BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//gyrobase/iCalendar//NONSGML v1.0//EN
BEGIN:VEVENT
DTSTART:20130502
RRULE:FREQ=MONTHLY;INTERVAL=1;UNTIL=20130526;BYDAY=1FR,1SA,1SU,1TH
SUMMARY:Red
END:VEVENT
END:VCALENDAR