index.wxml

<view class="van-calendar__header">
  <block wx:if="{{ showTitle }}">
    <view class="van-calendar__header-title"><slot name="title"></slot></view>
    <view class="van-calendar__header-title">{{ title }}</view>
  </block>

  <view wx:if="{{ showSubtitle }}" class="van-calendar__header-subtitle">
    {{ subtitle }}
  </view>

  <view class="van-calendar__weekdays">
    <view wx:for="{{ weekdays }}" wx:key="index" class="van-calendar__weekday">
      {{ item }}
    </view>
  </view>
</view>