Jetpack Visibility provides more freedom to control which on pages and posts widgets should be displayed. It’s pretty sweet. Set a filter that hides the widget from all Category archives, and the widget will be hidden without having to create a new sidebar.

The first issue is that The Events Calendar does not actually ship with a sidebar area. To get a sidebar in the calendar, we either need to switch the calendar template (under Events > Settings > Display) to use an existing theme page template with a sidebar, or add a sidebar area directly to the calendar’s default-template.php file