element组件el-date-picker禁用当前时分秒之前的日期时间选择

<el-date-picker
       v-model="expireDate"
       type="datetime"
       @change="handle"                  
       format='yyyy-MM-dd HH:mm:ss'
       value-format='yyyy-MM-dd HH:mm:ss'
       :picker-options="pickerOptions"
      placeholder="选择日期"
/>

data(){
return {
   pickerOptions: {
         disabledDate(time) {
          const date = new Date();
          const oneday = date.getTime();
          return time.getTime() < new Date().getTime() - 86400000;
        },
        selectableRange: (() => {
          let data = new Date();
          let hour = data.getHours();
          let minute = data.getMinutes();
          let second = data.getSeconds();
          return [`${hour}:${minute}:${second} - 23:59:59`]
        })(),
	}

}

<el-form-item label="开始日期"
              prop="startDate">
  <el-date-picker v-model="sizeForm.startDate"
                  :clearable='false'
                  type="datetime"
                  @change='changeStartTime'
                  placeholder="开始日期"
                  align="right">
  </el-date-picker>
</el-form-item>
<el-form-item label="结束日期"
              prop="endDate">
  <el-date-picker v-model="sizeForm.endDate"
                  :clearable='false'
                  type="datetime"
                  @change='changeEndTime'
                  placeholder="结束日期"
                  align="right">
  </el-date-picker>
</el-form-item>

data() {
	return {
		sizeForm: {
	        startTime: null,
	        endTime: null,
      	},
      	// 开始和结束日期转换的时间戳
      	startTime: null,	
      	endTime: null,
	}
}

methods：{
	//选择日期后触发change方法，将开始和结束时间转为时间戳进行对比，不符合约束条件就清空该日期重新选择
	changeStartTime(val) {
      let date = new Date(val).getTime();
      this.startTime = date;
      if (this.endTime) {
        if (this.endTime < this.startTime) {
          this.$message.success('开始时间不能大于结束时间');
          this.sizeForm.startDate = '';
          this.startTime = null;
        }
      }
    },
    changeEndTime(val) {
      let date = new Date(val).getTime();
      this.endTime = date;
      if (this.startTime) {
        if (this.endTime < this.startTime) {
          this.$message.success('结束时间不能小开始时间');
          this.sizeForm.endDate = '';
          this.endTime = null;
        }
      }
    },
}