An Appointment adds a number of components to a generic ScheduledItem. The
StartTime and Duration indicate when the appointment starts and how long it
lasts. The Location is where it is held. The Security indicates who can
see that the appointment is scheduled. AppointmentPriority is how important
the appointment is. RemindInfo indicates if and how the user is reminded of
the appointment. Details are free form text describing any specific
appointment details.
This object is derived from Section 2.2 of the Milestone 6 requirements, in
particular Figure 6.