NSCalendar数据误差
NSCalendar数据误差
提问于 2013-01-10 13:47:24
我正在尝试将NSCalendar与NSIslamicCalendar标识符结合使用。但是今天的结果不是很好，她是我的准则：
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]);日志：
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)正如您所看到的，第一个日期是正确的，而不是其他的日期，而且时间也不正确(当我编译它是14:20时)，并且它在最后两个日志(23:00:00 vs 23:19:16)之间有所不同。
此代码位于我的viewDidload: function中，其他代码在此之前或之后都不会运行。
另外，如果我想要一个月的天数，我还有一天：
NSCalendar *c = [[NSCalendar alloc]initWithCalendarIdentifier:NSIslamicCalendar];
NSRange dayRange = [c rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:date];
NSLog(@"dayRange.length = %i",dayRange.length);日志：
dayRange.length = 30 -----> but this islamic month have 29 day not 30.有什么问题，我怎么解决呢？谢谢。
编辑：
对于NSGregorianCalendar来说，似乎是一样的，有一个不同之处是，天数是正确的。使用NSGregorianCalendar记录日志
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回答 4
Stack Overflow用户
回答已采纳
发布于 2013-01-10 18:21:16
datee = 1434-02-27 23:19:16 +0000，也许这是伊斯兰历法的特色菜？在伊斯兰教中，祈祷的时间与日出方程有关，它可以在某一点上表达太阳的时间。例如，在沙特阿拉伯，由于宗教原因，太阳时间是唯一有效的时间。他们拒绝给同样的土地一次。如果太阳在最高点，那就是12:00。由于这在相距几百公里的城市有很大的不同，沙特阿拉伯的城市有不同的时代。
请注意，尽管在任何其他伊斯兰国家都使用正常时区，但这种实现是有意义的，因为伊斯兰日历最有效的用例可能是计算宗教事件--如果我使用Sun time，就会变得容易得多。
用这个代码
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);其结果是
2013-01-11 01:13:46.110 islamicCalendarTest[18346:303] Friday, Safar 29, 1434 12:00:00 AM Central European Standard TimeNSDateFormatter考虑到您的默认时区。
Stack Overflow用户
发布于 2013-01-10 13:51:11
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).
这是因为格林尼治时间和当地地区之间的时区差异。
Stack Overflow用户
发布于 2013-06-18 06:18:45
// 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]);页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/14259397
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