Drupal 7 Calendar - How do you disable the number link to the day page?
That functionality is automatic and means that you have month- and day-type calendar views defined.

If you don't want to use the daily display on your site, just find the calendar view that defines the daily display and disable that display or view.

That'll automatically disable the functionality of displaying a daily calendar on your monthly view.

Here's a step-by-step:
Look in the calendar view's format settings



If the calendar type is 'Day', then that's the one that's automatically being linked to your month's date number, just disable that view or display:



Hope this helps!