To remove a Hebcal calendar from your iPhone or iPad that was subscribed directly from the iOS device, follow these steps:
- Go to the Settings app, then touch Mail, Contacts, Calendars.
- Tap Subscribed Calendars:
- Tap the Hebcal calendar that you wish to remove from the list of subscribed calendars:
- Scroll to the bottom of the page, and tap Delete Account
- Tap Delete Account again to confirm.
See also: iCloud – remove Hebcal Jewish calendar