convert utc to local

date.m

    NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
    NSTimeZone* destinationTimeZone = [NSTimeZone localTimeZone];
    
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:formatter];
    [dateFormatter setTimeZone:sourceTimeZone];
    
    
    NSDate *rawDate = [dateFormatter dateFromString:dateTime];
    
    NSDateFormatter *localFormatter = [[NSDateFormatter alloc] init];
    
    [localFormatter setTimeZone:destinationTimeZone];

    [localFormatter setDateStyle:NSDateFormatterMediumStyle];
    [localFormatter setTimeStyle:NSDateFormatterShortStyle];
    
    return [localFormatter stringFromDate:rawDate];