1.  Go to Calendar once Outlook is open



2. Click on Open Calendar at the top ribbon and select From Address Book… from the drop-down menu.



3. On the next window make sure you click under Address Book and select the Global Address List to make sure you're looking at the updated contact list.



4. You can scroll through the list of contacts or simply type the first three letters or more of the last name of who you're looking for. Click on the person or shared calendar to select it and then click on the button named Calendar -> to add it before clicking OK. You can achieve the same by double clicking on the desired calendar.


5. The calendar will be added to your view separately. You can choose to overlay it with other calendars by clicking on the arrow that it's on the top left of the calendar, as shown below:



Below you can see the two calendars overlaid. You can revert this by clicking the arrow again or even close the calendar by clicking on the X mark (as marked by the blue arrow below)