# GregorianCalendar Class Reference

Concrete class which provides the standard calendar used by most of the world. More...

`#include <gregocal.h>`

Inheritance diagram for GregorianCalendar:

## Public Types
enum | EEras { BC, AD }
| Useful constants for GregorianCalendar and TimeZone. More...
## Public Member Functions
| GregorianCalendar (UErrorCode &success)
| Constructs a default GregorianCalendar using the current time in the default time zone with the default locale.
| GregorianCalendar (TimeZone *zoneToAdopt, UErrorCode &success)
| Constructs a GregorianCalendar based on the current time in the given time zone with the default locale.
| GregorianCalendar (const TimeZone &zone, UErrorCode &success)
| Constructs a GregorianCalendar based on the current time in the given time zone with the default locale.
| GregorianCalendar (const Locale &aLocale, UErrorCode &success)
| Constructs a GregorianCalendar based on the current time in the default time zone with the given locale.
| GregorianCalendar (TimeZone *zoneToAdopt, const Locale &aLocale, UErrorCode &success)
| Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.
| GregorianCalendar (const TimeZone &zone, const Locale &aLocale, UErrorCode &success)
| Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.
| GregorianCalendar (int32_t year, int32_t month, int32_t date, UErrorCode &success)
| Constructs a GregorianCalendar with the given AD date set in the default time zone with the default locale.
| GregorianCalendar (int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, UErrorCode &success)
| Constructs a GregorianCalendar with the given AD date and time set for the default time zone with the default locale.
| GregorianCalendar (int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, int32_t second, UErrorCode &success)
| Constructs a GregorianCalendar with the given AD date and time set for the default time zone with the default locale.
virtual | ~GregorianCalendar ()
| Destructor.
| GregorianCalendar (const GregorianCalendar &source)
| Copy constructor.
GregorianCalendar & | operator= (const GregorianCalendar &right)
| Default assignment operator.
virtual Calendar * | clone (void) const
| Create and return a polymorphic copy of this calendar.
void | setGregorianChange (UDate date, UErrorCode &success)
| Sets the GregorianCalendar change date.
UDate | getGregorianChange (void) const
| Gets the Gregorian Calendar change date.
UBool | isLeapYear (int32_t year) const
| Return true if the given year is a leap year.
virtual UBool | isEquivalentTo (const Calendar &other) const
| Returns TRUE if the given Calendar object is equivalent to this one.
virtual void | roll (EDateFields field, int32_t amount, UErrorCode &status)
| (Overrides Calendar) Rolls up or down by the given amount in the specified field.
virtual void | roll (UCalendarDateFields field, int32_t amount, UErrorCode &status)
| (Overrides Calendar) Rolls up or down by the given amount in the specified field.
int32_t | getActualMinimum (EDateFields field) const
| Return the minimum value that this field could have, given the current date.
int32_t | getActualMinimum (EDateFields field, UErrorCode &status) const
| Return the minimum value that this field could have, given the current date.
int32_t | getActualMinimum (UCalendarDateFields field, UErrorCode &status) const
| Return the minimum value that this field could have, given the current date.
int32_t | getActualMaximum (EDateFields field) const
| Return the maximum value that this field could have, given the current date.
virtual int32_t | getActualMaximum (UCalendarDateFields field, UErrorCode &status) const
| Return the maximum value that this field could have, given the current date.
virtual UBool | inDaylightTime (UErrorCode &status) const
| (Overrides Calendar) Return true if the current date for this Calendar is in Daylight Savings Time.
virtual UClassID | getDynamicClassID (void) const
| Override Calendar Returns a unique class ID POLYMORPHICALLY.
virtual const char * | getType () const
| Get the calendar type, "gregorian", for use in DateFormatSymbols.
virtual UBool | haveDefaultCentury () const
virtual UDate | defaultCenturyStart () const
virtual int32_t | defaultCenturyStartYear () const
## Static Public Member Functions
static UClassID | getStaticClassID (void)
| Return the class ID for this class.
## Protected Member Functions
virtual int32_t | internalGetEra () const
| Return the ERA.
virtual int32_t | handleComputeMonthStart (int32_t eyear, int32_t month, UBool useMonth) const
| Return the Julian day number of day before the first day of the given month in the given extended year.
virtual int32_t | handleComputeJulianDay (UCalendarDateFields bestField)
| Subclasses may override this.
virtual int32_t | handleGetMonthLength (int32_t extendedYear, int32_t month) const
| Return the number of days in the given month of the given extended year of this calendar system.
virtual int32_t | handleGetYearLength (int32_t eyear) const
| Return the number of days in the given extended year of this calendar system.
virtual int32_t | monthLength (int32_t month) const
| return the length of the given month.
virtual int32_t | monthLength (int32_t month, int32_t year) const
| return the length of the month according to the given year.
int32_t | yearLength (int32_t year) const
| return the length of the given year.
int32_t | yearLength (void) const
| return the length of the year field.
void | pinDayOfMonth (void)
| After adjustments such as add(MONTH), add(YEAR), we don't want the month to jump around.
virtual UDate | getEpochDay (UErrorCode &status)
| Return the day number with respect to the epoch.
virtual int32_t | handleGetLimit (UCalendarDateFields field, ELimitType limitType) const
| Subclass API for defining limits of different types.
virtual int32_t | handleGetExtendedYear ()
| Return the extended year defined by the current fields.
virtual int32_t | handleGetExtendedYearFromWeekFields (int32_t yearWoy, int32_t woy)
| Subclasses may override this to convert from week fields (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case where YEAR, EXTENDED_YEAR are not set.
virtual void | handleComputeFields (int32_t julianDay, UErrorCode &status)
| Subclasses may override this method to compute several fields specific to each calendar system.

