Almost complete rewrite of the code, done about a year ago. Now the Facebook API might have changed a bit again.

An almost complete implementation of the iCalendar Recurring Events (RRULE) specification, which can be used standalone, can be found in classes/modules/recurringEventsModule/recurrenceRuleParser.php. The corresponding unit tests are in tests/classes/modules/recurringEventsModule/recurrenceRuleParserTest.php