Merge 2.22.0 work into view morph (#184)

Paged and Split now page like the week and day views; Split keeps its
vertical expand drag, now vertical-only beside the pager, and the pane
follows the grid's row count mid-swipe. The old trigger swipe and slide
transition are gone with their last callers.

Closes #336

CHANGELOG.md

@@ -5,6 +5,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+- **Pages can open the split agenda.** Swipe up from a full month to reveal the compact grid and month agenda; tap a day to filter it, then swipe down to return. The transition gives haptic feedback ([#111]).
+- **Week numbers open their week.** Tap a week number in the month grid to open Week at that row; Back returns to Month ([#197]).
+
+### Changed
+- **Split view opens with the month's agenda.** It starts at today in the current month; tapping a day filters the list, and the filter chip restores the full month. Swiping the list moves by day when filtered and by month otherwise ([#142]).
+- **Today stands out in the month grid.** Its whole cell has a distinct background; tapping Today briefly expands that cell and nudges its neighbours aside ([#241]).
+
+### Fixed
+- **Multi-day events stay above shorter events.** Month and Week bars, Split day lists, and Agenda now place multi-day events before one-day all-day events, then timed events; declined events remain last ([#291]).
+
 ## [2.21.0] — 2026-09-23
 
 ### Added

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

@@ -170,6 +170,7 @@ class MainActivity : AppCompatActivity() {
             // weeks and switching between the week and day view.
             val timelineZoom = rememberTimelineZoom(
                 stored = settings.timelineScale,
+                hours = settings.timelineHours,
                 onPersist = settingsViewModel::setTimelineScale,
             )
             val fonts by settingsViewModel.fontState.collectAsStateWithLifecycle()

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

@@ -21,6 +21,7 @@ import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.TimelineHours
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.common.parseTimelineScale
 import de.jeanlucmakiola.calendula.ui.common.storageValue
@@ -296,6 +297,27 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[MULTI_DAY_COUNT_KEY] = count.coerceIn(MULTI_DAY_COUNTS) }
     }
 
+    /**
+     * The hours the day, week and multi-day timelines fit to the screen when they
+     * open (#322). Off by default; the hours survive switching it off.
+     */
+    val timelineHours: Flow<TimelineHours> = store.data.map { prefs ->
+        TimelineHours.of(
+            enabled = prefs[TIMELINE_HOURS_ENABLED_KEY] ?: false,
+            startHour = prefs[TIMELINE_HOURS_START_KEY] ?: TimelineHours.DEFAULT_START_HOUR,
+            endHour = prefs[TIMELINE_HOURS_END_KEY] ?: TimelineHours.DEFAULT_END_HOUR,
+        )
+    }
+
+    suspend fun setTimelineHours(hours: TimelineHours) {
+        val valid = TimelineHours.of(hours.enabled, hours.startHour, hours.endHour)
+        store.edit {
+            it[TIMELINE_HOURS_ENABLED_KEY] = valid.enabled
+            it[TIMELINE_HOURS_START_KEY] = valid.startHour
+            it[TIMELINE_HOURS_END_KEY] = valid.endHour
+        }
+    }
+
     /**
      * Where the jump-to-today control lives (issue #60). Default OFF — the
      * historical layout, where it's an extended FAB that fades in above the "+"
@@ -1037,6 +1059,9 @@ class SettingsPrefs @Inject constructor(
         private const val MINUTES_PER_DAY = 1_440
         internal val SNOOZE_MINUTES_KEY = intPreferencesKey("snooze_minutes")
         internal val MULTI_DAY_COUNT_KEY = intPreferencesKey("multi_day_count")
+        internal val TIMELINE_HOURS_ENABLED_KEY = booleanPreferencesKey("timeline_hours_enabled")
+        internal val TIMELINE_HOURS_START_KEY = intPreferencesKey("timeline_hours_start")
+        internal val TIMELINE_HOURS_END_KEY = intPreferencesKey("timeline_hours_end")
         /** Default snooze delay for the notification "Snooze" action. */
         const val DEFAULT_SNOOZE_MINUTES = 10
         const val DEFAULT_MULTI_DAY_COUNT = 3

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

@@ -88,6 +88,7 @@ class ReminderNotifier @Inject constructor(
             is24Hour = is24Hour,
             today = Instant.now().atZone(zone).toLocalDate(),
             firstDayOfWeek = firstDayOfWeek,
+            todayLabel = context.getString(R.string.reminder_day_today),
             tomorrowLabel = context.getString(R.string.reminder_day_tomorrow),
             yesterdayLabel = context.getString(R.string.reminder_day_yesterday),
         )

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

@@ -27,12 +27,12 @@ import java.util.Locale
  *                                                          alone would be ambiguous)
  * - timed, crossing days: "11 Jun, 23:30 – 12 Jun, 00:30" (medium date + short time,
  *                                                          already unambiguous)
- * - all-day, one day:     "11 Jun 2026"
- * - all-day, multi-day:   "11 Jun 2026 – 12 Jun 2026"
+ * - all-day, one day:     "Tomorrow" / "Thu" / "11 Jun 2026" (same relative rules,
+ *                                                          plus [todayLabel] — no time range to lean on)
+ * - all-day, multi-day:   "Tomorrow – 12 Jun 2026"        (relative start, explicit end)
  *
- * All-day instances already carry an explicit date, so they never gain a
- * relative prefix. They store UTC midnights with an exclusive end, so they are
- * read in UTC and the end day is the last *covered* day.
+ * All-day instances store UTC midnights with an exclusive end, so they are read
+ * in UTC and the end day is the last *covered* day (issue #308).
  */
 fun reminderTimeText(
     beginMillis: Long,
@@ -43,6 +43,7 @@ fun reminderTimeText(
     is24Hour: Boolean,
     today: LocalDate,
     firstDayOfWeek: DayOfWeek,
+    todayLabel: String,
     tomorrowLabel: String,
     yesterdayLabel: String,
 ): String {
@@ -53,11 +54,16 @@ fun reminderTimeText(
         val lastDay = Instant.ofEpochMilli(endMillis).atZone(ZoneOffset.UTC).toLocalDate()
             .minusDays(1)
             .coerceAtLeast(firstDay)
-        return if (lastDay == firstDay) {
-            dateFormat.format(firstDay)
-        } else {
-            dateFormat.format(firstDay) + RANGE + dateFormat.format(lastDay)
-        }
+        val start = relativeDayPrefix(
+            day = firstDay,
+            today = today,
+            firstDayOfWeek = firstDayOfWeek,
+            locale = locale,
+            dateFormat = dateFormat,
+            tomorrowLabel = tomorrowLabel,
+            yesterdayLabel = yesterdayLabel,
+        ) ?: todayLabel
+        return if (lastDay == firstDay) start else start + RANGE + dateFormat.format(lastDay)
     }
 
     val timeFormat = timeOfDayFormatter(is24Hour, locale)

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

@@ -0,0 +1,18 @@
+package de.jeanlucmakiola.calendula.domain
+
+import kotlinx.datetime.TimeZone
+
+/** Lower values appear first in lists and get the upper visible lanes in grids. */
+fun EventInstance.displayPriority(zone: TimeZone): Int = when {
+    isDeclined -> 3
+    spansMultipleDays(zone) -> 0
+    isAllDay -> 1
+    else -> 2
+}
+
+/** Shared order for agenda and split day lists. Grid bars add their lane geometry. */
+fun eventDisplayComparator(zone: TimeZone): Comparator<EventInstance> =
+    compareBy<EventInstance> { it.displayPriority(zone) }
+        .thenBy { it.start }
+        .thenBy { it.title }
+        .thenBy { it.instanceId }

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

@@ -3,22 +3,36 @@ package de.jeanlucmakiola.calendula.ui
 import androidx.activity.compose.BackHandler
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionLayout
 import androidx.compose.animation.fadeIn
-import androidx.compose.animation.fadeOut
 import androidx.compose.animation.slideInHorizontally
-import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.DrawerValue
+import androidx.compose.material3.ModalNavigationDrawer
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.material3.rememberDrawerState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
 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
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.saveable.listSaver
 import androidx.compose.runtime.saveable.rememberSaveable
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
+import de.jeanlucmakiola.calendula.ui.common.screen
+import de.jeanlucmakiola.calendula.ui.common.ViewScreen
+import androidx.compose.runtime.SideEffect
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.layout.positionInWindow
+import androidx.compose.ui.platform.LocalDensity
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.domain.EventForm
@@ -26,18 +40,38 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaScreen
 import de.jeanlucmakiola.calendula.ui.calendars.BackupScreen
 import de.jeanlucmakiola.calendula.ui.calendars.CalendarsScreen
+import de.jeanlucmakiola.calendula.ui.common.BelowTopBarClip
+import de.jeanlucmakiola.calendula.ui.common.StayingPut
+import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
+import de.jeanlucmakiola.calendula.ui.common.CalendarFab
+import de.jeanlucmakiola.calendula.ui.common.CalendarTopBar
+import de.jeanlucmakiola.calendula.ui.common.ChromeHost
+import de.jeanlucmakiola.calendula.ui.common.ChromeSlot
+import de.jeanlucmakiola.calendula.ui.common.LocalChromeSlot
+import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.floret.identity.fadeThrough
+import de.jeanlucmakiola.floret.identity.predictiveBackExit
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 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.LocalManageCalendars
+import de.jeanlucmakiola.calendula.ui.common.LocalTimelineScroll
+import de.jeanlucmakiola.calendula.ui.common.LocalViewFocus
+import de.jeanlucmakiola.calendula.ui.common.ViewFocus
+import de.jeanlucmakiola.calendula.ui.common.ViewFocusSaver
+import de.jeanlucmakiola.calendula.ui.common.LocalViewMorph
 import de.jeanlucmakiola.calendula.ui.common.RescheduleViewModel
+import de.jeanlucmakiola.calendula.ui.common.TimelineScrollMemory
+import de.jeanlucmakiola.calendula.ui.common.ViewMorphScope
+import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
+import de.jeanlucmakiola.calendula.ui.common.rememberViewMorphBoundsTransform
 import de.jeanlucmakiola.calendula.ui.common.drillToDay
+import de.jeanlucmakiola.calendula.ui.common.drillToWeek
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
 import de.jeanlucmakiola.calendula.ui.common.selectView
 import de.jeanlucmakiola.calendula.ui.common.viewBaseStack
-import de.jeanlucmakiola.calendula.ui.day.DayScreen
 import de.jeanlucmakiola.calendula.ui.detail.EventDetailScreen
 import de.jeanlucmakiola.calendula.ui.edit.EventEditScreen
 import de.jeanlucmakiola.calendula.ui.edit.ImportSource
@@ -45,8 +79,8 @@ import de.jeanlucmakiola.calendula.ui.imports.ImportScreen
 import de.jeanlucmakiola.calendula.ui.month.MonthScreen
 import de.jeanlucmakiola.calendula.ui.search.SearchScreen
 import de.jeanlucmakiola.calendula.ui.settings.SettingsScreen
-import de.jeanlucmakiola.calendula.ui.week.MultiDayScreen
-import de.jeanlucmakiola.calendula.ui.week.WeekScreen
+import de.jeanlucmakiola.calendula.ui.week.TimelineScreen
+import kotlinx.coroutines.launch
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toLocalDateTime
@@ -54,8 +88,9 @@ import kotlin.time.Clock
 
 /**
  * Holds the top-level view back stack (spec M1) and swaps between the calendar
- * screens. Each screen owns its own ViewModel and date anchor; the view-switcher
- * pill in their top bars writes back here via [onSelectView].
+ * screens. Each screen owns its own ViewModel; they all open on the one focused
+ * date held here ([ViewFocus]), and the view-switcher pill in their top bars
+ * writes back here via [onSelectView].
  *
  * The stack's bottom is the user's [CalendarHostViewModel.defaultView] home view.
  * A lateral switch (pill / drawer) builds a visit history so back retraces it
@@ -72,6 +107,7 @@ import kotlin.time.Clock
  * as [WidgetNavRequest.OpenEvent], which also roots the back stack in the
  * widget's view.)
  */
+@OptIn(ExperimentalSharedTransitionApi::class)
 @Composable
 fun CalendarHost(
     modifier: Modifier = Modifier,
@@ -103,14 +139,33 @@ fun CalendarHost(
     var viewStack by rememberSaveable(stateSaver = viewStackSaver) {
         mutableStateOf(listOf(defaultView))
     }
+    var navigationVersion by remember { mutableIntStateOf(0) }
     val view = viewStack.last()
-    val onSelectView: (CalendarView) -> Unit = { viewStack = viewStack.selectView(it) }
+    // The timeline view last shown, so the timeline leaving for another screen
+    // keeps drawing the view it was on while it goes.
+    var heldTimeline by rememberSaveable {
+        mutableStateOf(if (view.screen == ViewScreen.Timeline) view else CalendarView.Week)
+    }
+    val timelineView = if (view.screen == ViewScreen.Timeline) view else heldTimeline
+    SideEffect { heldTimeline = timelineView }
 
-    // Tapping a day in the month grid opens the day view anchored to that date.
-    var pendingDayIso by rememberSaveable { mutableStateOf<String?>(null) }
+    // The date every view opens on and carries along (#184); tapping a day
+    // anywhere focuses it and opens the day view there.
+    val focus = rememberSaveable(saver = ViewFocusSaver) { ViewFocus(localToday()) }
+
+    val switchScope = rememberCoroutineScope()
+    val switchTo: ((List<CalendarView>) -> List<CalendarView>) -> Unit = { move ->
+        navigationVersion++
+        viewStack = move(viewStack)
+    }
+    val onSelectView: (CalendarView) -> Unit = { target -> switchTo { it.selectView(target) } }
     val onOpenDay: (LocalDate) -> Unit = { date ->
-        pendingDayIso = date.toString()
-        viewStack = viewStack.drillToDay()
+        focus.navigateTo(date)
+        switchTo { it.drillToDay() }
+    }
+    val onOpenWeek: (LocalDate) -> Unit = { date ->
+        focus.navigateTo(date)
+        switchTo { it.drillToWeek() }
     }
 
     // The event-detail screen (S4) is a full-screen destination hoisted here so
@@ -260,13 +315,14 @@ fun CalendarHost(
     // [requestedDetailKey]. Date/event opens root the stack in the widget's own
     // view so backing out returns there (then home), not to the default.
     LaunchedEffect(widgetNavRequest) {
+        if (widgetNavRequest != null) navigationVersion++
         when (val req = widgetNavRequest) {
             is WidgetNavRequest.OpenDate -> {
                 // Drill the day view in over the widget's view: drop any overlay
                 // that would cover it, so the open doesn't land under Settings/form.
                 dismissCoveringOverlays()
                 createDateIso = null
-                pendingDayIso = req.dateIso
+                focus.navigateTo(LocalDate.parse(req.dateIso))
                 // No widget source (an external date tap) roots over the default
                 // home view, so backing out of the day returns home then exits.
                 viewStack = viewBaseStack(defaultView, req.source ?: defaultView).drillToDay()
@@ -290,7 +346,7 @@ fun CalendarHost(
                 // default home — so backing out returns to the default, then exits.
                 dismissCoveringOverlays()
                 createDateIso = null
-                pendingDayIso = null
+                focus.navigateTo(localToday())
                 viewStack = viewBaseStack(defaultView, req.view ?: defaultView)
                 onWidgetNavConsumed()
             }
@@ -341,6 +397,9 @@ fun CalendarHost(
     }
 
     val slideSpec = rememberCalendarSlideSpec()
+    // Overlays leave from the predictive-back preview (#184): shrinking on from
+    // where the gesture let go instead of snapping back and sliding off.
+    val overlayExit = predictiveBackExit()
 
     // Base-level back: pop the view stack while no overlay covers it (each overlay
     // owns its own BackHandler and takes precedence). Disabled at the home view,
@@ -349,87 +408,129 @@ fun CalendarHost(
         editKey != null || showSettings || showCalendars || showBackup ||
         importUri != null || importForm != null
     BackHandler(enabled = !anyOverlayVisible && viewStack.size > 1) {
+        navigationVersion++
         viewStack = viewStack.dropLast(1)
     }
 
     Box(modifier = modifier.fillMaxSize()) {
-        // Switching between the peer views (month/week/day/agenda) is lateral
+        // Switching between the month, timeline and agenda screens is lateral
         // navigation, so it fades through rather than sliding — paging *within* a
-        // view keeps the directional slide. AnimatedContent keyed on the view type.
+        // view keeps the directional slide. What both views show morphs across
+        // (#184): see [ViewMorphKey]. Reduced motion keeps the plain fade.
         val viewSwitch = fadeThrough()
+        val reduceMotion = rememberReduceMotion()
+        val morphBounds = rememberViewMorphBoundsTransform()
+        val morphFade = rememberCalendarFadeSpec()
+        val morphClip = remember { BelowTopBarClip() }
+        val stayingPut = remember { StayingPut() }
+        val chromeHost = remember { ChromeHost() }
+        val drawerState = rememberDrawerState(DrawerValue.Closed)
+        val density = LocalDensity.current
+        val topBarBottom = TopAppBarDefaults.windowInsets.getTop(density) +
+            with(density) { TopAppBarDefaults.TopAppBarExpandedHeight.toPx() }
+        val timelineScroll = remember { TimelineScrollMemory() }
         CompositionLocalProvider(
             LocalEventMove provides moveScope,
+            LocalTimelineScroll provides timelineScroll,
+            LocalViewFocus provides focus,
             // The failure state's way out when every calendar is switched off
             // (#239); nothing else in the calendar surfaces navigates here.
-            LocalManageCalendars provides { showCalendars = true },
+            LocalManageCalendars provides remember { { showCalendars = true } },
         ) {
+        // One drawer, top bar and FAB for every screen (#184): a switch changes
+        // what they say, from what the screen on show publishes, rather than
+        // swapping them for another screen's.
+        ModalNavigationDrawer(
+            drawerState = drawerState,
+            // Open only via the menu button where edge-swipe would fight paging;
+            // the agenda has no paging to fight.
+            gesturesEnabled = drawerState.isOpen || view.screen == ViewScreen.Agenda,
+            drawerContent = {
+                CalendarDrawer(
+                    currentView = view,
+                    currentDate = chromeHost.chrome?.drawerDate ?: focus.date,
+                    drawerState = drawerState,
+                    viewOrder = drawerViewOrder,
+                    onSelectView = { target ->
+                        // Once the drawer is out of the way, so the switch is seen whole.
+                        val requestVersion = ++navigationVersion
+                        switchScope.launch {
+                            drawerState.close()
+                            if (navigationVersion == requestVersion) onSelectView(target)
+                        }
+                    },
+                    onJumpToDate = { target ->
+                        chromeHost.actions?.onJumpToDate?.invoke(target)
+                        switchScope.launch { drawerState.close() }
+                    },
+                    onSettings = {
+                        onOpenSettings()
+                        switchScope.launch { drawerState.close() }
+                    },
+                )
+            },
+        ) {
+        Scaffold(
+            topBar = {
+                CalendarTopBar(
+                    host = chromeHost,
+                    selectedView = view,
+                    quickSwitchViews = quickSwitchViews,
+                    onCycleView = { onSelectView(viewStack.last().next(quickSwitchViews)) },
+                    onOpenDrawer = { switchScope.launch { drawerState.open() } },
+                    onOpenSearch = onOpenSearch,
+                    showTodayButton = todayInToolbar,
+                )
+            },
+            floatingActionButton = { CalendarFab(chromeHost, todayInToolbar) },
+        ) { innerPadding ->
+        SharedTransitionLayout(
+            Modifier
+                .padding(innerPadding)
+                .fillMaxSize()
+.onGloballyPositioned { morphClip.top = topBarBottom - it.positionInWindow().y },
+        ) {
+        // Keyed on the screen, not the view: the day, multi-day and week views
+        // are one timeline that resizes between them itself (#184), so switching
+        // among them must not replay this transition.
         AnimatedContent(
-            targetState = view,
+            targetState = view.screen,
             transitionSpec = { viewSwitch },
             label = "view-switch",
-        ) { currentView ->
-            when (currentView) {
-                CalendarView.Week -> WeekScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
+        ) { screen ->
+            val sharedScope = this@SharedTransitionLayout
+            val visibilityScope = this@AnimatedContent
+            val viewMorph = remember(reduceMotion, sharedScope, visibilityScope, morphBounds, morphFade, morphClip, stayingPut) {
+                if (reduceMotion) null else ViewMorphScope(sharedScope, visibilityScope, morphBounds, morphFade, morphClip, stayingPut)
+            }
+            CompositionLocalProvider(
+                LocalViewMorph provides viewMorph,
+                LocalChromeSlot provides ChromeSlot(chromeHost, current = screen == view.screen),
+            ) {
+            when (screen) {
+                ViewScreen.Timeline -> TimelineScreen(
+                    view = timelineView,
                     onOpenDay = onOpenDay,
                     onEventClick = onEventClick,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
-                    quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                    todayInToolbar = todayInToolbar,
                 )
-                CalendarView.MultiDay -> MultiDayScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
+                ViewScreen.Month -> MonthScreen(
+                    onOpenDay = onOpenDay,
+                    onOpenWeek = onOpenWeek,
+                    onEventClick = onEventClick,
+                    onCreateEvent = onCreateEvent,
+                )
+                ViewScreen.Agenda -> AgendaScreen(
                     onOpenDay = onOpenDay,
                     onEventClick = onEventClick,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
                     quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                    todayInToolbar = todayInToolbar,
-                )
-                CalendarView.Day -> DayScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
-                    onEventClick = onEventClick,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
-                    onCreateEvent = onCreateEvent,
-                    initialDateIso = pendingDayIso,
-                    quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                    todayInToolbar = todayInToolbar,
-                )
-                CalendarView.Month -> MonthScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
-                    onOpenDay = onOpenDay,
-                    onEventClick = onEventClick,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
-                    onCreateEvent = onCreateEvent,
-                    quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                    todayInToolbar = todayInToolbar,
-                )
-                CalendarView.Agenda -> AgendaScreen(
-                    selectedView = currentView,
-                    onSelectView = onSelectView,
-                    onOpenDay = onOpenDay,
-                    onEventClick = onEventClick,
-                    onOpenSettings = onOpenSettings,
-                    onOpenSearch = onOpenSearch,
-                    onCreateEvent = onCreateEvent,
-                    quickSwitchViews = quickSwitchViews,
-                    drawerViewOrder = drawerViewOrder,
-                    todayInToolbar = todayInToolbar,
                 )
             }
+            }
+        }
+        }
+        }
         }
         }
 
