GMT and Localtime in ObjectiveC

  NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
  dateFormatter.dateFormat = @"yyyy-MM-dd HH:mm:ss zzz, zzzz";

  NSTimeZone *gmt = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
  [dateFormatter setTimeZone:gmt];
  NSString *gmtTimeStamp = [dateFormatter stringFromDate:[NSDate date]];
  NSLog(@"GMT Time : %@", gmtTimeStamp);

 
 
  NSTimeZone *localTimeZone = [NSTimeZone localTimeZone];
  //NSTimeZone *localTimeZone = [NSTimeZone systemTimeZone];
  //NSTimeZone *localTimeZone = [NSTimeZone defaultTimeZone];

  [dateFormatter setTimeZone:localTimeZone];
  NSString *localTimeStamp = [dateFormatter stringFromDate:[NSDate date]];
  NSLog(@"Local Time : %@", localTimeStamp);