freeze

# File activesupport/lib/active_support/core_ext/date/freeze.rb, line 19
        def freeze
          self.class.private_instance_methods(false).each do |m|
            if m.to_s =~ /\A__\d+__\Z/
              instance_variable_set(:"@#{m}", [send(m)])
            end
          end

          super
        end