How to add a Calendar to Outlook in the Web? These instructions are for adding another account’s calendar to your Outlook for the Web (OWA): Open a web browser and go to https://outlook.office.com. Select Outlook from the dot menu in the top-left corner. Open the Calendar by clicking on the calendar icon in the bottom left corner. Click Add calendar. Then select Add from directory. Search for the calendar owner’s email address or name. If they do not appear in suggestions, then click Search Directory. Confirm the appropriate account has been selected, choose where you would like to add the calendar to, then click Add. You should now see this calendar in the left side menu under the section chosen in the previous step.