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++ // Copyright (C) 2024 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #ifndef CALENDARBACKEND_H
++ #define CALENDARBACKEND_H
++
++ #include "private/qromancalendar_p.h"
++ #include "qdatetime.h"
++
++ #include <QtCore/private/qcalendarbackend_p.h>
++ //![0]
++ class JulianGregorianCalendar : public QRomanCalendar
++ {
++ public:
++ JulianGregorianCalendar(QDate endJulian, QAnyStringView name);
++ QString name() const override;
++ int daysInMonth(int month, int year = QCalendar::Unspecified) const override;
++ bool isLeapYear(int year) const override;
++ bool dateToJulianDay(int year, int month, int day, qint64 *jd) const override;
++ QCalendar::YearMonthDay julianDayToDate(qint64 jd) const override;
++ private:
++ static inline const QCalendar julian = QCalendar(QCalendar::System::Julian);
++ static inline const QCalendar gregorian = QCalendar(QCalendar::System::Gregorian);
++ QCalendar::YearMonthDay m_julianUntil;
++ QCalendar::YearMonthDay m_gregorianSince;
++ QString m_name;
++ };
++ //![0]
++ #endif // CALENDARBACKEND_H