object expansion

object_expansion.rb

module YMD
  def year
    self.split("-")[0]
  end
  def month
    self.split("-")[1]
  end
  def day
    self.split("-")[2]
  end
end

date = "2010-12-17"

class << date
  include YMD
end
# or "date.extend YMD" can be replaced with above

p date.year #=> "2010"
p date.month #=> "12"
p date.day #=> "17"