I've successfully added a repeating event to the last day of every month using the below syntax:
BEGIN:VCALENDAR BEGIN:VEVENT DTSTART:20110731 DTEND:20110731 RRULE:FREQ=MONTHLY;BYDAY=SU,MO,TU,WE,TH,FR,SA;BYSETPOS=-1;WKST=SU SUMMARY:Name of your event END:VEVENT END:VCALENDAR
thanks to the advice of this article (How to make a task repeat on the last day of each month in Google Calendar?) but I need to set up a quarterly repeating event.
Does anyone know how to edit frequency syntax so that the event repeats on the last day of the month every three months (or every x months)?