private void ButtonProv_Click()
        {
            var DateRange = new List <DateTime>();

            DateRange.AddRange(pairsToDays.ReducedDay.Select(x => x.DatePair));
            DateRange.AddRange(pairsToDays.WorkDay.Select(x => x.DatePair));
            helperDate       = new HelperDate(DateRange);
            TextBoxInfo.Text = helperDate.ToString();
        }
        private void ButtonOK_Click()
        {
            helperDate       = new HelperDate(DatePickerBegin.SelectedDate.Value, DatePickerEnd.SelectedDate.Value);
            TextBoxInfo.Text = helperDate.ToString();

            Calendar1.DisplayDateStart = DatePickerBegin.SelectedDate;
            Calendar1.DisplayDateEnd   = DatePickerEnd.SelectedDate;
            Calendar1.SelectionMode    = CalendarSelectionMode.MultipleRange;



            ContextMenu contextMenu     = new ContextMenu();
            MenuItem    menuItemWorkDay = new MenuItem();

            menuItemWorkDay.Header = "Рабочие дни";
            menuItemWorkDay.Click += (sender1, EventArgs1) => { MenuItemDayCountPair_Click(null); };
            contextMenu.Items.Add(menuItemWorkDay);
            MenuItem menuItemDayOff = new MenuItem();

            menuItemDayOff.Header = "Выходные дни";
            menuItemDayOff.Click += (sender1, EventArgs1) => { MenuItemDayCountPair_Click(0); };
            contextMenu.Items.Add(menuItemDayOff);
            MenuItem menuItemReducedDay = new MenuItem();

            menuItemReducedDay.Header = "Сокращенные дни";
            for (int i = 1; i <= 6; i++)
            {
                int      z = i;
                MenuItem menuItemReducedDayCountPair = new MenuItem();
                menuItemReducedDayCountPair.Header = $"Кол-во пар: {z}";
                menuItemReducedDayCountPair.Click += (sender1, EventArgs1) => { MenuItemDayCountPair_Click(z); };
                menuItemReducedDay.Items.Add(menuItemReducedDayCountPair);
            }
            contextMenu.Items.Add(menuItemReducedDay);
            //TODO: это перенос дня, не сделано. после надо подумать над реализацией
            MenuItem menuItemPerenos = new MenuItem();

            menuItemDayOff.Header = "Перенос дня";
            contextMenu.Items.Add(menuItemPerenos);
            Calendar1.ContextMenu = contextMenu;

            pairsToDays = new PairsToDays(DatePickerBegin.SelectedDate.Value, DatePickerEnd.SelectedDate.Value, 6);

            UpdateAllListView();
        }