Unofficial
See what the school is serving each day, right in your phone's calendar. It updates by itself.
Paste it into any calendar app's "subscribe" or "add from URL" option.
To remove it later: open Calendar, tap Calendars at the bottom, tap the ⓘ next to the school menu, then Delete Calendar.
The Google Calendar app can't add a calendar from a link, so this is done once on Google's website, in Chrome.
Easier on a computer? Open this page there, tap Add to my calendar, and it will show up on your phone too.
To remove it later: on calendar.google.com, find the school menu under Other calendars, click the ✕ next to it.
Calendars added on a computer show up on your phone too.