- Navigate to https://outlook.office365.com and login, if prompted
- In the App list in the top-left corner, select Calendar
- The Outlook Calendar view will appear. At the top of the page, click Add Calendar, then select From directory from the drop-down list.
- A small window will appear. In the From directory field, enter the full resource name of the calendar you want to add, or start typing part of the calendar name and select Search Directory for a complete list.
- After you've selected the calendar you want to add, click Open. The calendar will start loading in the background.
- Depending on the size and number of events in the calendar, it may take a few minutes to populate.