计算出一个月内有几个星期

我想要计算出一个月内的星期。我找到在IOS5实现的方法了，但是在IOS6中不知道应该怎么办？

- (int)weeksOfMonth:(int)month inYear:(int)year
{
    NSCalendar *cCalendar = [NSCalendar currentCalendar];

    NSDateComponents *components = [[NSDateComponents alloc] init];
    [components setMonth:month];
    [components setYear:year];

    NSRange range = [cCalendar rangeOfUnit:NSDayCalendarUnit
                               inUnit:NSMonthCalendarUnit
                              forDate:[cCalendar dateFromComponents:components]];

    cCalendar = [NSCalendar currentCalendar];
    [cCalendar setMinimumDaysInFirstWeek:4];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    [dateFormatter setLocale: [[NSLocale alloc] initWithLocaleIdentifier:@"fr"]];
    [dateFormatter setDateFormat:@"yyyy-MM-dd"];
    NSMutableSet *weeks = [[NSMutableSet alloc] init ];

    for(int i = 0; i < range.length; i++)
    {
        NSString *temp = [NSString stringWithFormat:@"%4d-%2d-   %2d",year,month,range.location+i];
        NSDate *date = [dateFormatter dateFromString:temp ];
        int week = [[cCalendar components: NSWeekOfYearCalendarUnit fromDate:date] weekOfYear];
        [weeks addObject:[NSNumber numberWithInt:week]];
    }

    return [weeks count];
}

结果在ios5中返回了5，在ios6中返回了6，这应该怎么解决？