AC.AvalonControlsLibrary.Controls.DatePicker.BackButtonClick C# (CSharp) Метод

        void BackButtonClick(object sender, RoutedEventArgs e)
        {
            //move the month back
            DateHelper.MoveMonthBack(currentlyViewedMonth, currentlyViewedYear, out currentlyViewedMonth, out currentlyViewedYear);
            ChangeDate();
        }