Publishing Calendar Availability
This tutorial will demonstrate a quick method for publishing your Outlook calendar availability, from OWA, anonymously on a webpage.
Login to OWA - and switch to your calendar.
Right click on the desired calendar and select "Permissions…"
Set the permissions for Public Calendar to Availability Only. This will publish the calendar anonymously.
Press the save button in the upper left of the permissions panel to set the changes.
Re-open the permissions panel by right clicking on the calendar and selecting Permissions… Right click on the View calendar link and copy the link location. This link can then be used in an iFrame, or an anchor in your favorite web editor and will link to the calendar.