效果图：
1.以下时html文件
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>时钟特效</title>
<script type="text/javascript" src="../js/time.js" ></script>
</head>
<body>
<div id="getTime"></div>
</body>
</html>
2.以下是js代码
function showTime(){
//创建日期对象，使用new操作符和Date构造函数创建
var today=new Date();
//获取年
var year=today.getFullYear();
//获取月
var moth=today.getMonth()+1;
//获得一月中某一天
var day=today.getDate();
//星期几
var dayToday=today.getDay();
//利用if判断星期对应的中文
if(dayToday==0){
dayToday="星期天"
}else if(dayToday==1){
dayToday="星期一"
}else if(dayToday==2){
dayToday="星期二"
}else if(dayToday==3){
dayToday="星期三"
}else if(dayToday==4){
dayToday="星期四"
}else if(dayToday==5){
dayToday="星期五"
}else if(dayToday==6){
dayToday="星期六"
}
//获取时间
var minute=today.getMinutes();
//获取秒
var second=today.getSeconds();
//获取24小时时间
var hour=today.getHours();
//利用if判断转换12小时
if(hour<12){
time=number(hour)+":"+minute+":"+second+" "+"am"
}else if(hour>=12){
hour=hour-12
time=hour+":"+minute+":"+second+" "+"pm";
}
//声明变量nowtime得到年月日等
var nowTime = year+"年"+moth+"月"+day+"日"+" "+time+" "+dayToday;
//先获取demo所在框架再修改
document.getElementById("getTime").innerHTML=nowTime;
}
//加入定时器
setInterval(function() {showTime()},1000);