According to the docs, CFTimeZone (and by extension, NSTimeZone) uses time zone names, abbreviations, GMT offset, and DST information from the TZ (or “Olsen”) Database. Looking at the source, you’ll see that while semantically “GMT” and “UTC” are quite distinct, in practice they’re no different: “GMT” is just a zero offset timezone. Update: While this … Read more
I figured it out, its pretty easy. I just added this code to viewDidLoad : NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; [formatter setLocale:[NSLocale currentLocale]]; [formatter setDateStyle:NSDateFormatterNoStyle]; [formatter setTimeStyle:NSDateFormatterShortStyle]; NSString *dateString = [formatter stringFromDate:[NSDate date]]; NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]]; NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]]; BOOL is24h = (amRange.location == NSNotFound && pmRange.location == … Read more
The language in the docs is a bit on the dry side, to be sure, and the similarity of the names is potentially confusing. I’ll quote the NSTimeZone docs here and try to explain them: systemTimeZone The time zone currently used by the system. If the current time zone cannot be determined, returns the GMT … Read more
I found solution. NSLog(@”%@”, [NSTimeZone knownTimeZoneNames]);
edit/update: Xcode 8 or later • Swift 3 or later var secondsFromGMT: Int { return TimeZone.current.secondsFromGMT() } secondsFromGMT // -7200 if you need the abbreviation: var localTimeZoneAbbreviation: String { return TimeZone.current.abbreviation() ?? “” } localTimeZoneAbbreviation // “GMT-2” if you need the timezone identifier: var localTimeZoneIdentifier: String { return TimeZone.current.identifier } localTimeZoneIdentifier // “America/Sao_Paulo” To know … Read more