/*
*******************************************************************************
* Copyright (C) 1997-1999, 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.
********************************************************************************
*/
#ifndef _GREGOCAL
#include "unicode/gregocal.h"
#endif
// *****************************************************************************
// class GregorianCalendar
// *****************************************************************************
const int32_t GregorianCalendar::kJan1_1JulianDay = 1721426; // January 1, year 1 (Gregorian)
/**
* 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]
*/
const int32_t GregorianCalendar::kEpochStartAsJulianDay = 2440588; // January 1, 1970 (Gregorian)
const int32_t GregorianCalendar::kEpochYear = 1970;
const int32_t GregorianCalendar::kNumDays[]
= {0,31,59,90,120,151,181,212,243,273,304,334}; // 0-based, for day-in-year
const int32_t GregorianCalendar::kLeapNumDays[]
= {0,31,60,91,121,152,182,213,244,274,305,335}; // 0-based, for day-in-year
const int32_t GregorianCalendar::kMonthLength[]
= {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
const int32_t GregorianCalendar::kLeapMonthLength[]
= {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
// Useful millisecond constants
const int32_t GregorianCalendar::kOneSecond = 1000;
const int32_t GregorianCalendar::kOneMinute = 60 * kOneSecond; // 60,000
const int32_t GregorianCalendar::kOneHour = 60 * kOneMinute; // 3,600,000
const double GregorianCalendar::kOneDay = 24.0 * kOneHour; // 86,400,000
const double GregorianCalendar::kOneWeek = 7.0 * kOneDay; // 604,800,000
// These numbers are 2^52 - 1, the largest allowable mantissa in a 64-bit double
// with a 0 exponent. These are the absolute largest numbers for millis that
// this calendar will handle reliably. It will work for larger values, however.
// The problem is that, once the exponent is not 0, the calendar will jump.
// When translated into a year, LATEST_SUPPORTED_MILLIS corresponds to 144,683 AD
// and EARLIEST_SUPPORTED_MILLIS corresponds to 140,742 BC
const UDate GregorianCalendar::EARLIEST_SUPPORTED_MILLIS = - 4503599627370495.0;
const UDate GregorianCalendar::LATEST_SUPPORTED_MILLIS = 4503599627370495.0;
/*
*
* 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 6
* 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
*
* (*) In units of one-hour
*/
const int32_t GregorianCalendar::kMinValues[] = {
0,1,0,1,0,1,1,1,-1,0,0,0,0,0,0,-12*U_MILLIS_PER_HOUR,0,1,1
};
const int32_t GregorianCalendar::kLeastMaxValues[] = {
1,140742,11,52,4,28,365,7,4,1,11,23,59,59,999,12*U_MILLIS_PER_HOUR,1*U_MILLIS_PER_HOUR,140742,7
};
const int32_t GregorianCalendar::kMaxValues[] = {
1,144683,11,53,6,31,366,7,6,1,11,23,59,59,999,12*U_MILLIS_PER_HOUR,1*U_MILLIS_PER_HOUR, 144683,7
};
char GregorianCalendar::fgClassID = 0; // Value is irrelevant
// 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;
const UDate GregorianCalendar::kPapalCutover = (2299161.0 - kEpochStartAsJulianDay) * kOneDay;
// -------------------------------------
GregorianCalendar::GregorianCalendar(UErrorCode& status)
: Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(TimeZone* zone, UErrorCode& status)
: Calendar(zone, Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const TimeZone& zone, UErrorCode& status)
: Calendar(zone, Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const Locale& aLocale, UErrorCode& status)
: Calendar(TimeZone::createDefault(), aLocale, status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(TimeZone* zone, const Locale& aLocale,
UErrorCode& status)
: Calendar(zone, aLocale, status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const TimeZone& zone, const Locale& aLocale,
UErrorCode& status)
: Calendar(zone, aLocale, status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
setTimeInMillis(getNow(), status);
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
UErrorCode& status)
: Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
fGregorianCutover(kPapalCutover),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
set(Calendar::ERA, AD);
set(Calendar::YEAR, year);
set(Calendar::MONTH, month);
set(Calendar::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),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
set(Calendar::ERA, AD);
set(Calendar::YEAR, year);
set(Calendar::MONTH, month);
set(Calendar::DATE, date);
set(Calendar::HOUR_OF_DAY, hour);
set(Calendar::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),
fNormalizedGregorianCutover(fGregorianCutover),
fGregorianCutoverYear(1582)
{
set(Calendar::ERA, AD);
set(Calendar::YEAR, year);
set(Calendar::MONTH, month);
set(Calendar::DATE, date);
set(Calendar::HOUR_OF_DAY, hour);
set(Calendar::MINUTE, minute);
set(Calendar::SECOND, second);
}
// -------------------------------------
GregorianCalendar::~GregorianCalendar()
{
}
// -------------------------------------
GregorianCalendar::GregorianCalendar(const GregorianCalendar &source)
: Calendar(source),
fGregorianCutover(source.fGregorianCutover),
fNormalizedGregorianCutover(source.fNormalizedGregorianCutover),
fGregorianCutoverYear(source.fGregorianCutoverYear)
{
}
// -------------------------------------
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;
}
return *this;
}
// -------------------------------------
UBool
GregorianCalendar::operator==(const Calendar& that) const
{
GregorianCalendar* other = (GregorianCalendar*)&that;
return (this == &that) ||
(Calendar::operator==(that) &&
getDynamicClassID() == that.getDynamicClassID() &&
fGregorianCutover == other->fGregorianCutover);
}
// {sfb} API change?
UBool GregorianCalendar::equivalentTo(const Calendar& other) 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.
return Calendar::equivalentTo(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.
UDate cutoverDay = floorDivide(fGregorianCutover, 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);
if(U_FAILURE(status))
return;
cal->setTime(date, status);
fGregorianCutoverYear = cal->get(YEAR, status);
if (cal->get(ERA, status) == BC)
fGregorianCutoverYear = 1 - fGregorianCutoverYear;
delete cal;
}
// -------------------------------------
UDate
GregorianCalendar::getGregorianChange() const
{
return fGregorianCutover;
}
// -------------------------------------
UBool
GregorianCalendar::isLeapYear(int32_t year) const
{
return (year >= fGregorianCutoverYear ?
