A date component for the non-Gregorian birthday of the contact.
- iOS 9.0+
- macOS 10.11+
- Mac Catalyst 13.0+Beta
- watchOS 2.0+
A non-Gregorian birthday such as Lunisolar birthdays can be displayed using this property, whose values are the relevant properties of an
NSDate object. Day and month are required;
is are optional. The calendar property is also required and must be non-Gregorian. Some supported calendars are Buddhist, Chinese, or Islamic. All other date components are invalid.