select_tag and select_date how to change inline font

rubyonrails-talk
1

I have been trying to change the font size in the select_date but i haven't had any luck

here's what i did:

<%= select_date( Date.today, :prefix => 'prom_date_end', :order => [ :day,:month, :year], :html => {:style => "font-size: xx-small;"}) %>