Many years ago, I built a calendaring system and I ended up implementing iCalendar but in a database instead of a file. I would not recommend doing it the way I

Many years ago, I built a calendaring system and I ended up implementing iCalendar but in a database instead of a file. I would not recommend doing it the way I did, but I did come to the conclusion that if you want to support the same types of recurrences, you really should be very familiar with how icalendar handles things or you'll forget something important.