代码：

<br>余温博客提醒您:<span id="span_dt_dt" style='border:2px solid black;background-color:#ffc252' ></span>
<SCRIPT language=javascript>
<!--
//document.write("");
function show_time(){
window.setTimeout("show_time()", 1000);
BirthDay=new Date("2018-7-9");//改成你的计时日期
today=new Date();
timeold=(BirthDay.getTime()-today.getTime());
sectimeold=timeold/1000
secondsold=Math.floor(sectimeold);
msPerDay=24*60*60*1000
e_daysold=timeold/msPerDay
daysold=Math.floor(e_daysold);
e_hrsold=(e_daysold-daysold)*24;
hrsold=Math.floor(e_hrsold);
e_minsold=(e_hrsold-hrsold)*60;
minsold=Math.floor((e_hrsold-hrsold)*60);
seconds=Math.floor((e_minsold-minsold)*60);
span_dt_dt.innerHTML=daysold+"天"+hrsold+"小时"+minsold+"分"+seconds+"秒" ;
}
show_time();
//-->
</SCRIPT>