获取当前日期或者某个日期相隔N天内的全部日期以及星期几

业务需要需要获取当前日期相隔30天内的全部日期以及星期几，没插件因此特地写了一个：

/*
  说明：获取当前日期或者某个日期相隔N天内的全部日期以及星期几
  使用：
    let test = new getdiffdate(2, '2019-08-08')
    console.log(test.getdiffdate());
*/
class Getdiffdate {
  /**
   * @param {Number} n       //必传，相隔多少天
   * @param {String} stime   //可选，开始日期，如2019-08-08，不传则为当前时间
   */
  constructor(n, stime) {
    this.n = n
    this.stime = stime
  }
  getdiffdate () {
    let weekArray = ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"]
    let i = 0         //数组key值
    let diffdate = [] //存放时间数组
    let week = ''     //当前星期几
    // 开始时间
    let stime_date = this.stime ? new Date(this.stime) : new Date()
    let stime_stamp = stime_date.getTime()
    week = weekArray[stime_date.getDay()]
    // 结束时间
    let etime_date = new Date(stime_date)
    etime_date.setDate(stime_date.getDate() + this.n)
    let etime_stamp = new Date(etime_date).getTime()
    //未设置开始时间，格式化当前时间
    if (!this.stime) {
      this.stime = this._getdate(stime_date)
    }
    //开始日期小于等于结束日期,并循环
    while (stime_stamp <= etime_stamp) {
      let day_obj = { date: this.stime, week: week }
      diffdate[i] = day_obj;
      //增加一天时间戳后的日期
      let next_date = stime_stamp + (24 * 60 * 60 * 1000);
      let next_date_obj = new Date(next_date)
      this.stime = this._getdate(next_date_obj)
      week = weekArray[next_date_obj.getDay()]
      i++;
      stime_stamp = next_date
    }
    return diffdate
  }
  // 格式化时间
  _getdate (date) {
    let etime_date_y = date.getFullYear() + '-';
    let etime_date_m = (date.getMonth() + 1 < 10) ? '0' + (date.getMonth() + 1) + '-' : (date.getMonth() + 1) + '-';
    let etime_date_d = (date.getDate() < 10) ? '0' + date.getDate() : date.getDate();
    let fomatterdate = etime_date_y + etime_date_m + etime_date_d
    return fomatterdate
  }
}

export default Getdiffdate