Saves changes made to the selected event. Until this function is called, changes made to an event will not be saved -- they will not propagate to guild members or invitees, and the event will revert to its previous state if the player closes the calendar, reloads the UI, or goes to view or edit another event.

Only applies to existing events; for newly created events use CalendarAddEvent() once the event's attributes and initial invite list are set.