blob: 3bc77cf149448d637cf180f39e0964da8feba8e2 [file] [log] [blame]
/*
*******************************************************************************
* Copyright (C) 1997-2010, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*
* File GREGOCAL.CPP
*
* Modification History:
*
* Date Name Description
* 02/05/97 clhuang Creation.
* 03/28/97 aliu Made highly questionable fix to computeFields to
* handle DST correctly.
* 04/22/97 aliu Cleaned up code drastically. Added monthLength().
* Finished unimplemented parts of computeTime() for
* week-based date determination. Removed quetionable
* fix and wrote correct fix for computeFields() and
* daylight time handling. Rewrote inDaylightTime()
* and computeFields() to handle sensitive Daylight to
* Standard time transitions correctly.
* 05/08/97 aliu Added code review changes. Fixed isLeapYear() to
* not cutover.
* 08/12/97 aliu Added equivalentTo. Misc other fixes. Updated
* add() from Java source.
* 07/28/98 stephen Sync up with JDK 1.2
* 09/14/98 stephen Changed type of kOneDay, kOneWeek to double.
* Fixed bug in roll()
* 10/15/99 aliu Fixed j31, incorrect WEEK_OF_YEAR computation.
* 10/15/99 aliu Fixed j32, cannot set date to Feb 29 2000 AD.
* {JDK bug 4210209 4209272}
* 11/15/99 weiv Added YEAR_WOY and DOW_LOCAL computation
* to timeToFields method, updated kMinValues, kMaxValues & kLeastMaxValues
* 12/09/99 aliu Fixed j81, calculation errors and roll bugs
* in year of cutover.
* 01/24/2000 aliu Revised computeJulianDay for YEAR YEAR_WOY WOY.
********************************************************************************
*/
#include "unicode/utypes.h"
#include <float.h>
#if !UCONFIG_NO_FORMATTING
#include "unicode/gregocal.h"
#include "gregoimp.h"
#include "umutex.h"
#include "uassert.h"
// *****************************************************************************
// class GregorianCalendar
// *****************************************************************************
/**
* Note that the Julian date used here is not a true Julian date, since
* it is measured from midnight, not noon. This value is the Julian
* day number of January 1, 1970 (Gregorian calendar) at noon UTC. [LIU]
*/
static const int16_t kNumDays[]
= {0,31,59,90,120,151,181,212,243,273,304,334}; // 0-based, for day-in-year
static const int16_t kLeapNumDays[]
= {0,31,60,91,121,152,182,213,244,274,305,335}; // 0-based, for day-in-year
static const int8_t kMonthLength[]
= {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
static const int8_t kLeapMonthLength[]
= {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
// setTimeInMillis() limits the Julian day range to +/-7F000000.
// This would seem to limit the year range to:
// ms=+183882168921600000 jd=7f000000 December 20, 5828963 AD
// ms=-184303902528000000 jd=81000000 September 20, 5838270 BC
// HOWEVER, CalendarRegressionTest/Test4167060 shows that the actual
// range limit on the year field is smaller (~ +/-140000). [alan 3.0]
static const int32_t kGregorianCalendarLimits[UCAL_FIELD_COUNT][4] = {
// Minimum Greatest Least Maximum
// Minimum Maximum
{ 0, 0, 1, 1}, // ERA
{ 1, 1, 140742, 144683}, // YEAR
{ 0, 0, 11, 11}, // MONTH
{ 1, 1, 52, 53}, // WEEK_OF_YEAR
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
{ 1, 1, 28, 31}, // DAY_OF_MONTH
{ 1, 1, 365, 366}, // DAY_OF_YEAR
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
{ -1, -1, 4, 5}, // DAY_OF_WEEK_IN_MONTH
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
{ -140742, -140742, 140742, 144683}, // YEAR_WOY
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
{ -140742, -140742, 140742, 144683}, // EXTENDED_YEAR
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
{/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
};
/*
* <pre>
* Greatest Least
* Field name Minimum Minimum Maximum Maximum
* ---------- ------- ------- ------- -------
* ERA 0 0 1 1
* YEAR 1 1 140742 144683
* MONTH 0 0 11 11
* WEEK_OF_YEAR 1 1 52 53
* WEEK_OF_MONTH 0 0 4 6
* DAY_OF_MONTH 1 1 28 31
* DAY_OF_YEAR 1 1 365 366
* DAY_OF_WEEK 1 1 7 7
* DAY_OF_WEEK_IN_MONTH -1 -1 4 5
* AM_PM 0 0 1 1
* HOUR 0 0 11 11
* HOUR_OF_DAY 0 0 23 23
* MINUTE 0 0 59 59
* SECOND 0 0 59 59
* MILLISECOND 0 0 999 999
* ZONE_OFFSET -12* -12* 12* 12*
* DST_OFFSET 0 0 1* 1*
* YEAR_WOY 1 1 140742 144683
* DOW_LOCAL 1 1 7 7
* </pre>
* (*) In units of one-hour
*/
#if defined( U_DEBUG_CALSVC ) || defined (U_DEBUG_CAL)
#include <stdio.h>
#endif
U_NAMESPACE_BEGIN
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(GregorianCalendar)
// 00:00:00 UTC, October 15, 1582, expressed in ms from the epoch.
