public EventEditorViewModel(IMessageBoxService service,
            IAppointmentService appointmentService)
        {
            messageBox = service;
            this.appointmentService = appointmentService;

            this.Title = string.Empty;
            this.technicalId = Guid.Empty;

            StartTimeViewModel = new DateTimeViewModel();
            EndTimeViewModel = new DateTimeViewModel();
            EndTimeViewModel.SelectedHour = StartTimeViewModel.SelectedHour + 1;

            LoadDaySchedule();
            NotifyOfPropertyChange(() => CanDelete);
        }
        private void CheckTime()
        {
            if (StartTimeViewModel.SelectedDay > EndTimeViewModel.SelectedDay)
                EndTimeViewModel = new DateTimeViewModel(EndTimeViewModel.DateTime.AddDays(StartTimeViewModel.SelectedDay - EndTimeViewModel.SelectedDay));

            if (StartTimeViewModel.SelectedHour > EndTimeViewModel.SelectedHour)
                EndTimeViewModel = new DateTimeViewModel(EndTimeViewModel.DateTime.AddHours(StartTimeViewModel.SelectedHour - EndTimeViewModel.SelectedHour + 1));
        }