@@ -442,11 +543,12 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = showSearch,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             SearchScreen(
                 onBack = { showSearch = false },
                 onEventClick = onEventClick,
+                visible = showSearch,
             )
         }
 
@@ -455,7 +557,7 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = detailKey != null,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             activeKey?.let { key ->
                 EventDetailScreen(
@@ -475,6 +577,7 @@ fun CalendarHost(
                         importForm = form
                         detailKey = null
                     },
+                    visible = detailKey != null,
                 )
             }
         }
@@ -483,7 +586,7 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = createDateIso != null,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             (createDateIso ?: heldCreateIso)?.let { iso ->
                 EventEditScreen(
@@ -492,6 +595,7 @@ fun CalendarHost(
                     onClose = { createDateIso = null },
                     onSaved = { createDateIso = null },
                     onManageCalendars = { showCalendars = true },
+                    visible = createDateIso != null,
                 )
             }
         }
@@ -500,7 +604,7 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = editKey != null,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             (editKey ?: heldEditKey)?.let { key ->
                 EventEditScreen(
@@ -512,6 +616,7 @@ fun CalendarHost(
                         detailKey = null
                     },
                     onManageCalendars = { showCalendars = true },
+                    visible = editKey != null,
                 )
             }
         }
@@ -520,12 +625,13 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = showSettings,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             SettingsScreen(
                 onBack = { showSettings = false },
                 onManageCalendars = { showCalendars = true },
                 onOpenBackup = { showBackup = true },
+                visible = showSettings,
             )
         }
 
@@ -577,11 +683,12 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = showCalendars,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             CalendarsScreen(
                 onBack = { showCalendars = false },
                 onOpenBackup = { showBackup = true },
+                visible = showCalendars,
             )
         }
 
@@ -589,7 +696,7 @@ fun CalendarHost(
         AnimatedVisibility(
             visible = showBackup,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             // Settings can open this screen without the manager underneath, so
             // its failure states' "Manage calendars" way out has to open the
@@ -616,6 +723,7 @@ fun CalendarHost(
                         showBackup = false
                         showCalendars = false
                     },
+                    visible = showBackup,
                 )
             }
         }
@@ -627,3 +735,6 @@ private val viewStackSaver = listSaver<List<CalendarView>, Int>(
     save = { stack -> stack.map(CalendarView::ordinal) },
     restore = { ordinals -> ordinals.map { CalendarView.entries[it] } },
 )
+
+private fun localToday(): LocalDate =
+    Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault()).date

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

@@ -1,5 +1,18 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
+import de.jeanlucmakiola.calendula.ui.common.PublishChrome
+import de.jeanlucmakiola.calendula.ui.common.ScreenActions
+import de.jeanlucmakiola.calendula.ui.common.ScreenBody
+import de.jeanlucmakiola.calendula.ui.common.ScreenChrome
+import de.jeanlucmakiola.calendula.ui.common.LocalViewFocus
+import de.jeanlucmakiola.calendula.ui.common.EnterOnFocus
+import kotlinx.coroutines.flow.drop
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.runtime.rememberUpdatedState
+import de.jeanlucmakiola.calendula.ui.common.ViewMorphKey
+import de.jeanlucmakiola.calendula.ui.common.morphEvent
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -18,34 +31,22 @@ import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Coffee
-import androidx.compose.material.icons.filled.Menu
-import androidx.compose.material.icons.filled.Search
 import androidx.compose.material3.ButtonDefaults
-import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.ModalNavigationDrawer
-import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
-import androidx.compose.material3.TopAppBar
-import androidx.compose.material3.TopAppBarDefaults
-import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.derivedStateOf
-import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
@@ -58,14 +59,9 @@ import de.jeanlucmakiola.calendula.ui.common.AppBarSpacing
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.floret.identity.animateItemMotion
-import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
-import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
-import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
-import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
-import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
 import de.jeanlucmakiola.floret.locale.currentLocale
@@ -81,26 +77,22 @@ import kotlin.time.Instant
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun AgendaScreen(
-    selectedView: CalendarView,
-    onSelectView: (CalendarView) -> Unit,
     onOpenDay: (LocalDate) -> Unit,
     onEventClick: (EventInstance) -> Unit,
-    onOpenSettings: () -> Unit,
-    onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
     quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
-    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
-    todayInToolbar: Boolean = false,
     modifier: Modifier = Modifier,
     viewModel: AgendaViewModel = hiltViewModel(),
 ) {
+    // Opens on the focused date and hands back the day scrolled to the top.
+    val focus = LocalViewFocus.current
+    EnterOnFocus(viewModel) { if (it != viewModel.anchor.value) viewModel.goToDate(it) }
     val state by viewModel.state.collectAsStateWithLifecycle()
     val anchor by viewModel.anchor.collectAsStateWithLifecycle()
     val pastDisplay by viewModel.pastEventDisplay.collectAsStateWithLifecycle()
     val showToday by viewModel.showToday.collectAsStateWithLifecycle()
     val weekStart by viewModel.weekStart.collectAsStateWithLifecycle()
 
-    val drawerState = rememberDrawerState(DrawerValue.Closed)
     val scope = rememberCoroutineScope()
     var showRangePicker by remember { mutableStateOf(false) }
 
@@ -124,112 +116,88 @@ fun AgendaScreen(
     // requested: scrolling before the new rows compose leaves the list keyed to
     // a row that reappears further down, and it follows it there.
     LaunchedEffect(successState?.anchor) { listState.scrollToItem(0) }
-    val jumpToToday = {
+    val jumpToToday: () -> Unit = {
         // Off today, moving the anchor is what resets the list (above); on today
         // the window doesn't change, so the scroll back is the whole action.
         if (isOnToday) scope.launch { listState.animateScrollToItem(0) }
         viewModel.goToToday()
+        (state as? AgendaUiState.Success)?.today?.let { focus?.date = it }
     }
 
-    ModalNavigationDrawer(
-        drawerState = drawerState,
-        drawerContent = {
-            CalendarDrawer(
-                currentView = selectedView,
-                currentDate = anchor,
-                drawerState = drawerState,
-                viewOrder = drawerViewOrder,
-                onSelectView = { view ->
-                    onSelectView(view)
-                    scope.launch { drawerState.close() }
-                },
-                onJumpToDate = { target ->
-                    viewModel.goToDate(target)
-                    scope.launch { drawerState.close() }
-                },
-                onSettings = {
-                    onOpenSettings()
-                    scope.launch { drawerState.close() }
-                },
-            )
-        },
-    ) {
-        Scaffold(
-            modifier = modifier,
-            topBar = {
-                AgendaTopBar(
-                    selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
-                    quickSwitchViews = quickSwitchViews,
-                    onOpenDrawer = { scope.launch { drawerState.open() } },
-                    onOpenSearch = onOpenSearch,
-                    showTodayButton = todayInToolbar,
-                    onToday = jumpToToday,
-                )
+    PublishChrome(
+        ScreenChrome(
+            title = stringResource(R.string.view_agenda),
+            titleDate = null,
+            drawerDate = anchor,
+            awayFromToday = !isOnToday || (scrolledAway && successState != null),
+            todayText = stringResource(R.string.agenda_today_action),
+        ),
+        ScreenActions(
+            onToday = jumpToToday,
+            onJumpToDate = { target ->
+                focus?.date = target
+                viewModel.goToDate(target)
             },
-            floatingActionButton = {
-                CalendarFabColumn(
-                    todayVisible = (!isOnToday || (scrolledAway && successState != null)) &&
-                        !todayInToolbar,
-                    todayText = stringResource(R.string.agenda_today_action),
-                    onToday = jumpToToday,
-                    onCreate = { onCreateEvent(anchor, null) },
-                )
-            },
-        ) { innerPadding ->
-            Column(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(innerPadding),
-            ) {
-                // One bar at the top: the "showing …" header on the left and the
-                // session range switcher on the right (one settings toggle).
-                successState?.takeIf { it.showRangeBar }?.let { s ->
-                    // end lines the selector up with whatever ends the top bar:
-                    // the view switcher's background, or — once #150 hides it —
-                    // the search icon's glyph.
-                    val selectorEnd = if (quickSwitchViews.size >= QuickSwitchConfig.MIN_CYCLE) {
-                        AppBarSpacing.Inset
-                    } else {
-                        AppBarSpacing.IconTrailingInset
-                    }
-                    Row(
-                        verticalAlignment = Alignment.CenterVertically,
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .padding(
-                                start = RANGE_BAR_TEXT_INSET,
-                                end = selectorEnd,
-                                top = 8.dp,
-                                bottom = 8.dp,
-                            ),
-                    ) {
-                        AgendaRangeBanner(
-                            range = s.range,
-                            start = s.anchor,
-                            end = s.rangeEnd,
-                            modifier = Modifier.weight(1f),
-                        )
-                        AgendaRangePill(
-                            range = s.range,
-                            isOverride = s.rangeIsOverride,
-                            onClick = { showRangePicker = true },
-                        )
-                    }
+            onCreate = { onCreateEvent(anchor, null) },
+        ),
+    )
+
+    ScreenBody(modifier = modifier) { innerPadding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(innerPadding),
+        ) {
+            // One bar at the top: the "showing …" header on the left and the
+            // session range switcher on the right (one settings toggle).
+            successState?.takeIf { it.showRangeBar }?.let { s ->
+                // end lines the selector up with whatever ends the top bar:
+                // the view switcher's background, or — once #150 hides it —
+                // the search icon's glyph.
+                val selectorEnd = if (quickSwitchViews.size >= QuickSwitchConfig.MIN_CYCLE) {
+                    AppBarSpacing.Inset
+                } else {
+                    AppBarSpacing.IconTrailingInset
                 }
-                AgendaContent(
-                    state = state,
-                    pastDisplay = pastDisplay,
-                    showToday = showToday,
-                    listState = listState,
-                    onRetry = viewModel::goToToday,
-                    onEventClick = onEventClick,
-                    onOpenDay = onOpenDay,
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
                     modifier = Modifier
-                        .weight(1f)
-                        .fillMaxWidth(),
-                )
+                        .fillMaxWidth()
+                        .padding(
+                            start = RANGE_BAR_TEXT_INSET,
+                            end = selectorEnd,
+                            top = 8.dp,
+                            bottom = 8.dp,
+                        ),
+                ) {
+                    AgendaRangeBanner(
+                        range = s.range,
+                        start = s.anchor,
+                        end = s.rangeEnd,
+                        modifier = Modifier.weight(1f),
+                    )
+                    AgendaRangePill(
+                        range = s.range,
+                        isOverride = s.rangeIsOverride,
+                        onClick = { showRangePicker = true },
+                    )
+                }
             }
+            AgendaContent(
+                state = state,
+                pastDisplay = pastDisplay,
+                showToday = showToday,
+                listState = listState,
+                onRetry = viewModel::goToToday,
+                onEventClick = onEventClick,
+                onOpenDay = onOpenDay,
+                onTopDay = if (successState?.anchor == anchor) {
+                    { focus?.date = it }
+                } else null,
+                modifier = Modifier
+                    .weight(1f)
+                    .fillMaxWidth(),
+            )
         }
     }
 
@@ -326,6 +294,7 @@ internal fun AgendaContent(
     onOpenDay: (LocalDate) -> Unit,
     modifier: Modifier = Modifier,
     listState: LazyListState = rememberLazyListState(),
+    onTopDay: ((LocalDate) -> Unit)? = null,
 ) {
     when (state) {
         AgendaUiState.Loading -> Box(modifier)
@@ -368,6 +337,7 @@ internal fun AgendaContent(
                     now = now,
                     onEventClick = onEventClick,
                     onOpenDay = onOpenDay,
+                    onTopDay = onTopDay,
                     modifier = modifier,
                 )
             }
@@ -386,8 +356,20 @@ private fun AgendaList(
     now: Instant,
     onEventClick: (EventInstance) -> Unit,
     onOpenDay: (LocalDate) -> Unit,
+    onTopDay: ((LocalDate) -> Unit)?,
     modifier: Modifier = Modifier,
 ) {
+    if (onTopDay != null) {
+        val itemDates by rememberUpdatedState(agendaItemDates(days))
+        val currentOnTopDay by rememberUpdatedState(onTopDay)
+        // The day the list opened on is where the view already is; only a
+        // scroll moves it on.
+        LaunchedEffect(listState) {
+            snapshotFlow { listState.firstVisibleItemIndex }
+                .drop(1)
+                .collect { index -> itemDates.getOrNull(index)?.let(currentOnTopDay) }
+        }
+    }
     LazyColumn(
         modifier = modifier,
         state = listState,
@@ -420,7 +402,7 @@ private fun AgendaList(
                         zone = zone,
                         position = positionOf(index, day.events.size),
                         dimmed = dimPast && event.hasEnded(now),
-                        modifier = animateItemMotion(),
+                        modifier = animateItemMotion().morphEvent(ViewMorphKey.event(event, day.date)),
                         onClick = { onEventClick(event) },
                     )
                 }
@@ -430,6 +412,13 @@ private fun AgendaList(
     }
 }
 
+/** The day of each item [AgendaList] lays out for [days], in its order. */
+internal fun agendaItemDates(days: List<AgendaDay>): List<LocalDate> =
+    days.flatMap { day ->
+        // Header, the placeholder or the events, then the gap.
+        List(2 + day.events.size.coerceAtLeast(1)) { day.date }
+    }
+
 @Composable
 private fun AgendaEmpty(modifier: Modifier = Modifier) {
     Column(
@@ -451,58 +440,3 @@ private fun AgendaEmpty(modifier: Modifier = Modifier) {
         )
     }
 }
-
-@OptIn(ExperimentalMaterial3Api::class)
-@Composable
-private fun AgendaTopBar(
-    selectedView: CalendarView,
-    onCycleView: () -> Unit,
-    quickSwitchViews: List<CalendarView>,
-    onOpenDrawer: () -> Unit,
-    onOpenSearch: () -> Unit,
-    showTodayButton: Boolean,
-    onToday: () -> Unit,
-) {
-    TopAppBar(
-        title = {
-            // A plain label rather than a CalendarTitleButton, so it takes that
-            // one's inset and one-line clamp itself.
-            Text(
-                text = stringResource(R.string.view_agenda),
-                style = MaterialTheme.typography.titleLarge,
-                maxLines = 1,
-                overflow = TextOverflow.Ellipsis,
-                modifier = Modifier.padding(start = AppBarSpacing.TitleInset),
-            )
-        },
-        navigationIcon = {
-            IconButton(onClick = onOpenDrawer) {
-                Icon(
-                    imageVector = Icons.Default.Menu,
-                    contentDescription = stringResource(R.string.month_open_menu),
-                )
-            }
-        },
-        actions = {
-            TodayAction(show = showTodayButton, onToday = onToday)
-            IconButton(onClick = onOpenSearch) {
-                Icon(
-                    imageVector = Icons.Default.Search,
-                    contentDescription = stringResource(R.string.search_action),
-                )
-            }
-            ViewSwitcherPill(
-                current = selectedView,
-                cycle = quickSwitchViews,
-                onCycle = onCycleView,
-            )
-        },
-        // Deliberately flat: M3 lifts the bar to mark content scrolling under
-        // it, but here the bar meets the header on the same surface and the
-        // tint is what makes that seam look like a separate block (#186).
-        colors = TopAppBarDefaults.topAppBarColors(
-            containerColor = MaterialTheme.colorScheme.surface,
-            scrolledContainerColor = MaterialTheme.colorScheme.surface,
-        ),
-    )
-}

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

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.eventDisplayComparator
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.spanFirstDay
 import de.jeanlucmakiola.calendula.domain.spanLastDay
@@ -86,11 +87,7 @@ fun groupAgendaDays(
     return byDay.map { (date, dayEvents) ->
         AgendaDay(
             date = date,
-            events = dayEvents.sortedWith(
-                compareByDescending<EventInstance> { it.isAllDay }
-                    .thenBy { it.start }
-                    .thenBy { it.title },
-            ),
+            events = dayEvents.sortedWith(eventDisplayComparator(zone)),
         )
     }
 }

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

@@ -82,6 +82,7 @@ private val RESTORE_MIME_TYPES = arrayOf(
 fun BackupScreen(
     onBack: () -> Unit,
     onImport: (Uri) -> Unit,
+    visible: Boolean = true,
     viewModel: CalendarsViewModel = hiltViewModel(),
 ) {
     val state by viewModel.backupState.collectAsStateWithLifecycle()
@@ -137,6 +138,7 @@ fun BackupScreen(
         scrollable = state is BackupUiState.Ready,
         snackbarHost = { SnackbarHost(snackbarHostState) },
         predictiveBack = true,
+        visible = visible,
     ) {
         when (val s = state) {
             BackupUiState.Loading -> BackupLoading()

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

@@ -133,6 +133,7 @@ private const val NEW_CALENDAR_ID = Long.MIN_VALUE
 fun CalendarsScreen(
     onBack: () -> Unit,
     onOpenBackup: () -> Unit,
+    visible: Boolean = true,
     viewModel: CalendarsViewModel = hiltViewModel(),
 ) {
     val calendars by viewModel.calendars.collectAsStateWithLifecycle()
@@ -177,6 +178,7 @@ fun CalendarsScreen(
             onConsumeError = viewModel::consumeError,
             onOpenBackup = onOpenBackup,
             onBack = onBack,
+            visible = visible,
             onAdd = { editorSession++; editorId = NEW_CALENDAR_ID },
             onEdit = { calendar -> editorSession++; editorId = calendar.id },
             onSetVisible = viewModel::setCalendarVisible,
@@ -193,6 +195,7 @@ private fun CalendarsList(
     onConsumeError: () -> Unit,
     onOpenBackup: () -> Unit,
     onBack: () -> Unit,
+    visible: Boolean,
     onAdd: () -> Unit,
     onEdit: (CalendarSource) -> Unit,
     onSetVisible: (Long, Boolean) -> Unit,
@@ -218,6 +221,7 @@ private fun CalendarsList(
         onBack = onBack,
         snackbarHost = { SnackbarHost(snackbarHostState) },
         predictiveBack = true,
+        visible = visible,
     ) {
         // What the per-calendar / per-account switches below actually do.
         HintText(stringResource(R.string.calendars_visibility_hint))

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

@@ -3,6 +3,7 @@ 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.animateFloatAsState
 import androidx.compose.animation.core.snap
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialTheme
@@ -13,15 +14,19 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.Layout
+import androidx.compose.ui.layout.ParentDataModifier
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.rememberTextMeasurer
 import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.unit.Constraints
+import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import kotlin.math.roundToInt
 
 /** Gap a timed block leaves to its neighbours in the column. */
 val BLOCK_OUTER_INSET = 1.dp
@@ -224,9 +229,13 @@ fun BlockTimeLabel(
     }
 }
 
-/** Where a timed block sits in its column, after tweening. */
+/**
+ * Where a timed block sits in its column, after tweening: across as shares of
+ * the column's width, so a column resizing carries its blocks with it (#184),
+ * down in the timeline's own units.
+ */
 @Immutable
-data class BlockPlacement(val x: Dp, val y: Dp, val width: Dp, val height: Dp)
+data class BlockPlacement(val xFraction: Float, val widthFraction: Float, val y: Dp, val height: Dp)
 
 /**
  * A timed block's placement, tweened rather than jumped. Continuity comes from
@@ -239,17 +248,49 @@ data class BlockPlacement(val x: Dp, val y: Dp, val width: Dp, val height: Dp)
  */
 @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()
+fun animatedBlockPlacement(xFraction: Float, widthFraction: Float, y: Dp, height: Dp): BlockPlacement {
+    val still = rememberReduceMotion() || LocalTimelineZoom.current.isPinching
+    val dpSpec: FiniteAnimationSpec<Dp> = if (still) snap() else MaterialTheme.motionScheme.fastSpatialSpec()
+    val shareSpec: FiniteAnimationSpec<Float> = if (still) snap() else MaterialTheme.motionScheme.fastSpatialSpec()
+    val animatedX by animateFloatAsState(xFraction, shareSpec, label = "block-x")
+    val animatedWidth by animateFloatAsState(widthFraction, shareSpec, label = "block-width")
+    val animatedY by animateDpAsState(y, dpSpec, label = "block-y")
+    val animatedHeight by animateDpAsState(height, dpSpec, label = "block-height")
+    return BlockPlacement(animatedX, animatedWidth, animatedY, animatedHeight)
+}
+
+/** Seats a block across its [placement]'s share of a [LaneColumn]. */
+fun Modifier.laneSlot(placement: BlockPlacement): Modifier =
+    then(LaneSlot(placement.xFraction, placement.widthFraction))
+
+private data class LaneSlot(val x: Float, val width: Float) : ParentDataModifier {
+    override fun Density.modifyParentData(parentData: Any?): Any = this@LaneSlot
+}
+
+/**
+ * A day column's blocks, each measured across the share of the column its
+ * [laneSlot] gives it; anything else fills the column. The shares are applied
+ * at layout time, so the column can change width every frame without its
+ * blocks recomposing.
+ */
+@Composable
+fun LaneColumn(modifier: Modifier = Modifier, content: @Composable () -> Unit) {
+    Layout(content = content, modifier = modifier) { measurables, constraints ->
+        val width = constraints.maxWidth
+        val loose = constraints.copy(minWidth = 0, minHeight = 0)
+        val placed = measurables.map { measurable ->
+            val slot = measurable.parentData as? LaneSlot
+            if (slot == null) {
+                measurable.measure(loose) to 0
+            } else {
+                val left = (slot.x * width).roundToInt()
+                val right = ((slot.x + slot.width) * width).roundToInt()
+                val laneWidth = (right - left).coerceAtLeast(0)
+                measurable.measure(loose.copy(minWidth = laneWidth, maxWidth = laneWidth)) to left
+            }
+        }
+        layout(width, constraints.maxHeight) {
+            placed.forEach { (placeable, x) -> placeable.placeRelative(x, 0) }
+        }
     }
-    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/CalendarChrome.kt

