Exchange is ubiquitous for email hosting, and it enables the creation of shared calednars. Once your IT department has created a shared calendar you can follow these steps to add it to Outlook on your Mac.

• In Outlook, go to Tools > Public Folders
• Under your email address click on the folder which has been created by your IT department which houses the calendar
• Select the calendar(s) shown in the folder
• Click on Subscribe

The calendar will appear in the calendars part of Outlook, under "Subscribed Public Folders".