((year%4 == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
(year%4 == 0)); // 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
GregorianCalendar::timeToFields(UDate theTime, UBool quick, UErrorCode& status)
{
if (U_FAILURE(status))
return;
int32_t rawYear;
int32_t year, yearOfWeekOfYear, month, date, dayOfWeek, locDayOfWeek, dayOfYear, era;
UBool isLeap;
// Compute the year, month, and day of month from the given millis
if (theTime >= fNormalizedGregorianCutover) {
// The Gregorian epoch day is zero for Monday January 1, year 1.
double gregorianEpochDay = millisToJulianDay(theTime) - kJan1_1JulianDay;
// Here we convert from the day number to the multiple radix
// representation. We use 400-year, 100-year, and 4-year cycles.
// For example, the 4-year cycle has 4 years + 1 leap day; giving
// 1461 == 365*4 + 1 days.
int32_t rem[1];
int32_t n400 = floorDivide(gregorianEpochDay, 146097, rem); // 400-year cycle length
int32_t n100 = floorDivide(rem[0], 36524, rem); // 100-year cycle length
int32_t n4 = floorDivide(rem[0], 1461, rem); // 4-year cycle length
int32_t n1 = floorDivide(rem[0], 365, rem);
rawYear = 400*n400 + 100*n100 + 4*n4 + n1;
dayOfYear = rem[0]; // zero-based day of year
if (n100 == 4 || n1 == 4)
dayOfYear = 365; // Dec 31 at end of 4- or 400-yr cycle
else
++rawYear;
isLeap = ((rawYear&0x3) == 0) && // equiv. to (rawYear%4 == 0)
(rawYear%100 != 0 || rawYear%400 == 0);
// Gregorian day zero is a Monday
dayOfWeek = (int32_t)uprv_fmod(gregorianEpochDay + 1, 7);
}
else {
// The Julian epoch day (not the same as Julian Day)
// is zero on Saturday December 30, 0 (Gregorian).
double julianEpochDay = millisToJulianDay(theTime) - (kJan1_1JulianDay - 2);
rawYear = (int32_t) floorDivide(4*julianEpochDay + 1464, 1461.0);
// Compute the Julian calendar day number for January 1, rawYear
double january1 = 365.0 * (rawYear - 1) + floorDivide((double)(rawYear - 1), 4.0);
dayOfYear = (int32_t)(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.
isLeap = ((rawYear & 0x3) == 0); // equiv. to (rawYear%4 == 0)
// Julian calendar day zero is a Saturday
dayOfWeek = (int32_t)uprv_fmod(julianEpochDay-1, 7);
}
// 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
date = dayOfYear -
(isLeap ? kLeapNumDays[month] : kNumDays[month]) + 1; // one-based DOM
// Normalize day of week
dayOfWeek += (dayOfWeek < 0) ? (SUNDAY+7) : SUNDAY;
era = AD;
year = rawYear;
if (year < 1) {
era = BC;
year = 1 - year;
}
// Adjust the doy for the cutover year. Do this AFTER the above
// computations using doy! [j81 - aliu]
if (rawYear == fGregorianCutoverYear &&
theTime >= fNormalizedGregorianCutover) {
dayOfYear -= 10;
}
// Calculate year of week of year
internalSet(ERA, era);
internalSet(YEAR, year);
internalSet(MONTH, month + JANUARY); // 0-based
internalSet(DATE, date);
internalSet(DAY_OF_WEEK, dayOfWeek);
internalSet(DAY_OF_YEAR, ++dayOfYear); // Convert from 0-based to 1-based
if (quick)
return;
yearOfWeekOfYear = year;
// Compute the week of the year. Valid week numbers run from 1 to 52
// or 53, depending on the year, the first day of the week, and the
// minimal days in the first week. Days at the start of the year may
// fall into the last week of the previous year; days at the end of
// the year may fall into the first week of the next year.
int32_t relDow = (dayOfWeek + 7 - getFirstDayOfWeek()) % 7; // 0..6
int32_t relDowJan1 = (dayOfWeek - dayOfYear + 701 - getFirstDayOfWeek()) % 7; // 0..6
int32_t woy = (dayOfYear - 1 + relDowJan1) / 7; // 0..53
if ((7 - relDowJan1) >= getMinimalDaysInFirstWeek()) {
++woy;
// Check to see if we are in the last week; if so, we need
// to handle the case in which we are the first week of the
// next year.
int32_t lastDoy = yearLength();
int32_t lastRelDow = (relDow + lastDoy - dayOfYear) % 7;
if (lastRelDow < 0) lastRelDow += 7;
if (dayOfYear > 359 && // Fast check which eliminates most cases
(6 - lastRelDow) >= getMinimalDaysInFirstWeek() &&
(dayOfYear + 7 - relDow) > lastDoy) {
woy = 1;
yearOfWeekOfYear++;
}
}
else if (woy == 0) {
// We are the last week of the previous year.
int32_t prevDoy = dayOfYear + yearLength(rawYear - 1);
woy = weekNumber(prevDoy, dayOfWeek);
yearOfWeekOfYear--;
}
internalSet(WEEK_OF_YEAR, woy);
internalSet(YEAR_WOY, yearOfWeekOfYear);
internalSet(WEEK_OF_MONTH, weekNumber(date, dayOfWeek));
internalSet(DAY_OF_WEEK_IN_MONTH, (date-1) / 7 + 1);
// Calculate localized day of week
locDayOfWeek = dayOfWeek-getFirstDayOfWeek()+1;
locDayOfWeek += (locDayOfWeek<1?7:0);
internalSet(DOW_LOCAL, locDayOfWeek);
}
// -------------------------------------
/**
* 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 dayOfPeriod 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.
*/
int32_t
GregorianCalendar::weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek)
{
// Determine the day of the week of the first day of the period
// in question (either a year or a month). Zero represents the
// first day of the week on this calendar.
int32_t periodStartDayOfWeek = (dayOfWeek - getFirstDayOfWeek() - dayOfPeriod + 1) % 7;
if (periodStartDayOfWeek < 0)
periodStartDayOfWeek += 7;
// Compute the week number. Initially, ignore the first week, which
// may be fractional (or may not be). We add periodStartDayOfWeek in
// order to fill out the first week, if it is fractional.
int32_t weekNo = (dayOfPeriod + periodStartDayOfWeek - 1)/7;
// If the first week is long enough, then count it. If
// the minimal days in the first week is one, or if the period start
// is zero, we always increment weekNo.
if ((7 - periodStartDayOfWeek) >= getMinimalDaysInFirstWeek())
++weekNo;
return weekNo;
}
// -------------------------------------
int32_t
GregorianCalendar::monthLength(int32_t month) const
{
int32_t year = internalGet(YEAR);
if(internalGetEra() == BC) {
year = 1 - year;
}
return monthLength(month, year);
}
// -------------------------------------
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(YEAR)) ? 366 : 365;
}
// -------------------------------------
/**
* Overrides Calendar
* Converts UTC as milliseconds to time field values.
