实验性早期执行The name that represents this world clock. Must have a namespace and use only valid identifier characters. (e.g., 'mypack:my_clock').
可选registrationOptions: WorldClockRegistrationOptionsAdditional options for registering a world clock, such as including time markers at registration time.
Provides the functionality for registering custom world clocks. World clocks can only be registered during the system startup event.