title: Swift Data convert to UInt64
body: <p>I read some Apple docs but I can't do the thing in object. I'm receiving through bluetooth a unix timestamp value in a variable of type Data and I wan't to convert it to an UInt64 var to populate an UIDatePicker but the function I implemented gives me the error :
  "Fatal error: UnsafeRawBufferPointer.load out of bounds"</p>
  
  <p>Do you have any suggestion? I'm using Swift 5.1</p>
  
  <p>This is my code:</p>
  
  <pre><code>import UIKit
  
  class ViewController: UIViewController {
  
      @IBOutlet weak var datePicker: UIDatePicker!
  
      private func setDate(value: Data) {
          let date = Date(timeIntervalSince1970: TimeInterval(value.uint64))
          datePicker.setDate(date, animated: true)
      }
  }
  </code></pre>
  
  <hr>
  
  <pre><code>extension Data {
      var uint64: UInt64 {
          withUnsafeBytes { $0.load(as: UInt64.self) }
      }
  }
  </code></pre>