Merge pull request 'fix(agenda): show multi-day events on every day they span' (!83) from fix/agenda-multiday into release/v2.16.0

Reviewed-on: #83

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

@@ -367,10 +367,14 @@ private fun AgendaList(
             } else {
                 itemsIndexed(
                     items = day.events,
-                    key = { _, event -> event.instanceId },
+                    // Scope the key by day: a multi-day event appears under every
+                    // day it spans, so its instanceId alone is not unique across
+                    // the list (LazyColumn requires unique keys).
+                    key = { _, event -> "${day.date}-${event.instanceId}" },
                 ) { index, event ->
                     AgendaEventRow(
                         event = event,
+                        day = day.date,
                         position = positionOf(index, day.events.size),
                         dimmed = dimPast && event.hasEnded(now),
                         modifier = animateItemMotion(),
@@ -449,6 +453,7 @@ private fun AgendaEmptyDayRow(onClick: () -> Unit) {
 @Composable
 private fun AgendaEventRow(
     event: EventInstance,
+    day: LocalDate,
     position: Position,
     dimmed: Boolean,
     modifier: Modifier = Modifier,
@@ -460,7 +465,7 @@ private fun AgendaEventRow(
     GroupedRow(
         modifier = if (dimmed) modifier.alpha(EventDimAlpha) else modifier,
         title = title,
-        summary = agendaTimeSummary(event),
+        summary = agendaTimeSummary(event, day),
         position = position,
         minHeight = 64.dp,
         leading = {
@@ -554,16 +559,29 @@ private fun agendaDayLabel(date: LocalDate, today: LocalDate): String {
     return if (relative != null) "$relative · $formatted" else formatted
 }
 
-/** Time line under the title: "09:00 – 10:00 · Location", "All day", etc. */
+/**
+ * Time line under the title: "09:00 – 10:00 · Location", "All day", etc.
+ *
+ * A multi-day event shows only the part relevant to [day], spelled out so each
+ * day reads on its own: its first day names the start ("Starts 14:00"), its last
+ * day the end ("Ends 10:00"), and any whole day in between reads as "All day".
+ * An all-day multi-day event is simply "All day" on every day it covers.
+ */
 @Composable
-private fun agendaTimeSummary(event: EventInstance): String {
+private fun agendaTimeSummary(event: EventInstance, day: LocalDate): String {
-    val time = if (event.isAllDay) {
+    val is24Hour = LocalUse24HourFormat.current
-        stringResource(R.string.event_detail_all_day)
+    val locale = currentLocale()
-    } else {
+
-        val is24Hour = LocalUse24HourFormat.current
+    val time = when (val label = agendaTimeLabel(event, day, zone)) {
-        val locale = currentLocale()
+        AgendaTimeLabel.AllDay -> stringResource(R.string.event_detail_all_day)
-        "${formatTime(event.start, is24Hour, locale)} – ${formatTime(event.end, is24Hour, locale)}"
+        is AgendaTimeLabel.Starts ->
+            stringResource(R.string.agenda_span_starts, formatTime(label.start, is24Hour, locale))
+        is AgendaTimeLabel.Ends ->
+            stringResource(R.string.agenda_span_ends, formatTime(label.end, is24Hour, locale))
+        is AgendaTimeLabel.Range ->
+            "${formatTime(label.start, is24Hour, locale)} – ${formatTime(label.end, is24Hour, locale)}"
     }
+
     val location = event.location?.takeIf { it.isNotBlank() }
     return if (location != null) "$time · $location" else time
 }

