Publish your free and busy times for others to see

For people who don't have access to your Outlook calendar, you can publish the times that you are already booked and the times that you are still available to a shared location on the Microsoft Office Internet Free/Busy Service or another Internet or intranet location. (If you're a Microsoft Exchange user, others in your organization can see your free/busy times by default when they schedule a meeting with you.)

Regardless of how you publish your free/busy times, you can change how often Microsoft Outlook publishes this information and for what period of time.

On the Tools menu, click Options, and then click Calendar Options.
Click Free/Busy Options.
To specify how often Microsoft Outlook automatically updates your free/busy information on your Exchange server or one of the servers used in the situations described below, enter a number in the Update free/busy information on the server every x minutes box.
To specify how many months of free/busy data is available on the server, enter a number in the Publish x month(s) of Calendar free/busy information on the server box. You can publish up to 36 months of free/busy schedule information.

Select the Publish and search using Microsoft Office Internet Free/Busy Service check box.
For attendees whose free/busy times you can't see when scheduling a meeting, Outlook can automatically add text to your meeting requests that invites these attendees to join the service. For attendees who are already members, the text invites them to authorize you to access their free/busy times on the service. Click Request free/busy information in meeting invitations.
Click Manage, and then follow the directions on the subsequent screens.

Note Anyone who isn't a member and who you haven't specifically authorized to view your free/busy times won't be able to access the information you publish to the service.

Anyone who you give the location to or who acquires it through other means can access your free/busy times.

In the Publish at my location box, type the name of the server where your free/busy information is stored.
Note The name you specify, such as file://computername/public/name.vfb, can include FTP, HTTP, or file URLs.