title: Swift UTC TimeZone is not UTC
body: <p>I have a question about Swift type TimeZone.
  I need to get a UTC0 time zone to format my Date object. I'm creating TimeZone object like this.</p>
  
  <p><code>let utcTimeZone = TimeZone(abbreviation: "UTC")</code></p>
  
  <p>But when created this object gives me GMT0 time zone. Is this possible to get UTC0 time zone in Swift? Also what is the difference between <code>GMT (fixed)</code> and  <code>GMT (GMT) offset 0</code> in playground?</p>
  
  <p>Xcode 10.3 Playground
  <a href="https://i.stack.imgur.com/0jof2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0jof2.png" alt="enter image description here"></a></p>