转自: Js中国
http://javascriptxml.5d6d.com/thread-4-1-1.html
<div>
<div class="Bjday" id="timeDate" width="60">
</div>
<div class="Bjtim" id="times">
</div>
<SCRIPT>
var now = new Date();
function createtime(){
var grt= new Date("8/08/2008 20:00:00");
now.setTime(now.getTime()+250);
days = (grt - now) / 1000 / 60 / 60 / 24;
dnum = Math.floor(days);
hours = (grt - now) / 1000 / 60 / 60 - (24 * dnum);
hnum = Math.floor(hours);
if(String(hnum).length ==1 ){hnum = "0" + hnum;}
minutes = (grt - now) / 1000 /60 - (24 * 60 * dnum) - (60 * hnum);
mnum = Math.floor(minutes);
if(String(mnum).length ==1 ){mnum = "0" + mnum;}
seconds = (grt - now) / 1000 - (24 * 60 * 60 * dnum) - (60 * 60 * hnum) - (60 * mnum);
snum = Math.round(seconds);
if(String(snum).length ==1 ){snum = "0" + snum;}
document.getElementById("timeDate").innerHTML = dnum;
document.getElementById("times").innerHTML = hnum + "<span style='margin:0 7px 0 7px'>:</span>"+ mnum + "<span style='margin:0 7px 0 7px'>:</span>"+ snum;
}
setInterval("createtime()",250);
</SCRIPT>
</DIV>