHeight.toPx() }
+                                it.columnGapPx = gap
+                                it.columnWidthPx = (coords.size.width + gap) / state.days.size
+                                it.days = state.days
+                                it.isRtl = isRtl
+                            }
+                        },
+                    horizontalArrangement = Arrangement.spacedBy(COLUMN_GAP),
                 ) {
                     state.days.forEach { day ->
                         DayColumnCard(
@@ -697,8 +738,10 @@ private fun Timeline(
                             date = day,
                             today = state.today,
                             hourHeight = hourHeight,
+                            dragController = dragController,
                             onEventClick = onEventClick,
                             onCreateAt = onCreateAt,
+                            onDrop = onDrop,
                             modifier = Modifier
                                 .weight(1f)
                                 .fillMaxHeight(),
@@ -717,13 +760,19 @@ private fun DayColumnCard(
     date: LocalDate,
     today: LocalDate,
     hourHeight: Dp,
+    dragController: TimelineDragController,
     onEventClick: (EventInstance) -> Unit,
     onCreateAt: (LocalDate, Int) -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     val hourPx = with(LocalDensity.current) { hourHeight.toPx() }
     val showHourLines = LocalShowHourLines.current
     val hourLineColor = MaterialTheme.colorScheme.outlineVariant
+    // Tells a settled drop when this column has caught up with it.
+    LaunchedEffect(blocks, dragController.settling) {
+        dragController.noteGrid(date, blocks)
+    }
     // The tap detector outlives the composition that installed it — a pinch or a
     // Settings change moves the hour height without restarting it — so it reads
     // the height and the callback through state handles instead of capturing
@@ -758,23 +807,39 @@ private fun DayColumnCard(
         ) {
             val colWidth = maxWidth
             val minEventHeight = hourHeight * MIN_EVENT_FRACTION
+            // Keyed by event, so a block that changes time or lane is the *same*
+            // composable afterwards and tweens there. The ordinal disambiguates
+            // a column holding two occurrences of one series.
+            val ordinals = mutableMapOf<Long, Int>()
             blocks.forEach { block ->
-                val laneWidth = colWidth / block.laneCount
-                val top = hourHeight * (block.startMin / 60f)
-                val rawHeight = hourHeight * ((block.endMin - block.startMin) / 60f)
-                val height = if (rawHeight < minEventHeight) minEventHeight else rawHeight
-                EventBlock(
-                    block = block,
-                    dark = dark,
-                    height = height,
-                    width = laneWidth,
-                    onClick = { onEventClick(block.event) },
-                    modifier = Modifier
-                        .offset(x = laneWidth * block.lane, y = top)
-                        .width(laneWidth)
-                        .height(height)
-                        .padding(horizontal = 1.dp),
-                )
+                val ordinal = ordinals.merge(block.event.eventId, 1, Int::plus)!! - 1
+                key(block.event.eventId, ordinal) {
+                    val laneWidth = colWidth / block.laneCount
+                    val top = hourHeight * (block.startMin / 60f)
+                    val rawHeight = hourHeight * ((block.endMin - block.startMin) / 60f)
+                    val height = if (rawHeight < minEventHeight) minEventHeight else rawHeight
+                    val place = animatedBlockPlacement(
+                        x = laneWidth * block.lane,
+                        y = top,
+                        width = laneWidth,
+                        height = height,
+                    )
+                    EventBlock(
+                        block = block,
+                        dark = dark,
+                        height = place.height,
+                        width = place.width,
+                        date = date,
+                        dragController = dragController,
+                        onClick = { onEventClick(block.event) },
+                        onDrop = onDrop,
+                        modifier = Modifier
+                            .offset(x = place.x, y = place.y)
+                            .width(place.width)
+                            .height(place.height)
+                            .padding(horizontal = 1.dp),
+                    )
+                }
             }
             // Current-time line, on top of the events, only on today's column.
             if (date == today) {
@@ -790,7 +855,10 @@ private fun EventBlock(
     dark: Boolean,
     height: Dp,
     width: Dp,
+    date: LocalDate,
+    dragController: TimelineDragController,
     onClick: () -> Unit,
+    onDrop: (TimelineDrop) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     val title = block.event.title.ifBlank { stringResource(R.string.event_untitled) }
@@ -833,12 +901,35 @@ private fun EventBlock(
     val dimmed = dimCutoff != null && block.event.hasEnded(dimCutoff)
     val soften = LocalSoftenColors.current
     val fill = eventFill(block.event.color, dark, soften)
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val moveAction = eventMoveAction(block.event)
+    // A block clipped at the top continues from the previous day: its top edge
+    // is midnight, not the event's start, so dragging it would invent a time.
