element ui el-date-picker 判断所选时间是否交叉

<el-date-picker
  v-model="aaa"
  type="daterange"
  range-separator="至"
  start-placeholder="开始日期"
  end-placeholder="结束日期"
  @change="e => timeChange(e, doindex)"
/>

// 判断时间是否交叉重复
timeChange(val,index){
  let start = []//开始时间
  let over = []//结束时间
  for(let i = 0; i < this.monthList96.length;i++){
    start.push(moment(this.monthList96[i].timeAry[0]).format('YYYY/MM/DD'))
    over.push(moment(this.monthList96[i].timeAry[1]).format('YYYY/MM/DD'))
  }
  start.sort()
  over.sort()
  console.log(start,over,'开始结束')
  for(let i=1;i<start.length;i++){
    console.log(start[i],over[i-1])
    if (  start[i] <= over[i-1]){
      this.$vMessage({
        type: 'warning',
        message: '所选时间段不能重合'
      })
      this.monthList96[index].timeAry = []
      return
    }
  }
},