main, handle the time being invalid better.

lib/main.dart

@@ -79,6 +79,7 @@ class _HomeScreenState extends State<HomeScreen> {
 
   String? _sunsetErrorText;
   String? _minuteErrorText;
+  bool _validTime = false;
 
   static const _alarmId = 1001;
 
@@ -362,6 +363,7 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   String? _validateTime(String? value) {
+    _validTime = false;
     if (value == null || !RegExp(r'^\d{2}:\d{2}$').hasMatch(value)) {
       return 'Use HH:MM Format';
     }
@@ -369,6 +371,7 @@ class _HomeScreenState extends State<HomeScreen> {
     final m = int.parse(value.substring(3, 5));
     if (h > 23) return 'Hour Must Be 0–23';
     if (m > 59) return 'Minute Must Be 0–59';
+    _validTime = true;
     return null; // valid
   }
 
@@ -545,19 +548,15 @@ class _HomeScreenState extends State<HomeScreen> {
                   Expanded(
                     child: SwitchListTile(
                       //title: const Text('Enable Sunset Alarm'),
-                      title: Text(_alarmEnabled ? 'Sunset Alarm Enabled' : ''),
+                      title: Text(_alarmEnabled ? 'Sunset Alarm Enabled' : ""),
                       subtitle: Text(
                         _alarmEnabled
                             ? '${_minutesBefore} Minute${_plural} Before @ $_alarmDisplayTime'
-                            : (_sunsetController.text == ""
-                                ? "Time Missing"
-                                : ""),
+                            : "",
                       ),
-                      value:
-                          _sunsetController.text != "" ? _alarmEnabled : false,
+                      value: _validTime ? _alarmEnabled : false,
                       // If _isDataLoaded is false, onChanged is null, disabling the switch
-                      onChanged:
-                          _sunsetController.text != "" ? _toggleAlarm : null,
+                      onChanged: _validTime ? _toggleAlarm : null,
                     ),
                   ),
                 ],