jquery/js实现一个网页同时调用多个倒计时(最新的)

<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>  

//js2  
var plugJs={  
    stamp:0,  
    tid:1,  
    stampnow:'<?php echo NOW_TIME;?>',//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');  
});