<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var t = null
t = setTimeout(time,1000) // 开始运行
function time(){
clearTimeout(t) // 清除定时器
dt = new Date()
var y = dt.getFullYear()
var mt = dt.getMonth()+1
var day = dt.getDate();
var h = dt.getHours()
var m = dt.getMinutes()
var s = dt.getSeconds()
document.querySelector(".showTime").innerHTML = '当前时间:'+y + '年' +mt + '月' + day + '_' +h + '时' + m +'分' + s + '秒'
t = setTimeout(time, 1000)
}
</script>
</head>
<body>
<div class="showTime"></div>
</body>
</html>