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5.2. Recurrences

  • The RECURRENCE-ID is a property of each instance of a recurring event. It is calculated from the DTSTART and the recurrence rules or added to the set by the RDATE property.

  • RDATE, EXDATE and RECURRENCE-ID must take the same form as the DTSTART. That is if DTSTART is a DATE value then the RDATE and EXDATE must be DATE. If DTSTART is a date-time the RDATE and EXDATE values must take the same form, including the same timezone.

  • Overrides to an instance are specified by completely specifying the instance with the appropriate RECURRENCE-ID property.

  • An RDATE adds an instance to the recurrence set.

  • An EXDATE deletes an instance by specifying the recurrence id(s) to be deleted. Applications SHOULD NOT specify overrides for instances so deleted.

  • The recurrence set is calculated from the RRULE and RDATES and then applying any EXDATE properties. That is EXDATE takes precedence over RDATE and the RRULE.