New Post: Change FORMAT of DateTimeUpDown in PropertyGrid

How do I change the "format" of the standard DateTime editor in the property grid? I want to display a date only. I tried something like this but nothing has changed at all. I also tried "Text=" in the DateTimeUpDown

<xctk:PropertyGrid x:Name="propertyGridOut" Margin="0,0,0,0" BorderBrush="black" >
<xctk:PropertyGrid.EditorDefinitions>
<xctk:EditorTemplateDefinition>
<xctk:EditorTemplateDefinition.TargetProperties>
<xctk:TargetPropertyType Type="{x:Type sys:DateTime}" />
</xctk:EditorTemplateDefinition.TargetProperties>
<xctk:EditorTemplateDefinition.EditingTemplate>
<DataTemplate>
<xctk:DateTimeUpDown Value="{Binding Value}" Format="ShortDate" />
</DataTemplate>
</xctk:EditorTemplateDefinition.EditingTemplate>
</xctk:EditorTemplateDefinition>
</xctk:PropertyGrid.EditorDefinitions>
</xctk:PropertyGrid>