Add holiday calendars. View holiday calendars from different regions around the world. Choose File > New Holiday Calendar, then choose a holiday calendar you want to add.
See all your calendars—or just a few. Click the Calendars button to see a list of all your calendars; click the ones you want to see in the window.
Filter your calendars with Focus. Choose which calendars to show during a particular Focus. For example, have a calendar with assignment due dates that turns on only while studying. Choose Apple Menu > System Settings, then click Focus in the sidebar. Select a Focus on the right, click Calendar User Guide.