title: Converting NSDate to String gets empty object
body: <p>In the app, there is a screen in which I use a <code>Date Picker</code> in mode <code>Date</code> to get the date input.</p>
  
  <p>Then this screen will pass the date input in <code>NSDate</code> type to the previous screen to display as <code>textFiled</code> after a conversion to string.</p>
  
  <pre><code>func dateDetector(aDate: UIDatePicker) {
  
      let dateFormat = NSDateFormatter()
  
      dateFormat.dateStyle = NSDateFormatterStyle.MediumStyle
      dateFormat.timeStyle = NSDateFormatterStyle.NoStyle
  
      dueDate = aDate.date
  </code></pre>