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

@@ -2,9 +2,70 @@ package de.jeanlucmakiola.calendula.ui.agenda
 
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
+import kotlinx.datetime.plus
 import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Instant
+
+/**
+ * The zone the event's calendar dates live in. Timed events are resolved in the
+ * device [zone]; all-day events live at UTC midnights with an exclusive end, so
+ * resolving them anywhere but UTC shifts the boundaries — east of UTC that leaks
+ * a one-day event onto its next day. Matches the Week view and detail card.
+ */
+private fun EventInstance.dateZone(zone: TimeZone): TimeZone =
+    if (isAllDay) TimeZone.UTC else zone
+
+/** The first calendar day this event occupies. */
+fun EventInstance.spanFirstDay(zone: TimeZone): LocalDate =
+    start.toLocalDateTime(dateZone(zone)).date
+
+/**
+ * The last calendar day this event actually occupies. An event ending exactly at
+ * midnight (all-day events end at the exclusive next-midnight) does not reach
+ * into that boundary day, so resolve the instant just before [end].
+ */
+fun EventInstance.spanLastDay(zone: TimeZone): LocalDate {
+    val lastInstant = if (end > start) end - 1.milliseconds else start
+    return lastInstant.toLocalDateTime(dateZone(zone)).date
+}
+
+/** Whether this event occupies more than one calendar day in [zone]. */
+fun EventInstance.spansMultipleDays(zone: TimeZone): Boolean =
+    spanFirstDay(zone) != spanLastDay(zone)
+
+/**
+ * What an agenda row's time line should convey for an event on a given day —
+ * the part of a multi-day span that [day] falls in. Pure and shared so the
+ * agenda screen and the agenda widget label multi-day events identically; each
+ * surface only formats the instants into its own locale/24h string.
+ */
+sealed interface AgendaTimeLabel {
+    /** An all-day event, or a whole in-between day of a multi-day span. */
+    data object AllDay : AgendaTimeLabel
+    /** The first day of a multi-day timed event: when it begins. */
+    data class Starts(val start: Instant) : AgendaTimeLabel
+    /** The last day of a multi-day timed event: when it ends. */
+    data class Ends(val end: Instant) : AgendaTimeLabel
+    /** A single-day timed event: its start–end range. */
+    data class Range(val start: Instant, val end: Instant) : AgendaTimeLabel
+}
+
+/** The [AgendaTimeLabel] for [event] as it appears on [day], resolved in [zone]. */
+fun agendaTimeLabel(event: EventInstance, day: LocalDate, zone: TimeZone): AgendaTimeLabel {
+    if (event.isAllDay) return AgendaTimeLabel.AllDay
+    val firstDay = event.spanFirstDay(zone)
+    val lastDay = event.spanLastDay(zone)
+    return when {
+        firstDay == lastDay -> AgendaTimeLabel.Range(event.start, event.end)
+        day <= firstDay -> AgendaTimeLabel.Starts(event.start)
+        day >= lastDay -> AgendaTimeLabel.Ends(event.end)
+        else -> AgendaTimeLabel.AllDay // a full in-between day
+    }
+}
 
 /** One calendar day with at least one event, for the agenda list. */
 data class AgendaDay(
@@ -15,31 +76,45 @@ data class AgendaDay(
 
 /**
  * Group flat [instances] into forward-looking [AgendaDay]s (only days that
- * actually carry events). An event that began before [anchor] (ongoing or
+ * actually carry events). A multi-day event surfaces on *every* day it spans,
- * multi-day) is clamped to the anchor day so it still surfaces on top. Within a
+ * not just its first — clamped to [[anchor], [windowEnd]] so an event that began
- * day, all-day events sort first, then ascending by start time, then title.
+ * before the window (ongoing) still lists from the anchor day, and one running
+ * past the window stops at the last visible day. Within a day, all-day events
+ * sort first, then ascending by start time, then title.
  *
  * Shared by the Agenda screen and the agenda home-screen widget so both group
  * and order identically.
  */
 fun groupAgendaDays(
     anchor: LocalDate,
+    windowEnd: LocalDate,
     instances: List<EventInstance>,
     zone: TimeZone,
-): List<AgendaDay> =
+): List<AgendaDay> {
-    instances
+    val byDay = sortedMapOf<LocalDate, MutableList<EventInstance>>()
-        .groupBy { it.start.toLocalDateTime(zone).date.coerceAtLeast(anchor) }
+    for (instance in instances) {
-        .toSortedMap()
+        val firstDay = instance.spanFirstDay(zone).coerceAtLeast(anchor)
-        .map { (date, dayEvents) ->
+        // Never below firstDay: an instance the query returned always surfaces on
-            AgendaDay(
+        // at least its first visible day, even if its end resolves earlier (e.g. a
-                date = date,
+        // zero-length or boundary instant) — otherwise the loop would drop it.
-                events = dayEvents.sortedWith(
+        val lastDay = instance.spanLastDay(zone).coerceAtMost(windowEnd).coerceAtLeast(firstDay)
-                    compareByDescending<EventInstance> { it.isAllDay }
+        var day = firstDay
-                        .thenBy { it.start }
+        while (day <= lastDay) {
-                        .thenBy { it.title },
+            byDay.getOrPut(day) { mutableListOf() }.add(instance)
-                ),
+            day = day.plus(1, DateTimeUnit.DAY)
-            )
         }
+    }
+    return byDay.map { (date, dayEvents) ->
+        AgendaDay(
+            date = date,
+            events = dayEvents.sortedWith(
+                compareByDescending<EventInstance> { it.isAllDay }
+                    .thenBy { it.start }
+                    .thenBy { it.title },
+            ),
+        )
+    }
+}
 
