# File lib/action_view/helpers/date_helper.rb, line 415
      def select_hour(datetime, options = {}, html_options = {})
        val = datetime ? (datetime.kind_of?(Fixnum) ? datetime : datetime.hour) : ''
        if options[:use_hidden]
          hidden_html(options[:field_name] || 'hour', val, options)
        else
          hour_options = []
          0.upto(23) do |hour|
            hour_options << ((val == hour) ?
              content_tag(:option, leading_zero_on_single_digits(hour), :value => leading_zero_on_single_digits(hour), :selected => "selected") :
              content_tag(:option, leading_zero_on_single_digits(hour), :value => leading_zero_on_single_digits(hour))
            )
            hour_options << "\n"
          end
          select_html(options[:field_name] || 'hour', hour_options.join, options, html_options)
        end
      end