Add Shared Calendars in Outlook
Go to Outlook (browser or desktop app) -> Calendar (it may at the bottom as an icon)
On the left you should see your calendar (and any copied over from google - they are no longer current - you can delete these). You can add the newest versions from the address book/directory.
See screenshots (from a PC laptop - please note slightly different to navigate for a Mac.)
Type in the name of the calendar and add to the bottom box/field (could be a person or group) e.g. CCS Internal Calendar, CCS Public Calendar, JS Calendar. You will only have read only access to shared calendars. Admins can edit/update these calendars as needed.