1. Open your Outlook 2013 Client.
2. Click the Calendar button located in the bottom left corner of Outlook.
3. Once the ribbon has adjusted to reflect calendaring options, select the Folder Tab.
4. Within the Folder tab, click the Open Calendar icon drop down menu and choose Open Shared Calendar.
5. Type in the Username or click to locate the user that has shared their calendar with you. Once their name has been selected, the Calendar will appear within the left-hand panel under Shared Calendars.
Note: When a member of your organization shares a calendar, typically a Sharing Invitation message is generated and sent to the user. Selecting Open this Calendar will accept the invitation and place the calendar under Share Calendars.