## Detailed Description

Concrete class which provides the standard calendar used by most of the world.

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.

Values calculated for the `WEEK_OF_YEAR` field range from 1 to 53. Week 1 for a year is the first week that contains at least `getMinimalDaysInFirstWeek()` days from that year. It thus depends on the values of `getMinimalDaysInFirstWeek()`, `getFirstDayOfWeek()`, and the day of the week of January 1. Weeks between week 1 of one year and week 1 of the following year are numbered sequentially from 2 to 52 or 53 (as needed).

For example, January 1, 1998 was a Thursday. If `getFirstDayOfWeek()` is `MONDAY` and `getMinimalDaysInFirstWeek()` is 4 (these are the values reflecting ISO 8601 and many national standards), then week 1 of 1998 starts on December 29, 1997, and ends on January 4, 1998. If, however, `getFirstDayOfWeek()` is `SUNDAY`, then week 1 of 1998 starts on January 4, 1998, and ends on January 10, 1998; the first three days of 1998 then are part of week 53 of 1997.

Example for using GregorianCalendar:

          // get the supported ids for GMT-08:00 (Pacific Standard Time)
         UErrorCode success = U_ZERO_ERROR;
         const StringEnumeration *ids = TimeZone::createEnumeration(-8 * 60 * 60 * 1000);
         // if no ids were returned, something is wrong. get out.
         if (ids == 0 || ids->count(success) == 0) {
             return;
         }

         // begin output
         cout << "Current Time" << endl;

         // create a Pacific Standard Time time zone
         SimpleTimeZone* pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids->unext(NULL, success)));

         // set up rules for daylight savings time
         pdt->setStartRule(UCAL_MARCH, 1, UCAL_SUNDAY, 2 * 60 * 60 * 1000);
         pdt->setEndRule(UCAL_NOVEMBER, 2, UCAL_SUNDAY, 2 * 60 * 60 * 1000);

         // create a GregorianCalendar with the Pacific Daylight time zone
         // and the current date and time
         Calendar* calendar = new GregorianCalendar( pdt, success );

         // print out a bunch of interesting things
         cout << "ERA: " << calendar->get( UCAL_ERA, success ) << endl;
         cout << "YEAR: " << calendar->get( UCAL_YEAR, success ) << endl;
         cout << "MONTH: " << calendar->get( UCAL_MONTH, success ) << endl;
         cout << "WEEK_OF_YEAR: " << calendar->get( UCAL_WEEK_OF_YEAR, success ) << endl;
         cout << "WEEK_OF_MONTH: " << calendar->get( UCAL_WEEK_OF_MONTH, success ) << endl;
         cout << "DATE: " << calendar->get( UCAL_DATE, success ) << endl;
         cout << "DAY_OF_MONTH: " << calendar->get( UCAL_DAY_OF_MONTH, success ) << endl;
         cout << "DAY_OF_YEAR: " << calendar->get( UCAL_DAY_OF_YEAR, success ) << endl;
         cout << "DAY_OF_WEEK: " << calendar->get( UCAL_DAY_OF_WEEK, success ) << endl;
         cout << "DAY_OF_WEEK_IN_MONTH: " << calendar->get( UCAL_DAY_OF_WEEK_IN_MONTH, success ) << endl;
         cout << "AM_PM: " << calendar->get( UCAL_AM_PM, success ) << endl;
         cout << "HOUR: " << calendar->get( UCAL_HOUR, success ) << endl;
         cout << "HOUR_OF_DAY: " << calendar->get( UCAL_HOUR_OF_DAY, success ) << endl;
         cout << "MINUTE: " << calendar->get( UCAL_MINUTE, success ) << endl;
         cout << "SECOND: " << calendar->get( UCAL_SECOND, success ) << endl;
         cout << "MILLISECOND: " << calendar->get( UCAL_MILLISECOND, success ) << endl;
         cout << "ZONE_OFFSET: " << (calendar->get( UCAL_ZONE_OFFSET, success )/(60*60*1000)) << endl;
         cout << "DST_OFFSET: " << (calendar->get( UCAL_DST_OFFSET, success )/(60*60*1000)) << endl;

