diff --git a/README.md b/README.md
index 1ca5805..87d7cb5 100644
--- a/README.md
+++ b/README.md
@@ -297,6 +297,12 @@ aren't obvious from using it.
   about, unlike a timer, so there's nothing worth a permanent notification for; it keeps
   running across tab swipes and a trip to Settings and back (both stay under the same
   `TabsScreen` back-stack entry) but not past the app process being killed.
+- **Changing an alarm's time switches it on**, the way the stock Clock app does. Setting a
+  time is how you set an alarm, so picking one on a switched-off alarm and leaving it off
+  would just mean it silently doesn't ring. The quick time popup always enables; the full
+  editor sheet only does so when the time actually changed, since that sheet has no on/off
+  switch of its own (that lives on the list row) and merely renaming a switched-off alarm
+  shouldn't quietly turn it on.
 - **Editing is in-place, not a separate screen.** Tap an alarm's time for a quick
   time-only popup — which now also has a Delete action, so removing an alarm doesn't
   require opening the full editor either — or tap its label/repeat area for the full
diff --git a/app/src/main/java/com/targetcrafter/haalarmclock/data/AlarmRepository.kt b/app/src/main/java/com/targetcrafter/haalarmclock/data/AlarmRepository.kt
index 3d471db..8d45128 100644
--- a/app/src/main/java/com/targetcrafter/haalarmclock/data/AlarmRepository.kt
+++ b/app/src/main/java/com/targetcrafter/haalarmclock/data/AlarmRepository.kt
@@ -48,10 +48,13 @@ class AlarmRepository(
         save(alarm.copy(enabled = enabled))
     }
 
-    /** Updates just the time, leaving every other setting untouched — used by the quick time-edit popup. */
+    /** Updates just the time, leaving every other setting untouched — used by the quick time-edit
+     * popup — and switches the alarm on. Setting a time is how you set an alarm: picking one on a
+     * switched-off alarm and having it stay off means it silently won't ring, which is never what
+     * was meant. Matches the stock Clock app. */
     suspend fun updateTime(id: Long, hour: Int, minute: Int) {
         val alarm = dao.getById(id) ?: return
-        save(alarm.copy(hour = hour, minute = minute))
+        save(alarm.copy(hour = hour, minute = minute, enabled = true))
     }
 
     /** Re-arms every enabled alarm's AlarmManager entry; alarms don't survive a reboot on their own.
diff --git a/app/src/main/java/com/targetcrafter/haalarmclock/ui/editor/AlarmEditorViewModel.kt b/app/src/main/java/com/targetcrafter/haalarmclock/ui/editor/AlarmEditorViewModel.kt
index d5d06c2..fac07e6 100644
--- a/app/src/main/java/com/targetcrafter/haalarmclock/ui/editor/AlarmEditorViewModel.kt
+++ b/app/src/main/java/com/targetcrafter/haalarmclock/ui/editor/AlarmEditorViewModel.kt
@@ -43,12 +43,17 @@ class AlarmEditorViewModel(
     private val _state = MutableStateFlow(AlarmEditorUiState(isNew = alarmId == null))
     val state: StateFlow<AlarmEditorUiState> = _state.asStateFlow()
 
+    /** The time an existing alarm had when the sheet opened, so [save] can tell whether the user
+     * actually changed it. Null for a new alarm, which starts switched on anyway. */
+    private var loadedTime: Pair<Int, Int>? = null
+
     init {
         val defaults = appDefaultsStore.defaults.value
         val id = alarmId
         if (id != null) {
             viewModelScope.launch {
                 val alarm = repository.getById(id)
+                loadedTime = alarm?.let { it.hour to it.minute }
                 _state.value = if (alarm != null) {
                     AlarmEditorUiState(
                         id = alarm.id,
@@ -107,6 +112,12 @@ class AlarmEditorViewModel(
 
     fun save(onDone: () -> Unit) {
         val s = _state.value
+        // Changing the time switches the alarm on, the same as the quick time popup does: picking
+        // a new time for a switched-off alarm and leaving it off means it silently won't ring.
+        // Only when the time actually changed, though — this sheet has no on/off switch of its own
+        // (that lives on the list row), so saving it after only renaming a switched-off alarm must
+        // not quietly turn it on.
+        val timeChanged = loadedTime?.let { (hour, minute) -> hour != s.hour || minute != s.minute } ?: false
         viewModelScope.launch {
             repository.save(
                 Alarm(
@@ -114,7 +125,7 @@ class AlarmEditorViewModel(
                     hour = s.hour,
                     minute = s.minute,
                     label = s.label,
-                    enabled = s.enabled,
+                    enabled = s.enabled || timeChanged,
                     repeatDaysMask = s.repeatDaysMask,
                     vibrate = s.vibrate,
                     fadeInEnabled = s.fadeInEnabled,