实现效果：

通过计算属性来获取当前时间

  <div class="mounth">
        <div
          class="datatime"
          @click="showTimePopup(userCheckMonth ? userCheckMonth : current_date)"
        >
          <span class="time">{{
            userCheckMonth ? userCheckMonth : current_date
          }}</span>
          <van-icon name="arrow-down" />
        </div>
      </div>

 computed: {
    current_date() {
      var nowDate = new Date();
      let date = {
        year: nowDate.getFullYear(),
        month: nowDate.getMonth() + 1
      };
      // console.log(date);
      let systemDate = date.year + "年" + date.month + "月";
      return systemDate;
    }
  },

另外感觉关于文章写得也挺不错，学习一下
vue 获取当前时间 格式YYYY-MM-DD
Vue实现获取当前时间、日期并实时刷新