In the Calendar app 
, you can set up multiple calendars to keep track of different kinds of events. You can keep track of all your events and appointments in one calendar, but additional calendars are easy to set up and a great way to stay organized.
Tap Calendars at the bottom of the screen, then tap Add Calendar.
Tap Add Subscription Calendar, enter the URL of the calendar you want to subscribe to, then click Subscribe.
You can also subscribe to an iCalendar (.ics) calendar by tapping a link to it.