birthday
A date component for the Gregorian birthday of the contact.
Declaration
var birthday: DateComponents? { get }Discussion
Birthdays are represented by this property, whose values are the relevant properties of an NSDateComponents object. Day and month components are required for this property, and year is optional. The calendar component can be nil or gregorian. All other date components are invalid and including them results in an NSError object that includes the key paths of the invalid components and the error code CNError.Code.validationConfigurationError.