jquery实现一个网页同时调用多个倒计时

<div class="time countdown_1" data-time="1449429731">
    <span class="t_h_1">00</span>
    <i class="lay_line">:</i>
    <span class="t_m_1">00</span>
    <i class="lay_line">:</i>
    <span class="t_s_1">00</span>
</div>
<div class="time countdown_2" data-time="1449456731">
    <span class="t_h_2">00</span>
    <i class="lay_line">:</i>
    <span class="t_m_2">00</span>
    <i class="lay_line">:</i>
    <span class="t_s_2">00</span>

</div>

《p》

//js2
var plugJs={
    stamp:0,
    tid:1,
    stampnow:Date.parse(new Date())/1000,//统一开始时间戳
    intervalTime:function(){
        if(plugJs.stamp > 0){
            var day = Math.floor(plugJs.stamp / (60 * 60 * 24));
            var hour = Math.floor(plugJs.stamp / (60 * 60)) - (day * 24);
            var minute = Math.floor(plugJs.stamp / 60) - (day * 24 * 60) - (hour * 60);
            var second = Math.floor(plugJs.stamp) - (day * 24 * 60 * 60) - (hour * 60 * 60) - (minute * 60);
            
            if (day <= 9) day = '0' + day;
            if (hour <= 9) hour = '0' + hour;
            if (minute <= 9) minute = '0' + minute;
            if (second <= 9) second = '0' + second;
            jQuery('.t_h_'+plugJs.tid).html(hour);
            jQuery('.t_m_'+plugJs.tid).html(minute);
            jQuery('.t_s_'+plugJs.tid).html(second);
            plugJs.stamp--;
            setTimeout('if(typeof(plugJs.intervalTime) == "function"){plugJs.intervalTime();}',1000);
        }
    },
    timer:function (stampend,tid){
        plugJs.stamp = parseInt(stampend)-parseInt(plugJs.stampnow);//剩余时间戳
        setTimeout('if(typeof(plugJs.intervalTime) == "function"){plugJs.intervalTime();}',1000);
    }
};
jQuery(document).ready(function(){
    var stampend = parseInt(jQuery('.countdown_1').attr('data-time'));//灵活读取表里的结束时间戳
    plugJs.timer(stampend,'1');
});