//css样式请自行设置
<span id="timer"><span>
<script>
var timer = document.getElementById("timer");
//获取标签
setInterval ( function(){ //setInterval按照指定周期调用函数
var today = new Date(); //声明一个变量用来存储当时时间
var year = today.getFullYear;//声明一个变量year用来存储从当时时间里获取的年份
var month = today.getMonth;
var day = today.getDay;
var hour = today.getHour;
var minutes = today.getMinutes;
var secound = today.getSecound;
if(month<10){
month = "0"+month
//在月份前面加个0,如果是10月以内就价格0
}
if(secound<10){
secound = "0"+secound;
}
//60秒结束后,从0开始个位数加个0
timer.innerHTML = year+"年份"+month+"月"+day+"日"+hour+":"+minutes+":"+secound
把年月日组合在一起的结果输出到timer里面
},1000)//每秒调用一次
//
<script/>
后面可以加很多css央视
原文:https://www.cnblogs.com/wangjiahui/p/10849827.html