If you already use Zimbra to view your calendar through Outlook, use the following steps to subscribe to calendars you have been given permissions to.
1. In Outlook 2010/2013, click the Zimbra tab at the top. If you don't have this tab, the Zimbra Connector will need to be installed by the DECS Support Office.
2. Next, click Open Other User's mailbox (circled below).
3. On the next screen under Address Book, click on the drop down arrow and select Global Address List (circled below).
4. Select the calendar you want to subscribe to. Select a name by double clicking it, or click them once and then click the To -> button. Then click OK and the calendar should be added to the Calendars view in Outlook. Repeat this process from the top of the page to add more calendars. Unfortunately, calendars must be added individually.
This process will only work if you have permissions to the calendars you attempting to access. To gain access to other calendars, please request access by sending an e-mail to email@example.com.