title: Drupal 7 date popup default value is blank
body: <p>I am trying to get a default value in for the default value of a date_popup that exists within a fieldset and I have followed the other suggestions here but the value is always blank.</p>
  
  <pre><code>$format = 'm/d/Y';
  $primary_start1 = null;
  if(isset($vals["primary_start"])){
      if("-1" != $vals["primary_start"]){
          $primary_start1 = (int)$vals["primary_start"];
  
      }
  }
  
   $form['dates']['primary']['primary_start'] = array(
      '#title' =&gt; t('Start date'),
      '#name' =&gt; 'primary_start',
      '#type' =&gt; 'date_popup',
      '#date_timezone' =&gt; FALSE,
      '#default_value' =&gt; date('m/d/Y',$primary_start1),
      '#date_format' =&gt; $format,
      '#required' =&gt; TRUE,
      '#date_label_position' =&gt; 'none',
  
  
  );
  </code></pre>
  
  <p>The date comes in as a string, so I convert it to an int...which I know works because I dump the variable.</p>
  
  <p>Am I doing anything wrong here?</p>
  
  <p>Drupal v 7.22</p>
  
  <p>Date Module - 7.x-2.6</p>
  
  <p>Date Popup - 7.x-2.6</p>