Share Calendar or Change Calendar Permissions in Outlook
Windows
Outlook 2016
Click Calendar Icon in lower left corner
In the left side bar Right Click the calendar you want to share, then click Properties.
Click the Permissions tab
Click Add to add permissions for a new user, or click the name of the existing user in the list to change their current permissions.
Either select a predefined set of permissions from the Permissions Level pull down or specify the permission in the checkboxes below. Common options are:
Free/Busy Time
Allow the user to view when you are busy or free, but not the information of any of the events on your calendar
Reviewer
Allow the user to view all of the information on your calendar, but they cannot create or edit events.
Author
Allow the user to view all calendar information and can create new events, but they cannot edit or delete events they did not create.
Editor
Allow the user to view all calendar information, create new events, and edit and delete existing events.