maria_sapatao.rb

class Time
  def day_light?
    (6..18).include? self.hour
  end
end

class Maria
  def greet
    p "Bom dia"
  end
end

class Joao
  def greet
    p "E aê mano?"
  end
end

class MariaSapatao < Time.now.day_light? ? Maria : Joao
  
end

MariaSapatao.new.greet