         cout << "Current Time, with hour reset to 3" << endl;
         calendar->clear(UCAL_HOUR_OF_DAY); // so doesn't override
         calendar->set(UCAL_HOUR, 3);
         cout << "ERA: " << calendar->get( UCAL_ERA, success ) << endl;
         cout << "YEAR: " << calendar->get( UCAL_YEAR, success ) << endl;
         cout << "MONTH: " << calendar->get( UCAL_MONTH, success ) << endl;
         cout << "WEEK_OF_YEAR: " << calendar->get( UCAL_WEEK_OF_YEAR, success ) << endl;
         cout << "WEEK_OF_MONTH: " << calendar->get( UCAL_WEEK_OF_MONTH, success ) << endl;
         cout << "DATE: " << calendar->get( UCAL_DATE, success ) << endl;
         cout << "DAY_OF_MONTH: " << calendar->get( UCAL_DAY_OF_MONTH, success ) << endl;
         cout << "DAY_OF_YEAR: " << calendar->get( UCAL_DAY_OF_YEAR, success ) << endl;
         cout << "DAY_OF_WEEK: " << calendar->get( UCAL_DAY_OF_WEEK, success ) << endl;
         cout << "DAY_OF_WEEK_IN_MONTH: " << calendar->get( UCAL_DAY_OF_WEEK_IN_MONTH, success ) << endl;
         cout << "AM_PM: " << calendar->get( UCAL_AM_PM, success ) << endl;
         cout << "HOUR: " << calendar->get( UCAL_HOUR, success ) << endl;
         cout << "HOUR_OF_DAY: " << calendar->get( UCAL_HOUR_OF_DAY, success ) << endl;
         cout << "MINUTE: " << calendar->get( UCAL_MINUTE, success ) << endl;
         cout << "SECOND: " << calendar->get( UCAL_SECOND, success ) << endl;
         cout << "MILLISECOND: " << calendar->get( UCAL_MILLISECOND, success ) << endl;
         cout << "ZONE_OFFSET: " << (calendar->get( UCAL_ZONE_OFFSET, success )/(60*60*1000)) << endl; // in hours
         cout << "DST_OFFSET: " << (calendar->get( UCAL_DST_OFFSET, success )/(60*60*1000)) << endl; // in hours

         if (U_FAILURE(success)) {
             cout << "An error occured. success=" << u_errorName(success) << endl;
         }

         delete ids;
         delete calendar; // also deletes pdt

Stable:
  ICU 2.0

Definition at line 149 of file gregocal.h.

## Member Enumeration Documentation

enum GregorianCalendar::EEras

Useful constants for GregorianCalendar and TimeZone.

Stable:
  ICU 2.0

Definition at line 156 of file gregocal.h.

## Constructor & Destructor Documentation

GregorianCalendar::GregorianCalendar | ( | UErrorCode & | success | ) |

Constructs a default GregorianCalendar using the current time in the default time zone with the default locale.

Parameters:

  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | TimeZone * | zoneToAdopt,
|  | UErrorCode & | 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.

Parameters:

  | zoneToAdopt | The given timezone.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | const TimeZone & | zone,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar based on the current time in the given time zone with the default locale.

Parameters:

  | zone | The given timezone.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | const Locale & | aLocale,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar based on the current time in the default time zone with the given locale.

Parameters:

  | aLocale | The given locale.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | TimeZone * | zoneToAdopt,
|  | const Locale & | aLocale,
|  | UErrorCode & | 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.