// Note that only Italy and other Catholic countries actually
// observed this cutover. Most other countries followed in
// the next few centuries, some as late as 1928. [LIU]
// in Java, -12219292800000L
//const UDate GregorianCalendar::kPapalCutover = -12219292800000L;
static const uint32_t kCutoverJulianDay = 2299161;
static const UDate kPapalCutover = (2299161.0 - kEpochStartAsJulianDay) * U_MILLIS_PER_DAY;
//static const UDate kPapalCutoverJulian = (2299161.0 - kEpochStartAsJulianDay);
// -------------------------------------
GregorianCalendar::GregorianCalendar(UErrorCode& status)
: Calendar(status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(TimeZone* zone, UErrorCode& status)
: Calendar(zone, Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const TimeZone& zone, UErrorCode& status)
: Calendar(zone, Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const Locale& aLocale, UErrorCode& status)
: Calendar(TimeZone::createDefault(), aLocale, status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(TimeZone* zone, const Locale& aLocale,
UErrorCode& status)
: Calendar(zone, aLocale, status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const TimeZone& zone, const Locale& aLocale,
UErrorCode& status)
: Calendar(zone, aLocale, status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
UErrorCode& status)
: Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
set(UCAL_ERA, AD);
set(UCAL_YEAR, year);
set(UCAL_MONTH, month);
set(UCAL_DATE, date);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
int32_t hour, int32_t minute, UErrorCode& status)
: Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
set(UCAL_ERA, AD);
set(UCAL_YEAR, year);
set(UCAL_MONTH, month);
set(UCAL_DATE, date);
set(UCAL_HOUR_OF_DAY, hour);
set(UCAL_MINUTE, minute);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
int32_t hour, int32_t minute, int32_t second,
UErrorCode& status)
: Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
fIsGregorian(TRUE), fInvertGregorian(FALSE)
{
set(UCAL_ERA, AD);
set(UCAL_YEAR, year);
set(UCAL_MONTH, month);
set(UCAL_DATE, date);
set(UCAL_HOUR_OF_DAY, hour);
set(UCAL_MINUTE, minute);
set(UCAL_SECOND, second);
}
// -------------------------------------
GregorianCalendar::~GregorianCalendar()
{
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const GregorianCalendar &source)
: Calendar(source),
fGregorianCutover(source.fGregorianCutover),
fCutoverJulianDay(source.fCutoverJulianDay), fNormalizedGregorianCutover(source.fNormalizedGregorianCutover), fGregorianCutoverYear(source.fGregorianCutoverYear),
fIsGregorian(source.fIsGregorian), fInvertGregorian(source.fInvertGregorian)
{
}
// -------------------------------------
Calendar* GregorianCalendar::clone() const
{
return new GregorianCalendar(*this);
}
// -------------------------------------
GregorianCalendar &
GregorianCalendar::operator=(const GregorianCalendar &right)
{
if (this != &right)
{
Calendar::operator=(right);
fGregorianCutover = right.fGregorianCutover;
fNormalizedGregorianCutover = right.fNormalizedGregorianCutover;
fGregorianCutoverYear = right.fGregorianCutoverYear;
fCutoverJulianDay = right.fCutoverJulianDay;
}
return *this;
}
// -------------------------------------
UBool GregorianCalendar::isEquivalentTo(const Calendar& other) const
{
// Calendar override.
return Calendar::isEquivalentTo(other) &&
fGregorianCutover == ((GregorianCalendar*)&other)->fGregorianCutover;
}
// -------------------------------------
void
GregorianCalendar::setGregorianChange(UDate date, UErrorCode& status)
{
if (U_FAILURE(status))
return;
fGregorianCutover = date;
// Precompute two internal variables which we use to do the actual
// cutover computations. These are the normalized cutover, which is the
// midnight at or before the cutover, and the cutover year. The
// normalized cutover is in pure date milliseconds; it contains no time
// of day or timezone component, and it used to compare against other
// pure date values.
int32_t cutoverDay = (int32_t)ClockMath::floorDivide(fGregorianCutover, (double)kOneDay);
fNormalizedGregorianCutover = cutoverDay * kOneDay;
// Handle the rare case of numeric overflow. If the user specifies a
// change of UDate(Long.MIN_VALUE), in order to get a pure Gregorian
// calendar, then the epoch day is -106751991168, which when multiplied
// by ONE_DAY gives 9223372036794351616 -- the negative value is too
// large for 64 bits, and overflows into a positive value. We correct
// this by using the next day, which for all intents is semantically
// equivalent.
if (cutoverDay < 0 && fNormalizedGregorianCutover > 0) {
fNormalizedGregorianCutover = (cutoverDay + 1) * kOneDay;
}
// Normalize the year so BC values are represented as 0 and negative
// values.