 /**
  * Ensure [today] surfaces as the first agenda day even when it carries no

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

@@ -159,11 +159,11 @@ class AgendaViewModel @Inject constructor(
             return AgendaUiState.Failure(FailureReason.NoCalendarsConfigured)
         }
         val anchor = params.anchor
-        val days = groupAgendaDays(anchor, instances, zone)
         val rangeEnd = anchor.plus(
             params.range.dayCount(anchor, params.weekStart) - 1,
             DateTimeUnit.DAY,
         )
+        val days = groupAgendaDays(anchor, rangeEnd, instances, zone)
         return AgendaUiState.Success(
             anchor = anchor,
             today = todayDate,

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

@@ -131,13 +131,14 @@ internal suspend fun Context.loadAgendaWidgetData(): AgendaWidgetData {
     // the composition from Glance state, so changing the range is a plain
     // recomposition and never depends on the widget session restarting.
     val window = agendaRange(anchor, AgendaRange.MAX_CUSTOM_DAYS - 1, zone)
+    val windowEnd = anchor.plus(AgendaRange.MAX_CUSTOM_DAYS - 1, DateTimeUnit.DAY)
     val instances = ep.calendarRepository().instances(window).first()
     val is24Hour = prefs.timeFormat.first()
         .is24Hour(android.text.format.DateFormat.is24HourFormat(this))
     val soften = prefs.softenCalendarColors.first()
     return AgendaWidgetData.Ready(
         today = anchor,
-        days = groupAgendaDays(anchor, instances, zone),
+        days = groupAgendaDays(anchor, windowEnd, instances, zone),
         is24Hour = is24Hour,
         soften = soften,
         weekStart = weekStart,

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

@@ -49,6 +49,8 @@ import de.jeanlucmakiola.calendula.data.prefs.parsePastEventDisplay
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.hasEnded
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaTimeLabel
+import de.jeanlucmakiola.calendula.ui.agenda.agendaTimeLabel
 import de.jeanlucmakiola.calendula.ui.agenda.anchorTodayIfMissing
 import de.jeanlucmakiola.calendula.ui.agenda.dayCount
 import de.jeanlucmakiola.calendula.ui.agenda.parseAgendaRange
@@ -127,7 +129,7 @@ class RefreshAgendaAction : ActionCallback {
 /** Flat row model so the [LazyColumn] can mix day headers and events. */
 private sealed interface AgendaRow {
     data class Header(val date: LocalDate, val today: LocalDate) : AgendaRow
-    data class Event(val event: EventInstance) : AgendaRow
+    data class Event(val date: LocalDate, val event: EventInstance) : AgendaRow
     /** "Nothing left today" line under an anchored, event-less today (#35). */
     data class Placeholder(val date: LocalDate) : AgendaRow
 }
@@ -185,7 +187,7 @@ private fun AgendaWidgetBody(data: AgendaWidgetData, dark: Boolean) {
                             if (day.events.isEmpty()) {
                                 add(AgendaRow.Placeholder(day.date))
                             } else {
-                                day.events.forEach { add(AgendaRow.Event(it)) }
+                                day.events.forEach { add(AgendaRow.Event(day.date, it)) }
                             }
                         }
                     }
@@ -196,6 +198,7 @@ private fun AgendaWidgetBody(data: AgendaWidgetData, dark: Boolean) {
                                 is AgendaRow.Placeholder -> PlaceholderRow(row.date)
                                 is AgendaRow.Event -> EventRow(
                                     event = row.event,
+                                    day = row.date,
                                     dark = dark,
                                     soften = data.soften,
                                     is24Hour = data.is24Hour,
@@ -312,6 +315,7 @@ private fun PlaceholderRow(date: LocalDate) {
 @Composable
 private fun EventRow(
     event: EventInstance,
+    day: LocalDate,
     dark: Boolean,
     soften: Boolean,
     is24Hour: Boolean,
@@ -357,7 +361,7 @@ private fun EventRow(
                 style = TextStyle(color = titleColor, fontSize = 14.sp),
             )
             Text(
-                text = eventTimeSummary(context, event, is24Hour),
+                text = eventTimeSummary(context, event, day, is24Hour),
                 maxLines = 1,
                 style = TextStyle(color = GlanceTheme.colors.onSurfaceVariant, fontSize = 12.sp),
             )
@@ -396,11 +400,20 @@ private fun agendaDayLabel(context: Context, date: LocalDate, today: LocalDate):
     return if (relative != null) "$relative · $formatted" else formatted
 }
 