@@ -0,0 +1,161 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Menu
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.SideEffect
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import de.jeanlucmakiola.calendula.R
+import kotlinx.datetime.LocalDate
+
+/**
+ * What a calendar screen shows in the top bar, the FAB and the drawer, which the
+ * host draws once for all of them (#184): switching screens changes what they
+ * say rather than swapping one bar for another.
+ *
+ * @param titleDate the date the title's picker opens on, or null for a title
+ *   that is only a label.
+ * @param drawerDate the date the drawer's picker opens on.
+ * @param awayFromToday whether "today" is worth offering.
+ */
+@Immutable
+data class ScreenChrome(
+    val title: String,
+    val shortTitle: String = title,
+    val titleDate: LocalDate?,
+    val drawerDate: LocalDate,
+    val awayFromToday: Boolean,
+    val todayText: String,
+)
+
+/** What the chrome does for the screen on show; read when used, so not observed. */
+class ScreenActions(
+    val onToday: () -> Unit,
+    val onJumpToDate: (LocalDate) -> Unit,
+    val onCreate: () -> Unit,
+)
+
+/** The screen on show's [ScreenChrome] and [ScreenActions], for the host to draw. */
+@Stable
+class ChromeHost {
+    var chrome by mutableStateOf<ScreenChrome?>(null)
+        private set
+
+    var actions: ScreenActions? = null
+        private set
+
+    internal fun publish(chrome: ScreenChrome, actions: ScreenActions) {
+        this.chrome = chrome
+        this.actions = actions
+    }
+}
+
+/** The host's chrome, and whether the screen reading it is the one on show rather than one leaving. */
+class ChromeSlot(val host: ChromeHost, val current: Boolean)
+
+val LocalChromeSlot = staticCompositionLocalOf<ChromeSlot?> { null }
+
+/** Hands [chrome] and [actions] to the host, while this screen is the one on show. */
+@Composable
+fun PublishChrome(chrome: ScreenChrome, actions: ScreenActions) {
+    val slot = LocalChromeSlot.current ?: return
+    if (slot.current) SideEffect { slot.host.publish(chrome, actions) }
+}
+
+/** The top bar every calendar screen shares. */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun CalendarTopBar(
+    host: ChromeHost,
+    selectedView: CalendarView,
+    quickSwitchViews: List<CalendarView>,
+    onCycleView: () -> Unit,
+    onOpenDrawer: () -> Unit,
+    onOpenSearch: () -> Unit,
+    showTodayButton: Boolean,
+) {
+    val chrome = host.chrome
+    TopAppBar(
+        title = {
+            if (chrome != null) {
+                CalendarTitleButton(
+                    title = chrome.title,
+                    currentDate = chrome.titleDate,
+                    onJumpToDate = { host.actions?.onJumpToDate?.invoke(it) },
+                    shortTitle = chrome.shortTitle,
+                )
+            }
+        },
+        navigationIcon = {
+            IconButton(onClick = onOpenDrawer) {
+                Icon(
+                    imageVector = Icons.Default.Menu,
+                    contentDescription = stringResource(R.string.month_open_menu),
+                )
+            }
+        },
+        actions = {
+            TodayAction(show = showTodayButton, onToday = { host.actions?.onToday?.invoke() })
+            IconButton(onClick = onOpenSearch) {
+                Icon(
+                    imageVector = Icons.Default.Search,
+                    contentDescription = stringResource(R.string.search_action),
+                )
+            }
+            ViewSwitcherPill(
+                current = selectedView,
+                cycle = quickSwitchViews,
+                onCycle = onCycleView,
+            )
+        },
+        // Deliberately flat: M3 lifts the bar to mark content scrolling under
+        // it, but here the bar meets the header on the same surface and the
+        // tint is what makes that seam look like a separate block (#186).
+        colors = TopAppBarDefaults.topAppBarColors(
+            containerColor = MaterialTheme.colorScheme.surface,
+            scrolledContainerColor = MaterialTheme.colorScheme.surface,
+        ),
+    )
+}
+
+/** The FAB column every calendar screen shares. */
+@Composable
+fun CalendarFab(host: ChromeHost, todayInToolbar: Boolean) {
+    val chrome = host.chrome ?: return
+    CalendarFabColumn(
+        todayVisible = chrome.awayFromToday && !todayInToolbar,
+        todayText = chrome.todayText,
+        onToday = { host.actions?.onToday?.invoke() },
+        onCreate = { host.actions?.onCreate?.invoke() },
+    )
+}
+
+/**
+ * A calendar screen's body under the shared chrome, on the ground the screen's
+ * own Scaffold used to give it; the host's Scaffold has already made room for
+ * the bars, so [content] gets no padding of its own.
+ */
+@Composable
+fun ScreenBody(modifier: Modifier = Modifier, content: @Composable (PaddingValues) -> Unit) {
+    Box(modifier.fillMaxSize().background(MaterialTheme.colorScheme.background)) {
+        content(PaddingValues())
+    }
+}

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

@@ -1,5 +1,13 @@
 package de.jeanlucmakiola.calendula.ui.common
 
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.expandHorizontally
+import androidx.compose.animation.shrinkHorizontally
+import androidx.compose.animation.SizeTransform
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.togetherWith
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.BoxWithConstraints
 import androidx.compose.foundation.layout.Row
@@ -10,12 +18,12 @@ import androidx.compose.material.icons.filled.ArrowDropDown
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.Composable
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -33,7 +41,8 @@ import kotlinx.datetime.LocalDate
  * drawer uses and reporting the chosen day through [onJumpToDate].
  *
  * [currentDate] seeds the picker with whatever the bar is currently naming (the
- * visible day, week start or month anchor).
+ * visible day, week start or month anchor); null makes the title a plain label,
+ * as the agenda's is, and the caret folds away.
  *
  * [shortTitle] replaces [title] when the full one does not fit the width the app
  * bar hands the title slot (#165). Either way the line clamps to one and
@@ -42,7 +51,7 @@ import kotlinx.datetime.LocalDate
 @Composable
 fun CalendarTitleButton(
     title: String,
-    currentDate: LocalDate,
+    currentDate: LocalDate?,
     onJumpToDate: (LocalDate) -> Unit,
     modifier: Modifier = Modifier,
     shortTitle: String = title,
@@ -54,6 +63,7 @@ fun CalendarTitleButton(
             .heightIn(min = 48.dp)
             .clip(MaterialTheme.shapes.large)
             .clickable(
+                enabled = currentDate != null,
                 onClickLabel = stringResource(R.string.drawer_jump_to_date),
                 role = Role.Button,
             ) { showDatePicker = true }
@@ -71,21 +81,38 @@ fun CalendarTitleButton(
                     availableWidth = constraints.maxWidth,
                 )
             }
-            Text(
-                text = shown,
-                style = style,
-                maxLines = 1,
-                overflow = TextOverflow.Ellipsis,
+            // Cross-fades, so switching views or paging turns the title over
+            // rather than snapping it (#184).
+            val fadeSpec = rememberCalendarFadeSpec()
+            AnimatedContent(
+                targetState = shown,
+                transitionSpec = {
+                    (fadeIn(fadeSpec) togetherWith fadeOut(fadeSpec)).using(SizeTransform(clip = false))
+                },
+                contentAlignment = Alignment.CenterStart,
+            ) { text ->
+                Text(
+                    text = text,
+                    style = style,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                )
+            }
+        }
+        AnimatedVisibility(
+            visible = currentDate != null,
+            enter = fadeIn(rememberCalendarFadeSpec()) + expandHorizontally(),
+            exit = fadeOut(rememberCalendarFadeSpec()) + shrinkHorizontally(),
+        ) {
+            Icon(
+                imageVector = Icons.Default.ArrowDropDown,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
             )
         }
-        Icon(
-            imageVector = Icons.Default.ArrowDropDown,
-            contentDescription = null,
-            tint = MaterialTheme.colorScheme.onSurfaceVariant,
-        )
     }
 
-    if (showDatePicker) {
+    if (showDatePicker && currentDate != null) {
         CalendarDatePickerDialog(
             initial = currentDate,
             onConfirm = {

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

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.common
 
 import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.animation.core.spring
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
@@ -52,3 +53,19 @@ fun rememberCalendarPageSpec(): FiniteAnimationSpec<Float> =
 @Composable
 fun rememberCalendarFadeSpec(): FiniteAnimationSpec<Float> =
     MaterialTheme.motionScheme.defaultEffectsSpec()
+
+/**
+ * A switch between views (#184): the default spatial spring, a little softer, as
+ * the whole screen reshapes rather than a page sliding by; softer still when
+ * [long], for a change the eye has further to follow.
+ */
+@Composable
+fun <T> rememberViewSwitchSpec(long: Boolean = false): FiniteAnimationSpec<T> =
+    spring(
+        dampingRatio = VIEW_SWITCH_DAMPING,
+        stiffness = if (long) LONG_VIEW_SWITCH_STIFFNESS else VIEW_SWITCH_STIFFNESS,
+    )
+
+private const val VIEW_SWITCH_DAMPING = 0.9f
+private const val VIEW_SWITCH_STIFFNESS = 450f
+private const val LONG_VIEW_SWITCH_STIFFNESS = 340f

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

@@ -129,3 +129,16 @@ fun viewBaseStack(default: CalendarView, source: CalendarView): List<CalendarVie
 /** Push the day view as a drill-in over the current stack (no-op if already on it). */
 fun List<CalendarView>.drillToDay(): List<CalendarView> =
     if (lastOrNull() == CalendarView.Day) this else this + CalendarView.Day
+
+/** The screens the views are drawn by: the day, multi-day and week views share one timeline (#184). */
+enum class ViewScreen { Month, Timeline, Agenda }
+
+val CalendarView.screen: ViewScreen
+    get() = when (this) {
+        CalendarView.Month -> ViewScreen.Month
+        CalendarView.Agenda -> ViewScreen.Agenda
+        CalendarView.Week, CalendarView.MultiDay, CalendarView.Day -> ViewScreen.Timeline
+    }
+/** Push the week view over the month after a week-number tap. */
+fun List<CalendarView>.drillToWeek(): List<CalendarView> =
+    if (lastOrNull() == CalendarView.Week) this else this + CalendarView.Week

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

@@ -59,7 +59,11 @@ internal fun hourCellRadiusPx(cellHeight: Float, cellWidth: Float, maxRadius: Fl
  * coordinate space and keep spanning cells. [hourHeightPx] is one hour's pixel
  * height; [color] is resolved by the caller from the theme.
  */
-fun Modifier.hourGridCells(show: Boolean, hourHeightPx: Float, color: Color): Modifier =
+fun Modifier.hourGridCells(
+    show: Boolean,
+    hourHeightPx: Float,
+    color: Color,
+): Modifier =
     if (!show) {
         this
     } else {
@@ -71,10 +75,11 @@ fun Modifier.hourGridCells(show: Boolean, hourHeightPx: Float, color: Color): Mo
                 hourCellRadiusPx(cellHeight, size.width, HOUR_CELL_CORNER.toPx()),
             )
             val cellSize = Size(size.width, cellHeight)
+            val top = inset
             for (hour in 0 until 24) {
                 drawRoundRect(
                     color = color,
-                    topLeft = Offset(0f, hour * hourHeightPx + inset),
+                    topLeft = Offset(0f, hour * hourHeightPx + top),
                     size = cellSize,
                     cornerRadius = radius,
                 )

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

@@ -0,0 +1,328 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxScope
+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.shape.CircleShape
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.SideEffect
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.onClick
+import androidx.compose.ui.semantics.role
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.unit.dp
+import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.ui.week.TimedBlock
+import de.jeanlucmakiola.floret.identity.rememberReduceMotion
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+import kotlin.math.roundToInt
+
+/** Thickness of the out-of-view edge bar. */
+private val EDGE_BAR_THICKNESS = 3.dp
+
+/** Band the bar sits in, and the room a revealed event keeps from the edge. */
+private val EDGE_TOUCH_HEIGHT = 24.dp
+
+/** How far from the viewport's edge a tap on empty column still hits the bar. */
+private val EDGE_TAP_REACH = 16.dp
+
+/**
+ * How far the bar sits in from the viewport's edges — enough to clear the
+ * timeline's rounded 16dp corners on the outer columns.
+ */
+private val EDGE_BAR_VERTICAL_INSET = 4.dp
+private val EDGE_BAR_HORIZONTAL_INSET = 6.dp
+
+/** Distance outside the viewport over which a bar fades before its event appears. */
+private val EDGE_FADE_LEAD = 24.dp
+
+/** The nearest timed blocks wholly above and below a column's viewport. */
+@Immutable
+data class OutOfViewEvents(val above: TimedBlock?, val below: TimedBlock?) {
+    companion object {
+        val None = OutOfViewEvents(null, null)
+    }
+}
+
+/** Which edge of the viewport a hidden event sits past. */
+enum class ViewportEdge { Top, Bottom }
+
+/** Where [block]'s rendered bottom lands, in minutes — short blocks keep a floor. */
+internal fun renderedEndMin(block: TimedBlock): Float =
+    maxOf(block.endMin.toFloat(), block.startMin + MIN_EVENT_FRACTION * 60f)
+
+/**
+ * The blocks of one column lying out of a viewport spanning [topMin]..[bottomMin]
+ * (minutes of the day), nearest first. A block leaves this set as soon as any
+ * part of its rendered height enters the viewport.
+ */
+fun outOfViewEvents(
+    blocks: List<TimedBlock>,
+    topMin: Float,
+    bottomMin: Float,
+): OutOfViewEvents {
+    val above = blocks
+        .filter { renderedEndMin(it) <= topMin }
+        .maxWithOrNull(compareBy<TimedBlock>({ renderedEndMin(it) }, { it.startMin }))
+    val below = blocks
+        .filter { it.startMin >= bottomMin }
+        .minWithOrNull(compareBy<TimedBlock>({ it.startMin }, { -renderedEndMin(it) }))
+    return OutOfViewEvents(above, below)
+}
+
+/**
+ * The scroll offset that brings [block] into a [viewportPx]-tall viewport from
+ * past [edge], with [marginPx] of room so it clears the edge bar. An event above
+ * lands with its start at the top; one below lands whole at the bottom when it
+ * fits, and with its start at the top when it does not.
+ */
+fun revealScrollTarget(
+    block: TimedBlock,
+    edge: ViewportEdge,
+    hourPx: Float,
+    viewportPx: Int,
+    marginPx: Float,
+    maxScroll: Int,
+): Int {
+    val startPx = block.startMin / 60f * hourPx
+    val endPx = renderedEndMin(block) / 60f * hourPx
+    val target = when (edge) {
+        ViewportEdge.Top -> startPx - marginPx
+        ViewportEdge.Bottom -> minOf(endPx + marginPx - viewportPx, startPx - marginPx)
+    }
+    return target.roundToInt().coerceIn(0, maxOf(maxScroll, 0))
+}
+
+/**
+ * The edge whose bar a tap at [y] (content px) lands on, if that bar is showing
+ * and the tap is within [reachPx] of the viewport's edge.
+ */
+fun tappedEdge(
+    events: OutOfViewEvents,
+    y: Float,
+    viewportTop: Float,
+    viewportPx: Int,
+    reachPx: Float,
+): ViewportEdge? = when {
+    events.above != null && y - viewportTop <= reachPx -> ViewportEdge.Top
+    events.below != null && viewportTop + viewportPx - y <= reachPx -> ViewportEdge.Bottom
+    else -> null
+}
+
+/** Fade while the event is still outside; never draw its bar at the boundary. */
+internal fun edgeBarAlpha(gapPx: Float, fadeLeadPx: Float): Float = when {
+    gapPx <= 0f -> 0f
+    fadeLeadPx <= 0f -> 1f
+    else -> (gapPx / fadeLeadPx).coerceIn(0f, 1f)
+}
+
+/**
+ * The out-of-view state of one day column (#188): which events hide past its
+ * edges, and the scroll that reveals them.
+ *
+ * The bars take no touches themselves, so event blocks under them keep their
+ * taps and drags; the column's own tap handler offers taps to [tap] first.
+ */
+@Stable
+class OutOfViewEdges internal constructor(
+    private val scrollState: ScrollState,
+    private val scope: CoroutineScope,
+) {
+    internal var blocks by mutableStateOf(emptyList<TimedBlock>())
+    internal var hourPx by mutableFloatStateOf(0f)
+    internal var fadeLeadPx by mutableFloatStateOf(0f)
+    internal var marginPx by mutableFloatStateOf(0f)
+    internal var reachPx by mutableFloatStateOf(0f)
+    internal var reduceMotion = false
+    internal var revealSpec: FiniteAnimationSpec<Float>? = null
+
+    val events: OutOfViewEvents by derivedStateOf {
+        val viewport = scrollState.viewportSize
+        if (viewport <= 0 || hourPx <= 0f) {
+            OutOfViewEvents.None
+        } else {
+            val top = scrollState.value.toFloat()
+            outOfViewEvents(
+                blocks = blocks,
+                topMin = top / hourPx * 60f,
+                bottomMin = (top + viewport) / hourPx * 60f,
+            )
+        }
+    }
+
+    /** Scrolls the event hidden past [edge] into view, if there is one. */
+    fun reveal(edge: ViewportEdge) {
+        val block = if (edge == ViewportEdge.Top) events.above else events.below
+        block ?: return
+        val target = revealScrollTarget(
+            block = block,
+            edge = edge,
+            hourPx = hourPx,
+            viewportPx = scrollState.viewportSize,
+            marginPx = marginPx,
+            maxScroll = scrollState.maxValue,
+        )
+        val spec = revealSpec
+        scope.launch {
+            if (reduceMotion || spec == null) {
+                scrollState.scrollTo(target)
+            } else {
+                scrollState.animateScrollTo(target, spec)
+            }
+        }
+    }
+
+    /** Reveals the hidden event if a tap at [y] (content px) lands on a bar. */
+    fun tap(y: Float): Boolean {
+        val edge = tappedEdge(
+            events = events,
+            y = y,
+            viewportTop = scrollState.value.toFloat(),
+            viewportPx = scrollState.viewportSize,
+            reachPx = reachPx,
+        ) ?: return false
+        reveal(edge)
+        return true
+    }
+}
+
+@Composable
+fun rememberOutOfViewEdges(
+    blocks: List<TimedBlock>,
+    scrollState: ScrollState,
+    hourPx: Float,
+): OutOfViewEdges {
+    val scope = rememberCoroutineScope()
+    val edges = remember(scrollState, scope) { OutOfViewEdges(scrollState, scope) }
+    val density = LocalDensity.current
+    val reduceMotion = rememberReduceMotion()
+    val revealSpec = rememberCalendarPageSpec()
+    SideEffect {
+        edges.blocks = blocks
+        edges.hourPx = hourPx
+        edges.fadeLeadPx = with(density) { EDGE_FADE_LEAD.toPx() }
+        edges.marginPx = with(density) { EDGE_TOUCH_HEIGHT.roundToPx().toFloat() }
+        edges.reachPx = with(density) { EDGE_TAP_REACH.toPx() }
+        edges.reduceMotion = reduceMotion
+        edges.revealSpec = revealSpec
+    }
+    return edges
+}
+
+/**
+ * Thin bars at the top and bottom of a day column's visible viewport, tinted in
+ * the colour of the nearest timed event hidden past that edge (#188).
+ *
+ * Lives inside the column's scrolling content and follows the viewport by
+ * offsetting against [scrollState] at placement rather than recomposing every
+ * frame. Opacity follows the gap to the hidden event and reaches zero before
+ * the event enters view. Taps reach it through [OutOfViewEdges.tap]; screen
+ * readers get a button.
+ */
+@Composable
+fun BoxScope.OutOfViewEdgeBars(
+    edges: OutOfViewEdges,
+    scrollState: ScrollState,
+    dark: Boolean,
+) {
+    val touchPx = with(LocalDensity.current) { EDGE_TOUCH_HEIGHT.roundToPx() }
+    val events = edges.events
+    EdgeBar(
+        block = events.above,
+        edge = ViewportEdge.Top,
+        dark = dark,
+        onReveal = edges::reveal,
+        scrollState = scrollState,
+        hourPx = edges.hourPx,
+        fadeLeadPx = edges.fadeLeadPx,
+        modifier = Modifier
+            .align(Alignment.TopStart)
+            .offset { IntOffset(0, scrollState.value) },
+    )
+    EdgeBar(
+        block = events.below,
+        edge = ViewportEdge.Bottom,
+        dark = dark,
+        onReveal = edges::reveal,
+        scrollState = scrollState,
+        hourPx = edges.hourPx,
+        fadeLeadPx = edges.fadeLeadPx,
+        modifier = Modifier
+            .align(Alignment.TopStart)
+            .offset { IntOffset(0, scrollState.value + scrollState.viewportSize - touchPx) },
+    )
+}
+
+@Composable
+private fun EdgeBar(
+    block: TimedBlock?,
+    edge: ViewportEdge,
+    dark: Boolean,
+    onReveal: (ViewportEdge) -> Unit,
+    scrollState: ScrollState,
+    hourPx: Float,
+    fadeLeadPx: Float,
+    modifier: Modifier = Modifier,
+) {
+    block ?: return
+    val color = eventFill(block.event.color, dark, LocalSoftenColors.current)
+    val label = stringResource(
+        if (edge == ViewportEdge.Top) R.string.timeline_earlier_events else R.string.timeline_later_events,
+    )
+    Box(
+        modifier = modifier
+            .fillMaxWidth()
+            .height(EDGE_TOUCH_HEIGHT)
+            .graphicsLayer {
+                val gapPx = when (edge) {
+                    ViewportEdge.Top -> scrollState.value - renderedEndMin(block) / 60f * hourPx
+                    ViewportEdge.Bottom -> block.startMin / 60f * hourPx -
+                        (scrollState.value + scrollState.viewportSize)
+                }
+                alpha = edgeBarAlpha(gapPx, fadeLeadPx)
+            }
+            .semantics {
+                role = Role.Button
+                contentDescription = label
+                onClick {
+                    onReveal(edge)
+                    true
+                }
+            },
+        contentAlignment = if (edge == ViewportEdge.Top) Alignment.TopCenter else Alignment.BottomCenter,
+    ) {
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(
+                    horizontal = EDGE_BAR_HORIZONTAL_INSET,
+                    vertical = EDGE_BAR_VERTICAL_INSET,
+                )
+                .height(EDGE_BAR_THICKNESS)
+                .background(color, CircleShape),
+        )
+    }
+}

