Using Multiple Calendars
You can add multiple calendars to the same site or webpage. When you add multiple calendars and manage each one separately, their data doesn’t sync.
The easiest way to display the same events on multiple calendars is to connect them all to the same external calendar (Google Calendar, Outlook or Eventbrite), and manage your events there. Then you’ll be able to style each calendar differently, but they will display the same events.
Please see how to connect external calendars here.