attributes_before_type_cast

class Task < ActiveRecord::Base
end

task = Task.new(title: nil, is_done: true, completed_on: '2012-10-21')
task.attributes
# => {"id"=>nil, "title"=>nil, "is_done"=>true, "completed_on"=>Sun, 21 Oct 2012, "created_at"=>nil, "updated_at"=>nil}
task.attributes_before_type_cast
# => {"id"=>nil, "title"=>nil, "is_done"=>true, "completed_on"=>"2012-10-21", "created_at"=>nil, "updated_at"=>nil}