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

@@ -0,0 +1,58 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import kotlin.math.abs
+import kotlin.math.roundToInt
+
+/**
+ * The hours the week and day timelines fit to the screen when they open (#322).
+ *
+ * Nothing outside the range is hidden: [TimelineScale.FitHours] only sizes the
+ * hour so that [startHour]..[endHour] fills the viewport, and the timeline opens
+ * scrolled to [startHour]. The hours are kept when [enabled] is switched off, so
+ * switching it back on restores the chosen range.
+ */
+data class TimelineHours(
+    val enabled: Boolean = false,
+    val startHour: Int = DEFAULT_START_HOUR,
+    val endHour: Int = DEFAULT_END_HOUR,
+) {
+    val span: Int get() = endHour - startHour
+
+    companion object {
+        const val DEFAULT_START_HOUR = 7
+        const val DEFAULT_END_HOUR = 22
+
+        /** Shortest range that can be chosen, in hours. */
+        const val MIN_SPAN = 2
+
+        /**
+         * A range with [startHour] and [endHour] held to the day and at least
+         * [MIN_SPAN] apart; the start gives way when the two collide.
+         */
+        fun of(enabled: Boolean, startHour: Int, endHour: Int): TimelineHours {
+            val end = endHour.coerceIn(MIN_SPAN, 24)
+            val start = startHour.coerceIn(0, end - MIN_SPAN)
+            return TimelineHours(enabled, start, end)
+        }
+
+        /** Start hours that still leave [MIN_SPAN] before [endHour]. */
+        fun startOptions(endHour: Int): List<Int> = (0..endHour - MIN_SPAN).toList()
+
+        /** End hours at least [MIN_SPAN] after [startHour]; 24 is midnight. */
+        fun endOptions(startHour: Int): List<Int> = (startHour + MIN_SPAN..24).toList()
+    }
+}
+
+/**
+ * The scroll offset that puts [startHour] at the top of a timeline laid out
+ * with [maxValue] scroll range over a [viewportPx] viewport, or null while that
+ * layout is not yet at [hourPx] per hour — the scale changes a frame before the
+ * content grows to match it, and scrolling against the old layout would land on
+ * the wrong hour.
+ */
+internal fun startHourScroll(maxValue: Int, viewportPx: Int, startHour: Int, hourPx: Float): Int? {
+    if (viewportPx <= 0 || maxValue < 0 || maxValue == Int.MAX_VALUE) return null
+    val laidOutHourPx = (maxValue + viewportPx) / 24f
+    if (abs(laidOutHourPx - hourPx) > 1f) return null
+    return (startHour * laidOutHourPx).roundToInt().coerceIn(0, maxValue)
+}

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

@@ -38,6 +38,12 @@ sealed interface TimelineScale {
     /** A height the user pinched to. Build it through [custom], which clamps. */
     data class Custom(val hourHeight: Dp) : TimelineScale
 
+    /**
+     * [startHour]..[endHour] fills the viewport (#322). Applied when a timeline
+     * opens with [TimelineHours] on, never picked from the preset list.
+     */
+    data class FitHours(val startHour: Int, val endHour: Int) : TimelineScale
+
     companion object {
         /** The named steps the settings picker offers, coarse to roomy. */
         val presets: List<TimelineScale> = listOf(FitDay, Compact, Regular, Comfortable)
@@ -74,6 +80,9 @@ fun TimelineScale.hourHeight(viewportHeight: Dp): Dp = when (this) {
     is TimelineScale.Custom -> this.hourHeight
         .coerceAtMost(MAX_PINCH_HOUR_HEIGHT)
         .coerceAtLeast(fillHourHeight(viewportHeight))
+    is TimelineScale.FitHours -> (viewportHeight / (endHour - startHour).coerceIn(1, 24).toFloat())
+        .coerceAtMost(MAX_PINCH_HOUR_HEIGHT)
+        .coerceAtLeast(fillHourHeight(viewportHeight))
 }
 
 /**
@@ -134,6 +143,7 @@ val TimelineScale.labelRes: Int
         TimelineScale.Regular -> R.string.timeline_scale_regular
         TimelineScale.Comfortable -> R.string.timeline_scale_comfortable
         is TimelineScale.Custom -> R.string.timeline_scale_custom
+        is TimelineScale.FitHours -> R.string.settings_visible_hours
     }
 
 @get:StringRes
@@ -144,11 +154,15 @@ val TimelineScale.descriptionRes: Int
         TimelineScale.Regular -> R.string.timeline_scale_regular_summary
         TimelineScale.Comfortable -> R.string.timeline_scale_comfortable_summary
         is TimelineScale.Custom -> R.string.timeline_scale_custom_summary
+        is TimelineScale.FitHours -> R.string.settings_visible_hours_summary
     }
 
 /** Marks a stored custom height; the rest of the value is its dp. */
 private const val CUSTOM_PREFIX = "custom:"
 
+/** Marks a stored hour range, as `start-end`. */
+private const val HOURS_PREFIX = "hours:"
+
 /**
  * Stored names for the presets. Spelled out rather than taken from `toString()`
  * so R8 can't rename them out from under an existing install — and they match
@@ -171,6 +185,7 @@ private val PRESET_NAMES: Map<TimelineScale, String> = mapOf(
  */
 fun TimelineScale.storageValue(): String = when (this) {
     is TimelineScale.Custom -> CUSTOM_PREFIX + hourHeight.value
+    is TimelineScale.FitHours -> "$HOURS_PREFIX$startHour-$endHour"
     TimelineScale.FitDay,
     TimelineScale.Compact,
     TimelineScale.Regular,
@@ -188,5 +203,11 @@ fun parseTimelineScale(stored: String?): TimelineScale = when {
     stored.startsWith(CUSTOM_PREFIX) -> stored.removePrefix(CUSTOM_PREFIX).toFloatOrNull()
         ?.let { TimelineScale.custom(it.dp) }
         ?: TimelineScale.Regular
+    stored.startsWith(HOURS_PREFIX) -> stored.removePrefix(HOURS_PREFIX).split('-')
+        .mapNotNull { it.toIntOrNull() }
+        .takeIf { it.size == 2 }
+        ?.let { (start, end) -> TimelineHours.of(enabled = true, start, end) }
+        ?.let { TimelineScale.FitHours(it.startHour, it.endHour) }
+        ?: TimelineScale.Regular
     else -> PRESET_NAMES.entries.firstOrNull { it.value == stored }?.key ?: TimelineScale.Regular
 }

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

@@ -0,0 +1,101 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.Dp
+import kotlinx.coroutines.flow.filterNotNull
+import kotlinx.coroutines.flow.first
+import kotlin.math.roundToInt
+
+/**
+ * Where 00:00 sat in the last timeline shown, measured from the top of its
+ * view's content, so the next timeline view opens on the same hours (#184): an
+ * event in both keeps its place and only grows sideways.
+ */
+class TimelineScrollMemory {
+    var midnightY: Float? = null
+}
+
+val LocalTimelineScroll = staticCompositionLocalOf<TimelineScrollMemory?> { null }
+
+/** A timeline's scroll, and where it opens before it can scroll there. */
+@Stable
+class TimelineScroll(val state: ScrollState, noonPending: Boolean, private val openingHour: Int?) {
+    /** Whether it is still to be put on noon, which it only can be once laid out. */
+    var noonPending by mutableStateOf(noonPending)
+        internal set
+
+    /** The top of what it shows, or will once open, over [content] pixels in a [viewport] pixels high. */
+    fun top(viewport: Float, content: Float): Float =
+        if (noonPending) {
+            (openingHour?.let { it * content / 24f } ?: (content - viewport) / 2f)
+                .coerceIn(0f, (content - viewport).coerceAtLeast(0f))
+        } else state.value.toFloat()
+}
+
+val LocalOpeningTimeline = staticCompositionLocalOf<TimelineScroll?> { null }
+
+/**
+ * The scroll state of a timeline whose scrolling area starts [timelineTop] below
+ * its view's content top. Opens where the last timeline left off, or on noon the
+ * first time.
+ */
+@Composable
+fun rememberTimelineScrollState(timelineTop: Dp): TimelineScroll {
+    val memory = LocalTimelineScroll.current
+    val density = LocalDensity.current
+    val zoom = LocalTimelineZoom.current
+    val topPx = with(density) { timelineTop.toPx() }
+    val remembered = memory?.midnightY
+    val scrollState = rememberScrollState(
+        initial = remembered?.let { (topPx - it).roundToInt().coerceAtLeast(0) } ?: 0,
+    )
+    val scroll = remember(scrollState) {
+        TimelineScroll(
+            scrollState,
+            noonPending = remembered == null,
+            openingHour = zoom.hours.takeIf { it.enabled }?.startHour,
+        )
+    }
+    val currentTop by rememberUpdatedState(topPx)
+    var firstOpen by remember(scrollState) { mutableStateOf(true) }
+    LaunchedEffect(scrollState, zoom, zoom.hours) {
+        if (firstOpen && remembered != null) {
+            firstOpen = false
+            return@LaunchedEffect
+        }
+        firstOpen = false
+        val startHour = zoom.open()
+        if (startHour == null) {
+            snapshotFlow { scrollState.maxValue }.first { it > 0 }
+            scrollState.scrollTo(scrollState.maxValue / 2)
+        } else {
+            val (target, hourHeight) = snapshotFlow {
+                val viewport = scrollState.viewportSize
+                val hourHeight = zoom.scale.hourHeight(with(density) { viewport.toDp() })
+                val hourPx = with(density) { hourHeight.toPx() }
+                startHourScroll(scrollState.maxValue, viewport, startHour, hourPx)?.let { it to hourHeight }
+            }.filterNotNull().first()
+            scrollState.scrollTo(target)
+            zoom.holdFit(hourHeight)
+        }
+        scroll.noonPending = false
+    }
+    if (memory != null) {
+        LaunchedEffect(scrollState, memory) {
+            snapshotFlow { currentTop - scrollState.value }.collect { memory.midnightY = it }
+        }
+    }
+    return scroll
+}

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

@@ -49,13 +49,49 @@ class TimelineZoom(
     var isPinching: Boolean by mutableStateOf(false)
         private set
 
+    /** The visible-hours preference (#322); a timeline re-fits when it changes. */
+    var hours: TimelineHours by mutableStateOf(TimelineHours())
+        private set
+
+    private var stored: TimelineScale = initial
+
     /**
      * Take a value that came from the preference. Ignored mid-pinch: the stored
      * value is a frame or two behind the fingers there, and letting it land would
-     * snap the timeline back while the user is still pinching.
+     * snap the timeline back while the user is still pinching. With visible
+     * hours on it is only remembered, so a late-arriving preference can't undo
+     * the fit a timeline just opened with.
      */
     fun adopt(stored: TimelineScale) {
-        if (!isPinching) scale = stored
+        this.stored = stored
+        if (!isPinching && !hours.enabled) scale = stored
+    }
+
+    /** Take the visible-hours preference; switching it off hands back the stored scale. */
+    fun adoptHours(hours: TimelineHours) {
+        val wasEnabled = this.hours.enabled
+        this.hours = hours
+        if (wasEnabled && !hours.enabled && !isPinching) scale = stored
+    }
+
+    /**
+     * A timeline is opening. With visible hours on, the range replaces whatever
+     * scale is in force — a stored preset and a pinch alike — and its start hour
+     * is returned for the timeline to scroll to; otherwise null.
+     */
+    fun open(): Int? {
+        val hours = hours
+        if (!hours.enabled) return null
+        if (!isPinching) scale = TimelineScale.FitHours(hours.startHour, hours.endHour)
+        return hours.startHour
+    }
+
+    /**
+     * Holds the height [open] fitted, so a viewport that changes afterwards (the
+     * all-day strip following a swipe) doesn't rescale the hours under the scroll.
+     */
+    fun holdFit(hourHeight: Dp) {
+        if (!isPinching && scale is TimelineScale.FitHours) scale = TimelineScale.Custom(hourHeight)
     }
 
     fun beginPinch() {
@@ -66,9 +102,10 @@ class TimelineZoom(
         scale = TimelineScale.custom(hourHeight)
     }
 
+    /** Settles the pinch. With visible hours on it only lasts until the next [open]. */
     fun endPinch() {
         isPinching = false
-        persist(scale)
+        if (!hours.enabled) persist(scale)
     }
 }
 
@@ -82,16 +119,18 @@ private val DetachedTimelineZoom by lazy { TimelineZoom(TimelineScale.Regular) {
 val LocalTimelineZoom = staticCompositionLocalOf { DetachedTimelineZoom }
 
 /**
- * The app-wide [TimelineZoom], seeded from [stored] and writing settled pinches
- * back through [onPersist].
+ * The app-wide [TimelineZoom], seeded from [stored] and [hours] and writing
+ * settled pinches back through [onPersist].
  */
 @Composable
 fun rememberTimelineZoom(
     stored: TimelineScale,
+    hours: TimelineHours,
     onPersist: (TimelineScale) -> Unit,
 ): TimelineZoom {
     val persist by rememberUpdatedState(onPersist)
     val zoom = remember { TimelineZoom(stored) { persist(it) } }
+    LaunchedEffect(hours) { zoom.adoptHours(hours) }
     // Picking a preset in Settings has to reach the timelines, and so does the
     // stored value arriving after the first frame.
     LaunchedEffect(stored) { zoom.adopt(stored) }

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

@@ -7,9 +7,9 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.Text
+import androidx.compose.runtime.getValue
 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
@@ -59,7 +59,8 @@ fun TodayAction(show: Boolean, onToday: () -> Unit) {
     val description = stringResource(R.string.today_jump_action)
     IconButton(
         onClick = onToday,
-        modifier = Modifier.semantics { contentDescription = description },
+        modifier = Modifier
+            .semantics { contentDescription = description },
     ) {
         val textSize = with(LocalDensity.current) { GlyphTextHeight.toSp() }
         Box(

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

@@ -0,0 +1,49 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.Saver
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.staticCompositionLocalOf
+import kotlinx.datetime.LocalDate
+
+/**
+ * The date every calendar view is looking at (#184), so switching views keeps
+ * the same days on screen and what is shown in both can travel between them.
+ *
+ * A view reads it once, as it comes on screen, and writes it back only when the
+ * user moves: a view settling where it opened must not nudge it, or switching
+ * back and forth would drift.
+ */
+@Stable
+class ViewFocus(initial: LocalDate) {
+    var date by mutableStateOf(initial)
+    /** Explicit navigation, including a request for the view already on screen. */
+    var navigationVersion by mutableStateOf(0)
+        private set
+
+    fun navigateTo(target: LocalDate) {
+        date = target
+        navigationVersion++
+    }
+}
+
+val ViewFocusSaver: Saver<ViewFocus, String> = Saver(
+    save = { it.date.toString() },
+    restore = { ViewFocus(LocalDate.parse(it)) },
+)
+
+val LocalViewFocus = staticCompositionLocalOf<ViewFocus?> { null }
+
+/**
+ * Runs [enter] with the focused date once, as the view comes on screen, before
+ * it reads its own position: its first frame is then already on that date.
+ */
+@Composable
+fun <T : Any> EnterOnFocus(key: T, enter: (LocalDate) -> Unit) {
+    val focus = LocalViewFocus.current
+    remember(key) { focus?.date?.also(enter) }
+}

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

@@ -0,0 +1,166 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.animation.AnimatedVisibilityScope
+import androidx.compose.animation.BoundsTransform
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionScope
+import androidx.compose.animation.core.FiniteAnimationSpec
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.mutableStateSetOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Rect
+import androidx.compose.ui.graphics.Path
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.LayoutDirection
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+
+/**
+ * What the views share when switching between them (#184): an event visible in
+ * both grows from where it sat into where it lands, a date label travels to its
+ * new seat, and everything else fades through.
+ *
+ * An element is tagged with the day it is drawn *from*, not just its instance: a
+ * multi-day event is drawn once per day, per week row or per timeline column,
+ * and only one element per key may take part. The segment that starts on the
+ * same day in both views is the one that travels; the rest fade where they are.
+ */
+sealed interface ViewMorphKey {
+    data class Event(val eventId: Long, val beginMillis: Long, val day: LocalDate) : ViewMorphKey
+
+    data class Day(val date: LocalDate) : ViewMorphKey
+
+
+    companion object {
+        /** [event]'s occurrence as drawn from [day]. */
+        fun event(event: EventInstance, day: LocalDate): Event =
+            Event(event.eventId, event.start.toEpochMilliseconds(), day)
+    }
+}
+
+/** The view switch's scopes and specs, captured where they exist. Null under reduced motion. */
+@OptIn(ExperimentalSharedTransitionApi::class)
+class ViewMorphScope(
+    val shared: SharedTransitionScope,
+    val visibility: AnimatedVisibilityScope,
+    val boundsTransform: BoundsTransform,
+    val fadeSpec: FiniteAnimationSpec<Float>,
+    val clip: BelowTopBarClip,
+    val stayingPut: StayingPut,
+)
+
+/**
+ * The events a view has but keeps out of the switch, being scrolled out of
+ * sight: the other view leaves them untagged too, or its half would travel to
+ * nowhere and snap into place at the end.
+ */
+class StayingPut {
+    val keys = mutableStateSetOf<ViewMorphKey.Event>()
+}
+
+/** Marks [key] as staying put while [stays], for as long as it is composed. */
+@Composable
+fun StayPut(key: ViewMorphKey.Event, stays: Boolean) {
+    val stayingPut = LocalViewMorph.current?.stayingPut ?: return
+    if (!stays) return
+    DisposableEffect(stayingPut, key) {
+        stayingPut.keys += key
+        onDispose { stayingPut.keys -= key }
+    }
+}
+
+/**
+ * Keeps what travels below the top bar, which every view has at the same height:
+ * the overlay draws above the whole screen, so an event scrolled under the bar
+ * would otherwise cross it. [top] is the bar's bottom edge in the shared layout.
+ */
+@OptIn(ExperimentalSharedTransitionApi::class)
+class BelowTopBarClip : SharedTransitionScope.OverlayClip {
+    var top = 0f
+
+    override fun getClipPath(
+        sharedContentState: SharedTransitionScope.SharedContentState,
+        bounds: Rect,
+        layoutDirection: LayoutDirection,
+        density: Density,
+    ): Path = Path().apply { addRect(Rect(-FAR, top, FAR, FAR)) }
+
+    private companion object {
+        const val FAR = 1e6f
+    }
+}
+
+val LocalViewMorph = compositionLocalOf<ViewMorphScope?> { null }
+
+/**
+ * Whether a pager page may carry the morph tags: only the settled one. Its
+ * neighbours are composed ahead and repeat some of its dates, which would both
+ * claim its keys and fly in from off screen.
+ */
+fun morphPageActive(page: Int, settledPage: Int): Boolean = page == settledPage
+
+/** Provides the view morph to [content] only while [active] — see [morphPageActive]. */
+@Composable
+fun ViewMorphPage(active: Boolean, content: @Composable () -> Unit) {
+    val morph = LocalViewMorph.current
+    CompositionLocalProvider(LocalViewMorph provides morph.takeIf { active }, content = content)
+}
+
+/**
+ * Tags an event chip, bar, block or row. Its bounds are shared and the two faces
+ * cross-fade inside them; remeasured rather than scaled, so a title keeps its
+ * real size and is clipped while there is no room, instead of smearing.
+ *
+ * Goes after the element's offset and before its size, so the travelling bounds
+ * drive the measurement.
+ */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+fun Modifier.morphEvent(key: ViewMorphKey.Event): Modifier {
+    val morph = LocalViewMorph.current ?: return this
+    if (key in morph.stayingPut.keys) return this
+    return with(morph.shared) {
+        this@morphEvent.sharedBounds(
+            sharedContentState = rememberSharedContentState(key),
+            animatedVisibilityScope = morph.visibility,
+            enter = fadeIn(morph.fadeSpec),
+            exit = fadeOut(morph.fadeSpec),
+            boundsTransform = morph.boundsTransform,
+            clipInOverlayDuringTransition = morph.clip,
+            resizeMode = SharedTransitionScope.ResizeMode.RemeasureToBounds,
+            zIndexInOverlay = 1f,
+        )
+    }
+}
+
+/** Tags a day's number, which is small on both sides, so it scales on its way. */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+fun Modifier.morphDay(date: LocalDate): Modifier {
+    val morph = LocalViewMorph.current ?: return this
+    return with(morph.shared) {
+        this@morphDay.sharedBounds(
+            sharedContentState = rememberSharedContentState(ViewMorphKey.Day(date)),
+            animatedVisibilityScope = morph.visibility,
+            enter = fadeIn(morph.fadeSpec),
+            exit = fadeOut(morph.fadeSpec),
+            boundsTransform = morph.boundsTransform,
+            clipInOverlayDuringTransition = morph.clip,
+            zIndexInOverlay = 1f,
+        )
+    }
+}
+
+/** The view switch's travel, on the same spring as the timeline's columns resizing. */
+@OptIn(ExperimentalSharedTransitionApi::class)
+@Composable
+fun rememberViewMorphBoundsTransform(): BoundsTransform {
+    val spec = rememberViewSwitchSpec<Rect>()
+    return remember(spec) { BoundsTransform { _, _ -> spec } }
+}