* The time is not
* recomputed first; to recompute the time, then the fields, call the
* complete method.
* @see Calendar#complete
*/
void
GregorianCalendar::computeFields(UErrorCode& status)
{
if (U_FAILURE(status))
return;
int32_t rawOffset = getTimeZone().getRawOffset();
double localMillis = internalGetTime() + rawOffset;
/* Check for very extreme values -- millis near Long.MIN_VALUE or
* Long.MAX_VALUE. For these values, adding the zone offset can push
* the millis past MAX_VALUE to MIN_VALUE, or vice versa. This produces
* the undesirable effect that the time can wrap around at the ends,
* yielding, for example, a UDate(Long.MAX_VALUE) with a big BC year
* (should be AD). Handle this by pinning such values to Long.MIN_VALUE
* or Long.MAX_VALUE. - liu 8/11/98 bug 4149677 */
/* {sfb} 9/04/98
* Since in C++ we use doubles instead of longs for dates, there is
* an inherent loss of range in the calendar (because in Java you have all 64
* bits to store data, while in C++ you have only 52 bits of mantissa.
* So, I will pin to these (2^52 - 1) values instead */
if(internalGetTime() > 0 && localMillis < 0 && rawOffset > 0) {
localMillis = LATEST_SUPPORTED_MILLIS;
}
else if(internalGetTime() < 0 && localMillis > 0 && rawOffset < 0) {
localMillis = EARLIEST_SUPPORTED_MILLIS;
}
// Time to fields takes the wall millis (Standard or DST).
timeToFields(localMillis, FALSE, status);
uint8_t era = (uint8_t) internalGetEra();
int32_t year = internalGet(YEAR);
int32_t month = internalGet(MONTH);
int32_t date = internalGet(DATE);
uint8_t dayOfWeek = (uint8_t) internalGet(DAY_OF_WEEK);
double days = uprv_floor(localMillis / kOneDay);
int32_t millisInDay = (int32_t) (localMillis - (days * kOneDay));
if (millisInDay < 0)
millisInDay += U_MILLIS_PER_DAY;
// Call getOffset() to get the TimeZone offset. The millisInDay value must
// be standard local millis.
int32_t dstOffset = getTimeZone().getOffset(era, year, month, date, dayOfWeek, millisInDay,
monthLength(month), status) - rawOffset;
if(U_FAILURE(status))
return;
// Adjust our millisInDay for DST, if necessary.
millisInDay += dstOffset;
// If DST has pushed us into the next day, we must call timeToFields() again.
// This happens in DST between 12:00 am and 1:00 am every day. The call to
// timeToFields() will give the wrong day, since the Standard time is in the
// previous day.
if (millisInDay >= U_MILLIS_PER_DAY) {
UDate dstMillis = localMillis + dstOffset;
millisInDay -= U_MILLIS_PER_DAY;
// As above, check for and pin extreme values
if(localMillis > 0 && dstMillis < 0 && dstOffset > 0) {
dstMillis = LATEST_SUPPORTED_MILLIS;
}
else if(localMillis < 0 && dstMillis > 0 && dstOffset < 0) {
dstMillis = EARLIEST_SUPPORTED_MILLIS;
}
timeToFields(dstMillis, FALSE, status);
}
// Fill in all time-related fields based on millisInDay. Call internalSet()
// so as not to perturb flags.
internalSet(MILLISECOND, millisInDay % 1000);
millisInDay /= 1000;
internalSet(SECOND, millisInDay % 60);
millisInDay /= 60;
internalSet(MINUTE, millisInDay % 60);
millisInDay /= 60;
internalSet(HOUR_OF_DAY, millisInDay);
internalSet(AM_PM, millisInDay / 12); // Assume AM == 0
internalSet(HOUR, millisInDay % 12);
internalSet(ZONE_OFFSET, rawOffset);
internalSet(DST_OFFSET, dstOffset);
// Careful here: We are manually setting the time stamps[] flags to
// INTERNALLY_SET, so we must be sure that the above code actually does
// set all these fields.
for (int i=0; i monthLen)
set(DAY_OF_MONTH, monthLen);
}
// -------------------------------------
UBool
GregorianCalendar::validateFields() const
{
for (int32_t field = 0; field < FIELD_COUNT; field++) {
// Ignore DATE and DAY_OF_YEAR which are handled below
if (field != DATE &&
field != DAY_OF_YEAR &&
isSet((EDateFields)field) &&
! boundsCheck(internalGet((EDateFields)field), (EDateFields)field))
return FALSE;
}
// Values differ in Least-Maximum and Maximum should be handled
// specially.
if (isSet(DATE)) {
int32_t date = internalGet(DATE);
if (date < getMinimum(DATE) ||
date > monthLength(internalGet(MONTH))) {
return FALSE;
}
}
if (isSet(DAY_OF_YEAR)) {
int32_t days = internalGet(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(DAY_OF_WEEK_IN_MONTH) &&
0 == internalGet(DAY_OF_WEEK_IN_MONTH))
return FALSE;
return TRUE;
}
// -------------------------------------
UBool
GregorianCalendar::boundsCheck(int32_t value, EDateFields 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(ZONE_OFFSET) + internalGet(DST_OFFSET))/1000;
// {sfb} force conversion to double
return uprv_trunc(wallSec / (kOneDay/1000.0));
//return floorDivide(wallSec, kOneDay/1000.0);
}
// -------------------------------------
void
GregorianCalendar::computeTime(UErrorCode& status)
{
if (U_FAILURE(status))
return;
if (! isLenient() && ! validateFields()) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
// This function takes advantage of the fact that unset fields in
// the time field list have a value of zero.
