There’s little that annoys me as much as going to a website that is an authority on some subject, and it has an outdated copyright.
Here’s a very simple script to replace all of your copyrights, so that they are constantly updated with the latest year.
<p>Copyright 2007-<?php echo(date('Y'));?>.</p>
This is, of course, assuming that your copyright began in 2007. Replace 2007 with the year in which the copy was originally created.