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

@@ -1,12 +1,17 @@
 package de.jeanlucmakiola.calendula.ui.common
 
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.SizeTransform
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.togetherWith
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.Dp
 
 /**
@@ -30,11 +35,23 @@ fun ViewSwitcherPill(
     trailingInset: Dp = AppBarSpacing.ContainerTrailingInset,
 ) {
     if (cycle.size < QuickSwitchConfig.MIN_CYCLE) return
+    val fadeSpec = rememberCalendarFadeSpec()
     FilledTonalButton(
         onClick = onCycle,
         shape = MaterialTheme.shapes.large,
-        modifier = modifier.padding(end = trailingInset),
+        modifier = modifier
+            .padding(end = trailingInset),
     ) {
-        Text(current.label())
+        // The label cross-fades and the pill eases to its width, so cycling
+        // views turns it over rather than snapping it (#184).
+        AnimatedContent(
+            targetState = current.label(),
+            transitionSpec = {
+                (fadeIn(fadeSpec) togetherWith fadeOut(fadeSpec)).using(SizeTransform(clip = false))
+            },
+            contentAlignment = Alignment.Center,
+        ) { label ->
+            Text(label)
+        }
     }
 }

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

@@ -1,25 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.day
-
-import de.jeanlucmakiola.calendula.domain.FailureReason
-import de.jeanlucmakiola.calendula.ui.week.AllDaySpan
-import de.jeanlucmakiola.calendula.ui.week.TimedBlock
-import kotlinx.datetime.LocalDate
-
-/**
- * The day view is a single-column slice of the week view (spec S3). It reuses the
- * week's [TimedBlock] and [AllDaySpan] layout primitives — for one day, all-day
- * spans collapse to a single column ([AllDaySpan.startCol] == [AllDaySpan.endCol]
- * == 0) and only their [AllDaySpan.lane] (vertical stacking) matters.
- */
-sealed interface DayUiState {
-    data object Loading : DayUiState
-    data class Failure(val reason: FailureReason) : DayUiState
-    data class Success(
-        val date: LocalDate,
-        val today: LocalDate,
-        /** All-day/multi-day events covering this day, stacked by lane. */
-        val allDay: List<AllDaySpan>,
-        /** Timed events clipped to this day with overlap lanes resolved. */
-        val timed: List<TimedBlock>,
-    ) : DayUiState
-}

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

@@ -1,136 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.day
-
-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.di.IoDispatcher
-import de.jeanlucmakiola.calendula.domain.CalendarSource
-import de.jeanlucmakiola.calendula.domain.EventInstance
-import de.jeanlucmakiola.calendula.domain.FailureReason
-import de.jeanlucmakiola.calendula.domain.calendarListFailure
-import de.jeanlucmakiola.calendula.ui.common.PageStateCache
-import de.jeanlucmakiola.calendula.ui.week.layoutAllDay
-import de.jeanlucmakiola.calendula.ui.week.layoutDay
-import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-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.filterNot
-import kotlinx.coroutines.flow.flatMapLatest
-import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
-import kotlinx.datetime.LocalDate
-import kotlinx.datetime.TimeZone
-import kotlinx.datetime.atStartOfDayIn
-import kotlinx.datetime.atTime
-import kotlinx.datetime.daysUntil
-import kotlinx.datetime.toInstant
-import kotlinx.datetime.toLocalDateTime
-import kotlin.time.Clock
-import kotlin.time.Instant
-import javax.inject.Inject
-import kotlin.math.abs
-
-/** How far from the requested day [DayViewModel.day] keeps other days cached. */
-private const val DAY_CACHE_DAYS = 7
-
-@OptIn(ExperimentalCoroutinesApi::class)
-@HiltViewModel
-class DayViewModel @Inject constructor(
-    private val repository: CalendarRepository,
-    @IoDispatcher private val io: CoroutineDispatcher,
-) : ViewModel() {
-
-    private val zone = TimeZone.currentSystemDefault()
-
-    private val todayDate: LocalDate
-        get() = Clock.System.now().toLocalDateTime(zone).date
-
-    private val _date = MutableStateFlow(todayDate)
-
-    /** The pager page the anchor day sits on. */
-    val anchorPage: StateFlow<Int> = _date
-        .map { dayPageFor(it) }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = dayPageFor(todayDate),
-        )
-
-    /**
-     * The anchor day's state. Once loaded it never falls back to [DayUiState.Loading]:
-     * moving the anchor keeps the last result until the new day arrives, since
-     * the pages draw their own days and this only gates the failure screen.
-     */
-    val state: StateFlow<DayUiState> = _date
-        .flatMapLatest { date -> day(date).filterNot { it is DayUiState.Loading } }
-        .catch { emit(DayUiState.Failure(FailureReason.ProviderUnavailable)) }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = DayUiState.Loading,
-        )
-
-    private val days = PageStateCache<LocalDate, DayUiState>(
-        scope = viewModelScope,
-        initial = DayUiState.Loading,
-        // Far enough to cover the pages either side and a swipe back, so paging
-        // through a month doesn't keep a month of queries around.
-        keep = { cached, requested -> abs(cached.daysUntil(requested)) <= DAY_CACHE_DAYS },
-    ) { date ->
-        combine(
-            repository.calendars(),
-            repository.instances(dayRange(date, zone)),
-        ) { calendars, instances ->
-            buildState(date, calendars, instances)
-        }
-            .catch { emit(DayUiState.Failure(FailureReason.ProviderUnavailable)) }
-            .flowOn(io)
-    }
-
-    /** The day [date], shared between its pager page and [state]. Main thread only. */
-    fun day(date: LocalDate): StateFlow<DayUiState> = days.get(date)
-
-    /** The pager came to rest on [page]; follow it unless it is already the anchor's. */
-    fun onPageSettled(page: Int) {
-        if (dayPageFor(_date.value) != page) _date.value = dayForPage(page)
-    }
-
-    fun goToToday() {
-        _date.value = todayDate
-    }
-
-    /** Jump to a specific date (e.g. when opened from the month grid). */
-    fun goToDate(date: LocalDate) {
-        _date.value = date
-    }
-
-    private fun buildState(
-        day: LocalDate,
-        calendars: List<CalendarSource>,
-        instances: List<EventInstance>,
-    ): DayUiState {
-        calendarListFailure(calendars)?.let { return DayUiState.Failure(it) }
-        val days = listOf(day)
-        val allDay = instances.filter { it.isAllDay }
-        val timed = instances.filterNot { it.isAllDay }
-        return DayUiState.Success(
-            date = day,
-            today = todayDate,
-            allDay = layoutAllDay(allDay, days, zone),
-            timed = layoutDay(timed, day, zone),
-        )
-    }
-}
-
-/** Half-open instant range covering the single calendar [date]. */
-internal fun dayRange(date: LocalDate, zone: TimeZone): ClosedRange<Instant> {
-    val from = date.atStartOfDayIn(zone)
-    val to = date.atTime(23, 59, 59).toInstant(zone)
-    return from..to
-}

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

@@ -1,63 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.day
-
-import androidx.compose.foundation.rememberScrollState
-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,
-            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/detail/EventDetailScreen.kt

@@ -140,6 +140,7 @@ fun EventDetailScreen(
     onBack: () -> Unit,
     onEdit: () -> Unit,
     onDuplicate: (EventForm) -> Unit,
+    visible: Boolean = true,
     viewModel: EventDetailViewModel = hiltViewModel(),
 ) {
     LaunchedEffect(eventId, beginMillis, endMillis) {
@@ -227,7 +228,7 @@ fun EventDetailScreen(
     }
 
     Scaffold(
-        modifier = Modifier.predictiveBack(onBack = onBack),
+        modifier = Modifier.predictiveBack(onBack = onBack, visible = visible),
         snackbarHost = { SnackbarHost(snackbarHostState) },
         topBar = {
             TopAppBar(

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

@@ -203,6 +203,7 @@ fun EventEditScreen(
     initialForm: EventForm? = null,
     initialFormSource: ImportSource = ImportSource.File,
     onManageCalendars: (() -> Unit)? = null,
+    visible: Boolean = true,
     viewModel: EventEditViewModel = hiltViewModel(),
 ) {
     LaunchedEffect(initialDateIso, editKey, initialForm) {
@@ -285,7 +286,7 @@ fun EventEditScreen(
     }
 
     Scaffold(
-        modifier = Modifier.predictiveBack(onBack = close),
+        modifier = Modifier.predictiveBack(onBack = close, visible = visible),
         snackbarHost = { SnackbarHost(snackbarHostState) },
         topBar = {
             TopAppBar(

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

@@ -78,6 +78,7 @@ fun ImportScreen(
     onOpenSingle: (EventForm) -> Unit,
     forceMany: Boolean = false,
     onManageCalendars: (() -> Unit)? = null,
+    visible: Boolean = true,
     viewModel: ImportViewModel = hiltViewModel(),
 ) {
     // hiltViewModel() resolves to the Activity's store and is retained across
@@ -103,7 +104,7 @@ fun ImportScreen(
 
     Scaffold(
         modifier = Modifier
-            .predictiveBack(onBack = onClose)
+            .predictiveBack(onBack = onClose, visible = visible)
             .fillMaxSize(),
         topBar = {
             TopAppBar(

app/src/main/java/de/jeanlucmakiola/calendula/ui/licences/LicencesScreen.kt

@@ -23,13 +23,14 @@ import de.jeanlucmakiola.floret.components.positionOf
  * what the *recipient of the binary* is told. Each row opens the project's source.
  */
 @Composable
-internal fun LicencesScreen(onBack: () -> Unit) {
+internal fun LicencesScreen(onBack: () -> Unit, visible: Boolean = true) {
     val uriHandler = LocalUriHandler.current
 
     CollapsingScaffold(
         title = stringResource(R.string.licences_title),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         Text(
             stringResource(R.string.licences_intro),

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

@@ -13,6 +13,7 @@ import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.calendarListFailure
 import de.jeanlucmakiola.calendula.ui.common.PageStateCache
 import de.jeanlucmakiola.calendula.domain.isDeclined
+import de.jeanlucmakiola.calendula.domain.eventDisplayComparator
 import de.jeanlucmakiola.calendula.ui.week.coversDay
 import de.jeanlucmakiola.calendula.ui.week.layoutAllDay
 import de.jeanlucmakiola.calendula.ui.week.spansMultipleDays
@@ -292,12 +293,10 @@ class MonthViewModel @Inject constructor(
 
     // --- Split style (#53) ------------------------------------------------
     //
-    // The first selected-day concept in the app: the other views drill straight
-    // into a date, while the split style keeps one selected and lists it below
-    // the grid.
+    // Null means the full-month agenda; a date narrows the pane to that day.
 
-    private val _selectedDate = MutableStateFlow(todayDate)
-    val selectedDate: StateFlow<LocalDate> = _selectedDate
+    private val _selectedDate = MutableStateFlow<LocalDate?>(null)
+    val selectedDate: StateFlow<LocalDate?> = _selectedDate
 
     /**
      * Select [date], following it to its month if it sits in the grid's leading
@@ -305,23 +304,33 @@ class MonthViewModel @Inject constructor(
      * silently list a date the grid isn't pointing at.
      */
     fun selectDate(date: LocalDate) {
-        _selectedDate.value = date
         val target = YearMonth(date.year, date.month)
+        _selectedDate.value = if (target == _month.value && _selectedDate.value == date) null else date
         if (target != _month.value) _month.value = target
     }
 
-    /**
-     * Move the selection with the month: today if the new month holds it, else
-     * its 1st. Leaving the old date selected would list a day the grid no longer
-     * shows.
-     */
+    fun clearSelection() { _selectedDate.value = null }
+
+    /** A pane swipe walks days when filtered, months when showing the agenda. */
+    fun stepSplitPane(days: Int) {
+        val selected = _selectedDate.value
+        if (selected == null) {
+            _month.value = yearMonthForIndex(monthIndexOf(_month.value) + days)
+        } else {
+            val next = selected.plus(days, DateTimeUnit.DAY)
+            _selectedDate.value = next
+            _month.value = YearMonth(next.year, next.month)
+        }
+    }
+
+    /** Moving the grid to another month restores its full agenda. */
     private fun realignSelection() {
-        _selectedDate.value = selectionForMonth(_month.value, todayDate)
+        _selectedDate.value = null
     }
 
     fun goToToday() {
         _month.value = YearMonth(todayDate.year, todayDate.month)
-        _selectedDate.value = todayDate
+        _selectedDate.value = null
     }
 
     /**
@@ -330,13 +339,12 @@ class MonthViewModel @Inject constructor(
      * otherwise sit wherever paged navigation last left it (today's month, on a
      * fresh open) — and a switch to a paged style, or a reseed of the other
      * scrolling style's list, would jump there instead of holding position. The
-     * selection is realigned alongside it so that landing on the Split style
-     * shows a live day in the month on screen rather than a stale, off-month one.
+     * selection is cleared alongside it so Split opens the visible month's agenda.
      */
     fun syncScrollMonth(ym: YearMonth) {
         if (_month.value == ym) return
         _month.value = ym
-        _selectedDate.value = selectionForMonth(ym, todayDate)
+        _selectedDate.value = null
     }
 
     /** Jump to the month containing [date] (drawer jump-to-date). */
@@ -499,11 +507,7 @@ internal fun instancesByDay(
     days.associateWith { day ->
         instances
             .filter { it.coversDay(day, zone) }
-            .sortedWith(
-                compareBy<EventInstance> { it.isDeclined }
-                    .thenByDescending { it.isAllDay }
-                    .thenBy { it.start },
-            )
+            .sortedWith(eventDisplayComparator(zone))
     }
 
 /**
@@ -544,11 +548,10 @@ private const val WINDOW_EDGE = 2
 internal fun edgeForPad(pad: Int): Int = minOf(WINDOW_EDGE, pad - 1).coerceAtLeast(0)
 
 /**
- * Which day the split style should select when the grid lands on [month]:
- * [today] when the month holds it, otherwise the 1st. Pure so the rule can be
- * tested without standing up a view model and a provider behind it.
+ * First day shown in the split agenda: today in the current month, otherwise
+ * the first of the visible month.
  */
-internal fun selectionForMonth(month: YearMonth, today: LocalDate): LocalDate =
+internal fun agendaStartForMonth(month: YearMonth, today: LocalDate): LocalDate =
     if (YearMonth(today.year, today.month) == month) {
         today
     } else {

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

@@ -23,7 +23,6 @@ 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.label
-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
@@ -73,7 +72,7 @@ internal fun ViewStep(
                     height = PREVIEW_HEIGHT,
                     dayCount = LocalMultiDayCount.current,
                 )
-                CalendarView.Day -> DayViewPreview(height = PREVIEW_HEIGHT)
+                CalendarView.Day -> WeekViewPreview(weekStart = weekStart, height = PREVIEW_HEIGHT, dayCount = 1)
                 CalendarView.Agenda -> AgendaViewPreview(height = PREVIEW_HEIGHT)
             }
         }

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

@@ -126,6 +126,7 @@ fun SearchScreen(
     onBack: () -> Unit,
     onEventClick: (EventInstance) -> Unit,
     modifier: Modifier = Modifier,
+    visible: Boolean = true,
     viewModel: SearchViewModel = hiltViewModel(),
 ) {
     val query by viewModel.query.collectAsStateWithLifecycle()
@@ -184,7 +185,7 @@ fun SearchScreen(
     BackHandler(enabled = inSelection) { viewModel.clearSelection() }
 
     Scaffold(
-        modifier = modifier.predictiveBack(onBack = onBack, enabled = !inSelection),
+        modifier = modifier.predictiveBack(onBack = onBack, enabled = !inSelection, visible = visible),
         containerColor = MaterialTheme.colorScheme.surface,
         topBar = {
             SearchTopBar(

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

@@ -76,6 +76,7 @@ internal fun AppearanceScreen(
     state: SettingsUiState,
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    visible: Boolean = true,
 ) {
     var showTheme by remember { mutableStateOf(false) }
     var showBrandFont by remember { mutableStateOf(false) }
@@ -96,6 +97,7 @@ internal fun AppearanceScreen(
         title = stringResource(R.string.settings_section_appearance),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         // Theme & colour
         GroupedRow(

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

@@ -41,6 +41,7 @@ internal fun EventFormScreen(
     state: SettingsUiState,
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    visible: Boolean = true,
 ) {
     var showDefaultDuration by remember { mutableStateOf(false) }
     // The calendar whose duration-override picker is open, if any.
@@ -53,6 +54,7 @@ internal fun EventFormScreen(
         title = stringResource(R.string.settings_section_event_form),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         SettingsHint(stringResource(R.string.settings_form_fields_hint))
         Spacer(Modifier.height(8.dp))

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

@@ -63,6 +63,7 @@ internal fun NotificationsScreen(
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
     onOpenSpecialDates: () -> Unit,
+    visible: Boolean = true,
 ) {
     val context = LocalContext.current
     val launcher = rememberLauncherForActivityResult(
@@ -92,6 +93,7 @@ internal fun NotificationsScreen(
         title = stringResource(R.string.settings_section_notifications),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         GroupedRow(
             title = stringResource(R.string.settings_reminders),

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

@@ -2,9 +2,7 @@ package de.jeanlucmakiola.calendula.ui.settings
 
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.fadeIn
-import androidx.compose.animation.fadeOut
 import androidx.compose.animation.slideInHorizontally
-import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
@@ -66,6 +64,7 @@ import de.jeanlucmakiola.floret.crash.CrashReportDialog
 import de.jeanlucmakiola.floret.crash.CrashReporter
 import de.jeanlucmakiola.floret.crash.openIssueTracker
 import de.jeanlucmakiola.floret.crash.submitCrashReport
+import de.jeanlucmakiola.floret.identity.predictiveBackExit
 import de.jeanlucmakiola.floret.locale.AppLanguage
 
 /** The settings sub-screens reached from the hub's category rows. */
@@ -85,11 +84,14 @@ fun SettingsScreen(
     onManageCalendars: () -> Unit,
     onOpenBackup: () -> Unit,
     modifier: Modifier = Modifier,
+    visible: Boolean = true,
     viewModel: SettingsViewModel = hiltViewModel(),
 ) {
     val state by viewModel.state.collectAsStateWithLifecycle()
     var section by rememberSaveable { mutableStateOf<SettingsSection?>(null) }
     val slideSpec = rememberCalendarSlideSpec()
+    // Leaves from the predictive-back preview rather than sliding off at full size.
+    val overlayExit = predictiveBackExit()
 
     Box(
         modifier = modifier
@@ -101,61 +103,63 @@ fun SettingsScreen(
             onOpenSection = { section = it },
             onManageCalendars = onManageCalendars,
             onOpenBackup = onOpenBackup,
+            visible = visible,
         )
 
         AnimatedVisibility(
             visible = section == SettingsSection.Appearance,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            AppearanceScreen(state = state, viewModel = viewModel, onBack = { section = null })
+            AppearanceScreen(state = state, viewModel = viewModel, onBack = { section = null }, visible = section == SettingsSection.Appearance)
         }
         AnimatedVisibility(
             visible = section == SettingsSection.Views,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            ViewsScreen(state = state, viewModel = viewModel, onBack = { section = null })
+            ViewsScreen(state = state, viewModel = viewModel, onBack = { section = null }, visible = section == SettingsSection.Views)
         }
         AnimatedVisibility(
             visible = section == SettingsSection.EventForm,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            EventFormScreen(state = state, viewModel = viewModel, onBack = { section = null })
+            EventFormScreen(state = state, viewModel = viewModel, onBack = { section = null }, visible = section == SettingsSection.EventForm)
         }
         AnimatedVisibility(
             visible = section == SettingsSection.Notifications,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
             NotificationsScreen(
                 state = state,
                 viewModel = viewModel,
                 onBack = { section = null },
                 onOpenSpecialDates = { section = SettingsSection.SpecialDates },
+                visible = section == SettingsSection.Notifications,
             )
         }
         AnimatedVisibility(
             visible = section == SettingsSection.SpecialDates,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            SpecialDatesScreen(viewModel = viewModel, onBack = { section = null })
+            SpecialDatesScreen(viewModel = viewModel, onBack = { section = null }, visible = section == SettingsSection.SpecialDates)
         }
         AnimatedVisibility(
             visible = section == SettingsSection.Widgets,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            WidgetsScreen(state = state, viewModel = viewModel, onBack = { section = null })
+            WidgetsScreen(state = state, viewModel = viewModel, onBack = { section = null }, visible = section == SettingsSection.Widgets)
         }
         AnimatedVisibility(
             visible = section == SettingsSection.Licences,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+            exit = overlayExit,
         ) {
-            LicencesScreen(onBack = { section = null })
+            LicencesScreen(onBack = { section = null }, visible = section == SettingsSection.Licences)
         }
     }
 }
@@ -170,8 +174,14 @@ private fun SettingsHub(
     onOpenSection: (SettingsSection) -> Unit,
     onManageCalendars: () -> Unit,
     onOpenBackup: () -> Unit,
+    visible: Boolean,
 ) {
-    CollapsingScaffold(title = stringResource(R.string.settings_title), onBack = onBack, predictiveBack = true) {
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_title),
+        onBack = onBack,
+        predictiveBack = true,
+        visible = visible,
+    ) {
         // Card and support row are one grouped block, so the call to action
         // continues the container instead of sitting inside it as a button.
         Box(Modifier.padding(horizontal = GroupedListInset)) { AboutCard() }

