js方法实现网站已运行多少天的代码

            <span id="span"></span>
            <script type="text/javascript">
                function runtime(){
                    // 初始时间，日/月/年 时:分:秒
                    X = new Date("06/18/2023 8:32:00");
                    Y = new Date();
                    T = (Y.getTime()-X.getTime());
                    M = 24*60*60*1000;
                    a = T/M;
                    A = Math.floor(a);
                    b = (a-A)*24;
                    B = Math.floor(b);
                    c = (b-B)*60;
                    C = Math.floor((b-B)*60);
                    D = Math.floor((c-C)*60);
                    //信息写入到DIV中
                    span.innerHTML = "本站勉强运行: "+A+"天"+B+"小时"+C+"分"+D+"秒"
                }
                setInterval(runtime, 1000);
            </script>