Based on a post in this thread Looking for help with a repeating weekly Javascript countdown, the count down timer is made out of elements in the post a script section.

A bit rough and ready, if anyone finds a better route, please post here.
Html:
PHP Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<
html xmlns="http://www.w3.org/1999/xhtml">
<
head>
<
meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<
title>Untitled Document</title>
<
script>
function 
tween(rfcDateBegin,rfcDateEnd){
    
rfcDateBegin rfcDateBegin || false;
    
rfcDateEnd rfcDateEnd || false;
    if( 
rfcDateBegin && rfcDateEnd ) return new Date(rfcDateEnd).getTime() - new Date(rfcDateBegin).getTime();
return 
null;
}

Date.prototype.getNextDow = function(dow){
        
dow dow || 0;
        
// finds first dow from day in date object in the month set in the date object and likewise the year.
        
for(dayNo=this.getDate(); (this.getDate()+9)>dayNodayNo++){
            
futureDate = new Date(this.getFullYear(), this.getMonth() , dayNo);
            
// we only check forward 9 days, if we don't find anything then we have a problem!
            
if( futureDate.getDay()==dow ) return futureDate.getTime(); // return date value
            
}
return 
false// we return something because we have to!
}

Number.prototype.convertToReference = function(){

    
// reduce to seconds
    
tmp Math.floorthis 1000 );
    
= [];
    
days Math.floor(tmp / ( 60 60 24 )); // number of days
    
if( days>0){ r.push(  days " Days, " ); tmp -= ( days 60 60 24); }
    
    
hours Math.floortmp / ( 60 60 ));
    if( 
hours>0){ r.pushhours " Hrs, " ); tmp -= ( hours 60 60 ); }
    
    
minutes Math.floortmp 60 );
    if( 
minutes>){ r.pushminutes" Mins, "); tmp -= ( minutes 60 ); }
    
    
r.pushtmp " Secs.");
    return 
r.join("");
    
}
function 
update(){
// get the time now.
nowObj = new Date();
now = new Date().getTime();
// get the nearest Friday from 'now
target nowObj.getNextDow(5); // 4 == friday
remaining tweennow target offset );
tg.value remaining.convertToReference ();
}
offset tween("1 Jan 2012 00:00:00","1 Jan 2012 16:00:00"); // ==57600000 ms, this is midnight to 4pm as milliseconds
setIntervalupdate 1000);
</script>
</head>
<body onload="tg=document.getElementById('remain');"><input type="text" id="remain" value="" size="30" />

</body>
</html> 
The example above counts down to 4pm on Friday of the current week.

With some modification your able to create a count timer that auto resets, any event that you want to trigger at zero hour will be up to yourselves to implement.