给网站添加本站运行天数

<div style="font-size: 0.85rem">
<span id="timeDate">载入天数...</span>
<span id="times">载入时分秒...</span>
<script src="/runtime.js"></script>

/** 修改日期 2021/12/12 **/
/** 作者 张凯强，大白熊修改 **/
/** 网站 blog.changrui.xyz **/
/** 作者网站 hexo.fluid-dev.com **/
!(function() {
  /** 计时起始时间，自行修改 **/
  var start = new Date("2021/12/11 07:49:00");

  function update() {
    var now = new Date();
    now.setTime(now.getTime()+250);
    days = (now - start) / 1000 / 60 / 60 / 24;
    dnum = Math.floor(days);
    hours = (now - start) / 1000 / 60 / 60 - (24 * dnum);
    hnum = Math.floor(hours);
    if(String(hnum).length === 1 ){
      hnum = "0" + hnum;
    }
    minutes = (now - start) / 1000 /60 - (24 * 60 * dnum) - (60 * hnum);
    mnum = Math.floor(minutes);
    if(String(mnum).length === 1 ){
      mnum = "0" + mnum;
    }
    seconds = (now - start) / 1000 - (24 * 60 * 60 * dnum) - (60 * 60 * hnum) - (60 * mnum);
    snum = Math.round(seconds);
    if(String(snum).length === 1 ){
      snum = "0" + snum;
    }
    document.getElementById("timeDate").innerHTML = "本站艰难的存活了&nbsp"+dnum+"&nbsp天";
    document.getElementById("times").innerHTML = hnum + "&nbsp小时&nbsp" + mnum + "&nbsp分&nbsp" + snum + "&nbsp秒";
  }

  update();
  setInterval(update, 1000);
})();