如何将时区偏移缩写转换为官方时区标识符？

Question

When I call NSTimeZone's abbreviation method it returns GMT-07:00 . Then, when I use this value to lookup the time zone name or ( time zone identifier ) it returns nil .

I need to retrieve the official time zone identifier , eg, America/Los_Angeles . Therefore, how can I convert a time zone offset abbreviation (eg, GMT-07:00 ) to the official time zone identifier?

Here's my code:

NSTimeZone* localTimeZone = [NSTimeZone localTimeZone];
NSString* localAbbreviation = [localTimeZone abbreviation];
NSDictionary* abbreviationDictionary = [NSTimeZone abbreviationDictionary];
NSString* timeZoneID = 
[abbreviationDictionary objectForKey:localAbbreviation]; //should return 'America/Los_Angeles' if the abbreviation is ‘PDT’

Answer 1

(I rewrote my reply, I misunderstood the question before).

Here's an example on how to convert a timeZone from the abbreviation:

NSTimeZone* localTimeZone = [NSTimeZone localTimeZone];
NSString* localAbbreviation = [localTimeZone abbreviation];

To transform it back from the localAbbreviation, is just a matter to re-create the timeZone:

NSTimeZone* timeZoneFromAbbreviation = [NStimeZone timeZoneWithAbbreviation:abbreviation];
NSString* timeZoneIdentifier = timeZoneAbbreviation.name;

NSLog(@"Identifier: %@", timeZoneIdentifier); // Outputs America/Santiago for me.

Are you sure the abbreviation is returning "GMT-07:00"? Mine returns "CLT", not a GMT offset.

Answer 2

Hope this might be helpful Edit The + should be there to show exactly as normal Abbreviation

   -(NSString*)getTimeZoneStringForAbbriviation:(NSString*)abbr{
        NSTimeZone *atimezone=[NSTimeZone timeZoneWithAbbreviation:abbr];
        int minutes = (atimezone.secondsFromGMT / 60) % 60;
        int hours = atimezone.secondsFromGMT / 3600;
        NSString *aStrOffset=[NSString stringWithFormat:@"%02d:%02d",hours, minutes];
        return [NSString stringWithFormat:@"GMT+%@",aStrOffset];
    }