GregorianCalendar *cal = new GregorianCalendar(getTimeZone(), status);
/* test for NULL */
if (cal == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
if(U_FAILURE(status))
return;
cal->setTime(date, status);
fGregorianCutoverYear = cal->get(UCAL_YEAR, status);
if (cal->get(UCAL_ERA, status) == BC)
fGregorianCutoverYear = 1 - fGregorianCutoverYear;
fCutoverJulianDay = cutoverDay;
delete cal;
}
void GregorianCalendar::handleComputeFields(int32_t julianDay, UErrorCode& status) {
int32_t eyear, month, dayOfMonth, dayOfYear;
if(U_FAILURE(status)) {
return;
}
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: jd%d- (greg's %d)- [cut=%d]\n",
__FILE__, __LINE__, julianDay, getGregorianDayOfYear(), fCutoverJulianDay);
#endif
if (julianDay >= fCutoverJulianDay) {
month = getGregorianMonth();
dayOfMonth = getGregorianDayOfMonth();
dayOfYear = getGregorianDayOfYear();
eyear = getGregorianYear();
} else {
// The Julian epoch day (not the same as Julian Day)
// is zero on Saturday December 30, 0 (Gregorian).
int32_t julianEpochDay = julianDay - (kJan1_1JulianDay - 2);
eyear = (int32_t) ClockMath::floorDivide(4*julianEpochDay + 1464, 1461);
// Compute the Julian calendar day number for January 1, eyear
int32_t january1 = 365*(eyear-1) + ClockMath::floorDivide(eyear-1, (int32_t)4);
dayOfYear = (julianEpochDay - january1); // 0-based
// Julian leap years occurred historically every 4 years starting
// with 8 AD. Before 8 AD the spacing is irregular; every 3 years
// from 45 BC to 9 BC, and then none until 8 AD. However, we don't
// implement this historical detail; instead, we implement the
// computatinally cleaner proleptic calendar, which assumes
// consistent 4-year cycles throughout time.
UBool isLeap = ((eyear&0x3) == 0); // equiv. to (eyear%4 == 0)
// Common Julian/Gregorian calculation
int32_t correction = 0;
int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
if (dayOfYear >= march1) {
correction = isLeap ? 1 : 2;
}
month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
dayOfMonth = dayOfYear - (isLeap?kLeapNumDays[month]:kNumDays[month]) + 1; // one-based DOM
++dayOfYear;
#if defined (U_DEBUG_CAL)
// fprintf(stderr, "%d - %d[%d] + 1\n", dayOfYear, isLeap?kLeapNumDays[month]:kNumDays[month], month );
// fprintf(stderr, "%s:%d: greg's HCF %d -> %d/%d/%d not %d/%d/%d\n",
// __FILE__, __LINE__,julianDay,
// eyear,month,dayOfMonth,
// getGregorianYear(), getGregorianMonth(), getGregorianDayOfMonth() );
fprintf(stderr, "%s:%d: doy %d (greg's %d)- [cut=%d]\n",
__FILE__, __LINE__, dayOfYear, getGregorianDayOfYear(), fCutoverJulianDay);
#endif
}
// [j81] if we are after the cutover in its year, shift the day of the year
if((eyear == fGregorianCutoverYear) && (julianDay >= fCutoverJulianDay)) {
//from handleComputeMonthStart
int32_t gregShift = Grego::gregorianShift(eyear);
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: gregorian shift %d ::: doy%d => %d [cut=%d]\n",
__FILE__, __LINE__,gregShift, dayOfYear, dayOfYear+gregShift, fCutoverJulianDay);
#endif
dayOfYear += gregShift;
}
internalSet(UCAL_MONTH, month);
internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
internalSet(UCAL_EXTENDED_YEAR, eyear);
int32_t era = AD;
if (eyear < 1) {
era = BC;
eyear = 1 - eyear;
}
internalSet(UCAL_ERA, era);
internalSet(UCAL_YEAR, eyear);
}
// -------------------------------------
UDate
GregorianCalendar::getGregorianChange() const
{
return fGregorianCutover;
}
// -------------------------------------
UBool
GregorianCalendar::isLeapYear(int32_t year) const
{
// MSVC complains bitterly if we try to use Grego::isLeapYear here
// NOTE: year&0x3 == year%4
return (year >= fGregorianCutoverYear ?
(((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
((year&0x3) == 0)); // Julian
}
// -------------------------------------
int32_t GregorianCalendar::handleComputeJulianDay(UCalendarDateFields bestField)
{
fInvertGregorian = FALSE;
int32_t jd = Calendar::handleComputeJulianDay(bestField);
if((bestField == UCAL_WEEK_OF_YEAR) && // if we are doing WOY calculations, we are counting relative to Jan 1 *julian*
(internalGet(UCAL_EXTENDED_YEAR)==fGregorianCutoverYear) &&
jd >= fCutoverJulianDay) {
fInvertGregorian = TRUE; // So that the Julian Jan 1 will be used in handleComputeMonthStart
return Calendar::handleComputeJulianDay(bestField);
}
// The following check handles portions of the cutover year BEFORE the
// cutover itself happens.
