Customising the DatePicker Display Format in WPF

Overview

By default, the WPF DatePicker renders selected dates using the system locale format (e.g. 4/15/2026 on en-US). This article shows how to customise that format so the control always renders dates in the format your application requires.

Setting the Format in XAML

DatePicker exposes a SelectedDateFormat property with two values: Short (default) and Long. For full control you need to reach into the control template’s DatePickerTextBox via a style:

<DatePicker x:Name="datePicker" SelectedDate="{Binding SelectedDate}">
  <DatePicker.Resources>
    <Style TargetType="DatePickerTextBox">
      <Setter Property="Text"
              Value="{Binding SelectedDate,
                              RelativeSource={RelativeSource AncestorType=DatePicker},
                              StringFormat='yyyy/MM/dd'}" />
    </Style>
  </DatePicker.Resources>
</DatePicker>

Setting the Format in Code-Behind

If you prefer code-behind, subscribe to the SelectedDateChanged event and format the text manually:

private void DatePicker_SelectedDateChanged(object sender, SelectionChangedEventArgs e)
{
    if (datePicker.SelectedDate.HasValue)
    {
        datePicker.Text = datePicker.SelectedDate.Value.ToString("yyyy/MM/dd");
    }
}

Using a Converter

A cleaner MVVM approach uses a value converter:

public class DateFormatConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        => value is DateTime d ? d.ToString("yyyy/MM/dd") : string.Empty;

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        => DateTime.TryParse(value as string, out var d) ? d : DependencyProperty.UnsetValue;
}

Bind with:

<DatePicker SelectedDate="{Binding SelectedDate,
                           Converter={StaticResource DateFormatConverter}}" />

Summary

Choose the approach that fits your project’s architecture. For new MVVM projects the converter approach scales best as the number of date-displaying controls grows.