Is it possible to add or subscribe to a whole new calendar with iPhone's EventKit?
yes, though only for iOS5 onwards
- (BOOL)saveCalendar:(EKCalendar *)calendar commit:(BOOL)commit error:(NSError **)error
this will save the changes you made to a calendar or will add a new calendar to the database.
detailed step by step instructions for adding a new calendar can be found here how do I create a new EKCalendar on iOS device?