title: NSDateFormatter timezone (Etc/GMT) not getting parsed for dateFromString
body: <p>I am getting nil for trying to convert this <code>2011-07-11 13:28:59 Etc/GMT</code> into a NSDate by the following code</p>
  
  <pre><code>NSString *dateString=@"2011-07-11 13:28:59 Etc/GMT";
  NSDateFormatter *dateformatter=[[NSDateFormatter alloc] init];
  [dateformatter setDateFormat:@"yyyy-MM-dd hh:mm:ss z"];
  NSDate *purchaseDate = [dateformatter dateFromString:dateString];
  </code></pre>
  
  <p>This date is coming from apple server itself for in-app purchase validation. I've gone about lot of threads with timezone. but none of them show how to convert this <code>Etc/GMT</code></p>
  
  <p>i have tried <code>z</code> <code>zz</code> <code>zzz</code> <code>zzzz</code> <code>Z</code> <code>ZZ</code> <code>ZZZ</code> <code>ZZZZ</code></p>
  
  <p>what might be the issue here.</p>