You could use your status bar to display the time and date. You might also use it to display mouse-over text or a welcome message. View the source of the demo page for the source code.

The document object has a last modified date property. This specifys the date the file was last modified on. This can be useful for showing when the page was last modified without having to modify any HTML when you make a change. This tutorial shows how to display the last modified date in several different formats using JavaScript.