To view a person's free/busy time within Outlook 2011 for Mac for the purpose of scheduling a meeting, please follow these instructions:
1. From Calendaring, click on the Meeting icon from the menu.
2. A window will pop-up, much like an email, to create your meeting. Click on the Scheduling icon in the menu and the Scheduling Assistant will appear in the body of the window. From within Scheduling Assistant, click on Add New under All Attendees to add a meeting participant.
3. Type the meeting participants name in the search field and any matching names will appear below. Once you find the correct participant, click on Required and close the window.
4. The participant's name will now be in the list of All Attendees and you will see their free/busy time to the right of their name. A legend of the various colors is shown at the bottom of the window. (please note that free/busy times of Zimbra users will not appear)