private void Aufräumen()
        {
            var dp = new DatePicker_dark();

            i_turns = 1;

            cb_year.SelectedIndex        = 50;
            cb_month.SelectedIndex       = -1;
            cb_day.SelectedIndex         = -1;
            cb_hour.SelectedIndex        = -1;
            cb_minute_Copy.SelectedIndex = -1;
            cb_seconds.SelectedIndex     = -1;

            cb_month.IsEnabled       = false;
            cb_day.IsEnabled         = false;
            cb_hour.IsEnabled        = false;
            cb_minute_Copy.IsEnabled = false;
            cb_seconds.IsEnabled     = false;

            cb_month.Items.Clear();
            cb_day.Items.Clear();
            cb_hour.Items.Clear();
            cb_minute_Copy.Items.Clear();
            cb_seconds.Items.Clear();


            dp.UpdateLayout();
        }
        private void Aufräumen()
        {
            var dp = new DatePicker_dark();

            cb_month.SelectedIndex = -1;
            cb_day.SelectedIndex   = -1;

            cb_day.IsEnabled = false;


            dp.UpdateLayout();
        }