You can unsubscribe directly from your device at any time, or via Manage My ECAL.

Google and Outlook.com users, please visit Manage My ECAL  to easily remove or add publisher calendars.

Alternatively, you can remove subscriptions directly from the calendar application itself.

Google Calendar (computer): Under My Calendars, click the three dots of the calendar you want removed. Select Settings & Sharing > scroll to the bottom and click Delete.

Google Calendar (iPhone/iPad): Scroll to the bottom of the navigational menu and select Settings. Choose the calendar you want removed, click Unsubscribe from Calendar

Outlook 365: Calendar: My Calendars > click the three dots of the calendar you want removed and click Remove

Apple Calendar (Mac): Calendar > click on the calendar icon to display the schedules subscribed to, right click on the calendar you want removed and click Unsubscribe

Apple Calendar (iPhone): Click on the calendar icon to display the schedules subscribed to, right click on the red information icon for the schedule you want removed and click Unsubscribe