// The year is either the YEAR or the epoch year. YEAR_WOY is
// used only if WOY is the predominant field; see computeJulianDay.
int32_t year = (fStamp[YEAR] != kUnset) ? internalGet(YEAR) : kEpochYear;
int32_t era = AD;
if (fStamp[ERA] != kUnset) {
era = internalGet(ERA);
if (era == BC)
year = 1 - year;
// Even in lenient mode we disallow ERA values other than AD & BC
else if (era != AD) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
}
// First, use the year to determine whether to use the Gregorian or the
// Julian calendar. If the year is not the year of the cutover, this
// computation will be correct. But if the year is the cutover year,
// this may be incorrect. In that case, assume the Gregorian calendar,
// make the computation, and then recompute if the resultant millis
// indicate the wrong calendar has been assumed.
// A date such as Oct. 10, 1582 does not exist in a Gregorian calendar
// with the default changeover of Oct. 15, 1582, since in such a
// calendar Oct. 4 (Julian) is followed by Oct. 15 (Gregorian). This
// algorithm will interpret such a date using the Julian calendar,
// yielding Oct. 20, 1582 (Gregorian).
UBool isGregorian = year >= fGregorianCutoverYear;
double julianDay = computeJulianDay(isGregorian, year);
double millis = julianDayToMillis(julianDay);
// The following check handles portions of the cutover year BEFORE the
// cutover itself happens. The check for the julianDate number is for a
// rare case; it's a hardcoded number, but it's efficient. The given
// Julian day number corresponds to Dec 3, 292269055 BC, which
// corresponds to millis near Long.MIN_VALUE. The need for the check
// arises because for extremely negative Julian day numbers, the millis
// actually overflow to be positive values. Without the check, the
// initial date is interpreted with the Gregorian calendar, even when
// the cutover doesn't warrant it.
if (isGregorian != (millis >= fNormalizedGregorianCutover) &&
julianDay != -106749550580.0) { // See above
julianDay = computeJulianDay(!isGregorian, year);
millis = julianDayToMillis(julianDay);
}
// Do the time portion of the conversion.
int32_t millisInDay = 0;
// Find the best set of fields specifying the time of day. There
// are only two possibilities here; the HOUR_OF_DAY or the
// AM_PM and the HOUR.
int32_t hourOfDayStamp = fStamp[HOUR_OF_DAY];
int32_t hourStamp = fStamp[HOUR];
int32_t bestStamp = (hourStamp > hourOfDayStamp) ? hourStamp : hourOfDayStamp;
// Hours
if (bestStamp != kUnset) {
if (bestStamp == hourOfDayStamp)
// Don't normalize here; let overflow bump into the next period.
// This is consistent with how we handle other fields.
millisInDay += internalGet(HOUR_OF_DAY);
else {
// Don't normalize here; let overflow bump into the next period.
// This is consistent with how we handle other fields.
millisInDay += internalGet(HOUR);
millisInDay += 12 * internalGet(AM_PM); // Default works for unset AM_PM
}
}
// We use the fact that unset == 0; we start with millisInDay
// == HOUR_OF_DAY.
millisInDay *= 60;
millisInDay += internalGet(MINUTE); // now have minutes
millisInDay *= 60;
millisInDay += internalGet(SECOND); // now have seconds
millisInDay *= 1000;
millisInDay += internalGet(MILLISECOND); // now have millis
// Compute the time zone offset and DST offset. There are two potential
// ambiguities here. We'll assume a 2:00 am (wall time) switchover time
// for discussion purposes here.
// 1. The transition into DST. Here, a designated time of 2:00 am - 2:59 am
// can be in standard or in DST depending. However, 2:00 am is an invalid
// representation (the representation jumps from 1:59:59 am Std to 3:00:00 am DST).
// We assume standard time.
// 2. The transition out of DST. Here, a designated time of 1:00 am - 1:59 am
// can be in standard or DST. Both are valid representations (the rep
// jumps from 1:59:59 DST to 1:00:00 Std).
// Again, we assume standard time.
// We use the TimeZone object, unless the user has explicitly set the ZONE_OFFSET
// or DST_OFFSET fields; then we use those fields.
const TimeZone& zone = getTimeZone();
int32_t zoneOffset = (fStamp[ZONE_OFFSET] >= kMinimumUserStamp)
/*isSet(ZONE_OFFSET) && userSetZoneOffset*/ ?
internalGet(ZONE_OFFSET) : zone.getRawOffset();
// Now add date and millisInDay together, to make millis contain local wall
// millis, with no zone or DST adjustments
millis += millisInDay;
int32_t dstOffset = 0;
if (fStamp[ZONE_OFFSET] >= kMinimumUserStamp
/*isSet(DST_OFFSET) && userSetDSTOffset*/)
dstOffset = internalGet(DST_OFFSET);
else {
/* Normalize the millisInDay to 0..ONE_DAY-1. If the millis is out
* of range, then we must call timeToFields() to recompute our
* fields. */
int32_t normalizedMillisInDay [1];
floorDivide(millis, (int32_t)kOneDay, normalizedMillisInDay);
// We need to have the month, the day, and the day of the week.
// Calling timeToFields will compute the MONTH and DATE fields.
// If we're lenient then we need to call timeToFields() to
// normalize the year, month, and date numbers.
uint8_t dow;
if (isLenient() || fStamp[MONTH] == kUnset || fStamp[DATE] == kUnset
|| millisInDay != normalizedMillisInDay[0]) {
timeToFields(millis, TRUE, status); // Use wall time; true == do quick computation
dow = (uint8_t) internalGet(DAY_OF_WEEK); // DOW is computed by timeToFields
}
else {
// It's tempting to try to use DAY_OF_WEEK here, if it
// is set, but we CAN'T. Even if it's set, it might have
// been set wrong by the user. We should rely only on
// the Julian day number, which has been computed correctly
// using the disambiguation algorithm above. [LIU]
dow = julianDayToDayOfWeek(julianDay);
}
// It's tempting to try to use DAY_OF_WEEK here, if it
// is set, but we CAN'T. Even if it's set, it might have
// been set wrong by the user. We should rely only on
// the Julian day number, which has been computed correctly
// using the disambiguation algorithm above. [LIU]
dstOffset = zone.getOffset((uint8_t)era,
internalGet(YEAR),
internalGet(MONTH),
internalGet(DATE),
dow,
normalizedMillisInDay[0],
monthLength(internalGet(MONTH)),
status) -
zoneOffset;
// Note: Because we pass in wall millisInDay, rather than
// standard millisInDay, we interpret "1:00 am" on the day
// of cessation of DST as "1:00 am Std" (assuming the time
// of cessation is 2:00 am).
