网站运行时间siteTime()；

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(2016, 8, 27, 08, 19, 00) /*这里修改为建站时间*/

    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()

<p>本站已稳定运行<span id="sitetime" ></span></p>