title: WPF DatePicker Watermark uses wrong Language, but the Dateformat is correct
body: <p>I have a very strange Problem:</p>
  
  <p>On my machine the DatePicker changes its watermark AND date-format according to the language/culture i want to set.</p>
  
  <p>If i copy my application to other computers following happens:</p>
  
  <p>On some computer it works like it does on my machine. On other computers only the date-format changes but the watermark does not! Needless to say it is very ugly to have a datepicker with e.g. a german date but an english watermark.</p>
  
  <p><strong>What is the cause for that behaviour?</strong></p>
  
  <p>For i18n i use following code:</p>
  
  <p>App.xaml.cs: </p>
  
  <pre class="lang-cs prettyprint-override"><code>public partial class App : Application
  {
      public App()
      {
          CultureInfo ci = new CultureInfo("de-DE"); 
          Thread.CurrentThread.CurrentCulture = ci;
          Thread.CurrentThread.CurrentUICulture = ci;
      }
  }
  </code></pre>
  
  <p>WindowMain.xaml.cs:</p>
  
  <pre class="lang-cs prettyprint-override"><code>public partial class WindowMain : RibbonWindow
  {
      public WindowMain()
      {
          this.Language = XmlLanguage.GetLanguage("de-DE");
          this.InitializeComponent();
      }
  }
  </code></pre>