I have been unsuccessful in formulating a RRULE that would allow an event as shown below:
Repeats YEARLY, from first Sunday of April to last day of May, occuring on Monday, Wednesday and Friday, until forever.
FREQ=YEARLY;BYMONTH=4;BYDAY=SU (gives me the first Sunday of April repeating yearly)
and
FREQ=YEARLY;BYMONTH=5;BYMONTHDAY=-1 (gives me the last day of May repeating yearly...
2009-07-09 22:27:27 UTC in DDay.iCal - an iCalendar class library
