In the Calendar app, the Holidays calendar displays holidays based on the region set on your iPad.
Note: The Holidays calendar is a subscription calendar. You can’t add or delete holidays, because subscription calendars can be modified only by the calendar provider.
Go to the Calendar app at the top left.
Tap Add Calendar at the bottom of the screen, then tap Add Holiday Calendar.
Tap the holiday calendar you want to subscribe to, then tap Add.
To change settings, like notification alerts or the name of a holiday calendar you’ve subscribed to, see Share iCloud calendars on iPad