private void OnDateValueChangedCommandExecute()         // выбрали дату
        {
            Thread thread = new Thread(() =>
            {
                Thread.Sleep(200);                 // ожидание непосредственного изменения свойства

                FirstTimePickerHelper helper = new FirstTimePickerHelper(DateText);
                StartFirstTime = helper.StartFirstTime;
                FirstTime      = helper.FirstTime;
            });

            thread.Start();
        }
        private void SetViewModelProperties(Reservation reservation)
        {
            FirstTimePickerHelper fHelper = new FirstTimePickerHelper(reservation.Day.ToShortDateString());

            StartFirstTime = fHelper.StartFirstTime;
            FirstTime      = reservation.FirstTime.ToShortTimeString();

            LastTimePickerHelper lHelper = new LastTimePickerHelper(FirstTime);

            StartLastTime = lHelper.StartLastTime;
            LastTime      = reservation.LastTime.ToShortTimeString();

            DateText             = reservation.Day.ToShortDateString();
            SelectedItemTable    = Tables.FirstOrDefault(table => table.Id == reservation.TableId);
            IsEnabledTimePickers = true;
        }