Schedule items can recur in time, following a specific pattern. For example, an item could be set to occur each Monday, on the third day of each month, and so on. Assign a Recurrence object to an item through the setRecurrence method to specify the time period, pattern, and other properties for the repetition of that item in time.

When a recurrent item is displayed in a calendar control, the control creates multiple occurrences of the item in the time period being visualized. Occasionally you will get references to these occurrences passed as arguments to the various calendar events or returned by the calendar methods. Occurrences are instances of the same class as the item that was set recurrent, however their getRecurrenceState method will return Occurrence. If a user moves a recurrent item's occurrence, or in another way modifies the occurrence, an exception is created. Exceptions are item instances whose getRecurrenceState returns Exception.

Note
Recurrence is not automatically supported in user classes derived from Item or Appointment. To see how to implement custom classes, which support recurrence, see Tutorial 3: Creating Custom Appointment Classes.