System.Object
   System.EventArgs
      C1.Xaml.DateTimeEditors.TextValidationErrorEventArgs
      C1.Xaml.PropertyChangedEventArgs<T>
         C1.Xaml.DateTimeEditors.NullablePropertyChangedEventArgs<T>
   Windows.UI.Xaml.DependencyObject
      Windows.UI.Xaml.UIElement
         Windows.UI.Xaml.FrameworkElement
            Windows.UI.Xaml.Controls.Control
               C1.Xaml.DateTimeEditors.C1DatePicker
               C1.Xaml.DateTimeEditors.C1DateTimePicker
               C1.Xaml.DateTimeEditors.C1TimeEditor

Reference

C1.UWP.DateTimeEditors Assembly