* The standard (Gregorian) calendar has 2 eras, BC and AD. *
* This implementation handles a single discontinuity, which corresponds by default to * the date the Gregorian calendar was originally instituted (October 15, 1582). Not all * countries adopted the Gregorian calendar then, so this cutover date may be changed by * the caller. *
* Prior to the institution of the Gregorian Calendar, New Year's Day was March 25. To * avoid confusion, this Calendar always uses January 1. A manual adjustment may be made * if desired for dates that are prior to the Gregorian changeover and which fall * between January 1 and March 24. */ #ifdef NLS_MAC #pragma export on #endif class T_FORMAT_API GregorianCalendar: public Calendar { public: /** * Useful constants for GregorianCalendar and TimeZone. */ enum EEras { BC, AD }; /** * Constructs a default GregorianCalendar using the current time in the default time * zone with the default locale. * * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(ErrorCode& success); /** * Constructs a GregorianCalendar based on the current time in the given time zone * with the default locale. Clients are no longer responsible for deleting the given * time zone object after it's adopted. * * @param zoneToAdopt The given timezone. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(TimeZone* zoneToAdopt, ErrorCode& success); /** * Constructs a GregorianCalendar based on the current time in the given time zone * with the default locale. * * @param zone The given timezone. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(const TimeZone& zone, ErrorCode& success); /** * Constructs a GregorianCalendar 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 GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(const Locale& aLocale, ErrorCode& success); /** * Constructs a GregorianCalendar based on the current time in the given time zone * with the given locale. Clients are no longer responsible for deleting the given * time zone object after it's adopted. * * @param zoneToAdopt The given timezone. * @param aLocale The given locale. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(TimeZone* zoneToAdopt, const Locale& aLocale, ErrorCode& success); /** * Constructs a GregorianCalendar based on the current time in the given time zone * with the given locale. * * @param zone The given timezone. * @param aLocale The given locale. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(const TimeZone& zone, const Locale& aLocale, ErrorCode& success); /** * Constructs a GregorianCalendar with the given AD date set in the default time * zone with the default locale. * * @param year The value used to set the YEAR time field in the calendar. * @param month The value used to set the MONTH time field in the calendar. Month * value is 0-based. e.g., 0 for January. * @param date The value used to set the DATE time field in the calendar. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(t_int32 year, t_int32 month, t_int32 date, ErrorCode& success); /** * Constructs a GregorianCalendar with the given AD date and time set for the * default time zone with the default locale. * * @param year The value used to set the YEAR time field in the calendar. * @param month The value used to set the MONTH time field in the calendar. Month * value is 0-based. e.g., 0 for January. * @param date The value used to set the DATE time field in the calendar. * @param hour The value used to set the HOUR_OF_DAY time field in the calendar. * @param minute The value used to set the MINUTE time field in the calendar. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(t_int32 year, t_int32 month, t_int32 date, t_int32 hour, t_int32 minute, ErrorCode& success); /** * Constructs a GregorianCalendar with the given AD date and time set for the * default time zone with the default locale. * * @param year The value used to set the YEAR time field in the calendar. * @param month The value used to set the MONTH time field in the calendar. Month * value is 0-based. e.g., 0 for January. * @param date The value used to set the DATE time field in the calendar. * @param hour The value used to set the HOUR_OF_DAY time field in the calendar. * @param minute The value used to set the MINUTE time field in the calendar. * @param second The value used to set the SECOND time field in the calendar. * @param success Indicates the status of GregorianCalendar object construction. * Returns ZERO_ERROR if constructed successfully. */ GregorianCalendar(t_int32 year, t_int32 month, t_int32 date, t_int32 hour, t_int32 minute, t_int32 second, ErrorCode& success); /** * Destructor */ virtual ~GregorianCalendar(); /** * Copy constructor */ GregorianCalendar(const GregorianCalendar& source); /** * Default assignment operator */ GregorianCalendar& operator=(const GregorianCalendar& right); /** * Create and return a polymorphic copy of this calendar. */ virtual Calendar* clone() const; /** * Sets the GregorianCalendar change date. This is the point when the switch from * Julian dates to Gregorian dates occurred. Default is 00:00:00 local time, October * 15, 1582. Previous to this time and date will be Julian dates. * * @param date The given Gregorian cutover date. * @param success Output param set to success/failure code on exit. */ void setGregorianChange(Date date, ErrorCode& success); /** * Gets the Gregorian Calendar change date. This is the point when the switch from * Julian dates to Gregorian dates occurred. Default is 00:00:00 local time, October * 15, 1582. Previous to this time and date will be Julian dates. * * @return The Gregorian cutover time for this calendar. */ Date getGregorianChange() const; /** * Return true if the given year is a leap year. Determination of whether a year is * a leap year is actually very complicated. We do something crude and mostly * correct here, but for a real determination you need a lot of contextual * information. For example, in Sweden, the change from Julian to Gregorian happened * in a complex way resulting in missed leap years and double leap years between * 1700 and 1753. Another example is that after the start of the Julian calendar in * 45 B.C., the leap years did not regularize until 8 A.D. This method ignores these * quirks, and pays attention only to the Julian onset date and the Gregorian * cutover (which