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| |
| #include "qglobal.h" |
| #include "qmilankoviccalendar_p.h" |
| #include "qcalendarmath_p.h" |
| #include <QtCore/qmath.h> |
| #include <QtCore/qlocale.h> |
| #include <QtCore/qdatetime.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| using namespace QRoundingDown; |
| |
| /*! |
| \since 5.14 |
| |
| \class QMilankovicCalendar |
| \inmodule QtCore |
| \brief The QMilankovicCalendar class provides Milanković calendar system |
| implementation. |
| |
| The Revised Julian calendar, also known as the Milanković calendar, or, |
| less formally, new calendar, is a calendar, developed and proposed by the |
| Serbian scientist Milutin Milanković in 1923, which effectively discontinued |
| the 340 years of divergence between the naming of dates sanctioned by those |
| Eastern Orthodox churches adopting it and the Gregorian calendar that has |
| come to predominate worldwide. This calendar was intended to replace the |
| ecclesiastical calendar based on the Julian calendar hitherto in use by all |
| of the Eastern Orthodox Church. The Revised Julian calendar temporarily |
| aligned its dates with the Gregorian calendar proclaimed in 1582 by Pope |
| Gregory XIII for adoption by the Christian world. The calendar has been |
| adopted by the Orthodox churches of Constantinople, Albania, Alexandria, |
| Antioch, Bulgaria, Cyprus, Greece, Poland, and Romania. |
| |
| Source: \l {https://en.wikipedia.org/wiki/Revised_Julian_calendar}{Wikipedia |
| page on Milanković Calendar} |
| */ |
| |
| QMilankovicCalendar::QMilankovicCalendar() |
| : QRomanCalendar(QStringLiteral("Milankovic"), QCalendar::System::Milankovic) {} |
| |
| QString QMilankovicCalendar::name() const |
| { |
| return QStringLiteral("Milankovic"); |
| } |
| |
| QCalendar::System QMilankovicCalendar::calendarSystem() const |
| { |
| return QCalendar::System::Milankovic; |
| } |
| |
| bool QMilankovicCalendar::isLeapYear(int year) const |
| { |
| if (year == QCalendar::Unspecified) |
| return false; |
| if (year <= 0) |
| ++year; |
| if (qMod(year, 4)) |
| return false; |
| if (qMod(year, 100) == 0) { |
| const qint16 century = qMod(qDiv(year, 100), 9); |
| if (century != 2 && century != 6) |
| return false; |
| } |
| return true; |
| } |
| |
| bool QMilankovicCalendar::dateToJulianDay(int year, int month, int day, qint64 *jd) const |
| { |
| Q_ASSERT(jd); |
| if (!isDateValid(year, month, day)) |
| return false; |
| if (year <= 0) |
| ++year; |
| const qint16 c0 = month < 3 ? -1 : 0; |
| const qint16 x1 = month - 12 * c0 - 3; |
| const qint16 x4 = year + c0; |
| const qint16 x3 = qDiv(x4, 100); |
| const qint16 x2 = qMod(x4, 100); |
| *jd = qDiv(328718 * x3 + 6, 9) |
| + qDiv(36525 * x2 , 100) |
| + qDiv(153 * x1 + 2 , 5) |
| + day + 1721119; |
| return true; |
| } |
| |
| QCalendar::YearMonthDay QMilankovicCalendar::julianDayToDate(qint64 jd) const |
| { |
| const qint64 k3 = 9 * (jd - 1721120) + 2; |
| const qint64 x3 = qDiv(k3, 328718); |
| const qint64 k2 = 100 * qDiv(qMod(k3, 328718), 9) + 99; |
| const qint64 k1 = qDiv(qMod(k2, 36525), 100) * 5 + 2; |
| const qint64 x2 = qDiv(k2, 36525); |
| const qint64 x1 = qDiv(5 * qDiv(qMod(k2, 36525), 100) + 2, 153); |
| const qint64 c0 = qDiv(x1 + 2, 12); |
| const int y = 100 * x3 + x2 + c0; |
| const int month = x1 - 12 * c0 + 3; |
| const int day = qDiv(qMod(k1, 153), 5) + 1; |
| return QCalendar::YearMonthDay(y > 0 ? y : y - 1, month, day); |
| } |
| |
| QT_END_NAMESPACE |