首先我们先复制下面这一连串的代码到网站的 header

<script>
function siteTime(){
window.setTimeout("siteTime()", 1000);
var seconds = 1000
var minutes = seconds * 60
var hours = minutes * 60
var days = hours * 24
var years = days * 365
var today = new Date()
var todayYear = today.getFullYear()
var todayMonth = today.getMonth()
var todayDate = today.getDate()
var todayHour = today.getHours()
var todayMinute = today.getMinutes()
var todaySecond = today.getSeconds()
var t1 = Date.UTC(2019,10,17,08,19,00)
var t2 = Date.UTC(todayYear,todayMonth,todayDate,todayHour,todayMinute,todaySecond)
var diff = t2-t1
var diffYears = Math.floor(diff/years)
var diffDays = Math.floor((diff/days)-diffYears*365)
var diffHours = Math.floor((diff-(diffYears*365+diffDays)*days)/hours)
var diffMinutes = Math.floor((diff-(diffYears*365+diffDays)*days-diffHours*hours)/minutes)
var diffSeconds = Math.floor((diff-(diffYears*365+diffDays)*days-diffHours*hours-diffMinutes*minutes)/seconds)
document.getElementById("sitetime").innerHTML=""+diffYears+" 年 "+diffDays+" 天 "+diffHours+" 小时 "+diffMinutes+" 分钟 "+diffSeconds+" 秒"
}
siteTime()
</script>

将上面js代码中：var t1 = Date.UTC(2018,12,29,08,19,00) 改为你网站的建站时间，如时间是：2019年10月17号08点19分00秒。
将下列代码添加到你网站htm（模板文件）代码中，放在你想要显示网站运行时间的位置即可，可以是网站底部、侧边栏等。

调用代码

<span id="sitetime"</span>