diff --git a/src/Calculator/Views/DateCalculator.xaml b/src/Calculator/Views/DateCalculator.xaml
index 4bb8d5b..bcf2cae 100644
--- a/src/Calculator/Views/DateCalculator.xaml
+++ b/src/Calculator/Views/DateCalculator.xaml
@@ -516,6 +516,7 @@
                              MinWidth="80"
                              MaxWidth="160"
                              VerticalAlignment="Top"
+                             Checked="AddSubtractOption_Checked"
                              IsChecked="{Binding IsAddMode, Mode=TwoWay}"/>
                 <RadioButton x:Name="SubtractOption"
                              x:Uid="SubtractOption"
@@ -524,6 +525,7 @@
                              MaxWidth="160"
                              Margin="20,0,0,0"
                              VerticalAlignment="Top"
+                             Checked="AddSubtractOption_Checked"
                              IsChecked="{Binding IsAddMode, Converter={StaticResource BooleanNegationConverter}, Mode=TwoWay}"/>
 
             </Grid>
diff --git a/src/Calculator/Views/DateCalculator.xaml.cpp b/src/Calculator/Views/DateCalculator.xaml.cpp
index be7b737..386e524 100644
--- a/src/Calculator/Views/DateCalculator.xaml.cpp
+++ b/src/Calculator/Views/DateCalculator.xaml.cpp
@@ -209,7 +209,7 @@ void DateCalculator::ReselectCalendarDate(_In_ Windows::UI::Xaml::Controls::Cale
 
 void DateCalculator::OffsetDropDownClosed(_In_ Object^ sender, _In_ Object^ e)
 {
-    RaiseLiveRegionChangedAutomationEvent(false);
+    RaiseLiveRegionChangedAutomationEvent(/* DateDiff mode */ false);
 }
 
 void DateCalculator::CalendarFlyoutClosed(_In_ Object^ sender, _In_ Object^ e)
@@ -224,3 +224,8 @@ void DateCalculator::RaiseLiveRegionChangedAutomationEvent(_In_ bool isDateDiffM
     String^ automationName = AutomationProperties::GetName(resultTextBlock);
     TextBlockAutomationPeer::FromElement(resultTextBlock)->RaiseAutomationEvent(AutomationEvents::LiveRegionChanged);
 }
+
+void DateCalculator::AddSubtractOption_Checked(_In_ Object^ sender, _In_ RoutedEventArgs^ e)
+{
+    RaiseLiveRegionChangedAutomationEvent(/* DateDiff mode */ false);
+}
diff --git a/src/Calculator/Views/DateCalculator.xaml.h b/src/Calculator/Views/DateCalculator.xaml.h
index ad5917a..414dc6b 100644
--- a/src/Calculator/Views/DateCalculator.xaml.h
+++ b/src/Calculator/Views/DateCalculator.xaml.h
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 //
@@ -38,6 +38,7 @@ namespace CalculatorApp
         void OnLoaded(_In_ Platform::Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
         void DateCalcOption_Changed(_In_ Platform::Object^ sender, _In_ Windows::UI::Xaml::Controls::SelectionChangedEventArgs^ e);
         void AddSubtractDateGrid_Loaded(_In_ Platform::Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
+        void AddSubtractOption_Checked(_In_ Platform::Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
         void ReselectCalendarDate(_In_ Windows::UI::Xaml::Controls::CalendarDatePicker^ calendarDatePicker, Windows::Foundation::DateTime dateTime);
         void OffsetDropDownClosed(_In_ Platform::Object^ sender, _In_ Platform::Object^ e);
         void CalendarFlyoutClosed(_In_ Platform::Object^ sender, _In_ Platform::Object^ e);