diff --git a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreen.kt b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreen.kt
index e4ff328ad..d571733cc 100644
--- a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreen.kt
+++ b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreen.kt
@@ -204,6 +204,7 @@ fun FavoritesScreenPreview() {
                         currentDayFilter = persistentListOf(DroidKaigi2024Day.ConferenceDay1),
                         timetableItemMap = persistentMapOf(
                             TimeSlot(
+                                day = DroidKaigi2024Day.ConferenceDay1,
                                 startTimeString = "10:00",
                                 endTimeString = "11:00",
                             ) to listOf(
diff --git a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreenPresenter.kt b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreenPresenter.kt
index 6c70e3b1d..75ce58832 100644
--- a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreenPresenter.kt
+++ b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/FavoritesScreenPresenter.kt
@@ -107,7 +107,7 @@ private fun favoritesSheet(
                 ),
             )
             .timetableItems.groupBy {
-                TimeSlot(it.startsTimeString, it.endsTimeString)
+                TimeSlot(it.day, it.startsTimeString, it.endsTimeString)
             }.mapValues { entry ->
                 entry.value.sortedWith(
                     compareBy({ it.day?.name.orEmpty() }, { it.startsTimeString }),
diff --git a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteList.kt b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteList.kt
index c47e1c07e..9ec11e9a2 100644
--- a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteList.kt
+++ b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteList.kt
@@ -39,6 +39,7 @@ import io.github.droidkaigi.confsched.droidkaigiui.component.TimetableItemTag
 import io.github.droidkaigi.confsched.droidkaigiui.component.TimetableTime
 import io.github.droidkaigi.confsched.droidkaigiui.icon
 import io.github.droidkaigi.confsched.favorites.section.FavoritesSheetUiState.FavoriteListUiState.TimeSlot
+import io.github.droidkaigi.confsched.model.DroidKaigi2024Day
 import io.github.droidkaigi.confsched.model.TimetableItem
 import io.github.droidkaigi.confsched.model.TimetableItem.Session
 import io.github.droidkaigi.confsched.model.fake
@@ -162,6 +163,7 @@ fun FavoriteListPreview() {
             FavoriteList(
                 timetableItemMap = persistentMapOf(
                     TimeSlot(
+                        day = DroidKaigi2024Day.ConferenceDay1,
                         startTimeString = "10:00",
                         endTimeString = "11:00",
                     ) to listOf(
diff --git a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteSheet.kt b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteSheet.kt
index 0334def1a..5fe2ca2c8 100644
--- a/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteSheet.kt
+++ b/feature/favorites/src/commonMain/kotlin/io/github/droidkaigi/confsched/favorites/section/FavoriteSheet.kt
@@ -67,6 +67,7 @@ sealed interface FavoritesSheetUiState {
         val timetableItemMap: PersistentMap<TimeSlot, List<TimetableItem>>,
     ) : FavoritesSheetUiState {
         data class TimeSlot(
+            val day: DroidKaigi2024Day?,
             val startTimeString: String,
             val endTimeString: String,
         ) {
@@ -187,6 +188,7 @@ fun FavoriteSheetPreview() {
                     currentDayFilter = persistentListOf(ConferenceDay1, ConferenceDay2),
                     timetableItemMap = persistentMapOf(
                         TimeSlot(
+                            day = DroidKaigi2024Day.ConferenceDay1,
                             startTimeString = "10:00",
                             endTimeString = "11:00",
                         ) to listOf(