}
// Store our final computed GMT time, with timezone adjustments.
internalSetTime(millis - zoneOffset - dstOffset);
}
// -------------------------------------
/**
* 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 + 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 += floorDivide(y, 400) - floorDivide(y, 100) + 2;
}
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[DOW_LOCAL] > fStamp[DAY_OF_WEEK]) {
relDow = internalGet(DOW_LOCAL) - 1; // 1-based
} else if (fStamp[DAY_OF_WEEK] != kUnset) {
relDow = internalGet(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(WEEK_OF_YEAR) - 1))
// Adjust for the DOW
+ computeRelativeDOW();
}
double
GregorianCalendar::computeJulianDay(UBool isGregorian, int32_t year)
{
// Find the most recent set of fields specifying the day within
// the year. These may be any of the following combinations:
// MONTH* + DAY_OF_MONTH*
// MONTH* + WEEK_OF_MONTH* + DAY_OF_WEEK
// MONTH* + DAY_OF_WEEK_IN_MONTH* + DAY_OF_WEEK
// DAY_OF_YEAR*
// WEEK_OF_YEAR* + DAY_OF_WEEK*
// WEEK_OF_YEAR* + DOW_LOCAL
// We look for the most recent of the fields marked thus*. If other
// fields are missing, we use their default values, which are those of
// the epoch start, or in the case of DAY_OF_WEEK, the first day in
// the week.
int32_t monthStamp = fStamp[MONTH];
int32_t domStamp = fStamp[DAY_OF_MONTH];
int32_t womStamp = fStamp[WEEK_OF_MONTH];
int32_t dowimStamp = fStamp[DAY_OF_WEEK_IN_MONTH];
int32_t doyStamp = fStamp[DAY_OF_YEAR];
int32_t woyStamp = fStamp[WEEK_OF_YEAR];
UBool isLeap;
double julianDay;
int32_t bestStamp = (monthStamp > domStamp) ? monthStamp : domStamp;
if (womStamp > bestStamp) bestStamp = womStamp;
if (dowimStamp > bestStamp) bestStamp = dowimStamp;
if (doyStamp > bestStamp) bestStamp = doyStamp;
if (woyStamp >= bestStamp) {
// Note use of >= here, rather than >. We will see woy ==
// best if (a) all stamps are unset, in which case the
// specific handling of unset will be used below, or (b) all
// stamps are kInternallySet. In the latter case we want to
// use the YEAR_WOY if it is newer.
if (fStamp[YEAR_WOY] > fStamp[YEAR]) {
year = internalGet(YEAR_WOY);
if (fStamp[ERA] != kUnset && internalGet(ERA) == BC) {
year = 1 - year;
}
// Only the WOY algorithm correctly handles YEAR_WOY, so
// force its use by making its stamp the most recent.
// This only affects the situation in which all stamps are
// equal (see above).
bestStamp = ++woyStamp;
} else if (woyStamp > bestStamp) {
// The WOY stamp is not only equal to, but newer than any
// other stamp. This means the WOY has been explicitly
// set, and will be used for computation.
bestStamp = woyStamp;
if (fStamp[YEAR_WOY] != kUnset && fStamp[YEAR_WOY] >= fStamp[YEAR]) {
// The YEAR_WOY is set, and is not superceded by the
// YEAR; use it.
year = internalGet(YEAR_WOY);
}
/* At this point we cannot avoid using the WEEK_OF_YEAR together
* with the YEAR field, since the YEAR_WOY is unavailable. Our goal
* is round-trip field integrity. We cannot guarantee round-trip
* time integrity because the YEAR + WOY combination may be
* ambiguous; consider a calendar with MDFW 3 and FDW Sunday. YEAR
* 1997 + WOY 1 + DOW Wednesday specifies two days: Jan 1 1997, and
* Dec 31 1997. However, we can guarantee that the YEAR fields, as
* set, will remain unchanged.
*
* In general, YEAR and YEAR_WOY are equal, but at the ends of the
* years, the YEAR and YEAR_WOY can differ by one. To detect this
* in WOY 1, we look at the position of WOY 1. If it extends into
* the previous year, then we check the DOW and see if it falls in
* the previous year. If so, we increment the year. This allows us
* to have round-trip integrity on the YEAR field.
*
* If the WOY is >= 52, then we do an intial computation of the DOY
* for the current year. If this exceeds the length of this year,
* we decrement the year. Again, this provides round-trip integrity
* on the YEAR field. - aliu
*/
else if (internalGet(WEEK_OF_YEAR) == 1) {
// YEAR_WOY has not been set, so we must use the YEAR.
// Since WOY computations rely on the YEAR_WOY, not the
// YEAR, we must guess at its value. It is usually equal
// to the YEAR, but may be one greater in WOY 1, and may
// be one less in WOY >= 52. Note that YEAR + WOY is
// ambiguous (YEAR_WOY + WOY is not).
// FDW = Mon, MDFW = 2, Mon Dec 27 1999, WOY 1, YEAR_WOY 2000
// Find out where WOY 1 falls; some of it may extend
// into the previous year. If so, and if the DOW is
// one of those days, then increment the YEAR_WOY.
julianDay = computeJulianDayOfYear(isGregorian, year, isLeap);
int32_t fdy = computeRelativeDOW(1 + julianDay);
int32_t doy =
(((7 - fdy) < getMinimalDaysInFirstWeek())
? (8 - fdy) : (1 - fdy));
if (doy < 1) {
// Some of WOY 1 for YEAR year extends into YEAR
// year-1 if doy < 1. doy == 0 -- 1 day of WOY 1
// in previous year; doy == -1 -- 2 days, etc.
// Compute the day of week, relative to the first day of week,
// from 0..6.
int32_t relDow = computeRelativeDOW();
// Range of days that are in YEAR year (as opposed
// to YEAR year-1) are DOY == 1..6+doy. Range of
// days of the week in YEAR year are fdy..fdy + 5
// + doy. These are relative DOWs.
if ((relDow < fdy) || (relDow > (fdy + 5 + doy))) {
++year;
}
}
} else if (internalGet(WEEK_OF_YEAR) >= 52) {
// FDW = Mon, MDFW = 4, Sat Jan 01 2000, WOY 52, YEAR_WOY 1999
julianDay = computeJulianDayOfYear(isGregorian, year, isLeap);
if (computeDOYfromWOY(julianDay) > yearLength(year)) {
--year;
}
// It's tempting to take our julianDay and DOY here, in an else
// clause, and return them, since they are correct. However,
// this neglects the cutover adjustment, and it's easier to
// maintain the code if everything goes through the same control
// path below. - aliu
}
}
}
// The following if() clause checks if the month field
// predominates. This set of computations must be done BEFORE
// using the year, since the year value may be adjusted here.
