Outlook - How to Share a Calendar

Via Outlook Web Access (recommended)

1. On the Outlook web (outlook.office.com) page, click your profile icon in the top right of the window, then click Open another mailbox.
2. Search for the mailbox the calendar is associated with and click Open.
3. Go to the calendar page, then right click the calendar you want to share and select Sharing and permissions.
4. Select the person you want to add using the search field.
5. Once selected, you can select the Permission Level they will require. Once finalized, click Share. This will send an email invitation to the person selected.
6. The user will need to click Accept on the invitation email. After this the person invited should have access to the calendar within a few minutes of accepting the invitation email.

Via the Outlook Client

1. Right click the calendar you wish to share and select properties .
   
2. Go to the Permissions tab in the top.
3. Click on Add...
   
4. Select the person(s) you would like to add using the address list.
   
5. Select the Permission Level: that the person will require. 
   Publishing Editor will provide full read and modify
   Reviewer will provide full read.
   
6. Click Apply.
7. Have the other person add the calendar using the "Add Calendar" function in Outlook.