gistfile1.rb

module EventsHelper

  def previous_month(month)
    if month == 1
      12
    else
      month - 1
    end
  end
  def previous_year(month, year)
    if month == 1
      year - 1
    else
      year
    end
  end
  def next_month(month)
    if month == 12
      1
    else
      month + 1
    end
  end
  def next_year(month, year)
    if month == 12
      year + 1
    else
      year
    end
  end

end