UBool useMonth = FALSE;
int32_t month = 0;
if (bestStamp != kUnset &&
(bestStamp == monthStamp ||
bestStamp == domStamp ||
bestStamp == womStamp ||
bestStamp == dowimStamp)) {
useMonth = TRUE;
// We have the month specified. Make it 0-based for the algorithm.
month = (monthStamp != kUnset) ? internalGet(MONTH) - JANUARY : 0;
// If the month is out of range, adjust it into range
if (month < 0 || month > 11) {
int32_t rem[1];
year += floorDivide(month, 12, rem);
month = rem[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).
julianDay = computeJulianDayOfYear(isGregorian, year, isLeap);
if (useMonth) {
// Move julianDay to the day BEFORE the first of the month.
julianDay += isLeap ? kLeapNumDays[month] : kNumDays[month];
int32_t date = 0;
if (bestStamp == domStamp ||
bestStamp == monthStamp) {
date = (domStamp != kUnset) ? internalGet(DAY_OF_MONTH) : 1;
}
else { // assert(bestStamp == womStamp || bestStamp == dowimStamp)
// Compute from day of week plus week number or from the day of
// week plus the day of week in month. The computations are
// almost identical.
// Find the day of the week for the first of this month. This
// is zero-based, with 0 being the locale-specific first day of
// the week. Add 1 to get first day of month.
int32_t fdm = computeRelativeDOW(julianDay + 1);
// Find the start of the first week. This will be a date from
// 1..-6. It represents the locale-specific first day of the
// week of the first day of the month, ignoring minimal days in
// first week.
date = 1 - fdm + ((fStamp[DAY_OF_WEEK] != kUnset) ?
(internalGet(DAY_OF_WEEK) - getFirstDayOfWeek()) : 0);
if (bestStamp == womStamp) {
// Adjust for minimal days in first week.
if ((7 - fdm) < getMinimalDaysInFirstWeek())
date += 7;
// Now adjust for the week number.
date += 7 * (internalGet(WEEK_OF_MONTH) - 1);
}
else { // assert(bestStamp == dowimStamp)
// Adjust into the month, if needed.
if (date < 1) date += 7;
// We are basing this on the day-of-week-in-month. The only
// trickiness occurs if the day-of-week-in-month is
// negative.
int32_t dim = internalGet(DAY_OF_WEEK_IN_MONTH);
if (dim >= 0) {
date += 7*(dim - 1);
} else {
// Move date to the last of this day-of-week in this
// month, then back up as needed. If dim==-1, we don't
// back up at all. If dim==-2, we back up once, etc.
// Don't back up past the first of the given day-of-week
// in this month. Note that we handle -2, -3,
// etc. correctly, even though values < -1 are
// technically disallowed.
date += ((monthLength(internalGet(MONTH), year) - date) / 7 + dim + 1) * 7;
}
}
}
julianDay += date;
}
else {
// assert(bestStamp == doyStamp || bestStamp == woyStamp ||
// bestStamp == UNSET). In the last case we should use January 1.
// No month, start with January 0 (day before Jan 1), then adjust.
int32_t doy = 0;
UBool doCutoverAdjustment = TRUE;
if (bestStamp == kUnset) {
doy = 1; // Advance to January 1
doCutoverAdjustment = FALSE;
}
else if (bestStamp == doyStamp) {
doy = internalGet(DAY_OF_YEAR);
}
else if (bestStamp == woyStamp) {
doy = computeDOYfromWOY(julianDay);
}
// Adjust for cutover year [j81 - aliu]
if (doCutoverAdjustment && year == fGregorianCutoverYear && isGregorian) {
doy -= 10;
}
julianDay += doy;
}
return julianDay;
}
// -------------------------------------
double
GregorianCalendar::millisToJulianDay(UDate millis)
{
return (double)kEpochStartAsJulianDay + floorDivide(millis, kOneDay);
//return kEpochStartAsJulianDay + uprv_trunc(millis / kOneDay);
}
// -------------------------------------
UDate
GregorianCalendar::julianDayToMillis(double julian)
{
return (UDate) ((julian - kEpochStartAsJulianDay) * (double) kOneDay);
}
// -------------------------------------
double
GregorianCalendar::floorDivide(double numerator, double denominator)
{
return uprv_floor(numerator / denominator);
}
// -------------------------------------
int32_t
GregorianCalendar::floorDivide(int32_t numerator, int32_t denominator)
{
// We do this computation in order to handle
// a numerator of Long.MIN_VALUE correctly
return (numerator >= 0) ?
numerator / denominator :
((numerator + 1) / denominator) - 1;
}
// -------------------------------------
int32_t
GregorianCalendar::floorDivide(int32_t numerator, int32_t denominator, int32_t remainder[])
{
if (numerator >= 0) {
remainder[0] = numerator % denominator;
return numerator / denominator;
}
int32_t quotient = ((numerator + 1) / denominator) - 1;
remainder[0] = numerator - (quotient * denominator);
return quotient;
}
// -------------------------------------
int32_t
GregorianCalendar::floorDivide(double numerator, int32_t denominator, int32_t remainder[])
{
double quotient;
if (numerator >= 0) {
quotient = uprv_trunc(numerator / denominator);
remainder[0] = (int32_t)uprv_fmod(numerator, denominator);
} else {
quotient = uprv_trunc((numerator + 1) / denominator) - 1;
remainder[0] = (int32_t)(numerator - (quotient * denominator));
}
if (quotient < INT32_MIN || quotient > INT32_MAX) {
// Normalize out of range values. It doesn't matter what
// we return for these cases; the data is wrong anyway. This
// only occurs for years near 2,000,000,000 CE/BCE.
quotient = 0.0; // Or whatever
}
return (int32_t)quotient;
}
// -------------------------------------
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)
: kUnset));
}
// -------------------------------------
void
GregorianCalendar::add(EDateFields field, int32_t amount, UErrorCode& status)
{
if (U_FAILURE(status))
return;
if (amount == 0)
return; // Do nothing!
