Subscribing to calendars
You can subscribe to calendars that use the iCalendar (.ics) format. Many calendar-based services
support calendar subscriptions, including iCloud, Yahoo!, Google, and the iCal application in OS X.
Subscribed calendars are read-only. You can read events from subscribed calendars on iPhone, but
you can’t edit events or create new ones.
Subscribe to a calendar: Go to Settings > Mail, Contacts, Calendars, then tap Add Account. Tap
Other, then tap Add Subscribed Calendar.
You can also subscribe to an iCal (or other .ics) calendar published on the web, by tapping a link
to the calendar.