HebrewCalendar is a subclass of Calendar
+ * that that implements the traditional Hebrew calendar.
+ * This is the civil calendar in Israel and the liturgical calendar
+ * of the Jewish faith worldwide.
+ * + * The Hebrew calendar is lunisolar and thus has a number of interesting + * properties that distinguish it from the Gregorian. Months start + * on the day of (an arithmetic approximation of) each new moon. Since the + * solar year (approximately 365.24 days) is not an even multiple of + * the lunar month (approximately 29.53 days) an extra "leap month" is + * inserted in 7 out of every 19 years. To make matters even more + * interesting, the start of a year can be delayed by up to three days + * in order to prevent certain holidays from falling on the Sabbath and + * to prevent certain illegal year lengths. Finally, the lengths of certain + * months can vary depending on the number of days in the year. + *
+ * The leap month is known as "Adar 1" and is inserted between the + * months of Shevat and Adar in leap years. Since the leap month does + * not come at the end of the year, calculations involving + * month numbers are particularly complex. Users of this class should + * make sure to use the {@link #roll roll} and {@link #add add} methods + * rather than attempting to perform date arithmetic by manipulating + * the fields directly. + *
+ * Note: In the traditional Hebrew calendar, days start at sunset. + * However, in order to keep the time fields in this class + * synchronized with those of the other calendars and with local clock time, + * we treat days and months as beginning at midnight, + * roughly 6 hours after the corresponding sunset. + *
+ * If you are interested in more information on the rules behind the Hebrew + * calendar, see one of the following references: + *
+ * @see com.ibm.icu.util.GregorianCalendar + * + * @author Laura Werner + * @author Alan Liu + * @author Steven R. Loomis + *
+ * @internal + */ +class U_I18N_API HebrewCalendar : public Calendar { +public: + /** + * Useful constants for HebrewCalendar. + * @internal + */ + enum EEras { + /** + * Constant for Tishri, the 1st month of the Hebrew year. + */ + TISHRI, + /** + * Constant for Heshvan, the 2nd month of the Hebrew year. + */ + HESHVAN, + /** + * Constant for Kislev, the 3rd month of the Hebrew year. + */ + KISLEV, + + /** + * Constant for Tevet, the 4th month of the Hebrew year. + */ + TEVET, + + /** + * Constant for Shevat, the 5th month of the Hebrew year. + */ + SHEVAT, + + /** + * Constant for Adar I, the 6th month of the Hebrew year + * (present in leap years only). In non-leap years, the calendar + * jumps from Shevat (5th month) to Adar (7th month). + */ + ADAR_1, + + /** + * Constant for the Adar, the 7th month of the Hebrew year. + */ + ADAR, + + /** + * Constant for Nisan, the 8th month of the Hebrew year. + */ + NISAN, + + /** + * Constant for Iyar, the 9th month of the Hebrew year. + */ + IYAR, + + /** + * Constant for Sivan, the 10th month of the Hebrew year. + */ + SIVAN, + + /** + * Constant for Tammuz, the 11th month of the Hebrew year. + */ + TAMUZ, + + /** + * Constant for Av, the 12th month of the Hebrew year. + */ + AV, + + /** + * Constant for Elul, the 13th month of the Hebrew year. + */ + ELUL + }; + + /** + * Constructs a HebrewCalendar based on the current time in the default time zone + * with the given locale. + * + * @param aLocale The given locale. + * @param success Indicates the status of HebrewCalendar object construction. + * Returns U_ZERO_ERROR if constructed successfully. + * @internal + */ + HebrewCalendar(const Locale& aLocale, UErrorCode& success); + + + /** + * Destructor + * @internal + */ + virtual ~HebrewCalendar(); + + /** + * Copy constructor + * @param source the object to be copied. + * @internal + */ + HebrewCalendar(const HebrewCalendar& source); + + /** + * Default assignment operator + * @param right the object to be copied. + * @internal + */ + HebrewCalendar& operator=(const HebrewCalendar& right); + + /** + * Create and return a polymorphic copy of this calendar. + * @return return a polymorphic copy of this calendar. + * @internal + */ + virtual Calendar* clone(void) const; + +public: + /** + * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual + * override. This method is to implement a simple version of RTTI, since not all C++ + * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call + * this method. + * + * @return The class ID for this object. All objects of a given class have the + * same class ID. Objects of other classes have different class IDs. + * @internal + */ + virtual UClassID getDynamicClassID(void) const; + + /** + * Return the class ID for this class. This is useful only for comparing to a return + * value from getDynamicClassID(). For example: + * + * Base* polymorphic_pointer = createPolymorphicObject(); + * if (polymorphic_pointer->getDynamicClassID() == + * Derived::getStaticClassID()) ... + * + * @return The class ID for all objects of this class. + * @internal + */ + static UClassID U_EXPORT2 getStaticClassID(void); + + /** + * return the calendar type, "hebrew". + * + * @return calendar type + * @internal + */ + virtual const char * getType() const; + + + // Calendar API + public: + /** + * (Overrides Calendar) UDate Arithmetic function. Adds the specified (signed) amount + * of time to the given time field, based on the calendar's rules. For more + * information, see the documentation for Calendar::add(). + * + * @param