The start date of the Gregorian calendar for the receiver.
Mac Catalyst 13.0+Beta
This is used to specify the start date for the Gregorian calendar switch from the Julian calendar. Different locales switched at different times. Normally you should just accept the locale's default date for the switch.
The earliest date that can be denoted by a two-digit year specifier.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.