title: How do I resolve this build issue - cannot assign to property: 'date' is a get only property
body: <pre><code>class Event {
  
      var name : String?
      var FullDate : NSDate?
  
      var date: String? {
          let dateFormatter = NSDateFormatter()
          dateFormatter.dateFormat = "EEEE MMM dd"
          return dateFormatter.stringFromDate(FullDate!)
      }
  
      init ()
  }
  
  
  class EventsViewController: UIViewController, UITableViewDelegate , UITableViewDataSource 
  {
      let Event1 = Event()
  
      override func viewDidLoad() {
          super.viewDidLoad()
          Event1.date = "10.01.16" // here is the issue
          Event2.date = "12.11.16"  // "" "" "" ""
      }
  </code></pre>
  
  <p>I dont understand why I can use the FullDate variable from my custom class Event but not the date variable.
  thanks for your help</p>