diff --git a/src/MaaWpfGui/ViewModels/UI/TaskQueueViewModel.cs b/src/MaaWpfGui/ViewModels/UI/TaskQueueViewModel.cs
index 2266b6d855..8341c3af9e 100644
--- a/src/MaaWpfGui/ViewModels/UI/TaskQueueViewModel.cs
+++ b/src/MaaWpfGui/ViewModels/UI/TaskQueueViewModel.cs
@@ -488,7 +488,7 @@ namespace MaaWpfGui.ViewModels.UI
 
             for (int i = 0; i < 8; ++i)
             {
-                if (!SettingsViewModel.TimerSettings.TimerModels.Timers[i].IsOn)
+                if (SettingsViewModel.TimerSettings.TimerModels.Timers[i].IsOn == false)
                 {
                     continue;
                 }
@@ -547,6 +547,8 @@ namespace MaaWpfGui.ViewModels.UI
             {
                 _logger.Information($"Scheduled start: Timer Index: {configIndex}");
                 await HandleScheduledStart(configIndex);
+
+                SettingsViewModel.TimerSettings.TimerModels.Timers[configIndex].IsOn ??= false;
             }
         }
 
diff --git a/src/MaaWpfGui/ViewModels/UserControl/Settings/TimerSettingsUserControlModel.cs b/src/MaaWpfGui/ViewModels/UserControl/Settings/TimerSettingsUserControlModel.cs
index e2e2108ee9..9b4ab82868 100644
--- a/src/MaaWpfGui/ViewModels/UserControl/Settings/TimerSettingsUserControlModel.cs
+++ b/src/MaaWpfGui/ViewModels/UserControl/Settings/TimerSettingsUserControlModel.cs
@@ -82,7 +82,7 @@ public class TimerSettingsUserControlModel : PropertyChangedBase
     {
         public class TimerProperties : PropertyChangedBase
         {
-            public TimerProperties(int timeId, bool isOn, int hour, int min, string? timerConfig)
+            public TimerProperties(int timeId, bool? isOn, int hour, int min, string? timerConfig)
             {
                 TimerId = timeId;
                 _isOn = isOn;
@@ -102,17 +102,14 @@ public class TimerSettingsUserControlModel : PropertyChangedBase
 
             private readonly string _timerName = LocalizationHelper.GetString("Timer");
 
-            public string TimerName
-            {
-                get => $"{_timerName} {TimerId + 1}";
-            }
+            public string TimerName => $"{_timerName} {TimerId + 1}";
 
-            private bool _isOn;
+            private bool? _isOn;
 
             /// <summary>
             /// Gets or sets a value indicating whether the timer is set.
             /// </summary>
-            public bool IsOn
+            public bool? IsOn
             {
                 get => _isOn;
                 set
@@ -174,12 +171,12 @@ public class TimerSettingsUserControlModel : PropertyChangedBase
         {
             for (int i = 0; i < 8; i++)
             {
-                Timers[i] = new TimerProperties(
-                    i,
-                    ConfigurationHelper.GetTimer(i, bool.FalseString) == bool.TrueString,
-                    int.Parse(ConfigurationHelper.GetTimerHour(i, $"{i * 3}")),
-                    int.Parse(ConfigurationHelper.GetTimerMin(i, "0")),
-                    ConfigurationHelper.GetTimerConfig(i, ConfigurationHelper.GetCurrentConfiguration()));
+                var timerState = ConfigurationHelper.GetTimer(i, bool.FalseString);
+                bool? isOn = bool.TryParse(timerState, out bool parsedBool) ? parsedBool : null;
+                var hour = int.Parse(ConfigurationHelper.GetTimerHour(i, $"{i * 3}"));
+                var minute = int.Parse(ConfigurationHelper.GetTimerMin(i, "0"));
+                var config = ConfigurationHelper.GetTimerConfig(i, ConfigurationHelper.GetCurrentConfiguration());
+                Timers[i] = new(i, isOn, hour, minute, config);
             }
         }
     }
diff --git a/src/MaaWpfGui/Views/UserControl/Settings/TimerSettingsUserControl.xaml b/src/MaaWpfGui/Views/UserControl/Settings/TimerSettingsUserControl.xaml
index 85ddf7fa66..2e6768b1ee 100644
--- a/src/MaaWpfGui/Views/UserControl/Settings/TimerSettingsUserControl.xaml
+++ b/src/MaaWpfGui/Views/UserControl/Settings/TimerSettingsUserControl.xaml
@@ -87,7 +87,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[0].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[0].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[0].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -133,7 +136,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[1].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[1].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[1].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -179,7 +185,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[2].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[2].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[2].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -225,7 +234,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[3].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[3].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[3].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -271,7 +283,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[4].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[4].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[4].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -317,7 +332,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[5].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[5].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[5].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -363,7 +381,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[6].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[6].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[6].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"
@@ -409,7 +430,10 @@
                     <CheckBox
                         Margin="10"
                         Content="{Binding TimerModels.Timers[7].TimerName}"
-                        IsChecked="{Binding TimerModels.Timers[7].IsOn}" />
+                        IsChecked="{Binding TimerModels.Timers[7].IsOn}"
+                        MouseRightButtonUp="{s:Action ToggleCheckBoxNullOnRightClick,
+                                                      Target={x:Type helper:CheckBoxHelper}}"
+                        ToolTip="{DynamicResource CheckBoxesNotSaved}" />
                     <StackPanel Orientation="Horizontal">
                         <hc:NumericUpDown
                             Width="55"