class Chronic::RepeaterMonthName

def next(pointer)
  super
  unless @current_month_begin
    case pointer
    when :future
      if @now.month < index
        @current_month_begin = Chronic.construct(@now.year, index)
      elsif @now.month > index
        @current_month_begin = Chronic.construct(@now.year + 1, index)
      end
    when :none
      if @now.month <= index
        @current_month_begin = Chronic.construct(@now.year, index)
      elsif @now.month > index
        @current_month_begin = Chronic.construct(@now.year + 1, index)
      end
    when :past
      if @now.month >= index
        @current_month_begin = Chronic.construct(@now.year, index)
      elsif @now.month < index
        @current_month_begin = Chronic.construct(@now.year - 1, index)
      end
    end
    @current_month_begin || raise("Current month should be set by now")
  else
    case pointer
    when :future
      @current_month_begin = Chronic.construct(@current_month_begin.year + 1, @current_month_begin.month)
    when :past
      @current_month_begin = Chronic.construct(@current_month_begin.year - 1, @current_month_begin.month)
    end
  end
  cur_month_year = @current_month_begin.year
  cur_month_month = @current_month_begin.month
  if cur_month_month == 12
    next_month_year = cur_month_year + 1
    next_month_month = 1
  else
    next_month_year = cur_month_year
    next_month_month = cur_month_month + 1
  end
  Span.new(@current_month_begin, Chronic.construct(next_month_year, next_month_month))
end