To remove a Hebcal calendar from your iPhone or iPad, you’ll need to first determine if you subscribed via iCloud or whether you subscribed directly from your iOS device.
Subscribed via iCloud
- Log into iCloud in a web browser.
- Go to the iCloud Calendar.
- Click Edit in the sidebar.
- Click the Delete button to the right of the calendar’s name.
- Click Delete Calendar.
Source: iCloud: Delete a calendar
Subscribed directly from iOS device
To remove a Hebcal calendar from your iPhone or iPad, first go to the Settings app, then touch Mail, Contacts, Calendars. Scroll down until you see the Subscribed Calendars item:
Touch Subscribed Calendars to see the list:
Then, touch the Hebcal calendar to delete:
Touch the red Delete Account button, then touch Delete Account again to confirm.