complete(status);
if (field == YEAR || field == YEAR_WOY) {
int32_t year = internalGet(field);
int32_t era = internalGetEra();
year += (era == AD) ? amount : -amount;
if (year > 0)
set(field, year);
else { // year <= 0
set(field, 1 - year);
// if year == 0, you get 1 BC
set(ERA, (AD + BC) - era);
}
pinDayOfMonth();
}
else if (field == MONTH) {
int32_t month = internalGet(MONTH) + amount;
if (month >= 0) {
add(YEAR, (int32_t) (month / 12), status);
set(MONTH, (int32_t) (month % 12));
}
else { // month < 0
add(YEAR, (int32_t) ((month + 1) / 12) - 1, status);
month %= 12;
if (month < 0)
month += 12;
set(MONTH, JANUARY + month);
}
pinDayOfMonth();
}
else if (field == ERA) {
int32_t era = internalGet(ERA) + amount;
if (era < 0)
era = 0;
if (era > 1)
era = 1;
set(ERA, era);
}
else {
// We handle most fields here. The algorithm is to add a computed amount
// of millis to the current millis. The only wrinkle is with DST -- if
// the result of the add operation is to move from DST to Standard, or vice
// versa, we need to adjust by an hour forward or back, respectively.
// Otherwise you get weird effects in which the hour seems to shift when
// you add to the DAY_OF_MONTH field, for instance.
// We only adjust the DST for fields larger than an hour. For fields
// smaller than an hour, we cannot adjust for DST without causing problems.
// for instance, if you add one hour to April 5, 1998, 1:00 AM, in PST,
// the time becomes "2:00 AM PDT" (an illegal value), but then the adjustment
// sees the change and compensates by subtracting an hour. As a result the
// time doesn't advance at all.
// {sfb} do we want to use a double here, or a int32_t?
// probably a double, since if we used a int32_t in the
// WEEK_OF_YEAR clause below, if delta was greater than approx.
// 7.1 we would reach the limit of a int32_t
double delta = amount;
UBool adjustDST = TRUE;
switch (field) {
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
delta *= 7 * 24 * 60 * 60 * 1000; // 7 days
break;
case AM_PM:
delta *= 12 * 60 * 60 * 1000; // 12 hrs
break;
case DATE: // synonym of DAY_OF_MONTH
case DAY_OF_YEAR:
case DAY_OF_WEEK:
case DOW_LOCAL:
delta *= 24 * 60 * 60 * 1000; // 1 day
break;
case HOUR_OF_DAY:
case HOUR:
delta *= 60 * 60 * 1000; // 1 hour
adjustDST = FALSE;
break;
case MINUTE:
delta *= 60 * 1000; // 1 minute
adjustDST = FALSE;
break;
case SECOND:
delta *= 1000; // 1 second
adjustDST = FALSE;
break;
case MILLISECOND:
adjustDST = FALSE;
break;
case ZONE_OFFSET:
case DST_OFFSET:
default:
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
// Save the current DST state.
int32_t dst = 0;
if (adjustDST)
dst = internalGet(DST_OFFSET);
setTimeInMillis(internalGetTime() + delta, status); // Automatically computes fields if necessary
if (adjustDST) {
// Now do the DST adjustment alluded to above.
// Only call setTimeInMillis if necessary, because it's an expensive call.
dst -= internalGet(DST_OFFSET);
if(dst!= 0)
setTimeInMillis(internalGetTime() + dst, status);
}
}
}
// -------------------------------------
/**
* 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)
{
if(U_FAILURE(status))
return;
if (amount == 0)
return; // Nothing to do
int32_t min = 0, max = 0, gap;
if (field >= 0 && field < FIELD_COUNT) {
complete(status);
min = getMinimum(field);
max = getMaximum(field);
}
/* Some of the fields require special handling to work in the month
* containing the Gregorian cutover point. Do shared computations
* for these fields here. [j81 - aliu] */
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
if (field == DAY_OF_MONTH || field == WEEK_OF_MONTH) {
max = monthLength(internalGet(MONTH));
double 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(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;
}
}
switch (field) {
case ERA:
case YEAR:
case YEAR_WOY:
case AM_PM:
case MINUTE:
case SECOND:
case MILLISECOND:
// These fields are handled simply, since they have fixed minima
// and maxima. The field DAY_OF_MONTH is almost as simple. Other
// fields are complicated, since the range within they must roll
// varies depending on the date.
break;
case HOUR:
case HOUR_OF_DAY:
// Rolling the hour is difficult on the ONSET and CEASE days of
// daylight savings. For example, if the change occurs at
// 2 AM, we have the following progression:
// ONSET: 12 Std -> 1 Std -> 3 Dst -> 4 Dst
// CEASE: 12 Dst -> 1 Dst -> 1 Std -> 2 Std
// To get around this problem we don't use fields; we manipulate
// the time in millis directly.
{
// Assume min == 0 in calculations below
UDate start = getTime(status);
int32_t oldHour = internalGet(field);
int32_t newHour = (oldHour + amount) % (max + 1);
if(newHour < 0)
newHour += max + 1;
setTime(start + ((double)kOneHour * (newHour - oldHour)), status);
return;
}
case MONTH:
// Rolling the month involves both pinning the final value to [0, 11]
// and adjusting the DAY_OF_MONTH if necessary. We only adjust the
// DAY_OF_MONTH if, after updating the MONTH field, it is illegal.
// E.g., .roll(MONTH, 1) -> or .
{
int32_t mon = (internalGet(MONTH) + amount) % 12;
if (mon < 0)
mon += 12;
set(MONTH, mon);
// Keep the day of month in range. We don't want to spill over
// into the next month; e.g., we don't want jan31 + 1 mo -> feb31 ->
// mar3.
// NOTE: We could optimize this later by checking for dom <= 28
// first. Do this if there appears to be a need. [LIU]
int32_t monthLen = monthLength(mon);
int32_t dom = internalGet(DAY_OF_MONTH);
if (dom > monthLen)
set(DAY_OF_MONTH, monthLen);
return;
}
case WEEK_OF_YEAR:
{
// Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
// week. However, 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 = internalGet(WEEK_OF_YEAR);
// Get the ISO year, which matches the week of year. This
// may be one year before or after the calendar year.
int32_t isoYear = internalGet(YEAR_WOY);
int32_t isoDoy = internalGet(DAY_OF_YEAR);
if (internalGet(MONTH) == Calendar::JANUARY) {
if (woy >= 52) {
isoDoy += yearLength(isoYear);
}
}
else {
if (woy == 1) {
isoDoy -= yearLength(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 = yearLength(isoYear);
int32_t lastRelDow = (lastDoy - isoDoy + internalGet(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(WEEK_OF_YEAR, woy);
set(YEAR_WOY, isoYear); // make YEAR_WOY timestamp > YEAR timestamp
return;
}
case WEEK_OF_MONTH:
{
// 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(DAY_OF_WEEK) - getFirstDayOfWeek();
if (dow < 0)
dow += 7;
// Find the day of month, compensating for cutover discontinuity.
int32_t dom = inCutoverMonth ? cDayOfMonth : internalGet(DAY_OF_MONTH);
// 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 = inCutoverMonth ? cMonthLen : monthLength(internalGet(MONTH));
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).
