第一种方式：
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>系统时间</title>
<script language="javascript" type="text/javascript">
<!--
//获得当前时间,刻度为一千分一秒
var initializationTime=(new Date()).getTime();
function showLeftTime()
{
var now=new Date();
var year=now.getYear();
var month=now.getMonth();
var day=now.getDate();
var hours=now.getHours();
var minutes=now.getMinutes();
var seconds=now.getSeconds();
document.all.show.innerHTML=""+year+"年"+month+"月"+day+"日 "+hours+":"+minutes+":"+seconds+"";
//一秒刷新一次显示时间
var timeID=setTimeout(showLeftTime,1000);
}
//-->
</script>
</head>
<body onload="showLeftTime()">
<div id="time" style="margin-top:200px; margin-left:600px;">
<label id="show">显示时间的位置</label>
</div>
</body>
</html>
第二种的方式：
<!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=gb2312" />
<title>无标题文档</title>
</head>
<body>
<div id="webjx" style="margin-top:200px; margin-left:200px;">
<span id=nowDate></span>
<span id=nowTime></span>
<script><!--
var ns4up1 = (document.layers) ? 1 : 0; // browser sniffer
var ie4up1 = (document.all&&(navigator.appVersion.indexOf("MSIE 4") == -1)) ? 1 : 0;
var ns6up1 = (document.getElementById&&!document.all) ? 1 : 0;
function nowclock() {
if (!ns4up1 && !ie4up1 && !ns6up1) return false;
var digital = new Date();
var hours = digital.getHours();
var minutes = digital.getMinutes();
var seconds = digital.getSeconds();
var day = digital.getDate();
var month = digital.getMonth() + 1;
var year = digital.getYear();
var amOrPm = "AM";
if (hours > 11) amOrPm = "PM";
if (hours > 12) hours = hours - 12;
if (hours == 0) hours = 12;
if (minutes < 10) minutes = "0" + minutes;
if (seconds < 10) seconds = "0" + seconds;
if (day < 10) day = "0" + day;
if (month < 10) month = "0" + month;
dispTime = hours + ":" + minutes + ":" + seconds + " " + amOrPm;
dispDate = year + "年" + month + "月" + day+ "日, " ;
if (ns4up1) {
document.layers.nowTime.document.write(dispTime);
document.layers.nowTime.document.close();
document.layers.nowDate.document.write(dispDate);
document.layers.nowDate.document.close();
} else if (ns6up1){
document.getElementById("nowTime").innerHTML = dispTime;
document.getElementById("nowDate").innerHTML = dispDate;
} else if (ie4up1){
nowTime.innerHTML = dispTime;
nowDate.innerHTML = dispDate;
} setTimeout("nowclock()", 1000);
} nowclock();
//-->
</script>
</div>
</body>
</html>