Do you need an xml calendar? How about a calendar you can add to any page on your website to show your visitors your events?
The xml schema is simple to follow. There is a event editor included to help you create your events.
It is possible to generate the events from your database. Construct a page that will read from the database and render the xml. Use this page as the xml event file in the scriptcalendar. It will asynchronously get the dynamically rendered xml. You avoid concurrent user issues in a multiple user environment by dynamically rendering the xml instead of generating a file on the server.
This is an sample of the xml used by the scriptcalendar