To view the District calendar, as well as one or more school calendars simultaneously, click on Customize Calendar View below.  Click on the pencil next to Calendars to see the other calendars.  You will be prompted to Add/Remove which will then give you all school calendars.  Click on the schools you'd like to see along with the District calendar.  

Once that is done, you can sync the calendar to your personal device.  Click here for instructions.