title: NSDateFormatter in 12-hour mode
body: <p>I have the following code.</p>
  
  <pre><code>NSDateFormatter *df = ...;
  [df setTimeZone:[NSTimeZone defaultTimeZone]];
  [df setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSSZZZ"];
  NSDate * date = [df dateFromString:date_string]; //here is the problem
  </code></pre>
  
  <p>In 24-hour mode everything is ok. When 12-hour mode is set on device, stringFromDate returns null.
  Format of date_string is the same all the time, date format too. Why does it happen?</p>