+    val draggable = moveAction != null && block.beginsOn(date, zone)
+    val dragModifier = rememberEventDragSource(
+        enabled = draggable,
+        key = block.event.instanceId,
+        onPickUp = { pointer, blockRoot, _ -> dragController.begin(block, pointer, blockRoot) },
+        onMove = dragController::move,
+        onDrop = { dragController.finish()?.let(onDrop) },
+        onCancel = dragController::cancel,
+    )
+    val lifted = draggable && dragController.ghosts(block, date)
+    val ghost = ghostAlpha(lifted)
     Box(
         modifier = (if (dimmed) modifier.alpha(EventDimAlpha) else modifier)
+            // The source stays put as a ghost while its floating copy travels.
+            .then(if (ghost < 1f) Modifier.alpha(ghost) else Modifier)
             .background(fill, RoundedCornerShape(4.dp))
             .clickable(onClick = onClick)
+            // After clickable, so it is the inner node and wins the main pass;
+            // the tap still works, since a drag consumes the up.
+            .then(dragModifier)
             .padding(horizontal = 4.dp, vertical = 2.dp)
-            .semantics { contentDescription = "$title, $timeLabel" },
+            .semantics {
+                contentDescription = "$title, $timeLabel"
+                if (moveAction != null) customActions = listOf(moveAction)
+            },
     ) {
         Column {
             if (showTitle) {
@@ -851,11 +942,8 @@ private fun EventBlock(
                 )
             }
             if (showTime) {
-                Text(
-                    text = timeLabel,
-                    style = MaterialTheme.typography.labelSmall,
-                    maxLines = 1,
-                    overflow = TextOverflow.Ellipsis,
+                BlockTimeLabel(
+                    label = timeLabel,
                     color = eventInk(fill, alpha = SECONDARY_INK_ALPHA),
                 )
             }

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

@@ -0,0 +1,78 @@
+package de.jeanlucmakiola.calendula.ui.week
+
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
+import de.jeanlucmakiola.calendula.ui.common.rememberTimelineDragController
+import de.jeanlucmakiola.calendula.ui.common.sampleTimelineEvents
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.coroutines.flow.first
+import kotlinx.datetime.plus
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+
+/**
+ * A live, scaled-down Week view for the onboarding view chooser. The week and
+ * today's column are real; only the events are stand-ins.
+ *
+ * The timeline is scrolled to the working day rather than to midnight — the
+ * live view centres on noon once it knows its own scroll range, which a preview
+ * that is never interacted with would otherwise never do.
+ */
+@Composable
+internal fun WeekViewPreview(
+    weekStart: DayOfWeek,
+    height: Dp,
+    modifier: Modifier = Modifier,
+) {
+    val zone = remember { TimeZone.currentSystemDefault() }
+    val today = remember(zone) { Clock.System.now().toLocalDateTime(zone).date }
+    val state = remember(today, weekStart, zone) { sampleWeekState(today, weekStart, zone) }
+    val scrollState = rememberScrollState()
+    LaunchedEffect(Unit) {
+        snapshotFlow { scrollState.maxValue }.first { it > 0 }
+        // Half the scroll range is noon — the same centring the live view does.
+        scrollState.scrollTo(scrollState.maxValue / 2)
+    }
+
+    ScaledViewPreview(height = height, modifier = modifier) {
+        WeekSuccess(
+            state = state,
+            topSectionColor = MaterialTheme.colorScheme.surface,
+            scrollState = scrollState,
+            allDayHeight = state.allDayStripHeight(),
+            dragController = rememberTimelineDragController(),
+            onEventClick = {},
+            onOpenDay = {},
+            onCreateAt = { _, _ -> },
+            onDrop = {},
+        )
+    }
+}
+
+/** Sample week state, laid out through the same helpers the live view uses. */
+private fun sampleWeekState(
+    today: LocalDate,
+    weekStart: DayOfWeek,
+    zone: TimeZone,
+): WeekUiState.Success {
+    val start = today.startOfWeek(weekStart)
+    val days = (0 until 7).map { start.plus(it, DateTimeUnit.DAY) }
+    val events = sampleTimelineEvents(days, today, zone)
+    return WeekUiState.Success(
+        weekStart = start,
+        today = today,
+        days = days,
+        allDaySpans = layoutAllDay(events.filter { it.isAllDay }, days, zone),
+        timedByDay = days.associateWith { layoutDay(events, it, zone) },
+    )
+}