var dates=[
 {
 dat:324235235
 },
 {
 dat:7200000
 },
 {
 dat:675875754
 }
]
 
module.exports = {
 datetime: dates
}

<view wx:for="{{wearList.datetime}}" wx:for-item="item" wx:key="id">
 <view class='dates'>{{item.difftime}}</view>
</view>

var dates=require('../utils/dates.js');//数据文件
 
Page({
 data:{},
 onShow(a){
 // console.log(dates.datetime)//数据
 let that=this;
 let len=dates.datetime.length;//时间数据长度
 
 function nowTime() {//时间函数
  // console.log(a)
  for (var i = 0; i < len; i++) {
  var intDiff = dates.datetime[i].dat;//获取数据中的时间戳
  // console.log(intDiff)
  var day=0, hour=0, minute=0, second=0;  
  if(intDiff > 0){//转换时间
   day = Math.floor(intDiff / (60 * 60 * 24));
   hour = Math.floor(intDiff / (60 * 60)) - (day * 24);
   minute = Math.floor(intDiff / 60) - (day * 24 * 60) - (hour * 60);
   second = Math.floor(intDiff) - (day * 24 * 60 * 60) - (hour * 60 * 60) - (minute * 60);
   if(hour <=9) hour = '0' + hour;
   if (minute <= 9) minute = '0' + minute;
   if (second <= 9) second = '0' + second;
   dates.datetime[i].dat--;
   var str=hour+':'+minute+':'+ second 
   // console.log(str) 
  }else{
   var str = "已结束！";
   clearInterval(timer); 
  }
  // console.log(str);
  dates.datetime[i].difftime = str;//在数据中添加difftime参数名，把时间放进去
  }
  that.setData({
  wearList: dates
  })
  // console.log(that)
 }
 
 nowTime();
 var timer = setInterval(nowTime, 1000);
 
 }
})