There is a requirement in my application in which, when I take an appointment of a doctor for a particular day, that day should be added in iCal. and it should generate an a
You need the EventKit framework. You can ask the EKEventStore for its calendars, and then use those calendars to create a predicate that lets you find events that match the criteria you're looking for. Or you can create a new EKEvent object and save it into the event store.