title: RABL collection date format
body: <p>I Want to return the datetime of the <code>updated_at</code> attribute in another format, but, in a collection.</p>
  
  <p>If it was a single object, I'll do something like</p>
  
  <pre><code>object @person
    attributes :name, :phone
    node(:updated_at){|person|(person.created_on.strftime(%d,%m,%Y)}
  end
  </code></pre>
  
  <p>But, how can I do that in a people collection?</p>
  
  <p>Thanks in advance.</p>