iPhone: NSDate convert GMT to local time

Question

I currently have an API call returning me a date/time in the format: 2010-10-10T07:54:01.878926

Can I assume this is GMT? I also converted this to an NSDate object. Is there a way to use the local iPhone time to recalculate the time?

score 28 · Accepted Answer · answered Oct 10 '10 at 18:09

28

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm";

NSTimeZone *gmt = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
[dateFormatter setTimeZone:gmt];
NSString *timeStamp = [dateFormatter stringFromDate:[NSDate date]];
[dateFormatter release];

answered Oct 10 '10 at 18:09

Iñigo Beitia

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How does this convert GMT to local time? I believe it's doing the opposite and converting local to GMT right? – willhblackburn Jan 20 '15 at 15:08
Good example, but it converting from Local Time to GTM. – Юрий Сталоверов Sep 07 '20 at 07:53

nesimtunc · Answer 2 · 2020-07-09T17:40:28.833

23

This code will convert the GMT time to the device's local time.

NSDate* localDateTime = [NSDate dateWithTimeInterval:[[NSTimeZone systemTimeZone] secondsFromGMT] sinceDate:pubDate];

edited Jul 09 '20 at 17:40

answered Oct 10 '13 at 17:58

nesimtunc

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**Swift** : `let localDate = NSDate(timeInterval: NSTimeInterval(NSTimeZone.systemTimeZone().secondsFromGMT), sinceDate: date)` – Husam Apr 06 '16 at 19:33

score 1 · Answer 3 · answered Jun 18 '11 at 05:11

NSDate *sourceDate = [NSDate dateWithTimeIntervalSince1970:gmtTimestamp];
NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];
NSInteger sourceGMTOffset = [destinationTimeZone secondsFromGMTForDate:0];
NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate];
NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;
NSDate* destinationDate = [[[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate] autorelease];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm";
[dateFormatter setTimeZone:destinationTimeZone];
NSString *localTimeString = [dateFormatter stringFromDate:destinationDate];

score -2 · Answer 4 · edited Jul 25 '12 at 13:24

-2

NSDate *now = [NSDate date];
NSLog(@"%@", [now dateWithCalendarFormat:@"%Y-%m-%d %H:%M:%S" 
              timeZone:[NSTimeZone timeZoneWithName:@"GMT"]]);

edited Jul 25 '12 at 13:24

DisplayName

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answered Jul 25 '12 at 12:41

Minami

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The message `-(NSString *)dateWithCalendarFormat:timezone:` does not exist in Apple's documentation. – Paul Armstrong Jan 18 '13 at 19:09

iPhone: NSDate convert GMT to local time

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