Parameters:

  | zoneToAdopt | The given timezone.
  | aLocale | The given locale.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | const TimeZone & | zone,
|  | const Locale & | aLocale,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.

Parameters:

  | zone | The given timezone.
  | aLocale | The given locale.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | int32_t | year,
|  | int32_t | month,
|  | int32_t | date,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar with the given AD date set in the default time zone with the default locale.

Parameters:

  | year | The value used to set the YEAR time field in the calendar.
  | month | The value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January.
  | date | The value used to set the DATE time field in the calendar.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | int32_t | year,
|  | int32_t | month,
|  | int32_t | date,
|  | int32_t | hour,
|  | int32_t | minute,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar with the given AD date and time set for the default time zone with the default locale.

Parameters:

  | year | The value used to set the YEAR time field in the calendar.
  | month | The value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January.
  | date | The value used to set the DATE time field in the calendar.
  | hour | The value used to set the HOUR_OF_DAY time field in the calendar.
  | minute | The value used to set the MINUTE time field in the calendar.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | int32_t | year,
|  | int32_t | month,
|  | int32_t | date,
|  | int32_t | hour,
|  | int32_t | minute,
|  | int32_t | second,
|  | UErrorCode & | success |
| ) |  |  |

Constructs a GregorianCalendar with the given AD date and time set for the default time zone with the default locale.

Parameters:

  | year | The value used to set the YEAR time field in the calendar.
  | month | The value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January.
  | date | The value used to set the DATE time field in the calendar.
  | hour | The value used to set the HOUR_OF_DAY time field in the calendar.
  | minute | The value used to set the MINUTE time field in the calendar.
  | second | The value used to set the SECOND time field in the calendar.
  | success | Indicates the status of GregorianCalendar object construction. Returns U_ZERO_ERROR if constructed successfully.

Stable:
  ICU 2.0

virtual GregorianCalendar::~GregorianCalendar | ( |  | ) | `[virtual]`

Destructor.

Stable:
  ICU 2.0

GregorianCalendar::GregorianCalendar | ( | const GregorianCalendar & | source | ) |

Copy constructor.

Parameters:

  | source | the object to be copied.

Stable:
  ICU 2.0

## Member Function Documentation

virtual Calendar* GregorianCalendar::clone | ( | void |  | ) | const`[virtual]`

Create and return a polymorphic copy of this calendar.

Returns:
  return a polymorphic copy of this calendar.

Stable:
  ICU 2.0

Implements Calendar.

virtual UDate GregorianCalendar::defaultCenturyStart | ( |  | ) | const`[virtual]`

Internal:
  Do not use. This API is for internal use only.

Returns:
  the start of the default century

Implements Calendar.

virtual int32_t GregorianCalendar::defaultCenturyStartYear | ( |  | ) | const`[virtual]`

Internal:
  Do not use. This API is for internal use only.

Returns:
  the beginning year of the default century

Implements Calendar.

virtual int32_t GregorianCalendar::getActualMaximum | ( | UCalendarDateFields | field,
|  | UErrorCode & | status |
| ) |  |  | const`[virtual]`

Return the maximum value that this field could have, given the current date.

For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.

Parameters:

  | field | the time field.
  | status | returns any errors that may result from this function call.

Returns:
  the maximum value that this field could have, given the current date.

Stable:
  ICU 2.6

Reimplemented from Calendar.

int32_t GregorianCalendar::getActualMaximum | ( | EDateFields | field | ) | const

Return the maximum value that this field could have, given the current date.

For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.

Parameters:

  | field | the time field.

Returns:
  the maximum value that this field could have, given the current date.

Deprecated:
  ICU 2.6. Use getActualMaximum(UCalendarDateFields field) instead.

int32_t GregorianCalendar::getActualMinimum | ( | UCalendarDateFields | field,
|  | UErrorCode & | status |
| ) |  |  | const`[virtual]`

Return the minimum value that this field could have, given the current date.

For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().

Parameters:

  | field | the time field.
  | status | error result.

Returns:
  the minimum value that this field could have, given the current date.

Stable:
  ICU 3.0

Reimplemented from Calendar.

int32_t GregorianCalendar::getActualMinimum | ( | EDateFields | field,
|  | UErrorCode & | status |
| ) |  |  | const

Return the minimum value that this field could have, given the current date.

For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().

Parameters:

  | field | the time field.
  | status |

Returns:
  the minimum value that this field could have, given the current date.

