element ui datepicker 计算开始时间和结束时间的时间差

getTime(beginTime, endTime) {
      var dateDiff = endTime.getTime() - beginTime.getTime(); //时间差的毫秒数
      var dayDiff = Math.floor(dateDiff / (24 * 3600 * 1000)); //计算出相差天数
      var leave1 = dateDiff % (24 * 3600 * 1000); //计算天数后剩余的毫秒数
      var hours = Math.floor(leave1 / (3600 * 1000)); //计算出小时数
      //计算相差分钟数
      var leave2 = leave1 % (3600 * 1000); //计算小时数后剩余的毫秒数
      var minutes = Math.floor(leave2 / (60 * 1000)); //计算相差分钟数
      //计算相差秒数
      var leave3 = leave2 % (60 * 1000); //计算分钟数后剩余的毫秒数
      var seconds = Math.round(leave3 / 1000);
      console.log(
        " 相差 " +
          dayDiff +
          "天 " +
          hours +
          "小时 " +
          minutes +
          " 分钟" +
          seconds +
          " 秒"
      );
      return "相差 " + dayDiff + "天 " + hours + "小时 " + minutes + " 分钟";
    },

开始时间和结束时间时间差

<div class="des-status-df">开始</div>
              <div class="block">
                <el-date-picker
                 
                  v-model="startTime"
                  type="datetime"
                  placeholder="选择日期时间"
                  @change="jsTime"
                >
                </el-date-picker>
              </div>
              <div class="des-status-df">结束</div>
              <div class="block">
                <el-date-picker
                 
                  v-model="endTime"
                  type="datetime"
                  placeholder="选择日期时间"
                  @change="jsTime"
                >
                </el-date-picker>
              </div>
              <div class="des-time-box">
                <span class="des-time">共计</span>
                <span class="des-time-red">{{duration}}</span>
                <span class="des-time">小时</span>
              </div>

data

duration: "",
startTime: "",
endTime: "",