calculate the exact age

gistfile1.rb

def age(birthday)
  y = Date.today.year - birthday.year
  m = Date.today.month - birthday.month
  d = Date.today.day - birthday.day
  case
  when m < 0
    age = y-1
  when m = 0
    case
    when d = 0
      age = y
    end
  when m > 0
    age = y
  end
  age
end