-private fun eventTimeSummary(context: Context, event: EventInstance, is24Hour: Boolean): String {
+private fun eventTimeSummary(
-    val time = if (event.isAllDay) {
+    context: Context,
-        context.getString(R.string.event_detail_all_day)
+    event: EventInstance,
-    } else {
+    day: LocalDate,
-        "${formatTime(event.start, is24Hour)} – ${formatTime(event.end, is24Hour)}"
+    is24Hour: Boolean,
+): String {
+    val time = when (val label = agendaTimeLabel(event, day, zone())) {
+        AgendaTimeLabel.AllDay -> context.getString(R.string.event_detail_all_day)
+        is AgendaTimeLabel.Starts ->
+            context.getString(R.string.agenda_span_starts, formatTime(label.start, is24Hour))
+        is AgendaTimeLabel.Ends ->
+            context.getString(R.string.agenda_span_ends, formatTime(label.end, is24Hour))
+        is AgendaTimeLabel.Range ->
+            "${formatTime(label.start, is24Hour)} – ${formatTime(label.end, is24Hour)}"
     }
     val location = event.location?.takeIf { it.isNotBlank() }
     return if (location != null) "$time · $location" else time

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

@@ -270,6 +270,9 @@
     <string name="agenda_header_tomorrow">Tomorrow</string>
     <string name="agenda_empty_title">You\'re all caught up</string>
     <string name="agenda_no_more_today">No more events today</string>
+    <!-- Time line for a multi-day event, on its first / last day (%1$s is a time, e.g. "14:00"). -->
+    <string name="agenda_span_starts">Starts %1$s</string>
+    <string name="agenda_span_ends">Ends %1$s</string>
 
