Ics Guides

Ics Specification RFC 5545

Other related

Development and Testing Resources

Ics Validators:

These are helpful but not necessarily complete.  They have been described by some as ‘trailing edge’.  At the end of the day you need to ensure that your ics file will be accepted by the major calendar applications (eg: google calendar etc)

How to subscribe to calendars

Useful ics files for testing

Other discussions