Microsoft has a detailed tutorial on how to share an Outlook calendar.
In the Outlook Calendar app:
1. Select Share Calendar in the top navigation menu (folder - share calendar).
2. Enter the name or email address of the person(s) with whom you plan to share your calendar.
3. Choose Allow recipient to view your calendar.
4. Send.
View the Microsoft tutorial for more detailed instructions on sharing a calendar, changing calendar sharing permissions, adding another person's calendar to your calendar view, and stopping sharing of your calendar.