formating a datetimepicker

Some times we want to give a certain format on a datepicker control that we created. here's a quick example

private void picker_Loaded(object sender, RoutedEventArgs e)// the datapicker's load event.
{
this.picker.Text = DateTime.Now.ToString("dd-MMM-yyyy");
}

private void picker_SelectedDateChanged(object sender, SelectionChangedEventArgs e)
{
this.picker.Text = this.picker.SelectedDate.Value.ToString("dd-MMM-yyyy");
}

a quit of a short example

var valueDate = valueDatePicker.SelectedDate.Value.ToString("s");

returns the set with the ISO format (yyyy-mm-dd)