Deprecated:
  ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead. (Added to ICU 3.0 for signature consistency)

Reimplemented from Calendar.

int32_t GregorianCalendar::getActualMinimum | ( | EDateFields | field | ) | const

Return the minimum value that this field could have, given the current date.

For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().

Parameters:

  | field | the time field.

Returns:
  the minimum value that this field could have, given the current date.

Deprecated:
  ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.

virtual UClassID GregorianCalendar::getDynamicClassID | ( | void |  | ) | const`[virtual]`

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.

Returns:
  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.

Stable:
  ICU 2.0

Implements Calendar.

virtual UDate GregorianCalendar::getEpochDay | ( | UErrorCode & | status | ) | `[protected, virtual]`

Return the day number with respect to the epoch.

January 1, 1970 (Gregorian) is day zero.

Parameters:

  | status | Fill-in parameter which receives the status of this operation.

Returns:
  the day number with respect to the epoch.

Internal:
  Do not use. This API is for internal use only.

UDate GregorianCalendar::getGregorianChange | ( | void |  | ) | const

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.

Returns:
  The Gregorian cutover time for this calendar.

Stable:
  ICU 2.0

static UClassID GregorianCalendar::getStaticClassID | ( | void |  | ) | `[static]`

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()) ...

Returns:
  The class ID for all objects of this class.

Stable:
  ICU 2.0

virtual const char* GregorianCalendar::getType | ( |  | ) | const`[virtual]`

Get the calendar type, "gregorian", for use in DateFormatSymbols.

Returns:
  calendar type

Internal:
  Do not use. This API is for internal use only.

Implements Calendar.

virtual void GregorianCalendar::handleComputeFields | ( | int32_t | julianDay,
|  | UErrorCode & | status |
| ) |  |  | `[protected, virtual]`

Subclasses may override this method to compute several fields specific to each calendar system.

These are:

- ERA
- YEAR
- MONTH
- DAY_OF_MONTH
- DAY_OF_YEAR
- EXTENDED_YEAR

The GregorianCalendar implementation implements a calendar with the specified Julian/Gregorian cutover date.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from Calendar.

virtual int32_t GregorianCalendar::handleComputeJulianDay | ( | UCalendarDateFields | bestField | ) | `[protected, virtual]`

Subclasses may override this.

This method calls handleGetMonthLength() to obtain the calendar-specific month length.

Parameters:

  | bestField | which field to use to calculate the date

Returns:
  julian day specified by calendar fields.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from Calendar.

virtual int32_t GregorianCalendar::handleComputeMonthStart | ( | int32_t | eyear,
|  | int32_t | month,
|  | UBool | useMonth |
| ) |  |  | const`[protected, virtual]`

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.

Parameters:

  | eyear | the extended year
  | month | the zero-based month, or 0 if useMonth is false
  | 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

Returns:
  the Julian day number of the day before the first day of the given month and year

Internal:
  Do not use. This API is for internal use only.

Implements Calendar.

virtual int32_t GregorianCalendar::handleGetExtendedYear | ( |  | ) | `[protected, virtual]`

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.

Returns:
  the extended year

Internal:
  Do not use. This API is for internal use only.

Implements Calendar.

virtual int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields | ( | int32_t | yearWoy,
|  | int32_t | woy |
| ) |  |  | `[protected, virtual]`

Subclasses may override this to convert from week fields (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case where YEAR, EXTENDED_YEAR are not set.

The Gregorian implementation assumes a yearWoy in gregorian format, according to the current era.

Returns:
  the extended year, UCAL_EXTENDED_YEAR

Internal:
  Do not use. This API is for internal use only.

Reimplemented from Calendar.

virtual int32_t GregorianCalendar::handleGetLimit | ( | UCalendarDateFields | field,
|  | ELimitType | limitType |
| ) |  |  | const`[protected, virtual]`

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

Parameters:

  | field | one of the above field numbers
  | limitType | one of `MINIMUM`, `GREATEST_MINIMUM`, `LEAST_MAXIMUM`, or `MAXIMUM`

Internal:
  Do not use. This API is for internal use only.

Implements Calendar.

virtual int32_t GregorianCalendar::handleGetMonthLength | ( | int32_t | extendedYear,
|  | int32_t | month |
| ) |  |  | const`[protected, virtual]`

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:
  Do not use. This API is for internal use only.

Reimplemented from Calendar.

virtual int32_t GregorianCalendar::handleGetYearLength | ( | int32_t | eyear | ) | const`[protected, virtual]`

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

Reimplemented from Calendar.

virtual UBool GregorianCalendar::haveDefaultCentury | ( |  | ) | const`[virtual]`

Internal:
  Do not use. This API is for internal use only.