//if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: jd [invert] %d\n",
__FILE__, __LINE__, jd);
#endif
fInvertGregorian = TRUE;
jd = Calendar::handleComputeJulianDay(bestField);
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: fIsGregorian %s, fInvertGregorian %s - ",
__FILE__, __LINE__,fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
fprintf(stderr, " jd NOW %d\n",
jd);
#endif
} else {
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: jd [==] %d - %sfIsGregorian %sfInvertGregorian, %d\n",
__FILE__, __LINE__, jd, fIsGregorian?"T":"F", fInvertGregorian?"T":"F", bestField);
#endif
}
if(fIsGregorian && (internalGet(UCAL_EXTENDED_YEAR) == fGregorianCutoverYear)) {
int32_t gregShift = Grego::gregorianShift(internalGet(UCAL_EXTENDED_YEAR));
if (bestField == UCAL_DAY_OF_YEAR) {
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: [DOY%d] gregorian shift of JD %d += %d\n",
__FILE__, __LINE__, fFields[bestField],jd, gregShift);
#endif
jd -= gregShift;
} else if ( bestField == UCAL_WEEK_OF_MONTH ) {
int32_t weekShift = 14;
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: [WOY/WOM] gregorian week shift of %d += %d\n",
__FILE__, __LINE__, jd, weekShift);
#endif
jd += weekShift; // shift by weeks for week based fields.
}
}
return jd;
}
int32_t GregorianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month,
UBool /* useMonth */) const
{
GregorianCalendar *nonConstThis = (GregorianCalendar*)this; // cast away const
// If the month is out of range, adjust it into range, and
// modify the extended year value accordingly.
if (month < 0 || month > 11) {
eyear += ClockMath::floorDivide(month, 12, month);
}
UBool isLeap = eyear%4 == 0;
int32_t y = eyear-1;
int32_t julianDay = 365*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
nonConstThis->fIsGregorian = (eyear >= fGregorianCutoverYear);
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: (hcms%d/%d) fIsGregorian %s, fInvertGregorian %s\n",
__FILE__, __LINE__, eyear,month, fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
#endif
if (fInvertGregorian) {
nonConstThis->fIsGregorian = !fIsGregorian;
}
if (fIsGregorian) {
isLeap = isLeap && ((eyear%100 != 0) || (eyear%400 == 0));
// Add 2 because Gregorian calendar starts 2 days after
// Julian calendar
int32_t gregShift = Grego::gregorianShift(eyear);
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: (hcms%d/%d) gregorian shift of %d += %d\n",
__FILE__, __LINE__, eyear, month, julianDay, gregShift);
#endif
julianDay += gregShift;
}
// At this point julianDay indicates the day BEFORE the first
// day of January 1, <eyear> of either the Julian or Gregorian
// calendar.
if (month != 0) {
julianDay += isLeap?kLeapNumDays[month]:kNumDays[month];
}
return julianDay;
}
int32_t GregorianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const
{
// If the month is out of range, adjust it into range, and
// modify the extended year value accordingly.
if (month < 0 || month > 11) {
extendedYear += ClockMath::floorDivide(month, 12, month);
}
return isLeapYear(extendedYear) ? kLeapMonthLength[month] : kMonthLength[month];
}
int32_t GregorianCalendar::handleGetYearLength(int32_t eyear) const {
return isLeapYear(eyear) ? 366 : 365;
}
int32_t
GregorianCalendar::monthLength(int32_t month) const
{
int32_t year = internalGet(UCAL_EXTENDED_YEAR);
return handleGetMonthLength(year, month);
}
// -------------------------------------
int32_t
GregorianCalendar::monthLength(int32_t month, int32_t year) const
{
return isLeapYear(year) ? kLeapMonthLength[month] : kMonthLength[month];
}
// -------------------------------------
int32_t
GregorianCalendar::yearLength(int32_t year) const
{
return isLeapYear(year) ? 366 : 365;
}
// -------------------------------------
int32_t
GregorianCalendar::yearLength() const
{
return isLeapYear(internalGet(UCAL_YEAR)) ? 366 : 365;
}
// -------------------------------------
/**
* 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.
*/
void
GregorianCalendar::pinDayOfMonth()
{
int32_t monthLen = monthLength(internalGet(UCAL_MONTH));
int32_t dom = internalGet(UCAL_DATE);
if(dom > monthLen)
set(UCAL_DATE, monthLen);
}
// -------------------------------------
UBool
GregorianCalendar::validateFields() const
{
for (int32_t field = 0; field < UCAL_FIELD_COUNT; field++) {
// Ignore DATE and DAY_OF_YEAR which are handled below
if (field != UCAL_DATE &&
field != UCAL_DAY_OF_YEAR &&
isSet((UCalendarDateFields)field) &&
! boundsCheck(internalGet((UCalendarDateFields)field), (UCalendarDateFields)field))
return FALSE;
}
// Values differ in Least-Maximum and Maximum should be handled
// specially.
if (isSet(UCAL_DATE)) {
int32_t date = internalGet(UCAL_DATE);
if (date < getMinimum(UCAL_DATE) ||
date > monthLength(internalGet(UCAL_MONTH))) {
return FALSE;
}
}
if (isSet(UCAL_DAY_OF_YEAR)) {
int32_t days = internalGet(UCAL_DAY_OF_YEAR);
if (days < 1 || days > yearLength()) {
return FALSE;
}
}
// Handle DAY_OF_WEEK_IN_MONTH, which must not have the value zero.
