element-ui date-picker 开始时间小于结束时

<div class="input-box f-left birthday-picker-box">

            <span>生日</span>

            <el-date-picker

                    v-model="birthdayStart"

                    name="birthdayStart"

                    format="MM-dd"

                    value-format="timestamp"

                    type="date"

                    placeholder=""

                    :editable="inputEditable"

                    :picker-options="pickerBirthdayBefore"

            >

            </el-date-picker>

            <div class="line f-left">-</div>

        </div>

data() {

      return {

        pickerBirthdayBefore: { 

          //disabledDate通常是一个函数，

          disabledDate: time => { // time.getTime() >= beginDateVal false 可用，true 不可用

            let beginDateVal = this.birthdayEnd;

            if (beginDateVal) {

              return time.getTime() >= beginDateVal;  //开始时间小于结束时间

               return time.getTime() <= beginDateVal || time.getTime() > Date.now(); //结束时间大于开始时间且小于当前时间

                return time.getTime() >= Date.now()-8.64e7 //今天及以后的日期都不能选

            }

          }

        },