gistfile1.rb

module TimeAttributeExtensions
  module ClassMethods

    def define_attribute_methods
      if super
        columns_hash.each do |name, column|
          if [:datetime, :timestamp].include?(column.type)
            define_method("#{name}=") do |time|
              super parse_time_from_hash(time)
            end
          end
        end

        return true
      end
    end
  end
  
  module InstanceMethods
    def parse_time_from_hash(time)
      # Do time parsing here
    end
  end

  def self.included(receiver)
    receiver.send(:include, InstanceMethods)
    receiver.extend ClassMethods
  end
end