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

@@ -13,6 +13,7 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.TimelineHours
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.calendula.widget.WidgetSize
@@ -64,6 +65,7 @@ data class SettingsUiState(
     val monthViewStyle: MonthViewStyle = MonthViewStyle.Paged,
     /** How tall an hour is drawn in the week and day timelines (#56). */
     val timelineScale: TimelineScale = TimelineScale.Regular,
+    val timelineHours: TimelineHours = TimelineHours(),
     /** Order of the views in the navigation drawer (#24); every view is always listed. */
     val drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     /** Optional event-form fields shown by default (rest behind "more fields"). */

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

@@ -36,6 +36,7 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.TimelineHours
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.calendula.ui.theme.AppFontSettings
@@ -180,9 +181,11 @@ class SettingsViewModel @Inject constructor(
                     prefs.drawerViewOrder,
                     prefs.monthViewStyle,
                     prefs.widgetSize,
-                    prefs.timelineScale,
-                ) { quickSwitch, drawer, monthStyle, widgetSize, timelineScale ->
-                    ViewCustomization(quickSwitch, drawer, monthStyle, widgetSize, timelineScale)
+                    combine(prefs.timelineScale, prefs.timelineHours, ::Pair),
+                ) { quickSwitch, drawer, monthStyle, widgetSize, (timelineScale, timelineHours) ->
+                    ViewCustomization(
+                        quickSwitch, drawer, monthStyle, widgetSize, timelineScale, timelineHours,
+                    )
                 },
             ) { showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization ->
                 MiscSettings(showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization)
@@ -209,6 +212,7 @@ class SettingsViewModel @Inject constructor(
                 monthViewStyle = misc.viewCustomization.monthViewStyle,
                 widgetSize = misc.viewCustomization.widgetSize,
                 timelineScale = misc.viewCustomization.timelineScale,
+                timelineHours = misc.viewCustomization.timelineHours,
                 allowColorOnUnsupportedCalendars = defaults.allowColor,
                 defaultReminderMinutes = defaults.defaultReminder,
                 defaultAllDayReminderMinutes = defaults.allDayReminder,
@@ -328,6 +332,7 @@ class SettingsViewModel @Inject constructor(
         val monthViewStyle: MonthViewStyle,
         val widgetSize: WidgetSize,
         val timelineScale: TimelineScale,
+        val timelineHours: TimelineHours,
     )
 
     /** Contact special-dates sub-page (issue #15); its own flow — the main state is full. */
@@ -626,6 +631,10 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.setTimelineScale(scale) }
     }
 
+    fun setTimelineHours(hours: TimelineHours) {
+        viewModelScope.launch { prefs.setTimelineHours(hours) }
+    }
+
     fun setDrawerViewOrder(order: List<CalendarView>) {
         viewModelScope.launch { prefs.setDrawerViewOrder(order) }
     }

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

@@ -46,6 +46,7 @@ import de.jeanlucmakiola.floret.reminders.ReminderOverride
 internal fun SpecialDatesScreen(
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    visible: Boolean = true,
 ) {
     val state by viewModel.specialDatesState.collectAsStateWithLifecycle()
     val settings by viewModel.state.collectAsStateWithLifecycle()
@@ -76,6 +77,7 @@ internal fun SpecialDatesScreen(
         title = stringResource(R.string.settings_section_special_dates),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         // Paused banner: the permission was revoked after enabling.
         if (state.enabled && state.stalledPermission) {

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

@@ -34,9 +34,12 @@ import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.PickerDescription
+import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
+import de.jeanlucmakiola.calendula.ui.common.TimelineHours
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.calendula.ui.common.descriptionRes
+import de.jeanlucmakiola.calendula.ui.common.formatMinuteOfDay
 import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
 import de.jeanlucmakiola.calendula.ui.common.icon
 import de.jeanlucmakiola.calendula.ui.common.label
@@ -65,6 +68,7 @@ internal fun ViewsScreen(
     state: SettingsUiState,
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    visible: Boolean = true,
 ) {
     var showMonthStyle by remember { mutableStateOf(false) }
     var showDefaultView by remember { mutableStateOf(false) }
@@ -74,11 +78,15 @@ internal fun ViewsScreen(
     var showAgendaScreenRange by remember { mutableStateOf(false) }
     var showTimelineScale by remember { mutableStateOf(false) }
     var showMultiDayCount by remember { mutableStateOf(false) }
+    var showHoursStart by remember { mutableStateOf(false) }
+    var showHoursEnd by remember { mutableStateOf(false) }
+    val hours = state.timelineHours
 
     CollapsingScaffold(
         title = stringResource(R.string.settings_section_views),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         val config = state.quickSwitchConfig
 
@@ -170,10 +178,49 @@ internal fun ViewsScreen(
         )
         GroupedRow(
             title = stringResource(R.string.settings_timeline_scale),
-            summary = stringResource(state.timelineScale.labelRes),
+            summary = if (hours.enabled) {
+                stringResource(R.string.settings_timeline_scale_by_visible_hours)
+            } else {
+                stringResource(state.timelineScale.labelRes)
+            },
             position = Position.Middle,
-            onClick = { showTimelineScale = true },
+            dimmed = hours.enabled,
+            onClick = if (hours.enabled) null else ({ showTimelineScale = true }),
         )
+        GroupedRow(
+            title = stringResource(R.string.settings_visible_hours),
+            summary = if (hours.enabled) {
+                stringResource(
+                    R.string.settings_visible_hours_on_summary,
+                    hourLabel(hours.startHour),
+                    hourLabel(hours.endHour),
+                )
+            } else {
+                stringResource(R.string.settings_visible_hours_summary)
+            },
+            position = Position.Middle,
+            trailing = {
+                Switch(
+                    checked = hours.enabled,
+                    onCheckedChange = { viewModel.setTimelineHours(hours.copy(enabled = it)) },
+                )
+            },
+            onClick = { viewModel.setTimelineHours(hours.copy(enabled = !hours.enabled)) },
+        )
+        if (hours.enabled) {
+            GroupedRow(
+                title = stringResource(R.string.settings_visible_hours_start),
+                summary = hourLabel(hours.startHour),
+                position = Position.Middle,
+                onClick = { showHoursStart = true },
+            )
+            GroupedRow(
+                title = stringResource(R.string.settings_visible_hours_end),
+                summary = hourLabel(hours.endHour),
+                position = Position.Middle,
+                onClick = { showHoursEnd = true },
+            )
+        }
         GroupedRow(
             title = stringResource(R.string.settings_hour_lines),
             summary = stringResource(R.string.settings_hour_lines_summary),
@@ -378,6 +425,30 @@ internal fun ViewsScreen(
             onDismiss = { showTimelineScale = false },
         )
     }
+    if (showHoursStart) {
+        OptionPicker(
+            title = stringResource(R.string.settings_visible_hours_start),
+            header = { PickerDescription(stringResource(R.string.settings_visible_hours_start_hint)) },
+            predictiveBack = true,
+            options = TimelineHours.startOptions(hours.endHour),
+            selected = hours.startHour,
+            label = { hourLabel(it) },
+            onSelect = { viewModel.setTimelineHours(hours.copy(startHour = it)) },
+            onDismiss = { showHoursStart = false },
+        )
+    }
+    if (showHoursEnd) {
+        OptionPicker(
+            title = stringResource(R.string.settings_visible_hours_end),
+            header = { PickerDescription(stringResource(R.string.settings_visible_hours_end_hint)) },
+            predictiveBack = true,
+            options = TimelineHours.endOptions(hours.startHour),
+            selected = hours.endHour,
+            label = { hourLabel(it) },
+            onSelect = { viewModel.setTimelineHours(hours.copy(endHour = it)) },
+            onDismiss = { showHoursEnd = false },
+        )
+    }
     if (showAgendaScreenRange) {
         AgendaRangePicker(
             title = stringResource(R.string.settings_agenda_range),
@@ -475,3 +546,8 @@ internal fun pastEventDisplayLabelRes(mode: PastEventDisplay): Int = when (mode)
 @Composable
 private fun multiDayLabel(count: Int): String =
     pluralStringResource(R.plurals.view_multi_day, count, count)
+
+/** A whole hour in the app's clock convention; 24 reads as the end of the day. */
+@Composable
+private fun hourLabel(hour: Int): String =
+    formatMinuteOfDay(hour * 60, LocalUse24HourFormat.current, currentLocale())

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

@@ -42,6 +42,7 @@ internal fun WidgetsScreen(
     state: SettingsUiState,
     viewModel: SettingsViewModel,
     onBack: () -> Unit,
+    visible: Boolean = true,
 ) {
     var showAgendaWidgetRange by remember { mutableStateOf(false) }
     var showWidgetSize by remember { mutableStateOf(false) }
@@ -50,6 +51,7 @@ internal fun WidgetsScreen(
         title = stringResource(R.string.settings_section_widgets),
         onBack = onBack,
         predictiveBack = true,
+        visible = visible,
     ) {
         SettingsHint(stringResource(R.string.settings_widgets_hint))
         Spacer(Modifier.height(8.dp))

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

@@ -0,0 +1,169 @@
+package de.jeanlucmakiola.calendula.ui.week
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.key
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.Layout
+import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.daysUntil
+import kotlinx.datetime.plus
+import kotlin.math.roundToInt
+
+/** A day column's place across the timeline, in pixels from its start edge. */
+@Immutable
+data class ColumnSlot(val left: Float, val width: Float) {
+    val right: Float get() = left + width
+}
+
+/**
+ * [date]'s column on a page showing this span across [width] pixels, with [gap]
+ * between columns. A date off the page carries on at the same pitch, off screen
+ * on its side — where a view switch slides it in from, or out to.
+ */
+fun DaySpan.slot(date: LocalDate, width: Float, gap: Float): ColumnSlot {
+    val pitch = (width + gap) / count
+    return ColumnSlot(left = start.daysUntil(date) * pitch, width = pitch - gap)
+}
+
+/** The last day of the span. */
+val DaySpan.end: LocalDate get() = start.plus(count - 1, DateTimeUnit.DAY)
+
+/**
+ * The timeline's columns: one page's, or — while switching between the day, the
+ * multi-day and the week view (#184) — every day of both pages, each column
+ * between where it sits in the one and where it sits in the other.
+ *
+ * @param progress how far from [from] to [to], read at layout time only.
+ */
+@Stable
+class ColumnGeometry(val from: DaySpan, val to: DaySpan, val progress: () -> Float) {
+
+    /** Every day either page shows, in order: the two overlap, so they run on unbroken. */
+    val dates: List<LocalDate> = run {
+        val first = minOf(from.start, to.start)
+        val last = maxOf(from.end, to.end)
+        (0..first.daysUntil(last)).map { first.plus(it, DateTimeUnit.DAY) }
+    }
+
+    fun slot(date: LocalDate, width: Float, gap: Float): ColumnSlot {
+        val a = from.slot(date, width, gap)
+        if (from == to) return a
+        val b = to.slot(date, width, gap)
+        val p = progress()
+        return ColumnSlot(lerp(a.left, b.left, p), lerp(a.width, b.width, p))
+    }
+
+    /** The span of columns [range] covers, between its extent on each page. */
+    fun extent(fromRange: ClosedRange<LocalDate>, toRange: ClosedRange<LocalDate>, width: Float, gap: Float): ColumnSlot {
+        val a = from.extent(fromRange, width, gap)
+        if (from == to && fromRange == toRange) return a
+        val b = to.extent(toRange, width, gap)
+        val p = progress()
+        val left = lerp(a.left, b.left, p)
+        return ColumnSlot(left, lerp(a.right, b.right, p) - left)
+    }
+
+    companion object {
+        /** One page's columns, standing still. */
+        fun of(span: DaySpan): ColumnGeometry = ColumnGeometry(span, span) { 0f }
+    }
+}
+
+private fun DaySpan.extent(range: ClosedRange<LocalDate>, width: Float, gap: Float): ColumnSlot {
+    val left = slot(range.start, width, gap).left
+    return ColumnSlot(left, slot(range.endInclusive, width, gap).right - left)
+}
+
+internal fun lerp(a: Float, b: Float, p: Float): Float = a + (b - a) * p
+
+/**
+ * Lays [content] out once per day of [geometry], each across its column. The
+ * columns are placed in the layout pass, so a view switch moving them every
+ * frame re-lays them out without recomposing them. Children fill the height
+ * the layout is given, or wrap it when it has none.
+ */
+@Composable
+fun TimelineColumns(
+    geometry: ColumnGeometry,
+    gap: Dp,
+    modifier: Modifier = Modifier,
+    content: @Composable (LocalDate) -> Unit,
+) {
+    val dates = geometry.dates
+    Layout(
+        content = {
+            dates.forEach { date ->
+                key(date) { Box(propagateMinConstraints = true) { content(date) } }
+            }
+        },
+        modifier = modifier,
+    ) { measurables, constraints ->
+        val width = constraints.maxWidth
+        val gapPx = gap.toPx()
+        val slots = dates.map { geometry.slot(it, width.toFloat(), gapPx) }
+        val placeables = measurables.mapIndexed { i, measurable ->
+            val left = slots[i].left.roundToInt()
+            val columnWidth = (slots[i].right.roundToInt() - left).coerceAtLeast(0)
+            measurable.measure(constraints.copy(minWidth = columnWidth, maxWidth = columnWidth))
+        }
+        val height = placeables.maxOfOrNull { it.height }?.coerceAtLeast(constraints.minHeight)
+            ?: constraints.minHeight
+        layout(width, height) {
+            placeables.forEachIndexed { i, placeable ->
+                placeable.placeRelative(slots[i].left.roundToInt(), 0)
+            }
+        }
+    }
+}
+
+/**
+ * An all-day bar as each page lays it out: the days it covers there, clipped to
+ * the page, and its lane. A bar only one page has keeps its days on the other,
+ * so it slides out with them rather than vanishing.
+ */
+@Immutable
+data class PlacedBar(
+    val event: EventInstance,
+    /** The day the bar is drawn from on the page it is tagged on, for the view morph. */
+    val keyDate: LocalDate,
+    val fromRange: ClosedRange<LocalDate>,
+    val toRange: ClosedRange<LocalDate>,
+    val fromLane: Int,
+    val toLane: Int,
+)
+
+/** [state]'s all-day bars, standing still. */
+internal fun staticBars(state: WeekUiState.Success): List<PlacedBar> =
+    state.allDaySpans.map { span ->
+        val range = state.days[span.startCol]..state.days[span.endCol]
+        PlacedBar(span.event, range.start, range, range, span.lane, span.lane)
+    }
+
+/**
+ * The all-day bars of both pages of a view switch, each once: matched by
+ * occurrence, placed on each page as that page lays it out.
+ */
+internal fun morphBars(from: WeekUiState.Success?, to: WeekUiState.Success?): List<PlacedBar> {
+    val fromBars = from?.let(::staticBars).orEmpty().associateBy { it.event.occurrence() }
+    val toBars = to?.let(::staticBars).orEmpty().associateBy { it.event.occurrence() }
+    return (fromBars.keys + toBars.keys).map { occurrence ->
+        val a = fromBars[occurrence]
+        val b = toBars[occurrence]
+        PlacedBar(
+            event = (a ?: b)!!.event,
+            keyDate = (a ?: b)!!.keyDate,
+            fromRange = (a ?: b)!!.fromRange,
+            toRange = (b ?: a)!!.toRange,
+            fromLane = (a ?: b)!!.fromLane,
+            toLane = (b ?: a)!!.toLane,
+        )
+    }
+}
+
+private fun EventInstance.occurrence(): Pair<Long, Long> = eventId to start.toEpochMilliseconds()

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

@@ -0,0 +1,32 @@
+package de.jeanlucmakiola.calendula.ui.week
+
+import androidx.compose.animation.core.Animatable
+import androidx.compose.runtime.Stable
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.datetime.LocalDate
+
+/**
+ * A switch between two timeline views in progress (#184): the page on screen
+ * when it started, the page it ends on, and how far between the two it is.
+ */
+@Stable
+internal class TimelineMorph(
+    val fromKind: TimelineKind,
+    val toKind: TimelineKind,
+    val from: DaySpan,
+    val to: DaySpan,
+    val fromState: StateFlow<WeekUiState>,
+    val toState: StateFlow<WeekUiState>,
+) {
+    val progress = Animatable(0f)
+
+    /** Whether the columns change size a lot, from a single day to a week or back, and take longer for it. */
+    val isLong: Boolean get() = maxOf(from.count, to.count) > LONG_SWITCH_RATIO * minOf(from.count, to.count)
+
+    /** Where each day's events come from: the page it was on, else the page it goes to. */
+    fun sourceOf(date: LocalDate): Side = if (date in from.start..from.end) Side.From else Side.To
+
+    enum class Side { From, To }
+}
+
+private const val LONG_SWITCH_RATIO = 3

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

@@ -73,3 +73,35 @@ data class DaysGrid(override val dayCount: Int, val phase: Int) : PageGrid {
             DaysGrid(dayCount, Math.floorMod(DAYS_EPOCH.daysUntil(date), dayCount))
     }
 }
+
+/** Pages the day pager spans — a little under four centuries, centred on [DAY_EPOCH]. */
+internal const val DAY_PAGE_COUNT: Int = 140_000
+
+private const val DAY_EPOCH_PAGE = DAY_PAGE_COUNT / 2
+
+/** The day at [DAY_EPOCH_PAGE]; any date works, it only has to stay fixed. */
+private val DAY_EPOCH = LocalDate(2000, 1, 1)
+
+/** Single days: every date starts a page of its own. */
+data object DayGrid : PageGrid {
+    override val dayCount: Int get() = 1
+    override val pageCount: Int get() = DAY_PAGE_COUNT
+
+    override fun startForPage(page: Int): LocalDate =
+        DAY_EPOCH.plus(page - DAY_EPOCH_PAGE, DateTimeUnit.DAY)
+
+    override fun pageFor(date: LocalDate): Int =
+        (DAY_EPOCH_PAGE + DAY_EPOCH.daysUntil(date)).coerceIn(0, DAY_PAGE_COUNT - 1)
+}
+
+/**
+ * Where the focused date goes when the pager settles on [page] (#184): kept if
+ * the page still shows it, otherwise moved by the pages travelled, so it keeps
+ * its place in the page — the same weekday a week on.
+ */
+internal fun PageGrid.focusOnPage(focus: LocalDate, page: Int): LocalDate {
+    val start = startForPage(page)
+    val end = start.plus(dayCount - 1, DateTimeUnit.DAY)
+    if (focus in start..end) return focus
+    return focus.plus((page - pageFor(focus)) * dayCount, DateTimeUnit.DAY).coerceIn(start, end)
+}

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

@@ -9,9 +9,9 @@ import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.domain.displayPriority
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.calendarListFailure
-import de.jeanlucmakiola.calendula.domain.isDeclined
 import de.jeanlucmakiola.calendula.ui.common.PageStateCache
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -24,6 +24,7 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filterNot
 import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
@@ -55,6 +56,10 @@ data class DaySpan(val start: LocalDate, val count: Int)
 /** How the pager cuts the calendar, and the page the anchor sits on. */
 data class PagerPosition(val grid: PageGrid, val page: Int)
 
+/** Where [anchor] sits under [rule]. */
+fun positionOf(anchor: LocalDate, rule: (LocalDate) -> PageGrid): PagerPosition =
+    rule(anchor).let { PagerPosition(it, it.pageFor(anchor)) }
+
 /**
  * A timeline paged in runs of days: the week view, and the multi-day view (#193).
  * The pager leads; the anchor follows it once it settles, and the grid it is
@@ -89,14 +94,22 @@ abstract class PagedTimelineViewModel(
     // A day on the visible page; the page itself comes from the grid, so a
     // settings change re-frames the same days instead of jumping.
     private val _anchor = MutableStateFlow(todayDate)
+    val anchor: StateFlow<LocalDate> = _anchor
 
-    val position: StateFlow<PagerPosition> =
-        combine(_anchor, gridRule) { anchor, rule -> rule(anchor).let { PagerPosition(it, it.pageFor(anchor)) } }
+    /**
+     * The grid for a given anchor, held eagerly so a screen can place its pager
+     * on its very first frame rather than a frame after the anchor moved.
+     */
+    val rule: StateFlow<(LocalDate) -> PageGrid> =
+        gridRule.stateIn(viewModelScope, SharingStarted.Eagerly, initialRule)
+
+    private val position: StateFlow<PagerPosition> =
+        combine(_anchor, rule) { anchor, rule -> positionOf(anchor, rule) }
             .distinctUntilChanged()
             .stateIn(
                 scope = viewModelScope,
                 started = SharingStarted.WhileSubscribed(5_000L),
-                initialValue = initialRule(todayDate).let { PagerPosition(it, it.pageFor(todayDate)) },
+                initialValue = positionOf(todayDate, initialRule),
             )
 
