title: swift NSDateFormatter not working
body: <p>I'm trying to format time as follows:</p>
  
  <pre><code>let formatter = NSDateFormatter()
  formatter.dateFormat = "hh_mm_ss"
  let d = formatter.stringFromDate(NSDate())
  println("formatted text is: \(d)")
  </code></pre>
  
  <p>Suppose that current time is Sep 3, 2014 22:15:30</p>
  
  <ol>
  <li>When I run this script on playground, it prints the time correctly formatted: <code>22_15_30</code>.</li>
  <li>When running this on AppDelegate, it doesn't print the time formatted: <code>22:15:30</code> </li>
  </ol>
  
  <p>I'm using xcode 6 beta 5... Am I missing something? Why stringFromDate doesn't return the correct date formatted?</p>
  
  <p><strong>EDIT</strong>: I'm using xcode 6 beta 6.</p>
  
  <p>Thanks!</p>