// We've checked against minimum and maximum above already.
if (isSet(UCAL_DAY_OF_WEEK_IN_MONTH) &&
0 == internalGet(UCAL_DAY_OF_WEEK_IN_MONTH)) {
return FALSE;
}
return TRUE;
}
// -------------------------------------
UBool
GregorianCalendar::boundsCheck(int32_t value, UCalendarDateFields field) const
{
return value >= getMinimum(field) && value <= getMaximum(field);
}
// -------------------------------------
UDate
GregorianCalendar::getEpochDay(UErrorCode& status)
{
complete(status);
// Divide by 1000 (convert to seconds) in order to prevent overflow when
// dealing with UDate(Long.MIN_VALUE) and UDate(Long.MAX_VALUE).
double wallSec = internalGetTime()/1000 + (internalGet(UCAL_ZONE_OFFSET) + internalGet(UCAL_DST_OFFSET))/1000;
return ClockMath::floorDivide(wallSec, kOneDay/1000.0);
}
// -------------------------------------
// -------------------------------------
/**
* Compute the julian day number of the day BEFORE the first day of
* January 1, year 1 of the given calendar. If julianDay == 0, it
* specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
* or Gregorian).
*/
double GregorianCalendar::computeJulianDayOfYear(UBool isGregorian,
int32_t year, UBool& isLeap)
{
isLeap = year%4 == 0;
int32_t y = year - 1;
double julianDay = 365.0*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
if (isGregorian) {
isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
// Add 2 because Gregorian calendar starts 2 days after Julian calendar
julianDay += Grego::gregorianShift(year);
}
return julianDay;
}
// /**
// * Compute the day of week, relative to the first day of week, from
// * 0..6, of the current DOW_LOCAL or DAY_OF_WEEK fields. This is
// * equivalent to get(DOW_LOCAL) - 1.
// */
// int32_t GregorianCalendar::computeRelativeDOW() const {
// int32_t relDow = 0;
// if (fStamp[UCAL_DOW_LOCAL] > fStamp[UCAL_DAY_OF_WEEK]) {
// relDow = internalGet(UCAL_DOW_LOCAL) - 1; // 1-based
// } else if (fStamp[UCAL_DAY_OF_WEEK] != kUnset) {
// relDow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
// if (relDow < 0) relDow += 7;
// }
// return relDow;
// }
// /**
// * Compute the day of week, relative to the first day of week,
// * from 0..6 of the given julian day.
// */
// int32_t GregorianCalendar::computeRelativeDOW(double julianDay) const {
// int32_t relDow = julianDayToDayOfWeek(julianDay) - getFirstDayOfWeek();
// if (relDow < 0) {
// relDow += 7;
// }
// return relDow;
// }
// /**
// * Compute the DOY using the WEEK_OF_YEAR field and the julian day
// * of the day BEFORE January 1 of a year (a return value from
// * computeJulianDayOfYear).
// */
// int32_t GregorianCalendar::computeDOYfromWOY(double julianDayOfYear) const {
// // Compute DOY from day of week plus week of year
// // Find the day of the week for the first of this year. This
// // is zero-based, with 0 being the locale-specific first day of
// // the week. Add 1 to get first day of year.
// int32_t fdy = computeRelativeDOW(julianDayOfYear + 1);
// return
// // Compute doy of first (relative) DOW of WOY 1
// (((7 - fdy) < getMinimalDaysInFirstWeek())
// ? (8 - fdy) : (1 - fdy))
// // Adjust for the week number.
// + (7 * (internalGet(UCAL_WEEK_OF_YEAR) - 1))
// // Adjust for the DOW
// + computeRelativeDOW();
// }
// -------------------------------------
double
GregorianCalendar::millisToJulianDay(UDate millis)
{
return (double)kEpochStartAsJulianDay + ClockMath::floorDivide(millis, (double)kOneDay);
}
// -------------------------------------
UDate
GregorianCalendar::julianDayToMillis(double julian)
{
return (UDate) ((julian - kEpochStartAsJulianDay) * (double) kOneDay);
}
// -------------------------------------
int32_t
GregorianCalendar::aggregateStamp(int32_t stamp_a, int32_t stamp_b)
{
return (((stamp_a != kUnset && stamp_b != kUnset)
? uprv_max(stamp_a, stamp_b)
: (int32_t)kUnset));
}
// -------------------------------------
/**
* Roll a field by a signed amount.
* Note: This will be made public later. [LIU]
*/
void
GregorianCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
roll((UCalendarDateFields) field, amount, status);
}
void
GregorianCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status)
{
if((amount == 0) || U_FAILURE(status)) {
return;
}
// J81 processing. (gregorian cutover)
UBool inCutoverMonth = FALSE;
int32_t cMonthLen=0; // 'c' for cutover; in days
int32_t cDayOfMonth=0; // no discontinuity: [0, cMonthLen)
double cMonthStart=0.0; // in ms
// Common code - see if we're in the cutover month of the cutover year
if(get(UCAL_EXTENDED_YEAR, status) == fGregorianCutoverYear) {
switch (field) {
case UCAL_DAY_OF_MONTH:
case UCAL_WEEK_OF_MONTH:
{
int32_t max = monthLength(internalGet(UCAL_MONTH));
UDate t = internalGetTime();
// We subtract 1 from the DAY_OF_MONTH to make it zero-based, and an
// additional 10 if we are after the cutover. Thus the monthStart
// value will be correct iff we actually are in the cutover month.
cDayOfMonth = internalGet(UCAL_DAY_OF_MONTH) - ((t >= fGregorianCutover) ? 10 : 0);
cMonthStart = t - ((cDayOfMonth - 1) * kOneDay);
// A month containing the cutover is 10 days shorter.
