Remove Subscribed Calendar

Subscription calendars can only be removed in device settings

1. Go to device Settings on your iOS device
2. Go to
   iOS12: Passwords & Accounts
   iOS11: Accounts & Passwords
   iOS10: Calendar
   iOS9-: Mail, Contacts, Calendars
3. In the Accounts section go to Subscribed Calendars
4. Select the calendar you wish to remove
5. Tap on the red Delete Account button