If you want HTML, here is a Javascript program that you can use as an Active Desktop object!

CODE
<script LANGUAGE="JAVASCRIPT">
<!-- hide this script tag's contents from old browsers
today = new Date();
BigDay = new Date("August 27, 2003")
msPerDay = 24 * 60 * 60 * 1000;
timeLeft = (BigDay.getTime() - today.getTime());
e_daysLeft = timeLeft / msPerDay;
daysLeft = Math.floor(e_daysLeft);
e_hrsLeft = (e_daysLeft - daysLeft)*24;
hrsLeft = Math.floor(e_hrsLeft);
minsLeft = Math.floor((e_hrsLeft - hrsLeft)*60);
secsLeft = Math.floor((hrsLeft - minsLeft)*60);
document.write(" <font class='countdown'>" + daysLeft + " day(s), " + hrsLeft +" hour(s), " + minsLeft +" min(s) TEXT HERE TEXT HERE");
// -- done hiding from old browsers -->
</SCRIPT>