title: Changing the string format of the WPF DatePicker
body: <p>I need to change the string format of the DatePickerTextBox in the WPF Toolkit DatePicker, to use hyphens instead of slashes for the seperators.</p>
  
  <p>Is there a way to override this default culture or the display string format?</p>
  
  <pre><code>01-01-2010
  </code></pre>