app/views/admin/presentations/_date.html.erb
<article id='<%= date.to_s -%>' class='date'>
<header>
<h2><%= link_to_unless_current date.to_time.to_s(:date), month_presentations_path(:month => date.stamp('September-2011')) %></h2>
</header>
<%= render :partial => 'admin/presentations/presentation', :collection => @grouped_presentations[date] %>
</article>