Gets the normalized appointment start value which is recommended for use in interval-based appointment data source queries.
A DateTime value that is the start of the appointment.
The AppointmentItem.QueryStart and AppointmentItem.QueryEnd properties allows you to calculate the correct interval for use in a SELECT query when handling the SchedulerControl.VisibleIntervalsChanged event to fetch appointments from the data source. The use of the AppointmentItem.Start and AppointmentItem.End properties is not recommended in this situation because you can miss the appointment pattern and lose appointment exceptions.
The QueryStart property return values are dependent on the appointment type, as shown in the following table.
|Appointment Type||QueryStart Value|
|AppointmentType.Normal||The AppointmentItem.Start value.|
|AppointmentType.Pattern||The Start value of the first appointment in the recurring series.|
|AppointmentType.ChangedOccurrence||The Start value of an original occurrence before modification (as if an occurrence is restored from the exception).|
|AppointmentType.DeletedOccurrence||The Start value of an original occurrence before modification (as if an occurrence is restored from the exception).|