This document will explain how to access a published/external/internet calendar.
Note: If you've received an email invitation to a calendar, you can select the link in the email invitation to add the calendar to your calendar view.
You can also go to your Calendar to add a calendar (an internal person or external calendar) to your view.
Once you have an external link:
Outlook will reload this link/subscription each time you restart Outlook. These subscriptions are "read-only". If you edit any item in Outlook, those changes will NOT be reflected/saved.
"Your mileage may vary" with the ability of 3rd party applications to be able to parse the iCalendar data properly.
Currently, Outlook 2016 for Mac (and 2011) does not have the ability to subscribe to an external calendar. Microsoft is aware of this issue and we hope that they provide this feature in a future update to the application.
But, there is a work around. You can use Outlook on the web to subscribe to an external calendar. Once subscribed via Outlook on the web, the next time you start Outlook 2016 for Mac/2011, the subscribed calendar will appear within your calendar view.
Use the above instructions for Outlook on the web to subscribe to an external calendar.