Closest I could get was a flash countdown clock that you have to embed into the layout. below is the file and the code you need to enter into a cell to get it to show.
Code:-
<embed src="C:\Users\Gary\Desktop\free-flash-clock-95.swf" width="150" height="150" type="application/x-shockwave-flash">
</embed>
You will need to change the code to where you have the .swf file stored see picture.
Website where the clock came from and it has countless others:-
http://free-flash-clocks.com/Its more of a work around than a soloution for the countdown timer but the analouge clocks could work very well in future layouts.