网站底部加入已运行XX天的代码

看到很多站长，都喜欢在自己网站的底部加入“本站已稳定运行多少天”的小功能 下面用js把功能复现一遍

javascript代码：

function showsectime() {
    var birthDay = NewDate("2019-05-13");
    // 这里修改站点开启日期
    var today = new Date();
    var timeold = today.getTime() - birthDay.getTime();
    var sectimeold = timeold / 1000
    var secondsold = Math.floor(sectimeold);
    var msPerDay = 24 * 60 * 60 * 1000;
    var e_daysold = timeold / msPerDay;
    var daysold = Math.floor(e_daysold);
    var e_hrsold = (daysold - e_daysold) * -24;
    var hrsold = Math.floor(e_hrsold);
    var e_minsold = (hrsold - e_hrsold) * -60;
    var minsold = Math.floor((hrsold - e_hrsold) * -60);
    var seconds = Math.floor((minsold - e_minsold) * -60).toString();
    document.getElementById("showsectime")[xss_clean] = "稳定运行 :" + daysold + "天" + hrsold + "小时" + minsold + "分" + seconds + "秒";
    setTimeout(showsectime, 1000);
}
showsectime()

HTML代码：

<span id="showsectime"></span>

运行效果：