     <!-- Event search -->
     <string name="search_action">Search</string>

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

@@ -0,0 +1,76 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+class AgendaTimeLabelTest {
+
+    private val zone = TimeZone.UTC
+
+    private fun at(y: Int, mo: Int, d: Int, h: Int = 0, min: Int = 0): Instant =
+        LocalDateTime(y, mo, d, h, min).toInstant(zone)
+
+    private fun event(start: Instant, end: Instant, isAllDay: Boolean = false) = EventInstance(
+        instanceId = 1,
+        eventId = 1,
+        calendarId = 1,
+        title = "e",
+        start = start,
+        end = end,
+        isAllDay = isAllDay,
+        color = 0,
+        location = null,
+    )
+
+    private fun labelOn(y: Int, mo: Int, d: Int, event: EventInstance) =
+        agendaTimeLabel(event, LocalDate(y, mo, d), zone)
+
+    @Test
+    fun `a single-day timed event is a start-end range`() {
+        val e = event(at(2026, 7, 2, 12, 0), at(2026, 7, 2, 13, 0))
+
+        assertThat(labelOn(2026, 7, 2, e))
+            .isEqualTo(AgendaTimeLabel.Range(e.start, e.end))
+    }
+
+    @Test
+    fun `a single-day all-day event is all-day`() {
+        val e = event(at(2026, 7, 2), at(2026, 7, 3), isAllDay = true)
+
+        assertThat(labelOn(2026, 7, 2, e)).isEqualTo(AgendaTimeLabel.AllDay)
+    }
+
+    @Test
+    fun `a multi-day timed event names the start, middle, and end days`() {
+        val e = event(at(2026, 7, 1, 14, 0), at(2026, 7, 4, 10, 0))
+
+        assertThat(labelOn(2026, 7, 1, e)).isEqualTo(AgendaTimeLabel.Starts(e.start))
+        assertThat(labelOn(2026, 7, 2, e)).isEqualTo(AgendaTimeLabel.AllDay)
+        assertThat(labelOn(2026, 7, 3, e)).isEqualTo(AgendaTimeLabel.AllDay)
+        assertThat(labelOn(2026, 7, 4, e)).isEqualTo(AgendaTimeLabel.Ends(e.end))
+    }
+
+    @Test
+    fun `a multi-day all-day event is all-day on every day`() {
+        val e = event(at(2026, 7, 2), at(2026, 7, 5), isAllDay = true)
+
+        assertThat(labelOn(2026, 7, 2, e)).isEqualTo(AgendaTimeLabel.AllDay)
+        assertThat(labelOn(2026, 7, 3, e)).isEqualTo(AgendaTimeLabel.AllDay)
+        assertThat(labelOn(2026, 7, 4, e)).isEqualTo(AgendaTimeLabel.AllDay)
+    }
+
+    @Test
+    fun `an event begun before the shown day is not labelled as starting`() {
+        // Runs 29 Jun 09:00 → 2 Jul 09:00; on 1 Jul it is mid-span, on 2 Jul it ends.
+        val e = event(at(2026, 6, 29, 9, 0), at(2026, 7, 2, 9, 0))
+
+        assertThat(labelOn(2026, 7, 1, e)).isEqualTo(AgendaTimeLabel.AllDay)
+        assertThat(labelOn(2026, 7, 2, e)).isEqualTo(AgendaTimeLabel.Ends(e.end))
+    }
+}

