You may use the RSS Feeds to subscribe to any district or school calendar. 

Here's how:

1. Click on the RSS icon in the upper right corner of the calendar you want to subscribe to.  (
   it looks like a gray box with white radio waves)
2. A new window will pop up with district calendar options you can subscribe to by clicking on the green ICAL box.
3. Select from the options to connect with your personal calendar. The options include a Standard iCal URL, a Google iCal URL and a Default Calendar App that includes Outlook, Apple iCal etc. 
4. Copy the calendar feel URL
5. In your preferred calendar follow the steps ton add a calendar "From URL"
6. All set! Events will appear in your calendar automatically.

Follow the same steps with school calendars.