# File lib/action_view/helpers/date_helper.rb, line 399
      def select_hour(datetime, 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) ?
              %(<option value="#{leading_zero_on_single_digits(hour)}" selected="selected">#{leading_zero_on_single_digits(hour)}</option>\n) :
              %(<option value="#{leading_zero_on_single_digits(hour)}">#{leading_zero_on_single_digits(hour)}</option>\n)
            )
          end
          select_html(options[:field_name] || 'hour', hour_options, options)
        end
      end