Sorry, forgot to mention which file I modified. It's the calendar.js file included in the seam-ui.jar View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4036521#4036521 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4036521