倒计时 JS小例子

<span class="cd_item_txt" id="days">00</span></div>
<div class="cd_item cd_hour" ><span class="cd_item_txt" id="hours">00</span></div>
<div class="cd_item cd_minute"><span class="cd_item_txt" id="minutes">00</span></div>
<div class="cd_item cd_second"><span class="cd_item_txt" id="seconds">00</span></div></div>

<script type="text/javascript" src="js/jquery-1.9.1.min.js">
<!-- 秒杀时间js start-->
<div>

                                            function leftTimer(year,month,day,hour,minute,second){ 
                                              var leftTime = (new Date(year,month-1,day,hour,minute,second)) - (new Date()); //计算剩余的毫秒数 
                                            //  alert(leftTime);
                                              var days = parseInt(leftTime / 1000 / 60 / 60 / 24 , 10); //计算剩余的天数 
                                              var hours = parseInt(leftTime / 1000 / 60 / 60 % 24 , 10); //计算剩余的小时 
                                              var minutes = parseInt(leftTime / 1000 / 60 % 60, 10);//计算剩余的分钟 
                                              var seconds = parseInt(leftTime / 1000 % 60, 10);//计算剩余的秒数 

                                              days = checkTime(days); 
                                              hours = checkTime(hours); 
                                              minutes = checkTime(minutes); 
                                              seconds = checkTime(seconds); 

                                              document.getElementById("days").innerHTML = days;  
                                              document.getElementById("seconds").innerHTML = seconds;  
                                              document.getElementById("minutes").innerHTML = minutes;  
                                              document.getElementById("hours").innerHTML = hours;  
                                            } 

                                            function checkTime(i){ //将0-9的数字前面加上0，例1变为01 
                                              if(i<10) 
                                              { 
                                                i = "0" + i; 
                                              } 
                                              return i; 
                                            } 
                    //$seckill_time = ‘2018,04,04,10,00,00'；
                                            setInterval("leftTimer({$seckill_time})",1000); //在这里修改6个参数 ，根据后台传值  
                                            leftTimer();
    </div>

     <--秒杀时间js  end-->