通过后台的毫秒，运用计算，转变成时间

fmtDate () {
      return function (date) {
        let dateFn = new Date(date)
        let yy = dateFn.getFullYear()
        let mm = dateFn.getMonth() + 1
        let dd = dateFn.getDay()
        let hh = dateFn.getHours() < 10 ? ‘0‘ + dateFn.getHours() : ‘‘ + dateFn.getHours()
        let xx = dateFn.getMinutes() < 10 ? ‘0‘ + dateFn.getMinutes() : ‘‘ + dateFn.getMinutes()
        let ss = dateFn.getSeconds() < 10 ? ‘0‘ + dateFn.getSeconds() : ‘‘ + dateFn.getSeconds()
        let time = yy + ‘-‘ + mm + ‘-‘ + dd + ‘    ‘ + hh + ‘:‘ + xx + ‘:‘ + ss
        return time
      }
    }

<p class="down-date">{{fmtDate(item.createDate)}}</p>