The Nag_Recurrence class implements algorithms for calculating recurrences of events, including several recurrence types, intervals, exceptions, and conversion from and to vCalendar and iCalendar recurrence rules.
Recurs monthly on the same date.
Recurs monthly on the same week day.
Recurs yearly on the same date.
Recurs yearly on the same day of the year.
Recurs yearly on the same week day.
Returns the next active recurrence.
Finds the next recurrence of this event that's after $afterDate.