Sometimes you may no longer need a calendar for a country or you wanted to add a more detailed regional calendar and remove the country calendar. The following instructions are a a guide on how to do that in the most popular calendar applications.
Select your calendar programme
Google Calendar
To unsubscribe from an iCalendar feed using Google Calendar:
Click the cog at the top right of Google Calendar and click 'settings'.
Click 'calendar'.
For each calendar you want to remove, please click 'unsubscribe'.
Microsoft Outlook
To unsubscribe to an iCalendar feed in Outlook:
Subscribed calendars are separate from the primary and other calendars. To delete the events just delete the calendar.
In Outlook for Mac, locate and right-click or Control-click the subscribed calendar in the navigation pane on the left. Choose Delete.
This removes if from the Exchange account itself and therefore removes it when viewing the account in OWA too.
iCal
To unsubscribe to an iCalendar feed using Apple's iCal program:
Open iCalendar.
Click on calendars on top left. Under subscriptions you will find all your web calendars.
either uncheck to hide or right click - delete to remove.