Swift timezones with winter/summer times - swift

Question

I am working on a world clock, and i have gotten the times for various countries as so:
let date = NSDate();
var beltz = NSDateFormatter();
beltz.dateFormat = "HH:mm";
beltz.timeZone = NSTimeZone(name: "Europe/Brussels")
let belTzStr = beltz.stringFromDate(date);
println(belTzStr) //<-- correct time
My question is when summer/winter times adjust +- 1 hour, will this adjustment be reflected in the code by NSTimeZone? If not, how do i achieve this?

Answer 1

Consider this modified code:
let cal = NSCalendar.currentCalendar()
cal.timeZone = NSTimeZone(name: "America/Phoenix")!
let date = cal.dateWithEra(1, year: 2015, month: 12, day: 24, hour: 16, minute: 0, second: 0, nanosecond: 0)!
//date = NSDate();
var beltz = NSDateFormatter();
beltz.dateFormat = "dd MMMM HH:mm zzzz";
beltz.timeZone = NSTimeZone(name: "Europe/Brussels")
let belTzStr = beltz.stringFromDate(date);
print(belTzStr) //<-- correct time
I modified your code to add time as Phoenix AZ, which does not use summer time and added some extra formatting, especially the TZ to the printed data.
Now, if you use December (no DST in either region)
let date = cal.dateWithEra(1, year: 2015, month: 12, day: 24, hour: 16, minute: 0, second: 0, nanosecond: 0)!,
you get
25 December 00:00 Central European Standard Time
and if you use July (DST in EU)
let date = cal.dateWithEra(1, year: 2015, month: 7, day: 24, hour: 16, minute: 0, second: 0, nanosecond: 0)!,
you get
25 July 01:00 Central European Summer Time
So yes, it adjusts the TZ appropriately.