Estoy tratando de saber la diferencia entre dos fechas (incluidos días, horas, minutos y segundos). Para eso estoy usando el siguiente código, pero no está funcionando.

+ (void)UpdateTableViewCellWithNSTimer:(NSString *)gameTime :(UIView *)inputView{        
    NSDate *now = [NSDate date];
    NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init];
    [outputFormatter setLocale:[NSLocale systemLocale]];
    [outputFormatter setAMSymbol:@"AM"];
    [outputFormatter setPMSymbol:@"PM"];
    [outputFormatter setTimeZone:[NSTimeZone localTimeZone]];
    [outputFormatter setDateFormat:@"mm/dd/yyyy hh:mm a"];
    NSDate *gameDate = [outputFormatter dateFromString:gameTime];
    NSCalendar *gregorian = [[NSCalendar alloc]                             initWithCalendarIdentifier:NSGregorianCalendar];
    NSUInteger unitFlags = NSMonthCalendarUnit | NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit|NSSecondCalendarUnit;
    NSDateComponents *components = [gregorian components:unitFlags                                                fromDate:gameDate toDate:now options:0];
    NSInteger days = [components day];
    NSInteger hours = [components hour];
    NSInteger seconds = [components second];
    NSInteger minutes = [components minute];

    UITableView *dynamicTable = (UITableView *)[inputView viewWithTag:55];
    NSIndexPath *cellIndexPath = [NSIndexPath indexPathForRow:4 inSection:0];
    UITableViewCell *currentCell = [dynamicTable cellForRowAtIndexPath:cellIndexPath];
    NSString *challengeStartsIn=[NSString stringWithFormat:@"%01ddays:%02dhrs:%02dmins:%02dsec",abs(days),abs(hours), abs(minutes), abs(seconds)];
    NSString *Mystring =[NSString stringWithFormat:@"%@        %@", @"ChallengeStartsIn", challengeStartsIn];
    currentCell.textLabel.text = Mystring;
}
**Game and now dates on logs are:**

2013-05-18 11:36:42.609 FPPresent[2213:5203] gametime value=05/19/2013 5:30 AM
2013-05-18 11:36:42.610 FPPresent[2213:5203] now=2013-05-18 06:06:42 +0000

Después de usar outputformatter:

 gametime value =2013-01-19 00:00:00 +0000(It should be 2013-01-19 05:30:00 +0000 )
 now=2013-05-18 06:10:07 +0000(should be : 2013-05-18 11:40:07 +0000)

La fecha del juego y la fecha actual deben estar en localTimeZone. Pero, incluso trato de configurar

[outputFormatter setTimeZone:[NSTimeZone localTimeZone]];

Mi formato de datos se muestra (Exactamente 5.30 horas diferentes, nuestra zona horaria local es GMT + 5.30)

Por favor, hágamelo saber a dónde me voy mal