1. To convert UTC to local time zone

- (NSString *)convertLocalDateFromUTCDate:(NSString *)dateStr{
    NSDateFormatter *formatter = [self dateFormatter];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss Z"];
    NSDate *sourceDate = [formatter dateFromString:dateStr];
    NSDateFormatter* dateFormat = [self dateFormatter];
    [dateFormat setDateFormat:@"MMM dd @hh:mm aa"];
    NSString* localTime = [dateFormat stringFromDate:sourceDate];
    return [NSString stringWithFormat:@"%@",localTime];
}

- (NSDateFormatter *)dateFormatter
{
    static NSDateFormatter *formatter;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        formatter = [NSDateFormatter new];
    });
    return formatter;
}

2. To convert local time zone to UTC

-(NSString *)convertUTCDateFromLocalDate:(NSString *)utcDateStr
{
    NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"MMM dd @hh:mm aa"];
    NSTimeZone *utc = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
    [formatter setTimeZone:utc];
    [formatter setDateFormat:@"MMM dd @hh:mm aa"];
    NSDate *localDate = [formatter dateFromString:utcDateStr]; // get the date
    NSTimeInterval timeZoneOffset = [[NSTimeZone defaultTimeZone] secondsFromGMT]; // You could also use the systemTimeZone method
    NSTimeInterval utcTimeInterval = [localDate timeIntervalSinceReferenceDate] - timeZoneOffset;
    NSDate *utcCurrentDate = [NSDate dateWithTimeIntervalSinceReferenceDate:utcTimeInterval];
    return [formatter stringFromDate:utcCurrentDate];
}