<el-form-item label="时间：">
  <el-date-picker
   v-model="formInline.gpsTime"
   type="datetimerange"
   range-separator="-"
   start-placeholder="开始时间"
   end-placeholder="结束时间"
   :default-time="defaultTime2"
   @change="changeTime"
   />
</el-form-item>



function changeTime(val) {
  if (new Date(val[1]) - new Date(val[0]) > 1 * 24 * 60 * 60 * 1000 * 30) {
    message("选择时间范围不能大于30天", { type: "error" });
    formInline.gpsTime = "";
  }
}