<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>获取系统时间</title>
</head>
<body>
<div id="div1">
</div>
<script type="text/javascript">
function addZero(val){
return val<10?("0"+val):val;
} // 个位数补零
function getTimer(){
var nowtime = new Date();
var year = nowtime.getFullYear();
var month = nowtime.getMonth();
var day = nowtime.getDate();
var hours = nowtime.getHours();
var minute = nowtime.getMinutes();
var secon = nowtime.getSeconds();
//var msSecon = nowtime.getMilliseconds();
var week = nowtime.getDay();
var weekstr = "日一二三四五六" //getDay() 数字转换为中文的一二三四五等
var str = year+"年"+addZero(month+1)+"月"+addZero(day)+"日 星期"+weekstr.charAt(week)+" "+addZero(hours)+" : "+addZero(minute)+" : "+addZero(secon);
// 字符串拼接
return str;
}
var oDiv = document.getElementById("div1");
oDiv.innerHTML = getTimer();
var timer = setInterval(function(){
var oDiv = document.getElementById("div1");
oDiv.innerHTML = getTimer();
},1000) // 定时触发
</script>
</body>
</html>
原文：http://www.cnblogs.com/zjx2011/p/4439515.html