NSCalendar日期错误

Question

我想用 NSCalendar 与 NSIslamicCalendar identifier.但当天的结果并不好，这是我的代码。

NSCalendar *calandar = [[NSCalendar alloc]initWithCalendarIdentifier:NSIslamicCalendar];    
NSDateComponents *components = [calandar components:(NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit) fromDate:[NSDate date]];
NSInteger theDay = [components day];
NSInteger theMonth = [components month];
NSInteger theYear = [components year];


[components setDay:theDay];
[components setMonth:theMonth];
[components setYear:theYear];
NSDate *thisDate = [calandar dateFromComponents:components];    
NSLog(@"year=%i month=%i day=%i",theYear,theMonth,theDay);
NSLog(@"thisdate = %@", [thisDate description]);


NSString *strDate = [NSString stringWithFormat:@"%i-%i-%i",theYear,theMonth,theDay];
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setDateFormat:@"yyyy-MM-dd"];
NSDate *datee = [formatter dateFromString:strDate];
NSLog(@"datee = %@", [datee description]);

logs:

year=1434 month=2 day=28              ----> all good (it's islamic calandar)
thisdate = 2013-01-09 23:00:00 +0000  ----> not good (we are in 2013-01-10 not 09).
datee = 1434-02-27 23:19:16 +0000     ----> not good (we are in 1434-02-28 not 27)

正如你所看到的，第一个日期是正确的，而其他两个日期不正确，而且时间也不正确（当我编译的时候是14:20左右），最后两个日志之间也不一样（23:00:00 vs 23:19:16）。

这段代码在我的viewDidload:函数中，前后没有其他代码运行。

另外，如果我想得到一个月的天数，我得到的是多一天。

NSCalendar *c = [[NSCalendar alloc]initWithCalendarIdentifier:NSIslamicCalendar];
NSRange dayRange = [c rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:date];
NSLog(@"dayRange.length = %i",dayRange.length);

log:

dayRange.length = 30 -----> but this islamic month have 29 day not 30.

什么是问题，我如何解决它？ 谢谢。

编辑：我想说的是，如果我想获得一个月的天数，我得到的是多一天：日志：有什么问题，如何解决？

它似乎是相同的 NSGregorianCalendar 在一个不同的是，天数是正确的.日志使用。NSGregorianCalendar

 year=2013 month=1 day=10                -----> all good
 thisdate = 2013-01-09 23:00:00 +0000    -----> not good
 datee = 2013-01-09 23:00:00 +0000       -----> not good

 dayRange.length = 31 ------------------------> all good

Answer 1

datee = 1434-02-27 23:19:16 +0000 也许这是伊斯兰教历法的特长，因为在伊斯兰教中，祈祷的时间与日出等式有关，它可以尝试在某一点上表达太阳时间.即在沙特阿拉伯，由于宗教原因，太阳时间是唯一有效的时间.他们拒绝给同一土地一次。如果太阳是在最高点，它是12:00.由于这在相距几百公里的城市差异很大，沙特阿拉伯的城市有不同的时间。

请注意，虽然在任何其他伊斯兰国家都使用正常的时区，但这种实现是有意义的，因为伊斯兰日历最有效的使用案例可能是宗教事件的计算--如果我使用太阳时间，就会变得更加容易。

---

有了这个代码

    NSCalendar *islamicCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSIslamicCalendar];

     NSDate *today = [NSDate date];
    [islamicCalendar rangeOfUnit:NSDayCalendarUnit startDate:&today interval:NULL forDate:today];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setCalendar:islamicCalendar];
    [dateFormatter setTimeStyle:NSDateFormatterFullStyle];
    [dateFormatter setDateStyle:NSDateFormatterFullStyle];

    //english output 
    dateFormatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];

    NSString * islamicDateString = [dateFormatter stringFromDate:today];
    NSLog(@"%@", islamicDateString);

其结果

2013-01-11 01:13:46.110 islamicCalendarTest[18346:303] Friday, Safar 29, 1434 12:00:00 AM Central European Standard Time

NSDateFormatter会考虑到您的默认时区。

Answer 2

time is not correct (when i compile it's about 14:20) and it differs between the last 2 last log (23:00:00 vs 23:19:16).

这是因为格林威治标准时间和你的本地区域之间的时区差异。

Answer 3

// Create a Gregorian Calendar
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

// Set up components of a Gregorian date
NSDateComponents *gregorianComponents = [[NSCalendar currentCalendar] components:NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit fromDate:[NSDate date]];

NSLog(@"[In Gregorian calendar ->] Day: %ld, Month: %ld, Year:%ld",
      (long)[gregorianComponents day],
      (long)[gregorianComponents month],
      (long)[gregorianComponents year]);


gregorianComponents.day = [gregorianComponents day];
gregorianComponents.month = [gregorianComponents month];
gregorianComponents.year = [gregorianComponents year];

// Create the date
NSDate *date = [gregorianCalendar dateFromComponents:gregorianComponents];



// Then create an Islamic calendar
NSCalendar *hijriCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSIslamicCivilCalendar];

// And grab those date components for the same date
NSDateComponents *hijriComponents = [hijriCalendar components:(NSDayCalendarUnit |
                                                               NSMonthCalendarUnit |
                                                               NSYearCalendarUnit)
                                                     fromDate:date];


NSLog(@"[In Hijri calendar ->] Day: %ld, Month: %ld, Year:%ld",
      (long)[hijriComponents day],
      (long)[hijriComponents month],
      (long)[hijriComponents year]);

Answer 4

这里所有的答案都是好办法，但只是从科学的角度出发。但事实上，作为一个生活在土耳其的开发者，知道这个问题源于什么，苹果有不止一个伊斯兰教日历标识符。

- NSCalendarIdentifierIslamic
- NSCalendarIdentifierIslamicCivil
- NSCalendarIdentifierIslamicTabular
- NSCalendarIdentifierIslamicCivilUmmAlQura

我想他要找的是 NSCalendarIdentifierIslamicCivil. 我的应用程序也有一个 Hijri 日历在里面，并。NSCalendarIdentifierIslamicCivil 了却一桩心事