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

@@ -0,0 +1,150 @@
+package de.jeanlucmakiola.calendula.ui.agenda
+
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.EventInstance
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
+import kotlin.time.Instant
+import org.junit.jupiter.api.Test
+
+class GroupAgendaDaysTest {
+
+    private val zone = TimeZone.UTC
+    private val anchor = LocalDate(2026, 7, 1)
+    // A wide window so clamping to the window end is out of the way unless tested.
+    private val windowEnd = LocalDate(2026, 7, 31)
+
+    private fun at(y: Int, mo: Int, d: Int, h: Int = 0, min: Int = 0): Instant =
+        LocalDateTime(y, mo, d, h, min).toInstant(zone)
+
+    private fun event(
+        id: Long,
+        title: String,
+        start: Instant,
+        end: Instant,
+        isAllDay: Boolean = false,
+    ) = EventInstance(
+        instanceId = id,
+        eventId = id,
+        calendarId = 1,
+        title = title,
+        start = start,
+        end = end,
+        isAllDay = isAllDay,
+        color = 0,
+        location = null,
+    )
+
+    private fun days(instances: List<EventInstance>) =
+        groupAgendaDays(anchor, windowEnd, instances, zone)
+
+    @Test
+    fun `a timed multi-day event lists on every day it spans`() {
+        val e = event(1, "trip", at(2026, 7, 1, 14, 0), at(2026, 7, 3, 10, 0))
+
+        val result = days(listOf(e))
+
+        assertThat(result.map { it.date }).containsExactly(
+            LocalDate(2026, 7, 1),
+            LocalDate(2026, 7, 2),
+            LocalDate(2026, 7, 3),
+        ).inOrder()
+        result.forEach { assertThat(it.events).containsExactly(e) }
+    }
+
+    @Test
+    fun `an all-day multi-day event stops before its exclusive next-midnight end`() {
+        // 1–3 July inclusive: end is the exclusive midnight opening 4 July.
+        val e = event(1, "holiday", at(2026, 7, 1), at(2026, 7, 4), isAllDay = true)
+
+        val result = days(listOf(e))
+
+        assertThat(result.map { it.date }).containsExactly(
+            LocalDate(2026, 7, 1),
+            LocalDate(2026, 7, 2),
+            LocalDate(2026, 7, 3),
+        ).inOrder()
+    }
+
+    @Test
+    fun `a single-day event lists exactly once`() {
+        val e = event(1, "lunch", at(2026, 7, 2, 12, 0), at(2026, 7, 2, 13, 0))
+
+        assertThat(days(listOf(e)).map { it.date })
+            .containsExactly(LocalDate(2026, 7, 2))
+    }
+
+    @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))
+
+        assertThat(days(listOf(e)).map { it.date })
+            .containsExactly(LocalDate(2026, 7, 1))
+    }
+
+    @Test
+    fun `an event begun before the anchor is clamped to the anchor day`() {
+        val e = event(1, "ongoing", at(2026, 6, 29, 9, 0), at(2026, 7, 2, 9, 0))
+
+        assertThat(days(listOf(e)).map { it.date }).containsExactly(
+            LocalDate(2026, 7, 1),
+            LocalDate(2026, 7, 2),
+        ).inOrder()
+    }
+
+    @Test
+    fun `an event running past the window is clamped to the last visible day`() {
+        val narrowEnd = LocalDate(2026, 7, 2)
+        val e = event(1, "long", at(2026, 7, 1, 9, 0), at(2026, 7, 5, 9, 0))
+
+        val result = groupAgendaDays(anchor, narrowEnd, listOf(e), zone)
+
+        assertThat(result.map { it.date }).containsExactly(
+            LocalDate(2026, 7, 1),
+            LocalDate(2026, 7, 2),
+        ).inOrder()
+    }
+
+    // All-day events are stored at UTC midnights; resolving them in a device
+    // zone east of UTC would leak them onto the following day (see spanLastDay).
+    private val berlin = TimeZone.of("Europe/Berlin")
+
+    private fun utcMidnight(y: Int, mo: Int, d: Int): Instant =
+        LocalDateTime(y, mo, d, 0, 0).toInstant(TimeZone.UTC)
+
+    @Test
+    fun `a single-day all-day event does not leak onto the next day in an eastern zone`() {
+        val e = event(1, "birthday", utcMidnight(2026, 7, 2), utcMidnight(2026, 7, 3), isAllDay = true)
+
+        val result = groupAgendaDays(anchor, windowEnd, listOf(e), berlin)
+
+        assertThat(result.map { it.date }).containsExactly(LocalDate(2026, 7, 2))
+        assertThat(e.spansMultipleDays(berlin)).isFalse()
+    }
+
+    @Test
+    fun `an all-day multi-day event spans its true days in an eastern zone`() {
+        // 2–4 July inclusive: exclusive end is the UTC midnight opening 5 July.
+        val e = event(1, "holiday", utcMidnight(2026, 7, 2), utcMidnight(2026, 7, 5), isAllDay = true)
+
+        val result = groupAgendaDays(anchor, windowEnd, listOf(e), berlin)
+
+        assertThat(result.map { it.date }).containsExactly(
+            LocalDate(2026, 7, 2),
+            LocalDate(2026, 7, 3),
+            LocalDate(2026, 7, 4),
+        ).inOrder()
+    }
+
+    @Test
+    fun `within a day all-day events sort before timed ones`() {
+        val allDay = event(1, "birthday", at(2026, 7, 1), at(2026, 7, 2), isAllDay = true)
+        val timed = event(2, "call", at(2026, 7, 1, 9, 0), at(2026, 7, 1, 10, 0))
+
+        val dayOne = days(listOf(timed, allDay)).first { it.date == anchor }
+
+        assertThat(dayOne.events).containsExactly(allDay, timed).inOrder()
+    }
+}