Fix not updating the text of TimePicker and DateTimePicker after changing the culture

Author: punker76

docs/release-notes/1.6.0.md

@@ -30,6 +30,7 @@
   + `GroupBoxHeaderThemePadding` (default 4)
   + `ExpanderHeaderThemePadding` (default 2)
   + `ExpanderToggleButtonEllipseThemeSize` (default 18)
+- Fix not updating the text of `TimePicker` and `DateTimePicker` after changing the culture.
 
 ## Breaking Change
 
@@ -75,3 +76,4 @@ More informations about the reason of this decision can be found here:
 - [#3025](https://github.com/MahApps/MahApps.Metro/issues/3025) ComboBox popup border thickness problem
 - [#3043](https://github.com/MahApps/MahApps.Metro/issues/3043) Width parse error
 - [#3045](https://github.com/MahApps/MahApps.Metro/issues/3045) Clicking on the "X" button added by TextBoxHelper.ClearTextButton does not clear the databinding target
+- [#3049](https://github.com/MahApps/MahApps.Metro/issues/3049) TimePicker fails to parse times with an AM/PM. [#3050](https://github.com/MahApps/MahApps.Metro/pull/3050) [@toddburnside](https://github.com/toddburnside)

src/MahApps.Metro/MahApps.Metro.Shared/Controls/TimePicker/TimePickerBase.cs

@@ -450,6 +450,8 @@ protected virtual void ApplyCulture()
 
             SetDefaultTimeOfDayValues();
             _deactivateRangeBaseEvent = false;
+
+            WriteValueToTextBox();
         }
 
         protected Binding GetBinding(DependencyProperty property)
@@ -466,8 +468,7 @@ protected virtual string GetValueForTextBox()
 
         protected virtual void OnTextBoxLostFocus(object sender, RoutedEventArgs e)
         {
-            var text = DateTime.MinValue.ToString(SpecificCultureInfo.DateTimeFormat.ShortDatePattern) + " " +
-                       ((DatePickerTextBox)sender).Text;
+            var text = string.Intern($"{DateTime.MinValue.ToString(SpecificCultureInfo.DateTimeFormat.ShortDatePattern)} {((DatePickerTextBox)sender).Text}");
             DateTime dt;
             if (DateTime.TryParse(text, SpecificCultureInfo, DateTimeStyles.None, out dt))
             {