倒计时

//相差的总秒数
    var totalSeconds = parseInt((endDate - nowDate) / 1000);
    //天数
    var days = Math.floor(totalSeconds / (60 * 60 * 24));
    //取模（余数）
    var modulo = totalSeconds % (60 * 60 * 24);
    //小时数
    var hours = Math.floor(modulo / (60 * 60));
    modulo = modulo % (60 * 60);
    //分钟
    var minutes = Math.floor(modulo / 60);
    //秒
    var seconds = modulo % 60;
    //输出到页面
    document.getElementById(id).innerHTML = "还剩:" + days + "天" + hours + "小时" + minutes + "分钟" + seconds + "秒";