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.
if (inCutoverMonth) {
setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
} else {
set(DAY_OF_MONTH, newDom);
}
return;
}
case DAY_OF_MONTH:
if (inCutoverMonth) {
// 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;
}
setTimeInMillis(cMonthStart + msIntoMonth, status);
return;
} else {
max = monthLength(internalGet(MONTH));
// ...else fall through to default computation
}
break;
case DAY_OF_YEAR:
{
// Roll the day of year using millis. Compute the millis for
// the start of the year, and get the length of the year.
double delta = amount * kOneDay; // Scale up from days to millis
double min2 = internalGetTime() - (internalGet(DAY_OF_YEAR) - 1) * kOneDay;
int32_t yearLen = yearLength();
internalSetTime( uprv_fmod((internalGetTime() + delta - min2), (yearLen * kOneDay)));
if (internalGetTime() < 0)
internalSetTime( internalGetTime() + yearLen * kOneDay);
setTimeInMillis(internalGetTime() + min2, status);
return;
}
case DAY_OF_WEEK:
case DOW_LOCAL:
{
// Roll the day of week using millis. Compute the millis for
// the start of the week, using the first day of week setting.
// Restrict the millis to [start, start+7days).
double delta = amount * kOneDay; // Scale up from days to millis
// Compute the number of days before the current day in this
// week. This will be a value 0..6.
int32_t leadDays = internalGet(field) -
((field == DAY_OF_WEEK) ? getFirstDayOfWeek() : 1);
if (leadDays < 0)
leadDays += 7;
double min2 = internalGetTime() - leadDays * kOneDay;
internalSetTime(uprv_fmod((internalGetTime() + delta - min2), kOneWeek));
if (internalGetTime() < 0)
internalSetTime(internalGetTime() + kOneWeek);
setTimeInMillis(internalGetTime() + min2, status);
return;
}
case DAY_OF_WEEK_IN_MONTH:
{
// Roll the day of week in the month using millis. Determine
// the first day of the week in the month, and then the last,
// and then roll within that range.
double delta = amount * kOneWeek; // Scale up from weeks to millis
// Find the number of same days of the week before this one
// in this month.
int32_t preWeeks = (internalGet(DAY_OF_MONTH) - 1) / 7;
// Find the number of same days of the week after this one
// in this month.
int32_t postWeeks = (monthLength(internalGet(MONTH)) - internalGet(DAY_OF_MONTH)) / 7;
// From these compute the min and gap millis for rolling.
double min2 = internalGetTime() - preWeeks * kOneWeek;
double gap2 = kOneWeek * (preWeeks + postWeeks + 1); // Must add 1!
// Roll within this range
internalSetTime(uprv_fmod((internalGetTime() + delta - min2), gap2));
if (internalGetTime() < 0)
internalSetTime(internalGetTime() + gap2);
setTimeInMillis(internalGetTime() + min2, status);
return;
}
case ZONE_OFFSET:
case DST_OFFSET:
default:
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
// These fields cannot be rolled
}
// These are the standard roll instructions. These work for all
// simple cases, that is, cases in which the limits are fixed, such
// as the hour, the month, and the era.
gap = max - min + 1;
int32_t value = internalGet(field) + amount;
value = (value - min) % gap;
if (value < 0)
value += gap;
value += min;
set(field, value);
}
// -------------------------------------
int32_t
GregorianCalendar::getMinimum(EDateFields field) const
{
return kMinValues[field];
}
// -------------------------------------
int32_t
GregorianCalendar::getMaximum(EDateFields field) const
{
return kMaxValues[field];
}
// -------------------------------------
int32_t
GregorianCalendar::getGreatestMinimum(EDateFields field) const
{
return kMinValues[field];
}
// -------------------------------------
int32_t
GregorianCalendar::getLeastMaximum(EDateFields field) const
{
return kLeastMaxValues[field];
}
// -------------------------------------
int32_t
GregorianCalendar::getActualMinimum(EDateFields field) const
{
return getMinimum(field);
}
// -------------------------------------
int32_t
GregorianCalendar::getActualMaximum(EDateFields field) 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 */
UErrorCode status = U_ZERO_ERROR;
switch (field) {
// we have functions that enable us to fast-path number of days in month
// of year
case DAY_OF_MONTH:
return monthLength(get(MONTH, status));
case DAY_OF_YEAR:
return yearLength();
// for week of year, week of month, or day of week in month, we
// just fall back on the default implementation in Calendar (I'm not sure
// we could do better by having special calculations here)
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
return Calendar::getActualMaximum(field, status);
case YEAR:
case YEAR_WOY:
/* 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.
*/
{
Calendar *cal = (Calendar*)this->clone();
cal->setLenient(TRUE);
int32_t era = cal->get(ERA, status);
if(U_FAILURE(status))
return 0;
UDate d = cal->getTime(status);
if(U_FAILURE(status))
return 0;
/* Perform a binary search, with the invariant that lowGood is a
* valid year, and highBad is an out of range year.
*/
int32_t lowGood = kLeastMaxValues[field];
int32_t highBad = kMaxValues[field] + 1;
while((lowGood + 1) < highBad) {
int32_t y = (lowGood + highBad) / 2;
cal->set(field, y);
if(cal->get(field, status) == y && cal->get(ERA, status) == era) {
lowGood = y;
}
else {
highBad = y;
cal->setTime(d, status); // Restore original fields
}
}
delete cal;
return lowGood;
}
// and we know none of the other fields have variable maxima in
// GregorianCalendar, so we can just return the fixed maximum
default:
return getMaximum(field);
}
}
// -------------------------------------
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(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(ERA) ? internalGet(ERA) : AD;
}
//eof