     /**
@@ -140,7 +153,7 @@ abstract class PagedTimelineViewModel(
 
     /** The pager came to rest on [page]; follow it unless it is already the anchor's. */
     fun onPageSettled(page: Int) {
-        val grid = position.value.grid
+        val grid = rule.value(_anchor.value)
         if (grid.pageFor(_anchor.value) != page) _anchor.value = grid.startForPage(page)
     }
 
@@ -150,6 +163,7 @@ abstract class PagedTimelineViewModel(
     }
 
     fun goToToday() = jumpTo(todayDate)
+    fun goToDate(date: LocalDate) = jumpTo(date)
 
     private fun buildState(
         span: DaySpan,
@@ -208,6 +222,20 @@ class MultiDayViewModel @Inject constructor(
     initialRule = { DaysGrid.startingAt(it, SettingsPrefs.DEFAULT_MULTI_DAY_COUNT) },
 )
 
+/** The day view: the timeline one day at a time. */
+@HiltViewModel
+class DayViewModel @Inject constructor(
+    repository: CalendarRepository,
+    settingsPrefs: SettingsPrefs,
+    @IoDispatcher io: CoroutineDispatcher,
+) : PagedTimelineViewModel(
+    repository = repository,
+    settingsPrefs = settingsPrefs,
+    io = io,
+    gridRule = flowOf { _: LocalDate -> DayGrid },
+    initialRule = { DayGrid },
+)
+
 /**
  * Lay out all-day events as connected horizontal spans across the visible week.
  * Each event becomes one [AllDaySpan] from its first to its last covered column;
@@ -227,7 +255,13 @@ internal fun layoutAllDay(
         }
         // Declined bars are packed after every other one, so on any day they
         // cover they land in a lane below it (#230).
-        .sortedWith(compareBy({ it.event.isDeclined }, { it.startCol }, { it.endCol }))
+        .sortedWith(
+            compareBy<Raw> { it.event.displayPriority(zone) }
+                .thenBy { it.startCol }
+                .thenBy { it.endCol }
+                .thenBy { it.event.start }
+                .thenBy { it.event.instanceId },
+        )
 
     // What each lane already holds, rather than just how far right it reaches.
     // A single "last occupied column" only answers correctly while spans arrive

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

@@ -50,6 +50,7 @@ internal fun WeekViewPreview(
         WeekSuccess(
             state = state,
             showWeekNumber = dayCount == 7,
+            headerBias = if (dayCount == 1) TimelineKind.Day.headerBias else 0f,
             scrollState = scrollState,
             allDayHeight = state.allDayStripHeight(),
             dragController = rememberTimelineDragController(),

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

@@ -1,10 +1,10 @@
 <resources>
     <string name="app_name">Calendula</string>
     <string name="app_tagline">A modern calendar.</string>
-    <!-- Alternative launcher label offered by the "App name" setting (issue #44).
-         translatable="false": this string becomes a launcher component's label, so
-         it must never be changed by an unreviewed community translation. -->
-    <string name="app_name_calendar_alias" translatable="false">Calendar</string>
+    <!-- Alternative launcher label offered by the "App name" setting (issue #44),
+         shown under the app icon. Translate it as the plain, generic word your
+         language uses for a calendar app (e.g. "Kalender"), nothing else (#251). -->
+    <string name="app_name_calendar_alias">Calendar</string>
 
     <!-- Loading / Failure / Success generic strings (used across screens) -->
     <string name="state_loading">Loading…</string>
@@ -54,7 +54,9 @@
     <!-- Month view (S1) -->
     <string name="month_prev">Previous month</string>
     <string name="month_next">Next month</string>
+    <string name="month_open_week">Open week %1$d</string>
     <string name="month_today_action">Today</string>
+    <string name="month_split_clear_filter">Show full month agenda</string>
     <string name="month_more_actions">More actions</string>
     <string name="month_open_menu">Open menu</string>
     <string name="month_action_settings">Settings</string>
@@ -67,6 +69,10 @@
     <!-- Day view (S3) -->
     <string name="day_today_action">Today</string>
 
+    <!-- Week and day timelines — edge bar for events scrolled out of view (#188) -->
+    <string name="timeline_earlier_events">Earlier events</string>
+    <string name="timeline_later_events">Later events</string>
+
     <!-- Event detail screen (S4) -->
     <string name="event_detail_back">Back</string>
     <string name="event_detail_edit">Edit</string>
@@ -349,6 +355,7 @@
     <string name="reminder_action_snooze">Snooze</string>
     <string name="reminder_action_dismiss">Dismiss</string>
     <!-- Day context prefix in a reminder for an event on another day (v2.15.0) -->
+    <string name="reminder_day_today">Today</string>
     <string name="reminder_day_tomorrow">Tomorrow</string>
     <string name="reminder_day_yesterday">Yesterday</string>
 
@@ -478,6 +485,7 @@
     <string name="settings_multi_day_count">Multi-day view</string>
     <string name="settings_multi_day_count_hint">How many days the multi-day view shows side by side. Today opens in the first column.</string>
     <string name="settings_timeline_scale">Hour height</string>
+    <string name="settings_timeline_scale_by_visible_hours">Set by Visible hours</string>
     <string name="settings_timeline_scale_hint">How much vertical space one hour takes in week and day view. Both views share this setting. You can also pinch the timeline with two fingers to set any height in between.</string>
     <string name="timeline_scale_fit_day">Fit whole day</string>
     <string name="timeline_scale_fit_day_summary">All 24 hours on one screen, no scrolling</string>
@@ -489,6 +497,13 @@
     <string name="timeline_scale_comfortable_summary">Roomier blocks, more scrolling</string>
     <string name="timeline_scale_custom">Custom</string>
     <string name="timeline_scale_custom_summary">The height you pinched the timeline to</string>
+    <string name="settings_visible_hours">Visible hours</string>
+    <string name="settings_visible_hours_summary">Fit a range of hours to the screen when week, multi-day or day view opens</string>
+    <string name="settings_visible_hours_on_summary">%1$s – %2$s fills the screen when a view opens</string>
+    <string name="settings_visible_hours_start">From</string>
+    <string name="settings_visible_hours_end">Until</string>
+    <string name="settings_visible_hours_start_hint">The hour at the top of the screen when week, multi-day or day view opens. Earlier hours are still a scroll away.</string>
+    <string name="settings_visible_hours_end_hint">The hour at the bottom of the screen when a view opens. Later hours are still a scroll away, and pinching zooms until the view is opened again.</string>
     <string name="settings_dim_completed">Dim completed events</string>
     <string name="settings_dim_completed_summary">Fade events that have already ended in month and week view</string>
     <string name="settings_drag_to_reschedule">Drag to reschedule</string>
@@ -537,7 +552,7 @@
     <string name="settings_month_header">Month view</string>
     <string name="settings_month_view_style">Month view style</string>
     <string name="month_style_paged">Pages</string>
-    <string name="month_style_paged_summary">One month fills the screen. Swipe left or right to change month.</string>
+    <string name="month_style_paged_summary">One month fills the screen. Swipe left or right to change month, or swipe up to show the month agenda.</string>
     <string name="month_style_continuous">Scrolling months</string>
     <string name="month_style_continuous_summary">Each month sits under its own heading, with a little space setting it apart from the next.</string>
     <string name="month_style_dense">Seamless weeks</string>

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

@@ -14,6 +14,7 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.TimelineHours
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import kotlinx.coroutines.flow.first
@@ -125,6 +126,24 @@ class SettingsPrefsTest {
         assertThat(prefs.timelineScale.first()).isEqualTo(TimelineScale.Comfortable)
     }
 
+    @Test
+    fun `visible hours default off and round-trip`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        assertThat(prefs.timelineHours.first()).isEqualTo(TimelineHours(enabled = false, 7, 22))
+        prefs.setTimelineHours(TimelineHours(enabled = true, 6, 20))
+        assertThat(prefs.timelineHours.first()).isEqualTo(TimelineHours(enabled = true, 6, 20))
+        // Switching off keeps the chosen hours for next time.
+        prefs.setTimelineHours(TimelineHours(enabled = false, 6, 20))
+        assertThat(prefs.timelineHours.first()).isEqualTo(TimelineHours(enabled = false, 6, 20))
+    }
+
+    @Test
+    fun `visible hours are stored valid`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        prefs.setTimelineHours(TimelineHours(enabled = true, 23, 22))
+        assertThat(prefs.timelineHours.first()).isEqualTo(TimelineHours(enabled = true, 20, 22))
+    }
+
     @Test
     fun `week numbers default off and round-trips`(@TempDir tempDir: Path) = runTest {
         val prefs = SettingsPrefs(newDataStore(tempDir))

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

@@ -38,6 +38,7 @@ class ReminderTimeTextTest {
         is24Hour = is24Hour,
         today = today ?: java.time.Instant.ofEpochMilli(beginMillis).atZone(zone).toLocalDate(),
         firstDayOfWeek = firstDayOfWeek,
+        todayLabel = "Today",
         tomorrowLabel = "Tomorrow",
         yesterdayLabel = "Yesterday",
     )
@@ -130,38 +131,74 @@ class ReminderTimeTextTest {
     }
 
     @Test
-    fun `all-day single day shows one date, read in UTC`() {
+    fun `all-day single day today reads as today, read in UTC`() {
         val text = text(
             beginMillis = utcMidnight(LocalDate.of(2026, 6, 11)),
             endMillis = utcMidnight(LocalDate.of(2026, 6, 12)),
             isAllDay = true,
             // Zone must not matter for all-day events: UTC midnight is
-            // 02:00 in Berlin — naive local reading would shift the day.
+            // the previous evening in Los Angeles — naive local reading would shift the day.
+            zone = ZoneId.of("America/Los_Angeles"),
             today = LocalDate.of(2026, 6, 11),
         )
-        assertThat(text).isEqualTo("11.06.2026")
+        assertThat(text).isEqualTo("Today")
     }
 
     @Test
-    fun `all-day event tomorrow still shows the exact date, no relative prefix`() {
+    fun `all-day event tomorrow reads as tomorrow`() {
         val text = text(
             beginMillis = utcMidnight(LocalDate.of(2026, 6, 12)),
             endMillis = utcMidnight(LocalDate.of(2026, 6, 13)),
             isAllDay = true,
             today = LocalDate.of(2026, 6, 11),
         )
-        assertThat(text).isEqualTo("12.06.2026")
+        assertThat(text).isEqualTo("Tomorrow")
     }
 
     @Test
-    fun `all-day multi-day shows the last covered day, not the exclusive end`() {
+    fun `all-day event later this week reads as the short weekday`() {
+        // 2026-06-11 is a Thursday; Saturday the 13th shares its week.
         val text = text(
-            beginMillis = utcMidnight(LocalDate.of(2026, 6, 11)),
-            endMillis = utcMidnight(LocalDate.of(2026, 6, 13)),
+            beginMillis = utcMidnight(LocalDate.of(2026, 6, 13)),
+            endMillis = utcMidnight(LocalDate.of(2026, 6, 14)),
+            isAllDay = true,
+            locale = Locale.US,
+            today = LocalDate.of(2026, 6, 11),
+        )
+        assertThat(text).isEqualTo("Sat")
+    }
+
+    @Test
+    fun `all-day event next week falls back to the exact date`() {
+        val text = text(
+            beginMillis = utcMidnight(LocalDate.of(2026, 6, 16)),
+            endMillis = utcMidnight(LocalDate.of(2026, 6, 17)),
             isAllDay = true,
             today = LocalDate.of(2026, 6, 11),
         )
-        assertThat(text).isEqualTo("11.06.2026 – 12.06.2026")
+        assertThat(text).isEqualTo("16.06.2026")
+    }
+
+    @Test
+    fun `all-day multi-day reads relative start and the last covered day`() {
+        val text = text(
+            beginMillis = utcMidnight(LocalDate.of(2026, 6, 12)),
+            endMillis = utcMidnight(LocalDate.of(2026, 6, 14)),
+            isAllDay = true,
+            today = LocalDate.of(2026, 6, 11),
+        )
+        assertThat(text).isEqualTo("Tomorrow – 13.06.2026")
+    }
+
+    @Test
+    fun `all-day multi-day further out keeps both dates`() {
+        val text = text(
+            beginMillis = utcMidnight(LocalDate.of(2026, 7, 1)),
+            endMillis = utcMidnight(LocalDate.of(2026, 7, 3)),
+            isAllDay = true,
+            today = LocalDate.of(2026, 6, 11),
+        )
+        assertThat(text).isEqualTo("01.07.2026 – 02.07.2026")
     }
 
     @Test
@@ -173,6 +210,6 @@ class ReminderTimeTextTest {
             isAllDay = true,
             today = LocalDate.of(2026, 6, 11),
         )
-        assertThat(text).isEqualTo("11.06.2026")
+        assertThat(text).isEqualTo("Today")
     }
 }

app/src/test/java/de/jeanlucmakiola/calendula/domain/color/EventToneTest.kt

@@ -156,4 +156,5 @@ class EventToneTest {
         assertThat(eventTone(0xFFFFF6C0.toInt(), dark = false, harmonise = false).onContainer)
             .isEqualTo(0xFF000000.toInt())
     }
+
 }

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

@@ -0,0 +1,40 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+/** The day each agenda list item belongs to, for the focus it hands back (#184). */
+class AgendaItemDatesTest {
+
+    private val monday = LocalDate(2026, 9, 28)
+    private val tuesday = LocalDate(2026, 9, 29)
+
+    private fun event(id: Long) = EventInstance(
+        instanceId = id,
+        eventId = id,
+        calendarId = 1L,
+        title = "Event",
+        start = Instant.fromEpochMilliseconds(0),
+        end = Instant.fromEpochMilliseconds(0),
+        isAllDay = false,
+        color = 0xFF000000.toInt(),
+        location = null,
+    )
+
+    @Test
+    fun `each day counts its header, events and gap`() {
+        val days = listOf(AgendaDay(monday, listOf(event(1), event(2))), AgendaDay(tuesday, listOf(event(3))))
+        assertThat(agendaItemDates(days)).containsExactly(
+            monday, monday, monday, monday,
+            tuesday, tuesday, tuesday,
+        ).inOrder()
+    }
+
+    @Test
+    fun `an empty day counts its placeholder`() {
+        assertThat(agendaItemDates(listOf(AgendaDay(monday, emptyList())))).hasSize(3)
+    }
+}

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

@@ -77,6 +77,16 @@ class GroupAgendaDaysTest {
             .containsExactly(LocalDate(2026, 7, 2))
     }
 
+    @Test
+    fun `multi-day events precede single all-day and timed events`() {
+        val multi = event(1, "Multi", at(2026, 7, 1), at(2026, 7, 4), isAllDay = true)
+        val single = event(2, "Single", at(2026, 7, 2), at(2026, 7, 3), isAllDay = true)
+        val timed = event(3, "Timed", at(2026, 7, 2, 8), at(2026, 7, 2, 9))
+        val second = days(listOf(timed, single, multi)).first { it.date == LocalDate(2026, 7, 2) }
+        assertThat(second.events.map { it.title })
+            .containsExactly("Multi", "Single", "Timed").inOrder()
+    }
+
     @Test
     fun `an event ending exactly at midnight does not reach the next day`() {
         val e = event(1, "late", at(2026, 7, 1, 22, 0), at(2026, 7, 2, 0, 0))

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

@@ -0,0 +1,147 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import de.jeanlucmakiola.calendula.ui.week.TimedBlock
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+/** Which events a column's edge bars point at, and where a tap scrolls (#188). */
+class OutOfViewEdgesTest {
+
+    private fun block(id: Long, startMin: Int, endMin: Int) = TimedBlock(
+        event = EventInstance(
+            instanceId = id,
+            eventId = id,
+            calendarId = 1L,
+            title = "Event $id",
+            start = Instant.fromEpochMilliseconds(0),
+            end = Instant.fromEpochMilliseconds(0),
+            isAllDay = false,
+            color = 0xFF112233.toInt(),
+            location = null,
+        ),
+        startMin = startMin,
+        endMin = endMin,
+        lane = 0,
+        laneCount = 1,
+    )
+
+    private val early = block(1, 7 * 60, 8 * 60)
+    private val breakfast = block(2, 8 * 60, 9 * 60)
+    private val lunch = block(3, 12 * 60, 13 * 60)
+    private val dinner = block(4, 19 * 60, 20 * 60)
+    private val late = block(5, 21 * 60, 22 * 60)
+
+    // Viewport 10:00–17:00.
+    private fun outOf(vararg blocks: TimedBlock) =
+        outOfViewEvents(blocks.toList(), topMin = 600f, bottomMin = 1020f)
+
+    @Test
+    fun `the nearest hidden event on each side is picked`() {
+        val events = outOf(early, breakfast, lunch, dinner, late)
+        assertThat(events.above).isEqualTo(breakfast)
+        assertThat(events.below).isEqualTo(dinner)
+    }
+
+    @Test
+    fun `an event in view points nowhere`() {
+        assertThat(outOf(lunch)).isEqualTo(OutOfViewEvents.None)
+    }
+
+    @Test
+    fun `an event cut by the edge is not out of view`() {
+        val straddling = block(6, 9 * 60, 11 * 60)
+        assertThat(outOf(straddling).above).isNull()
+    }
+
+    @Test
+    fun `an event disappears from the edge as soon as a sliver enters view`() {
+        val sliver = block(6, 9 * 60, 10 * 60 + 5)
+        assertThat(outOf(sliver).above).isNull()
+        val tip = block(7, 17 * 60 - 5, 18 * 60)
+        assertThat(outOf(tip).below).isNull()
+        val justAbove = block(8, 9 * 60, 10 * 60)
+        val justBelow = block(9, 17 * 60, 18 * 60)
+        assertThat(outOf(justAbove).above).isEqualTo(justAbove)
+        assertThat(outOf(justBelow).below).isEqualTo(justBelow)
+    }
+
+    @Test
+    fun `the bar fades before its event reaches the viewport`() {
+        assertThat(edgeBarAlpha(gapPx = 24f, fadeLeadPx = 24f)).isEqualTo(1f)
+        assertThat(edgeBarAlpha(gapPx = 12f, fadeLeadPx = 24f)).isEqualTo(0.5f)
+        assertThat(edgeBarAlpha(gapPx = 0f, fadeLeadPx = 24f)).isEqualTo(0f)
+        assertThat(edgeBarAlpha(gapPx = -1f, fadeLeadPx = 24f)).isEqualTo(0f)
+    }
+
+    @Test
+    fun `a column scrolled to its top points at nothing above it`() {
+        val first = block(6, 0, 30)
+        val events = outOfViewEvents(listOf(first), topMin = 0f, bottomMin = 420f)
+        assertThat(events.above).isNull()
+    }
+
+    @Test
+    fun `a short event is judged by the height it renders at`() {
+        // Five minutes ending at 09:58 still draws 26 minutes tall, past 10:00.
+        val blip = block(6, 9 * 60 + 53, 9 * 60 + 58)
+        assertThat(outOf(blip).above).isNull()
+    }
+
+    @Test
+    fun `an event above scrolls to its start less the margin`() {
+        val target = revealScrollTarget(breakfast, ViewportEdge.Top, hourPx = 100f, viewportPx = 700, marginPx = 20f, maxScroll = 1700)
+        assertThat(target).isEqualTo(780)
+    }
+
+    @Test
+    fun `an event below that fits lands whole at the bottom`() {
+        val target = revealScrollTarget(dinner, ViewportEdge.Bottom, hourPx = 100f, viewportPx = 700, marginPx = 20f, maxScroll = 1700)
+        // Its end, 2000, plus the margin, sits at the viewport's bottom.
+        assertThat(target).isEqualTo(1320)
+    }
+
+    @Test
+    fun `an event below taller than the viewport lands with its start at the top`() {
+        val long = block(6, 12 * 60, 22 * 60)
+        val target = revealScrollTarget(long, ViewportEdge.Bottom, hourPx = 100f, viewportPx = 700, marginPx = 20f, maxScroll = 1700)
+        assertThat(target).isEqualTo(1180)
+    }
+
+    @Test
+    fun `the target stays within the scroll range`() {
+        val first = block(6, 0, 30)
+        assertThat(
+            revealScrollTarget(first, ViewportEdge.Top, hourPx = 100f, viewportPx = 700, marginPx = 20f, maxScroll = 1700),
+        ).isEqualTo(0)
+        val last = block(7, 23 * 60, 24 * 60)
+        assertThat(
+            revealScrollTarget(last, ViewportEdge.Bottom, hourPx = 100f, viewportPx = 700, marginPx = 20f, maxScroll = 1700),
+        ).isEqualTo(1700)
+    }
+
+    // Viewport 1000..1700 px with both bars showing, 40 px of reach.
+    private fun tapped(y: Float, events: OutOfViewEvents = OutOfViewEvents(breakfast, dinner)) =
+        tappedEdge(events, y, viewportTop = 1000f, viewportPx = 700, reachPx = 40f)
+
+    @Test
+    fun `a tap near an edge with a bar hits that bar`() {
+        assertThat(tapped(1010f)).isEqualTo(ViewportEdge.Top)
+        assertThat(tapped(1040f)).isEqualTo(ViewportEdge.Top)
+        assertThat(tapped(1690f)).isEqualTo(ViewportEdge.Bottom)
+    }
+
+    @Test
+    fun `a tap past the bar's reach is left to the column`() {
+        assertThat(tapped(1041f)).isNull()
+        assertThat(tapped(1350f)).isNull()
+        assertThat(tapped(1659f)).isNull()
+    }
+
+    @Test
+    fun `a tap near an edge without a bar is left to the column`() {
+        assertThat(tapped(1010f, OutOfViewEvents(null, dinner))).isNull()
+        assertThat(tapped(1690f, OutOfViewEvents(breakfast, null))).isNull()
+    }
+}

