What is the proper format for setting TimeZones in iOS ?

Question

I've tried using this Wiki to get the appropriate abbreviation for time zones to use in:

let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = formatString
        dateFormatter.timeZone = NSTimeZone(abbreviation: setZone)

and "GMT" works as does "GST", but for some reason a good portion of the abbreviations do not work (for example GYT). Is there some other format that I should be using ? I have also tried passing in UTC-X also but that didn't work either

Answer 1

Here is function I call from a NSTimer...

self.clock = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(ViewController.updateClock), userInfo: nil, repeats: true)

func updateClock() {
      dispatch_async(dispatch_get_main_queue()) {
        let date = NSDate();
        // "Apr 1, 2015, 8:53 AM" <-- local without seconds

        var formatter = NSDateFormatter();
        formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

        _ = formatter.stringFromDate(date);
                    // "2015-04-01 08:52:00 -0400" <-- same date, local, but with seconds
        formatter.timeZone = NSTimeZone(abbreviation: "CET");
        let cetTimeZoneStr = formatter.stringFromDate(date);
        // "2015-04-01 12:52:00 +0000" <-- same date, now in UTC

        self.timer.text = cetTimeZoneStr


    }
}

And here some code to get the timezones known to the system!

let blah = NSTimeZone.knownTimeZoneNames()
let blah2 = NSTimeZone.abbreviationDictionary()
print("\(blah) \(blah2)")