if ((cMonthStart < fGregorianCutover) &&
(cMonthStart + (cMonthLen=(max-10))*kOneDay >= fGregorianCutover)) {
inCutoverMonth = TRUE;
}
}
default:
;
}
}
switch (field) {
case UCAL_WEEK_OF_YEAR: {
// Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
// week. Also, rolling the week of the year can have seemingly
// strange effects simply because the year of the week of year
// may be different from the calendar year. For example, the
// date Dec 28, 1997 is the first day of week 1 of 1998 (if
// weeks start on Sunday and the minimal days in first week is
// <= 3).
int32_t woy = get(UCAL_WEEK_OF_YEAR, status);
// Get the ISO year, which matches the week of year. This
// may be one year before or after the calendar year.
int32_t isoYear = get(UCAL_YEAR_WOY, status);
int32_t isoDoy = internalGet(UCAL_DAY_OF_YEAR);
if (internalGet(UCAL_MONTH) == UCAL_JANUARY) {
if (woy >= 52) {
isoDoy += handleGetYearLength(isoYear);
}
} else {
if (woy == 1) {
isoDoy -= handleGetYearLength(isoYear - 1);
}
}
woy += amount;
// Do fast checks to avoid unnecessary computation:
if (woy < 1 || woy > 52) {
// Determine the last week of the ISO year.
// We do this using the standard formula we use
// everywhere in this file. If we can see that the
// days at the end of the year are going to fall into
// week 1 of the next year, we drop the last week by
// subtracting 7 from the last day of the year.
int32_t lastDoy = handleGetYearLength(isoYear);
int32_t lastRelDow = (lastDoy - isoDoy + internalGet(UCAL_DAY_OF_WEEK) -
getFirstDayOfWeek()) % 7;
if (lastRelDow < 0) lastRelDow += 7;
if ((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) lastDoy -= 7;
int32_t lastWoy = weekNumber(lastDoy, lastRelDow + 1);
woy = ((woy + lastWoy - 1) % lastWoy) + 1;
}
set(UCAL_WEEK_OF_YEAR, woy);
set(UCAL_YEAR_WOY,isoYear);
return;
}
case UCAL_DAY_OF_MONTH:
if( !inCutoverMonth ) {
Calendar::roll(field, amount, status);
return;
} else {
// [j81] 1582 special case for DOM
// The default computation works except when the current month
// contains the Gregorian cutover. We handle this special case
// here. [j81 - aliu]
double monthLen = cMonthLen * kOneDay;
double msIntoMonth = uprv_fmod(internalGetTime() - cMonthStart +
amount * kOneDay, monthLen);
if (msIntoMonth < 0) {
msIntoMonth += monthLen;
}
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: roll DOM %d -> %.0lf ms \n",
__FILE__, __LINE__,amount, cMonthLen, cMonthStart+msIntoMonth);
#endif
setTimeInMillis(cMonthStart + msIntoMonth, status);
return;
}
case UCAL_WEEK_OF_MONTH:
if( !inCutoverMonth ) {
Calendar::roll(field, amount, status);
return;
} else {
#if defined (U_DEBUG_CAL)
fprintf(stderr, "%s:%d: roll WOM %d ??????????????????? \n",
__FILE__, __LINE__,amount);
#endif
// NOTE: following copied from the old
// GregorianCalendar::roll( WEEK_OF_MONTH ) code
// This is tricky, because during the roll we may have to shift
// to a different day of the week. For example:
// s m t w r f s
// 1 2 3 4 5
// 6 7 8 9 10 11 12
// When rolling from the 6th or 7th back one week, we go to the
// 1st (assuming that the first partial week counts). The same
// thing happens at the end of the month.
// The other tricky thing is that we have to figure out whether
// the first partial week actually counts or not, based on the
// minimal first days in the week. And we have to use the
// correct first day of the week to delineate the week
// boundaries.
// Here's our algorithm. First, we find the real boundaries of
// the month. Then we discard the first partial week if it
// doesn't count in this locale. Then we fill in the ends with
// phantom days, so that the first partial week and the last
// partial week are full weeks. We then have a nice square
// block of weeks. We do the usual rolling within this block,
// as is done elsewhere in this method. If we wind up on one of
// the phantom days that we added, we recognize this and pin to
// the first or the last day of the month. Easy, eh?
// Another wrinkle: To fix jitterbug 81, we have to make all this
// work in the oddball month containing the Gregorian cutover.
// This month is 10 days shorter than usual, and also contains
// a discontinuity in the days; e.g., the default cutover month
// is Oct 1582, and goes from day of month 4 to day of month 15.
