title: Use of unresolved identifier NSSecondCalendarUnit in Swift
body: <p>I try to fetch hours minutes from current date:</p>
  
  <pre><code>var date:NSDate = NSDate()
          var calendar:NSCalendar = NSCalendar.currentCalendar()
          var components:NSDateComponents = calendar.components(unitFlags: NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit, fromDate: date)
          var hour = components.hour
          var minute = components.minute
          var seconds = components.second
  </code></pre>
  
  <p>However it doesn't recognize Calendar Units:</p>
  
  <pre><code>NSHourCalendarUnit, NSMinuteCalendarUnit andNSSecondCalendarUnit 
  </code></pre>
  
  <p>I get error:</p>
  
  <pre><code>use of unresolved identifier NSSecondCalendarUnit ...
  </code></pre>
  
  <p>Do I miss something?</p>