class Chronic::RepeaterMonth

def next(pointer)
  super
  unless @current_month_start
    @current_month_start = offset_by(Chronic.construct(@now.year, @now.month), 1, pointer)
  else
    @current_month_start = offset_by(Chronic.construct(@current_month_start.year, @current_month_start.month), 1, pointer)
  end
  Span.new(@current_month_start, Chronic.construct(@current_month_start.year, @current_month_start.month + 1))
end