Many departments have calendars stored in Public Folders and when you upgrade Outlook or get a new computer these can disappear and need to be re-added so that you can see it in your list of calendars.
- Find the calendar by clicking on the ellipsis (...) down at the bottom of your Outlook window and then click Folders
- In the navigation bar on the left of the Outlook window, navigate to near the end of the list to the Public Folders and click on the arrow to expand the folders
- Navigate down the Departments folder to find the department and find the calendar you are looking for
- Once you have found it (before clicking on it to see the calendar's contents) right click and select Add to favorites
- This calendar can now be seen in My Calendars along with your other calendars in the Calendar view