To subscribe to the calendar with your Apple device: Click on the iCAL LINK on the calendar page. If that doesn’t work, you can click here and follow the instructions: https://support.google.com/calendar/answer/99358?hl=en
If you have google calendar, and click on this box in the bottom right of the calendar, you can add it to yours.
If that doesn’t work, send an email to Matt Holliday and he will add you to the calendar (specify middle school or high school or both).