1.在<head></head>中加入下列代码
<script language=JavaScript>
var timerID = null;
var timerRunning = false;
function stopclock (){
if(timerRunning)
clearTimeout(timerID);
timerRunning = false;}
function startclock () {
stopclock();
showtime();}
function showtime () {
var now = new Date();
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds()
var timeValue = "" +((hours >= 12) ? "下午 " : "上午 " )
timeValue += ((hours >12) ? hours -12 :hours)
timeValue += ((minutes < 10) ? ":0" : ":") + minutes
timeValue += ((seconds < 10) ? ":0" : ":") + seconds
document.clock.thetime.value = timeValue;
timerID = setTimeout("showtime()",1000);
timerRunning = true;}
</SCRIPT>
2.在<body>中加入下列代码
onload=startclock()
3.在显示时间的位置插入下列代码,建议使用表格定位
[code]
<form name=clock >
<input name=thetime style="font-size: 9pt;color:#000000;border:0" size=12>
</form>
//只获得当前系统日期的函数
<script language="JavaScript" type="text/javascript">
document.write(new Date().getYear()+"-"+(new Date().getMonth()+1)+"-"+new Date().getDate());
</script>
https://www.jb51.net/article/12786.htm 