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

@@ -0,0 +1,115 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.ui.unit.dp
+import com.google.common.truth.Truth.assertThat
+import org.junit.jupiter.api.Test
+
+class TimelineHoursTest {
+
+    private val viewport = 600.dp
+
+    @Test
+    fun `the chosen range exactly fills the viewport`() {
+        // 07–22 is 15 hours: 600dp / 15 = 40dp an hour.
+        assertThat(TimelineScale.FitHours(7, 22).hourHeight(viewport)).isEqualTo(40.dp)
+    }
+
+    @Test
+    fun `the whole day fits like FitDay`() {
+        assertThat(TimelineScale.FitHours(0, 24).hourHeight(viewport))
+            .isEqualTo(TimelineScale.FitDay.hourHeight(viewport))
+    }
+
+    @Test
+    fun `a short range on a tall screen stops at the pinch ceiling`() {
+        assertThat(TimelineScale.FitHours(9, 11).hourHeight(2000.dp)).isEqualTo(MAX_PINCH_HOUR_HEIGHT)
+    }
+
+    @Test
+    fun `ranges are held to the day and the minimum span`() {
+        assertThat(TimelineHours.of(true, -3, 30)).isEqualTo(TimelineHours(true, 0, 24))
+        assertThat(TimelineHours.of(true, 23, 22)).isEqualTo(TimelineHours(true, 20, 22))
+        assertThat(TimelineHours.of(true, 5, 1)).isEqualTo(TimelineHours(true, 0, 2))
+    }
+
+    @Test
+    fun `the pickers only offer valid pairings`() {
+        assertThat(TimelineHours.startOptions(22)).isEqualTo((0..20).toList())
+        assertThat(TimelineHours.endOptions(7)).isEqualTo((9..24).toList())
+    }
+
+    @Test
+    fun `opening scrolls to the start hour once the layout is at the fitted height`() {
+        // 40px an hour over a 600px viewport: 960px of content, 360px of scroll.
+        assertThat(startHourScroll(maxValue = 360, viewportPx = 600, startHour = 7, hourPx = 40f))
+            .isEqualTo(280)
+    }
+
+    @Test
+    fun `a layout still at the previous scale is waited out`() {
+        // Still 56px an hour: 1344 - 600 = 744 of scroll.
+        assertThat(startHourScroll(maxValue = 744, viewportPx = 600, startHour = 7, hourPx = 40f))
+            .isNull()
+        // Not laid out at all yet.
+        assertThat(startHourScroll(maxValue = Int.MAX_VALUE, viewportPx = 0, startHour = 7, hourPx = 40f))
+            .isNull()
+    }
+
+    @Test
+    fun `the whole day needs no scroll`() {
+        assertThat(startHourScroll(maxValue = 0, viewportPx = 600, startHour = 0, hourPx = 25f))
+            .isEqualTo(0)
+    }
+
+    @Test
+    fun `a fitted range round-trips through storage`() {
+        val scale = TimelineScale.FitHours(6, 20)
+        assertThat(parseTimelineScale(scale.storageValue())).isEqualTo(scale)
+        assertThat(parseTimelineScale("hours:x-2")).isEqualTo(TimelineScale.Regular)
+    }
+
+    @Test
+    fun `opening with visible hours on replaces a pinched scale`() {
+        val persisted = mutableListOf<TimelineScale>()
+        val zoom = TimelineZoom(TimelineScale.custom(90.dp)) { persisted += it }
+        zoom.adoptHours(TimelineHours(true, 7, 22))
+
+        assertThat(zoom.open()).isEqualTo(7)
+        assertThat(zoom.scale).isEqualTo(TimelineScale.FitHours(7, 22))
+
+        // A pinch overrides it for the visit but is not saved over the preference.
+        zoom.beginPinch()
+        zoom.pinchTo(100.dp)
+        zoom.endPinch()
+        assertThat(zoom.scale).isEqualTo(TimelineScale.custom(100.dp))
+        assertThat(persisted).isEmpty()
+
+        // Opening again fits the range again.
+        zoom.open()
+        assertThat(zoom.scale).isEqualTo(TimelineScale.FitHours(7, 22))
+    }
+
+    @Test
+    fun `a late stored scale does not undo the fit, and switching off restores it`() {
+        val zoom = TimelineZoom(TimelineScale.Regular) {}
+        zoom.adoptHours(TimelineHours(true, 7, 22))
+        zoom.open()
+        zoom.adopt(TimelineScale.Comfortable)
+        assertThat(zoom.scale).isEqualTo(TimelineScale.FitHours(7, 22))
+
+        zoom.adoptHours(TimelineHours(false, 7, 22))
+        assertThat(zoom.open()).isNull()
+        assertThat(zoom.scale).isEqualTo(TimelineScale.Comfortable)
+    }
+
+    @Test
+    fun `with visible hours off a pinch is still saved`() {
+        val persisted = mutableListOf<TimelineScale>()
+        val zoom = TimelineZoom(TimelineScale.Regular) { persisted += it }
+        assertThat(zoom.open()).isNull()
+        zoom.beginPinch()
+        zoom.pinchTo(70.dp)
+        zoom.endPinch()
+        assertThat(persisted).containsExactly(TimelineScale.custom(70.dp))
+    }
+}

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

@@ -65,6 +65,14 @@ class ViewBackStackTest {
         assertThat(stack.drillToDay()).isEqualTo(stack)
     }
 
+    @Test
+    fun `week number drills into week and back returns to month`() {
+        val stack = listOf(CalendarView.Month).drillToWeek()
+        assertThat(stack).containsExactly(CalendarView.Month, CalendarView.Week).inOrder()
+        assertThat(stack.dropLast(1).last()).isEqualTo(CalendarView.Month)
+        assertThat(stack.drillToWeek()).isEqualTo(stack)
+    }
+
     @Test
     fun `agenda widget date tap backs out agenda then home`() {
         // openDate(source = Agenda): root in Agenda over the Week home, then drill.

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

@@ -0,0 +1,50 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+import org.junit.jupiter.api.Test
+import kotlin.time.Instant
+
+class ViewMorphKeyTest {
+
+    private fun instance(instanceId: Long, eventId: Long = 7, startMillis: Long = 1_000L) = EventInstance(
+        instanceId = instanceId,
+        eventId = eventId,
+        calendarId = 1,
+        title = "Standup",
+        start = Instant.fromEpochMilliseconds(startMillis),
+        end = Instant.fromEpochMilliseconds(startMillis + 3_600_000L),
+        isAllDay = false,
+        color = 0,
+        location = null,
+    )
+
+    private val day = LocalDate(2026, 9, 25)
+
+    @Test
+    fun `the same occurrence on the same day matches across views`() {
+        // Each view reads its own instances query, so the row id is no anchor.
+        assertThat(ViewMorphKey.event(instance(instanceId = 1), day))
+            .isEqualTo(ViewMorphKey.event(instance(instanceId = 99), day))
+    }
+
+    @Test
+    fun `a multi-day event keys each day it is drawn from apart`() {
+        assertThat(ViewMorphKey.event(instance(1), day))
+            .isNotEqualTo(ViewMorphKey.event(instance(1), LocalDate(2026, 9, 26)))
+    }
+
+    @Test
+    fun `two occurrences of one series stay apart`() {
+        assertThat(ViewMorphKey.event(instance(1, startMillis = 1_000L), day))
+            .isNotEqualTo(ViewMorphKey.event(instance(2, startMillis = 2_000L), day))
+    }
+
+    @Test
+    fun `only the settled page morphs`() {
+        assertThat(morphPageActive(page = 5, settledPage = 5)).isTrue()
+        assertThat(morphPageActive(page = 4, settledPage = 5)).isFalse()
+        assertThat(morphPageActive(page = 6, settledPage = 5)).isFalse()
+    }
+}

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

@@ -0,0 +1,20 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.jupiter.api.Test
+
+/** Which screen draws each view: the timeline views share one, so switching among them resizes it (#184). */
+class ViewScreenTest {
+
+    @Test
+    fun `the day, multi-day and week views share the timeline`() {
+        assertThat(listOf(CalendarView.Day, CalendarView.MultiDay, CalendarView.Week).map { it.screen }.toSet())
+            .containsExactly(ViewScreen.Timeline)
+    }
+
+    @Test
+    fun `month and agenda each have their own screen`() {
+        assertThat(CalendarView.Month.screen).isEqualTo(ViewScreen.Month)
+        assertThat(CalendarView.Agenda.screen).isEqualTo(ViewScreen.Agenda)
+    }
+}

app/src/test/java/de/jeanlucmakiola/calendula/ui/month/ContinuousMonthIndexTest.kt

@@ -222,17 +222,17 @@ class ContinuousMonthIndexTest {
     }
 
     @Test
-    fun `the split selection follows the month, landing on today when it's there`() {
+    fun `the split agenda starts at today in the current month`() {
         val today = LocalDate(2026, 6, 10)
-        assertThat(selectionForMonth(jun26, today)).isEqualTo(today)
+        assertThat(agendaStartForMonth(jun26, today)).isEqualTo(today)
     }
 
     @Test
-    fun `the split selection falls to the 1st of any other month`() {
+    fun `the split agenda starts at the 1st of another month`() {
         val today = LocalDate(2026, 6, 10)
-        assertThat(selectionForMonth(YearMonth(2026, Month.JULY), today))
+        assertThat(agendaStartForMonth(YearMonth(2026, Month.JULY), today))
             .isEqualTo(LocalDate(2026, 7, 1))
-        assertThat(selectionForMonth(YearMonth(2025, Month.JUNE), today))
+        assertThat(agendaStartForMonth(YearMonth(2025, Month.JUNE), today))
             .isEqualTo(LocalDate(2025, 6, 1))
     }
 }

app/src/test/java/de/jeanlucmakiola/calendula/ui/month/MonthLayoutTest.kt

@@ -163,6 +163,18 @@ class MonthLayoutTest {
         assertThat(week.spans.map { it.lane }).containsExactly(0, 1)
     }
 
+    @Test
+    fun `multi-day bar is above a one-day all-day bar on the same date`() {
+        val day = LocalDate(2026, 6, 10)
+        val single = allDay(day, id = 1L, title = "Single")
+        val multi = allDay(day, day.plus(2, DateTimeUnit.DAY), id = 2L, title = "Multi")
+        val week = layoutCalendarWeek(weekOf8th, listOf(single, multi), zone)
+        val lanes = week.spans.associate { it.event.title to it.lane }
+        assertThat(lanes.getValue("Multi")).isLessThan(lanes.getValue("Single"))
+        assertThat(instancesByDay(listOf(day), listOf(single, multi), zone).getValue(day).map { it.title })
+            .containsExactly("Multi", "Single").inOrder()
+    }
+
     @Test
     fun `single-day timed events stay pills and sort by start`() {
         val late = timed(LocalDate(2026, 6, 10), 14, 15, id = 1L)

app/src/test/java/de/jeanlucmakiola/calendula/ui/week/ColumnGeometryTest.kt

@@ -0,0 +1,107 @@
+package de.jeanlucmakiola.calendula.ui.week
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.plus
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+/** The timeline's columns, standing still and mid view switch (#184). */
+class ColumnGeometryTest {
+
+    // 2026-09-27 is a Sunday; the week runs Sun..Sat.
+    private val sunday = LocalDate(2026, 9, 27)
+    private val week = DaySpan(sunday, 7)
+    private val monday = sunday.plus(1, DateTimeUnit.DAY)
+    private val day = DaySpan(monday, 1)
+    private val width = 700f
+    private val gap = 7f
+
+    @Test
+    fun `a page's columns follow the pitch`() {
+        val slot = week.slot(sunday.plus(3, DateTimeUnit.DAY), width, gap)
+        assertThat(slot.left).isEqualTo(3 * 101f)
+        assertThat(slot.width).isEqualTo(94f)
+    }
+
+    @Test
+    fun `the ends of a switch are the two pages`() {
+        var p = 0f
+        val geometry = ColumnGeometry(week, day) { p }
+        assertThat(geometry.slot(monday, width, gap)).isEqualTo(week.slot(monday, width, gap))
+        p = 1f
+        assertThat(geometry.slot(monday, width, gap)).isEqualTo(day.slot(monday, width, gap))
+    }
+
+    @Test
+    fun `days off the target page end off screen on their side`() {
+        val geometry = ColumnGeometry(week, day) { 1f }
+        assertThat(geometry.slot(sunday, width, gap).right).isAtMost(0f)
+        assertThat(geometry.slot(monday.plus(1, DateTimeUnit.DAY), width, gap).left).isAtLeast(width)
+    }
+
+    @Test
+    fun `a switch covers both pages without a break`() {
+        // Focus on Saturday: the six-day run starting there reaches into next week.
+        val saturday = sunday.plus(6, DateTimeUnit.DAY)
+        val geometry = ColumnGeometry(week, DaySpan(saturday, 6)) { 0f }
+        assertThat(geometry.dates).hasSize(12)
+        assertThat(geometry.dates.first()).isEqualTo(sunday)
+        assertThat(geometry.dates.zipWithNext().all { (a, b) -> b == a.plus(1, DateTimeUnit.DAY) }).isTrue()
+    }
+
+    @Test
+    fun `a bar spans its extent on each page`() {
+        val tuesday = monday.plus(1, DateTimeUnit.DAY)
+        val range = monday..tuesday
+        val geometry = ColumnGeometry(week, day) { 0f }
+        val extent = geometry.extent(range, monday..monday, width, 0f)
+        assertThat(extent.left).isEqualTo(week.slot(monday, width, 0f).left)
+        assertThat(extent.right).isEqualTo(week.slot(tuesday, width, 0f).right)
+    }
+
+    @Test
+    fun `a bar only one page has keeps its days on the other`() {
+        val bar = AllDaySpan(event(1), startCol = 2, endCol = 3, lane = 1)
+        val from = state(week, listOf(bar))
+        val to = state(day, emptyList())
+        val placed = morphBars(from, to).single()
+        assertThat(placed.fromRange).isEqualTo(placed.toRange)
+        assertThat(placed.toLane).isEqualTo(1)
+    }
+
+    @Test
+    fun `a bar on both pages is placed once, clipped to each`() {
+        val event = event(1)
+        val from = state(week, listOf(AllDaySpan(event, startCol = 0, endCol = 6, lane = 0)))
+        val to = state(day, listOf(AllDaySpan(event, startCol = 0, endCol = 0, lane = 0)))
+        val placed = morphBars(from, to).single()
+        assertThat(placed.fromRange).isEqualTo(sunday..sunday.plus(6, DateTimeUnit.DAY))
+        assertThat(placed.toRange).isEqualTo(monday..monday)
+    }
+
+    private fun state(span: DaySpan, bars: List<AllDaySpan>): WeekUiState.Success {
+        val days = (0 until span.count).map { span.start.plus(it, DateTimeUnit.DAY) }
+        return WeekUiState.Success(
+            weekStart = span.start,
+            today = sunday,
+            days = days,
+            allDaySpans = bars,
+            timedByDay = emptyMap(),
+        )
+    }
+
+    private fun event(id: Long) = EventInstance(
+        instanceId = id,
+        eventId = id,
+        calendarId = 1L,
+        title = "Event",
+        start = Instant.fromEpochMilliseconds(0),
+        end = Instant.fromEpochMilliseconds(0),
+        isAllDay = true,
+        color = 0xFF000000.toInt(),
+        location = null,
+    )
+}

app/src/test/java/de/jeanlucmakiola/calendula/ui/week/FocusOnPageTest.kt

@@ -0,0 +1,40 @@
+package de.jeanlucmakiola.calendula.ui.week
+
+import com.google.common.truth.Truth.assertThat
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import org.junit.jupiter.api.Test
+
+/** Where the focused date goes as a timeline pages (#184). */
+class FocusOnPageTest {
+
+    // 2026-09-30 is a Wednesday.
+    private val wednesday = LocalDate(2026, 9, 30)
+
+    @Test
+    fun `a page that still shows the focus keeps it`() {
+        val grid = WeekGrid(DayOfWeek.MONDAY)
+        assertThat(grid.focusOnPage(wednesday, grid.pageFor(wednesday))).isEqualTo(wednesday)
+    }
+
+    @Test
+    fun `a week on keeps the weekday`() {
+        val grid = WeekGrid(DayOfWeek.MONDAY)
+        val page = grid.pageFor(wednesday)
+        assertThat(grid.focusOnPage(wednesday, page + 1)).isEqualTo(LocalDate(2026, 10, 7))
+        assertThat(grid.focusOnPage(wednesday, page - 2)).isEqualTo(LocalDate(2026, 9, 16))
+    }
+
+    @Test
+    fun `a run of days keeps the focus's column`() {
+        val grid = DaysGrid.startingAt(LocalDate(2026, 9, 29), 3)
+        val page = grid.pageFor(wednesday)
+        assertThat(grid.focusOnPage(wednesday, page + 1)).isEqualTo(LocalDate(2026, 10, 3))
+    }
+
+    @Test
+    fun `a day page is the focus`() {
+        val page = DayGrid.pageFor(wednesday)
+        assertThat(DayGrid.focusOnPage(wednesday, page + 5)).isEqualTo(LocalDate(2026, 10, 5))
+    }
+}

app/src/test/java/de/jeanlucmakiola/calendula/ui/week/WeekPagingTest.kt

@@ -64,4 +64,18 @@ class WeekPagingTest {
         assertThat(grid.startForPage(page)).isEqualTo(date)
         assertThat(grid.startForPage(page - 1)).isEqualTo(LocalDate(1990, 5, 13))
     }
+
+    @Test
+    fun `a day page and its day round-trip`() {
+        listOf(LocalDate(2026, 9, 27), LocalDate(1990, 5, 16), LocalDate(2100, 2, 28)).forEach { day ->
+            assertThat(DayGrid.startForPage(DayGrid.pageFor(day))).isEqualTo(day)
+        }
+    }
+
+    @Test
+    fun `adjacent day pages are adjacent days across a month end`() {
+        val page = DayGrid.pageFor(LocalDate(2026, 2, 28))
+        assertThat(DayGrid.startForPage(page + 1)).isEqualTo(LocalDate(2026, 3, 1))
+        assertThat(DayGrid.startForPage(page - 1)).isEqualTo(LocalDate(2026, 2, 27))
+    }
 }

docs/ARCHITECTURE.md

@@ -27,7 +27,7 @@ the package list (recurring writes, save conflicts, reminder delivery).
 ```mermaid
 flowchart TD
     subgraph UI ["ui/ — Compose screens + ViewModels"]
-        Screens["Month / Week / Day\nDetail / Edit / Settings\nOnboarding wizard"]
+        Screens["Month / Timeline / Agenda\nDetail / Edit / Settings\nOnboarding wizard"]
     end
     subgraph Data ["data/"]
         Repo["CalendarRepository\n(interface + impl, Flow-based, io-dispatched)"]
@@ -79,10 +79,42 @@ flowchart TD
 
 There is no navigation library. `MainActivity` hosts `RootScreen`, which
 gates on the first-launch wizard (`ui/onboarding/`), then shows
-`CalendarHost`. `CalendarHost` holds the active view (month/week/day)
-plus overlay state for detail, edit, and settings — full-screen overlays
+`CalendarHost`. `CalendarHost` holds the active view (month, day/multi-day/week,
+agenda) plus overlay state for detail, edit, and settings — full-screen overlays
 driven by `AnimatedVisibility` with a *held-key* pattern: the last shown
 key stays alive through the slide-out so content never flashes empty.
+Overlays leave through floret-kit's `predictiveBackExit`, so a committed back
+gesture finishes from its scaled preview.
+
+### Switching views (#184)
+
+- **One focused date.** `CalendarHost` owns a `ViewFocus` (`LocalViewFocus`)
+  that every view opens on and carries along. A view *reads* it once, on
+  entry, synchronously (`EnterOnFocus` before it reads its own position, so
+  its first frame is already on that date), and *writes* it only when the user
+  moves — a pager settling (`focusOnPage` keeps the date's place in the page),
+  a jump, Today, a tapped day, the agenda's top row. Writing on entry would
+  drift the date on every round trip.
+- **Three screens, not five.** The host's `AnimatedContent` is keyed on
+  `ViewScreen` (month, timeline, agenda), not on the view: day, multi-day and
+  week are one `TimelineScreen` with a `TimelineKind` each and a view model
+  each. Keying the three on one `contentKey` instead would still replay the
+  enter transition on every switch among them.
+- **Timeline ↔ timeline resizes in place.** `ColumnGeometry` places every
+  column (header cell, all-day bar, day column) in the layout pass; a switch
+  swaps the pager for a frame over both pages' days, each column lerped
+  between its slot on the one page and the other — a day the page doesn't
+  show carries on at its pitch, off screen, which is what slides it in or
+  out. Blocks sit in their column as shares of its width (`LaneColumn`), so
+  nothing recomposes per frame. The frame starts and ends exactly as the two
+  pages lay out, so the pagers either side hand over without a jump.
+- **Across screens, what both show morphs.** Inside a `SharedTransitionLayout`,
+  an event shown in both views travels from its old bounds to its new ones,
+  keyed per occurrence *and* per day it is drawn from (`ViewMorphKey`); only a
+  pager's settled page carries the tags. The drawer, top bar and FAB are not
+  per screen: CalendarHost draws them once, above the switch, from what the
+  screen on show publishes (`PublishChrome` in `CalendarChrome.kt`), so a
+  switch only changes what they say.
 A tapped reminder notification routes through `MainActivity` (`singleTop` +
 `onNewIntent`) as an external detail key that `CalendarHost` consumes
 exactly like an event tap.