private static void OnFormatStringChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
        {
            DateTimeUpDown dateTimeUpDown = o as DateTimeUpDown;

            if (dateTimeUpDown != null)
            {
                dateTimeUpDown.OnFormatStringChanged((string)e.OldValue, (string)e.NewValue);
            }
        }
 internal static bool IsFormatStringValid(object value)
 {
     return(DateTimeUpDown.IsFormatStringValid(value));
 }
 private static bool IsTimeFormatStringValid(object value)
 {
     return(DateTimeUpDown.IsFormatStringValid(value));
 }