title: NSDateComponents in Swift is not returning Weekday
body: <pre><code>import UIKit
  
  let components = NSDateComponents()
  components.setValue(1, forComponent: NSCalendarUnit.CalendarUnitDay)
  components.setValue(1, forComponent: NSCalendarUnit.CalendarUnitMonth)
  components.setValue(2014, forComponent: NSCalendarUnit.CalendarUnitYear)
  
  println(components.weekday) // 9223372036854775807
  </code></pre>
  
  <p>Anyone have any ideas as to why I'm getting <code>9223372036854775807</code> instead of a value from 1-7?</p>