Office 365 (Web) - Share Your Calendar
Use Outlook on the web to share your calendar with people. Depending on the permission you give them, they can view your calendar, edit it, or act as your delegate for meeting requests.
For the most current information on calendar sharing via Outlook on the Web, please check out the following Microsoft help article: https://support.office.com/en-us/article/Share-your-calendar-in-Outlook-on-the-web-7ecef8ae-139c-40d9-bae2-a23977ee58d5.