To remove one or more Caltrics internet calendars from your selection:
Your currently selected calendars will be listed under Public calendars (and Private calendars, if any).
Click on the cross in front of the calendar name(s) that you want to remove and a tab will appear ‘Confirm calendar selections (x)‘
When you have finalised your removals (and additions), click on the ‘Confirm Calendar Selections (x)’ tab and you’ll see ‘Your Calendar Selections‘ with changes listed. Removals will be preceded by an empty box in front of the calendar name, additions will show a tick.
Click on ‘Apply your changes above‘.
NB – The speed at which events will be removed from your actual calendar will be subject to the refresh frequency that applies to your calendar app.