This will let you count the number of days remaining to reach a given event : for instance days left before we reach the year 2004:

<script language="javascript">

function chrono()
{
jour=Date.parse("Jan 1, 2004 GMT") - Date.parse(new Date);
return(Math.round(jour/(24*60*60*1000)))
}
document.write("Still "+chrono()+" days before we reach the year 2004");

</script>

of course it is possible to change this to any date you want.