Returns:
  TRUE if this calendar has the notion of a default century

Implements Calendar.

virtual UBool GregorianCalendar::inDaylightTime | ( | UErrorCode & | status | ) | const`[virtual]`

(Overrides Calendar) Return true if the current date for this Calendar is in Daylight Savings Time.

Recognizes DST_OFFSET, if it is set.

Parameters:

  | status | Fill-in parameter which receives the status of this operation.

Returns:
  True if the current date for this Calendar is in Daylight Savings Time, false, otherwise.

Stable:
  ICU 2.0

Implements Calendar.

virtual int32_t GregorianCalendar::internalGetEra | ( |  | ) | const`[protected, virtual]`

Return the ERA.

We need a special method for this because the default ERA is AD, but a zero (unset) ERA is BC.

Returns:
  the ERA.

Internal:
  Do not use. This API is for internal use only.

virtual UBool GregorianCalendar::isEquivalentTo | ( | const Calendar & | other | ) | const`[virtual]`

Returns TRUE if the given Calendar object is equivalent to this one.

Calendar override.

Parameters:

  | other | the Calendar to be compared with this Calendar

Stable:
  ICU 2.4

UBool GregorianCalendar::isLeapYear | ( | int32_t | year | ) | 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).

Parameters:

  | year | The given year.

Returns:
  True if the given year is a leap year; false otherwise.

Stable:
  ICU 2.0

virtual int32_t GregorianCalendar::monthLength | ( | int32_t | month,
|  | int32_t | year |
| ) |  |  | const`[protected, virtual]`

return the length of the month according to the given year.

Parameters:

  | month | the given month.
  | year | the given year.

Returns:
  the length of the month

Internal:
  Do not use. This API is for internal use only.

virtual int32_t GregorianCalendar::monthLength | ( | int32_t | month | ) | const`[protected, virtual]`

return the length of the given month.

Parameters:

  | month | the given month.

Returns:
  the length of the given month.

Internal:
  Do not use. This API is for internal use only.

GregorianCalendar& GregorianCalendar::operator= | ( | const GregorianCalendar & | right | ) |

Default assignment operator.

Parameters:

  | right | the object to be copied.

Stable:
  ICU 2.0

Reimplemented from Calendar.

void GregorianCalendar::pinDayOfMonth | ( | void |  | ) | `[protected]`

After adjustments such as add(MONTH), add(YEAR), we don't want the month to jump around.

E.g., we don't want Jan 31 + 1 month to go to Mar 3, we want it to go to Feb 28. Adjustments which might run into this problem call this method to retain the proper month.

Internal:
  Do not use. This API is for internal use only.

virtual void GregorianCalendar::roll | ( | UCalendarDateFields | field,
|  | int32_t | amount,
|  | UErrorCode & | status |
| ) |  |  | `[virtual]`

(Overrides Calendar) Rolls up or down by the given amount in the specified field.

For more information, see the documentation for Calendar::roll().

Parameters:

  | field | The time field.
  | amount | Indicates amount to roll.
  | 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.

Stable:
  ICU 2.6.

Reimplemented from Calendar.

virtual void GregorianCalendar::roll | ( | EDateFields | field,
|  | int32_t | amount,
|  | UErrorCode & | status |
| ) |  |  | `[virtual]`

(Overrides Calendar) Rolls up or down by the given amount in the specified field.

For more information, see the documentation for Calendar::roll().

Parameters:

  | field | The time field.
  | amount | Indicates amount to roll.
  | 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.

Reimplemented from Calendar.

void GregorianCalendar::setGregorianChange | ( | UDate | date,
|  | UErrorCode & | success |
| ) |  |  |

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.

Parameters:

  | date | The given Gregorian cutover date.
  | success | Output param set to success/failure code on exit.

Stable:
  ICU 2.0

int32_t GregorianCalendar::yearLength | ( | void |  | ) | const`[protected]`

return the length of the year field.

Returns:
  the length of the year field

Internal:
  Do not use. This API is for internal use only.

int32_t GregorianCalendar::yearLength | ( | int32_t | year | ) | const`[protected]`

return the length of the given year.

Parameters:

  | year | the given year.

Returns:
  the length of the given year.

Internal:
  Do not use. This API is for internal use only.

The documentation for this class was generated from the following file:

- gregocal.h

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