diff --git a/app/lib/timetable/timetable_add_event/src/timetable_add_event_dialog_controller.dart b/app/lib/timetable/timetable_add_event/src/timetable_add_event_dialog_controller.dart
index dffccf99a..9a640be4c 100644
--- a/app/lib/timetable/timetable_add_event/src/timetable_add_event_dialog_controller.dart
+++ b/app/lib/timetable/timetable_add_event/src/timetable_add_event_dialog_controller.dart
@@ -66,12 +66,20 @@ class AddEventDialogController extends ChangeNotifier {
     notifyListeners();
   }
 
+  bool showEndTimeNotAfterStartTimeError = false;
+  void maybeClearEndTimeNotAfterStartTimeError() {
+    if (endTime.isAfter(startTime)) {
+      showEndTimeNotAfterStartTimeError = false;
+    }
+  }
+
   Time _startTime = Time(hour: 11, minute: 00);
 
   Time get startTime => _startTime;
 
   set startTime(Time value) {
     _startTime = value;
+    maybeClearEndTimeNotAfterStartTimeError();
     notifyListeners();
   }
 
@@ -81,6 +89,7 @@ class AddEventDialogController extends ChangeNotifier {
 
   set endTime(Time value) {
     _endTime = value;
+    maybeClearEndTimeNotAfterStartTimeError();
     notifyListeners();
   }
 
@@ -94,6 +103,10 @@ class AddEventDialogController extends ChangeNotifier {
       showEmptyCourseError = true;
       hasError = true;
     }
+    if (!endTime.isAfter(startTime)) {
+      showEndTimeNotAfterStartTimeError = true;
+      hasError = true;
+    }
     if (hasError) {
       notifyListeners();
       return false;
diff --git a/app/lib/timetable/timetable_add_event/timetable_add_event_dialog.dart b/app/lib/timetable/timetable_add_event/timetable_add_event_dialog.dart
index 69e1b2388..a6eea8118 100644
--- a/app/lib/timetable/timetable_add_event/timetable_add_event_dialog.dart
+++ b/app/lib/timetable/timetable_add_event/timetable_add_event_dialog.dart
@@ -396,7 +396,7 @@ class _DateAndTimePicker extends StatelessWidget {
                     timeFieldKey: EventDialogKeys.endTimeField,
                     time: controller.endTime,
                     showEndNotAfterBeginningError:
-                        !controller.endTime.isAfter(controller.startTime),
+                        controller.showEndTimeNotAfterStartTimeError,
                     isDatePickingEnabled: false,
                     onTimeChanged: (newTime) {
                       controller.endTime = newTime;
diff --git a/app/test/timetable/timetable_dialog_test.dart b/app/test/timetable/timetable_dialog_test.dart
index 74c1cc635..7c307afa5 100644
--- a/app/test/timetable/timetable_dialog_test.dart
+++ b/app/test/timetable/timetable_dialog_test.dart
@@ -215,22 +215,55 @@ void main() {
       expect(find.text(EventDialogErrorStrings.emptyCourse), findsNothing);
     });
 
-    testWidgets('shows error message if end time is not after start time',
+    testWidgets(
+        'shows "end time not after start time" error message when save was pressed',
         (tester) async {
       final dt = createDialogTester(tester);
       await dt.pumpDialog(isExam: false);
 
       await dt.selectStartTime(const TimeOfDay(hour: 13, minute: 15));
       await dt.selectEndTime(const TimeOfDay(hour: 13, minute: 15));
+      await dt.tapSaveButton();
       expect(find.text(EventDialogErrorStrings.endTimeMustBeAfterStartTime),
           findsOneWidget);
 
+      await dt.tapSaveButton();
       await dt.selectEndTime(const TimeOfDay(hour: 12, minute: 00));
       expect(find.text(EventDialogErrorStrings.endTimeMustBeAfterStartTime),
           findsOneWidget);
     });
+    testWidgets(
+        'doesnt show "end time not after start time" error message when save was not pressed',
+        (tester) async {
+      final dt = createDialogTester(tester);
+      await dt.pumpDialog(isExam: false);
+
+      await dt.selectStartTime(const TimeOfDay(hour: 13, minute: 15));
+      await dt.selectEndTime(const TimeOfDay(hour: 13, minute: 15));
+      expect(find.text(EventDialogErrorStrings.endTimeMustBeAfterStartTime),
+          findsNothing);
+
+      await dt.selectEndTime(const TimeOfDay(hour: 12, minute: 00));
+      expect(find.text(EventDialogErrorStrings.endTimeMustBeAfterStartTime),
+          findsNothing);
+    });
+
+    testWidgets(
+        'removes "end time not after start time" error message when the error is fixed by the user',
+        (tester) async {
+      final dt = createDialogTester(tester);
+      await dt.pumpDialog(isExam: false);
 
-    testWidgets('doesnt shows error message if end time after start time',
+      await dt.selectStartTime(const TimeOfDay(hour: 13, minute: 15));
+      await dt.selectEndTime(const TimeOfDay(hour: 10, minute: 30));
+      await dt.tapSaveButton();
+      await dt.selectEndTime(const TimeOfDay(hour: 15, minute: 30));
+      expect(find.text(EventDialogErrorStrings.endTimeMustBeAfterStartTime),
+          findsNothing);
+    });
+
+    testWidgets(
+        'doesnt show "end time not after start time" error message when end time is after start time',
         (tester) async {
       final dt = createDialogTester(tester);
       await dt.pumpDialog(isExam: false);
diff --git a/app/test_goldens/timetable/timetable_dialog/timetable_dialog_test.dart b/app/test_goldens/timetable/timetable_dialog/timetable_dialog_test.dart
index 206f815cc..334f26fe0 100644
--- a/app/test_goldens/timetable/timetable_dialog/timetable_dialog_test.dart
+++ b/app/test_goldens/timetable/timetable_dialog/timetable_dialog_test.dart
@@ -107,11 +107,11 @@ void main() {
           theme: testConfig.theme.data,
         );
 
-        // Set end time before start time to trigger the error message.
+        // Set end time before start time.
         await dt.selectStartTime(const TimeOfDay(hour: 12, minute: 0));
         await dt.selectEndTime(const TimeOfDay(hour: 10, minute: 0));
 
-        // Triggers empty title and no course chosen error messages.
+        // Triggers "empty title", "no course chosen" and "end time is before start time" error messages.
         await dt.tapSaveButton();
 
         await multiScreenGolden(