JSFiddle - React, Tailwind, and code Playground

HTML

<div id="d01">
    開始時間：<span class="start_pad"></span><br>
    結束時間：<span class="end_pad"></span><br>
    剩餘時間：<span class="pad"></span>
</div>

<br><br>

<div id="d02">
    開始時間：<span class="start_pad"></span><br>
    結束時間：<span class="end_pad"></span><br>
    剩餘時間：<span class="pad"></span>
</div>

JavaScript

$(document).ready(function() {

    countDown("\/Date(1310953619000)\/", "", 1, 'd01');
    countDown("", "\/Date(1310755619000)\/", 2, 'd02');

    function countDown(sTimestamp, eTimestamp, countType, obj) {
        if (countType == 1) {
            var sDateArr = getdateArray(sTimestamp); //getdateArray("\/Date(1310953619000)\/"); 
            var sDate = new Date(sDateArr[0], sDateArr[1], sDateArr[2], sDateArr[3], sDateArr[4]);
            var eDate = new Date(); //new Date(2012, 2, 24, 12, 25);
            var spantime = (sDate - eDate) / 1000;
        }
        else {
            var sDate = new Date();
            var eDateArr = getdateArray(eTimestamp);
            var eDate = new Date(eDateArr[0], eDateArr[1], eDateArr[2], eDateArr[3], eDateArr[4]);
            var spantime = (eDate - sDate) / 1000;
        }
        $("#" + obj).children(".start_pad").html(getString(sDate));
        $("#" + obj).children(".end_pad").html(getString(eDate));
        cal(spantime, obj);
    }

    function getString(dt) {
        return dt.getFullYear() + "年" + (dt.getMonth() + 1) + "月" + dt.getDate() + "日" + dt.getHours() + "時" + dt.getMinutes() + "分";
    }

    function cal(spantime, obj) {        
        
        setInterval(function() {
            spantime--;
            var d = Math.floor(spantime / (24 * 3600));
            var h = Math.floor((spantime % (24 * 3600)) / 3600);
            var m = Math.floor((spantime % 3600) / (60));
            var s = Math.floor(spantime % 60);
            str = d + "天 " + h + "時 " + m + "分 " + s + "秒 ";
            $("#"+obj).children(".pad").html(str);
        }, 1000);
    }

});

function getdateArray(daytime) {
    var gettime = new Date(parseInt(daytime.substr(6)));
    var dateArray = new Array(5);

    dateArray[0] = gettime.getFullYear();
    dateArray[1] = gettime.getMonth() + 1;
    dateArray[2] = gettime.getDate();
    dateArray[3] = gettime.getHours();
    dateArray[4] = gettime.getMinutes();

    dateArray[1] =...