It’s easy to add an auto-updating, colour-coded, read-only view of a public calendar without manually copying events or polluting your own calendar.
TL;DR generic instructions:
- find an option to Subscribe/Add calendar from URL/New Calendar Subscription/Add Subscribed Calendar
- paste the URL
Specific instructions for popular apps:
- open Google Calendar in a browser (not mobile)
- find Other calendars in the left sidebar and click +
- choose From URL
- paste the URL and click Add calendar
Outlook
- open Outlook Calendar
- click Add calendar and Subscribe from web
- paste the URL, give it a name, and click Import
Apple
Mac
- File and New Calendar Subscription
- paste the URL and click Subscribe
iPhone/iPad
- Settings -> Calendar
- Accounts -> Add Account -> Other -> Add Subscribed Calendar
- paste the URL