Calendar.CalendarDayChangedMessage
A message sent by a calendar when the system’s calendar day changes, as determined by the system calendar, locale, and time zone.
Declaration
struct CalendarDayChangedMessageOverview
If the device is asleep when the day changes, the calendar sends this message when the device wakes up. If the device has been asleep for multiple days, the calendar sends only one message.
Observe this message with the identifier calendarDayChanged, or specify its type directly to the addObserver(of:for:using:) method. The Subject of this message type is Calendar.
This message interoperates with the notification NSCalendarDayChanged. The system notifies observers of the message when the NotificationCenter posts the notification. Similarly, the system notifies observers of the notification when it posts the message.