field The time field. + * @param amount The amount of date or time to be added to the field. + * @param status Output param set to success/failure code on exit. If any value + * previously set in the time field is invalid, this will be set to + * an error status. + */ + virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode& status); + /** + * @deprecated ICU 2.6 use UCalendarDateFields instead of EDateFields + */ + virtual void add(EDateFields field, int32_t amount, UErrorCode& status); + + + /** + * (Overrides Calendar) Rolls up or down by the given amount in the specified field. + * For more information, see the documentation for Calendar::roll(). + * + * @param field The time field. + * @param amount Indicates amount to roll. + * @param status Output param set to success/failure code on exit. If any value + * previously set in the time field is invalid, this will be set to + * an error status. + * @internal + */ + virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode& status); + + /** + * (Overrides Calendar) Rolls up or down by the given amount in the specified field. + * For more information, see the documentation for Calendar::roll(). + * + * @param field The time field. + * @param amount Indicates amount to roll. + * @param status Output param set to success/failure code on exit. If any value + * previously set in the time field is invalid, this will be set to + * an error status. + * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead. +` */ + virtual void roll(EDateFields field, int32_t amount, UErrorCode& status); + + /** + * @internal + */ + static UBool isLeapYear(int32_t year) ; + + protected: + + /** + * Subclass API for defining limits of different types. + * Subclasses must implement this method to return limits for the + * following fields: + * + *
UCAL_ERA + * UCAL_YEAR + * UCAL_MONTH + * UCAL_WEEK_OF_YEAR + * UCAL_WEEK_OF_MONTH + * UCAL_DATE (DAY_OF_MONTH on Java) + * UCAL_DAY_OF_YEAR + * UCAL_DAY_OF_WEEK_IN_MONTH + * UCAL_YEAR_WOY + * UCAL_EXTENDED_YEAR+ * + * @param field one of the above field numbers + * @param limitType one of
MINIMUM, GREATEST_MINIMUM,
+ * LEAST_MAXIMUM, or MAXIMUM
+ * @internal
+ */
+ virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
+
+ /**
+ * Return the number of days in the given month of the given extended
+ * year of this calendar system. Subclasses should override this
+ * method if they can provide a more correct or more efficient
+ * implementation than the default implementation in Calendar.
+ * @internal
+ */
+ virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const;
+
+ /**
+ * Return the number of days in the given extended year of this
+ * calendar system. Subclasses should override this method if they can
+ * provide a more correct or more efficient implementation than the
+ * default implementation in Calendar.
+ * @stable ICU 2.0
+ */
+ virtual int32_t handleGetYearLength(int32_t eyear) const;
+ /**
+ * Subclasses may override this method to compute several fields
+ * specific to each calendar system. These are:
+ *
+ * The GregorianCalendar implementation implements + * a calendar with the specified Julian/Gregorian cutover date. + * @internal + */ + virtual void handleComputeFields(int32_t julianDay, UErrorCode &status); + /** + * Return the extended year defined by the current fields. This will + * use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such + * as UCAL_ERA) specific to the calendar system, depending on which set of + * fields is newer. + * @return the extended year + * @internal + */ + virtual int32_t handleGetExtendedYear(); + /** + * Return the Julian day number of day before the first day of the + * given month in the given extended year. Subclasses should override + * this method to implement their calendar system. + * @param eyear the extended year + * @param month the zero-based month, or 0 if useMonth is false + * @param useMonth if false, compute the day before the first day of + * the given year, otherwise, compute the day before the first day of + * the given month + * @param return the Julian day number of the day before the first + * day of the given month and year + * @internal + */ + virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, + UBool useMonth) const; + + + + protected: + + /** + * (Overrides Calendar) Return true if the current date for this Calendar is in + * Daylight Savings Time. Recognizes DST_OFFSET, if it is set. + * + * @param status Fill-in parameter which receives the status of this operation. + * @return True if the current date for this Calendar is in Daylight Savings Time, + * false, otherwise. + * @internal + */ + virtual UBool inDaylightTime(UErrorCode& status) const; + + /** + * Returns TRUE because the Hebrew Calendar does have a default century + * @internal + */ + virtual UBool haveDefaultCentury() const; + + /** + * Returns the date of the start of the default century + * @return start of century - in milliseconds since epoch, 1970 + * @internal + */ + virtual UDate defaultCenturyStart() const; + + /** + * Returns the year in which the default century begins + * @internal + */ + virtual int32_t defaultCenturyStartYear() const; + + private: // Calendar-specific implementation + /** + * Finds the day # of the first day in the given Hebrew year. + * To do this, we want to calculate the time of the Tishri 1 new moon + * in that year. + *
+ * The algorithm here is similar to ones described in a number of + * references, including: + *