What is "iCalendar" (iCal)? Marek Hrycak March 26, 2019 08:39 Updated Follow This is a calendar data exchange format. Related articles How does the synchronization of reservations via iCalendar work? What is iCalendar? What is ICS? Which data are synchronized via iCalendar? How can I download links to room calendars from Google Calendar? Comments 0 comments Please sign in to leave a comment.