Windows Calendar publishing
This feature is included in the following editions of Windows Vista:
When you are ready to publish your calendar you will need to contact your internet service provider to acquire the following information:
Location to publish calendar. Your calendar will be stored on a server at your internet service provider so that others may download it. You will need to know the URL for your calendar's location on your internet service provider's server so you can share the location with others. The server location provided by your internet service provider may require a user name and password when publishing your calendar. If so, Windows Calendar will ask for this information automatically after you click the Publish button.
Calendar name. This is the title of the calendar you are publishing. It can be any name you choose, such as "John Smith", and this entry may not be left blank. When proceeding with the publishing process the Calendar you are working in will be the default shown in the Calendar name: field of the dialogue box.
Automatically publishing changes. Once you have your Windows Calendar published, any changes you make will automatically be published as soon as the changes are made.