code: function endOf (unit = 'DD') {
    switch (unit) {
      case 'mm':
        return Miment(this.format('YYYY-MM-DD hh:mm:59'))
      case 'hh':
        return Miment(this.format('YYYY-MM-DD hh:59:59'))
      case 'DD':
        return Miment(this.format('YYYY-MM-DD 23:59:59'))
      case 'ww':
      case 'WW':
        return Miment(this.firstDayOfWeek().add(6, 'DD').format('YYYY-MM-DD 23:59:59'))
      case 'MM':
        return Miment(this.lastDay().format('YYYY-MM-DD 23:59:59'))
      case 'YY':
      case 'YYYY':
        return Miment(this.set(12, 'MM').lastDay().format('YYYY-MM-DD 23:59:59'))
    }
  }
docs: 获取结束时间