成对 (Java)：Hijri 到 Gregorian 转换 inasikarat？

Question

我目前正在实现一个日历转换器，给定回历输入日期和时间，使用 JodaTime 库输出相应的公历日期和时间。但是，对应的公历时间并不准确。无论我在同一天输入什么回历时间，得到的公历日期都是一样的。这似乎很奇怪，考虑到每个回历日跨越两个公历日，从日落到日落，如本回答 (https://islam.stackexchange.com/questions/71850/can-a-day-in-the-gregorian-calendar-correspond-to-two-different-days-in-the-isla) 中所述。

例如，下面是从回历日期时间（当前日期，可以指定一天中的不同时间）转换为相应的公历日期时间的代码：

Chronology iso = ISOChronology.getInstanceUTC();
Chronology hijri = IslamicChronology.getInstanceUTC();

DateTime currentDate = DateTime.now();
int year = currentDate.getYear();
int month = currentDate.getMonthOfYear();
int day = currentDate.getDayOfMonth();

int customHr = 23;
int customMin = 59;
int customSec = 59;

DateTime todayIso = new DateTime(year, month, day, customHr, customMin, customSec, 0, iso);
LocalDateTime todayHijri = new LocalDateTime(todayIso, hijri);
System.out.println(todayHijri.toString());

结果如下：

Hijri DateTime Input: 8/24/2021 at final second (23:59)
Gregorian DateTime Output: 1443-01-15T23:59:59.000

Hijri DateTime Input: 8/24/2021 at first second (0:01)
Gregorian DateTime Output: 1443-01-15T00:00:01.000

但是，当我运行这段从公历日期时间转换为回历日期时间的代码时：

Chronology hijri = IslamicChronology.getInstanceUTC();

int customHour = 0;
int customMin = 0;
int customSec = 1;

DateTime todayIso = new DateTime(2021, 8, 24, customHour, customMin, customSec);
LocalDateTime todayHijri = new LocalDateTime(todayIso, hijri);
System.out.println(todayHijri);

这些是我使用公历到回历转换的输出作为输入得到的结果。如您所见，在回历到公历的转换中，输出的回历日期时间与输入的回历日期时间不同，这意味着有问题。

Gregorian DateTime Input: 8-24-2021 at 0:01
Hijri DateTime Output: 1443-01-15T07:00:01.000

Gregorian DateTime Input: 8-24-2021 at 23:59:59
Hijri DateTime Output: 1443-01-16T06:59:59.000

Answer 1

发件人：http://joda-time.sourceforge.net/cal_islamic.html

A day in the Islamic calendar begins at sunset on the previous 'day'. Joda-Time does not model this, thus times and date rollover follow standard ISO definitions, in other words starting at midnight

如Joda-Time is in maintenance,

有关选项，请参阅：。

成对 (Java)：Hijri 到 Gregorian 转换 inasikarat？

JodaTime (Java): Hijri to Gregorian conversion inaccurate?

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