title: Datepicker formatting to UK format when already UK
body: <p>In WPF I have a datepicker with the following text style:</p>
  
  <pre><code>&lt;Style TargetType="{x:Type DatePickerTextBox}"&gt;
      &lt;Setter Property="Control.Template"&gt;
          &lt;Setter.Value&gt;
              &lt;ControlTemplate&gt;
                  &lt;TextBox x:Name="PART_TextBox"
                  Text="{Binding Path=SelectedDate, StringFormat='dd/MM/yyyy', 
                    RelativeSource={RelativeSource AncestorType={x:Type DatePicker}}}"
                           Foreground="white"/&gt;
              &lt;/ControlTemplate&gt;
          &lt;/Setter.Value&gt;
      &lt;/Setter&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>The datepicker item itself looks like this</p>
  
  <pre><code>&lt;DatePicker x:Name="datepickShowDate" Grid.Column="1" Foreground="white" CalendarStyle="{StaticResource styleCalendar}" 
      FontSize="14" HorizontalAlignment="Left" Height="30" 
      VerticalAlignment="Top" Width="139"/&gt;
  </code></pre>
  
  <p>If I select a date from the popout calendar then the date is displayed fine.
  However, if I type in a date, it appears to assume I am entering in US format and converts to UK.</p>
  
  <p>i.e. if I want to type in 5th June 2018 like 05/06/2018, on clicking out of the field it suddenly becomes 06/05/2018.  </p>
  
  <p>My question is, is there any way of defining what the input format will be rather than just what the date should look like after date selection?</p>