Calendar Subscription - Apple iCal
This page will teach you how to subscribe your MacOS calendar to your Projector schedule.
Refresh Interval
To change the update frequency of a subscribed calendar
Select the calendar in the sidebar and then choose Get Info from the Edit menu
If you selected a subscribed internet calendar, you will see an Auto-refresh popup menu
Select your desired refresh frequency from the Auto-refresh pop-up menu
Click OK to save your changes
Open the Calendar app and choose File -> New Calendar Subscription
Go to your My Profile page and click Subscribe to your Projector schedule
Click Copy Link
Enter the link and click Subscribe