Gets or sets the end date and time of the appointment.
A DateTime value representing the end of the appointment.
The End property is usually specified by the Appointment.Start and Appointment.Duration properties, and is always calculated as End = Start + Duration. When setting the End property, the Appointment.Start property retains its value, and the Appointment.Duration is changed according to the new value of the End property. If the new Appointment.End property's value is less than the Appointment.Start property's value, an exception is raised.