Here are some example input phrases and output recurrence rules:
- 'on weekdays' => 'RRULE:BYDAY=MO,TU,WE,TH,FR;INTERVAL=1;FREQ=WEEKLY'
- 'daily starting march 3rd until april 5th' => 'DTSTART:20120303\nRRULE:FREQ=DAILY;INTERVAL=1;UNTIL=20120405'
- 'the first and third friday of every month' => 'RRULE:BYDAY=1FR,3FR;INTERVAL=1;FREQ=MONTHLY'
- 'once a year on the fourth thursday in november' => 'RRULE:BYMONTH=11;BYDAY=4TH;INTERVAL=1;FREQ=YEARLY'
It's an alpha release currently, so please submit any issues you find.