Office 365 (Outlook 2013 / 2016 for Win) - Calendar Sharing
How to Request Someone Share their Calendar with You and share your Calendar with them all at once.
1. Click Calendar.
2. Click Share Calendar.
3. Check one or both: Request permission to view recipient's Calendar & Allow recipient to view your Calendar.
a.) set permission to Availability Only, Limited Details, or Full Details.
b.) click Send.
4. You will receive this e-mail when the recipient receives and responds to your share request, click Allow.
5. You will then receive this e-mail. Choose your permission level and then click Send.
6. Your permission level will be confirmed, click Yes.
7. You will then receive this message to confirm both your share request and invite, click OK.
8. Finally, you will receive this message. Click Open this Calendar to view the calendar and import appointments.