// Normalize the DAY_OF_WEEK so that 0 is the first day of the week
// in this locale. We have dow in 0..6.
int32_t dow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
if (dow < 0)
dow += 7;
// Find the day of month, compensating for cutover discontinuity.
int32_t dom = cDayOfMonth;
// Find the day of the week (normalized for locale) for the first
// of the month.
int32_t fdm = (dow - dom + 1) % 7;
if (fdm < 0)
fdm += 7;
// Get the first day of the first full week of the month,
// including phantom days, if any. Figure out if the first week
// counts or not; if it counts, then fill in phantom days. If
// not, advance to the first real full week (skip the partial week).
int32_t start;
if ((7 - fdm) < getMinimalDaysInFirstWeek())
start = 8 - fdm; // Skip the first partial week
else
start = 1 - fdm; // This may be zero or negative
// Get the day of the week (normalized for locale) for the last
// day of the month.
int32_t monthLen = cMonthLen;
int32_t ldm = (monthLen - dom + dow) % 7;
// We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
// Get the limit day for the blocked-off rectangular month; that
// is, the day which is one past the last day of the month,
// after the month has already been filled in with phantom days
// to fill out the last week. This day has a normalized DOW of 0.
int32_t limit = monthLen + 7 - ldm;
// Now roll between start and (limit - 1).
int32_t gap = limit - start;
int32_t newDom = (dom + amount*7 - start) % gap;
if (newDom < 0)
newDom += gap;
newDom += start;
// Finally, pin to the real start and end of the month.
if (newDom < 1)
newDom = 1;
if (newDom > monthLen)
newDom = monthLen;
// Set the DAY_OF_MONTH. We rely on the fact that this field
// takes precedence over everything else (since all other fields
// are also set at this point). If this fact changes (if the
// disambiguation algorithm changes) then we will have to unset
// the appropriate fields here so that DAY_OF_MONTH is attended
// to.
// If we are in the cutover month, manipulate ms directly. Don't do
// this in general because it doesn't work across DST boundaries
// (details, details). This takes care of the discontinuity.
setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
return;
}
default:
Calendar::roll(field, amount, status);
return;
}
}
// -------------------------------------
/**
* 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().
* @param field the time field.
* @return the minimum value that this field could have, given the current date.
* @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.
*/
int32_t GregorianCalendar::getActualMinimum(EDateFields field) const
{
return getMinimum((UCalendarDateFields)field);
}
int32_t GregorianCalendar::getActualMinimum(EDateFields field, UErrorCode& /* status */) const
{
return getMinimum((UCalendarDateFields)field);
}
/**
* 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().
* @param field the time field.
* @return the minimum value that this field could have, given the current date.
* @draft ICU 2.6.
*/
int32_t GregorianCalendar::getActualMinimum(UCalendarDateFields field, UErrorCode& /* status */) const
{
return getMinimum(field);
}
// ------------------------------------
/**
* Old year limits were least max 292269054, max 292278994.
*/
/**
* @stable ICU 2.0
*/
int32_t GregorianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
return kGregorianCalendarLimits[field][limitType];
}
/**
* 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.
* @stable ICU 2.0
*/
int32_t GregorianCalendar::getActualMaximum(UCalendarDateFields field, UErrorCode& status) const
{
/* It is a known limitation that the code here (and in getActualMinimum)
* won't behave properly at the extreme limits of GregorianCalendar's
* representable range (except for the code that handles the YEAR
* field). That's because the ends of the representable range are at
* odd spots in the year. For calendars with the default Gregorian
* cutover, these limits are Sun Dec 02 16:47:04 GMT 292269055 BC to Sun
* Aug 17 07:12:55 GMT 292278994 AD, somewhat different for non-GMT
* zones. As a result, if the calendar is set to Aug 1 292278994 AD,
* the actual maximum of DAY_OF_MONTH is 17, not 30. If the date is Mar
* 31 in that year, the actual maximum month might be Jul, whereas is
* the date is Mar 15, the actual maximum might be Aug -- depending on
* the precise semantics that are desired. Similar considerations
* affect all fields. Nonetheless, this effect is sufficiently arcane
* that we permit it, rather than complicating the code to handle such
* intricacies. - liu 8/20/98
* UPDATE: No longer true, since we have pulled in the limit values on
* the year. - Liu 11/6/00 */
switch (field) {
case UCAL_YEAR:
/* The year computation is no different, in principle, from the
* others, however, the range of possible maxima is large. In
* addition, the way we know we've exceeded the range is different.
* For these reasons, we use the special case code below to handle
* this field.
*
* The actual maxima for YEAR depend on the type of calendar:
*
* Gregorian = May 17, 292275056 BC - Aug 17, 292278994 AD
* Julian = Dec 2, 292269055 BC - Jan 3, 292272993 AD
* Hybrid = Dec 2, 292269055 BC - Aug 17, 292278994 AD
*
* We know we've exceeded the maximum when either the month, date,
* time, or era changes in response to setting the year. We don't
* check for month, date, and time here because the year and era are
* sufficient to detect an invalid year setting. NOTE: If code is
* added to check the month and date in the future for some reason,
* Feb 29 must be allowed to shift to Mar 1 when setting the year.
*/
{
if(U_FAILURE(status)) return 0;
Calendar *cal = clone();
if(!cal) {
status = U_MEMORY_ALLOCATION_ERROR;
return 0;
}
cal->setLenient(TRUE);
int32_t era = cal->get(UCAL_ERA, status);
UDate d = cal->getTime(status);
/* Perform a binary search, with the invariant that lowGood is a
* valid year, and highBad is an out of range year.
