活动开始时间

  <vac :start-time="new Date().getTime() + 10000" :end-time="new Date().getTime() + 20000">
    <span
      slot="preheat"
      slot-scope="{ startTime }">
        {{ `活动开始时间: ${new Date(startTime)}` }}
      </span>
    <span
      slot="process"
      slot-scope="{ timeObj }">
        {{ `距离开始剩余: ${timeObj.ceil.s}秒` }}
      </span>
      <span slot="finish"><button type="button">活动开始!!!</button></span>
  </vac>