can be changed). * * @param year The given year. * @return True if the given year is a leap year; false otherwise. */ t_bool isLeapYear(t_int32 year) const; /** * Compares the equality of two GregorianCalendar objects. Objects of different * subclasses are considered unequal. This is a strict equality test; see the * documentation for Calendar::operator==(). * * @param that The GregorianCalendar object to be compared with. * @return True if the given GregorianCalendar is the same as this * GregorianCalendar; false otherwise. */ virtual t_bool operator==(const Calendar& that) const; /** * Calendar override. * Return true if another Calendar object is equivalent to this one. An equivalent * Calendar will behave exactly as this one does, but may be set to a different time. */ virtual t_bool equivalentTo(const Calendar& other) const; /** * (Overrides Calendar) Date 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(EDateFields field, t_int32 amount, ErrorCode& 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. */ virtual void roll(EDateFields field, int amount, ErrorCode& status); /** * (Overrides Calendar) Returns minimum value for the given field. e.g. for * Gregorian DAY_OF_MONTH, 1. */ virtual t_int32 getMinimum(EDateFields field) const; /** * (Overrides Calendar) Returns maximum value for the given field. e.g. for * Gregorian DAY_OF_MONTH, 31. */ virtual t_int32 getMaximum(EDateFields field) const; /** * (Overrides Calendar) Returns highest minimum value for the given field if varies. * Otherwise same as getMinimum(). For Gregorian, no difference. */ virtual t_int32 getGreatestMinimum(EDateFields field) const; /** * (Overrides Calendar) Returns lowest maximum value for the given field if varies. * Otherwise same as getMaximum(). For Gregorian DAY_OF_MONTH, 28. */ virtual t_int32 getLeastMaximum(EDateFields field) const; /** * (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. */ virtual t_bool inDaylightTime(ErrorCode& status) 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. */ virtual ClassID getDynamicClassID() const { return (ClassID)&fgClassID; } /** * 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. */ static ClassID getStaticClassID() { return (ClassID)&fgClassID; } protected: /** * (Overrides Calendar) Converts GMT as milliseconds to time field values. */ virtual void computeFields(ErrorCode& status); /** * (Overrides Calendar) Converts Calendar's time field values to GMT as * milliseconds. * * @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 computeTime(ErrorCode& status); private: /** * Return the length of the given month in the given year, accounting for Gregorian * leap years. */ int monthLength(int month, int year) const; /** * Converts time as milliseconds to Julian date. The Julian date used here is not a * true Julian date, since it is measured from midnight, not noon. * * @param millis The given milliseconds. * @return The Julian date number. */ static long millisToJulianDay(Date millis); /** * Converts Julian date to time as milliseconds. The Julian date used here is not a * true Julian date, since it is measured from midnight, not noon. * * @param julian The given Julian date number. * @return Time as milliseconds. */ static Date julianDayToMillis(long julian); /** * Convert a quasi Julian date to the day of the week. The Julian date used here is * not a true Julian date, since it is measured from midnight, not noon. Return * value is one-based. * * @return Day number from 1..7 (SUN..SAT). */ static int julianDayToDayOfWeek(long julian); /** * Compute the date-based fields given the milliseconds since the epoch start. Do * not compute the time-based fields (HOUR, MINUTE, etc.). * * @param theTime The given time as LOCAL milliseconds, not UTC. */ void timeToFields(Date theTime, ErrorCode& status); /** * Return the week number of a day, within a period. This may be the week number in * a year, or the week number in a month. Usually this will be a value >= 1, but if * some initial days of the period are excluded from week 1, because * minimalDaysInFirstWeek is > 1, then the week number will be zero for those * initial days. Requires the day of week for the given date in order to determine * the day of week of the first day of the period. * * @param date Day-of-year or day-of-month. Should be 1 for first day of period. * @param day Day-of-week for given dayOfPeriod. 1-based with 1=Sunday. * @return Week number, one-based, or zero if the day falls in part of the * month before the first week, when there are days before the first * week because the minimum days in the first week is more than one. */ int weekNumber(int date, int day); /** * Validates the values of the set time fields. True if they're all valid. */ t_bool validateFields() const; /** * Validates the value of the given time field. True if it's valid. */ t_bool boundsCheck(t_int32 value, EDateFields field) const; // This is measured from the standard epoch, not in Julian Days. Date fGregorianCutover; static char fgClassID; static const Date kPapalCutover; // Cutover decreed by Pope Gregory static const Date kJulianOnset; // Onset of Julian calendar, 45 B.C. static const long kEpochStartAsJulianDay; // 1970-01-01 as Julian Day static const int kMonthLength[]; // lengths of months in non-leap year static const int kLeapMonthLength[]; // lengths of months in leap year static const int NUM_DAYS[]; // day-in-year numbers for the first of each month in non-leap years static const int LEAP_NUM_DAYS[]; // day-in-year numbers for the firstof each month in leap years static const Date EARLIEST_USABLE_MILLIS; // earliest Data value for which we can compute fields static const int EARLIEST_USABLE_YEAR; // earliest year for which we can compute dates and fields static const Date EARLIEST_INVALID_MILLIS; // earliest Date value for which we can't compute fields // (i.e., high bound of valid range) static const Date ONE_WEEK; // number of milliseconds in a week }; #ifdef NLS_MAC #pragma export off #endif inline int GregorianCalendar::julianDayToDayOfWeek(long julian) { // If julian is negative, then julian%7 will be negative, so we adjust // accordingly. We add 1 because Julian day 0 is Monday. int dayOfWeek = (julian + 1) % 7; return dayOfWeek + ((dayOfWeek < 0) ? (7 + SUNDAY) : SUNDAY); } #endif // _GREGOCAL //eof