*/
int32_t lowGood = kGregorianCalendarLimits[UCAL_YEAR][1];
int32_t highBad = kGregorianCalendarLimits[UCAL_YEAR][2]+1;
while ((lowGood + 1) < highBad) {
int32_t y = (lowGood + highBad) / 2;
cal->set(UCAL_YEAR, y);
if (cal->get(UCAL_YEAR, status) == y && cal->get(UCAL_ERA, status) == era) {
lowGood = y;
} else {
highBad = y;
cal->setTime(d, status); // Restore original fields
}
}
delete cal;
return lowGood;
}
default:
return Calendar::getActualMaximum(field,status);
}
}
int32_t GregorianCalendar::handleGetExtendedYear() {
// the year to return
int32_t year = kEpochYear;
// year field to use
int32_t yearField = UCAL_EXTENDED_YEAR;
// There are three separate fields which could be used to
// derive the proper year. Use the one most recently set.
if (fStamp[yearField] < fStamp[UCAL_YEAR])
yearField = UCAL_YEAR;
if (fStamp[yearField] < fStamp[UCAL_YEAR_WOY])
yearField = UCAL_YEAR_WOY;
// based on the "best" year field, get the year
switch(yearField) {
case UCAL_EXTENDED_YEAR:
year = internalGet(UCAL_EXTENDED_YEAR, kEpochYear);
break;
case UCAL_YEAR:
{
// The year defaults to the epoch start, the era to AD
int32_t era = internalGet(UCAL_ERA, AD);
if (era == BC) {
year = 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
} else {
year = internalGet(UCAL_YEAR, kEpochYear);
}
}
break;
case UCAL_YEAR_WOY:
year = handleGetExtendedYearFromWeekFields(internalGet(UCAL_YEAR_WOY), internalGet(UCAL_WEEK_OF_YEAR));
#if defined (U_DEBUG_CAL)
// if(internalGet(UCAL_YEAR_WOY) != year) {
fprintf(stderr, "%s:%d: hGEYFWF[%d,%d] -> %d\n",
__FILE__, __LINE__,internalGet(UCAL_YEAR_WOY),internalGet(UCAL_WEEK_OF_YEAR),year);
//}
#endif
break;
default:
year = kEpochYear;
}
return year;
}
int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy)
{
// convert year to extended form
int32_t era = internalGet(UCAL_ERA, AD);
if(era == BC) {
yearWoy = 1 - yearWoy;
}
return Calendar::handleGetExtendedYearFromWeekFields(yearWoy, woy);
}
// -------------------------------------
UBool
GregorianCalendar::inDaylightTime(UErrorCode& status) const
{
if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
return FALSE;
// Force an update of the state of the Calendar.
((GregorianCalendar*)this)->complete(status); // cast away const
return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
}
// -------------------------------------
/**
* Return the ERA. We need a special method for this because the
* default ERA is AD, but a zero (unset) ERA is BC.
*/
int32_t
GregorianCalendar::internalGetEra() const {
return isSet(UCAL_ERA) ? internalGet(UCAL_ERA) : (int32_t)AD;
}
const char *
GregorianCalendar::getType() const {
//static const char kGregorianType = "gregorian";
return "gregorian";
}
const UDate GregorianCalendar::fgSystemDefaultCentury = DBL_MIN;
const int32_t GregorianCalendar::fgSystemDefaultCenturyYear = -1;
UDate GregorianCalendar::fgSystemDefaultCenturyStart = DBL_MIN;
int32_t GregorianCalendar::fgSystemDefaultCenturyStartYear = -1;
UBool GregorianCalendar::haveDefaultCentury() const
{
return TRUE;
}
UDate GregorianCalendar::defaultCenturyStart() const
{
return internalGetDefaultCenturyStart();
}
int32_t GregorianCalendar::defaultCenturyStartYear() const
{
return internalGetDefaultCenturyStartYear();
}
UDate
GregorianCalendar::internalGetDefaultCenturyStart() const
{
// lazy-evaluate systemDefaultCenturyStart
UBool needsUpdate;
UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
if (needsUpdate) {
initializeSystemDefaultCentury();
}
// use defaultCenturyStart unless it's the flag value;
// then use systemDefaultCenturyStart
return fgSystemDefaultCenturyStart;
}
int32_t
GregorianCalendar::internalGetDefaultCenturyStartYear() const
{
// lazy-evaluate systemDefaultCenturyStartYear
UBool needsUpdate;
UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
if (needsUpdate) {
initializeSystemDefaultCentury();
}
// use defaultCenturyStart unless it's the flag value;
// then use systemDefaultCenturyStartYear
return fgSystemDefaultCenturyStartYear;
}
void
GregorianCalendar::initializeSystemDefaultCentury()
{
// initialize systemDefaultCentury and systemDefaultCenturyYear based
// on the current time. They'll be set to 80 years before
// the current time.
UErrorCode status = U_ZERO_ERROR;
Calendar *calendar = new GregorianCalendar(status);
if (calendar != NULL && U_SUCCESS(status))
{
calendar->setTime(Calendar::getNow(), status);
calendar->add(UCAL_YEAR, -80, status);
UDate newStart = calendar->getTime(status);
int32_t newYear = calendar->get(UCAL_YEAR, status);
umtx_lock(NULL);
if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
{
fgSystemDefaultCenturyStartYear = newYear;
fgSystemDefaultCenturyStart = newStart;
}
umtx_unlock(NULL);
delete calendar;
}
// We have no recourse upon failure unless we want to propagate the failure
// out.
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */
//eof