1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 * Copyright (C) 1997-2016, International Business Machines Corporation and
6 * others. All Rights Reserved.
7 *******************************************************************************
8 *
9 * File GREGOCAL.CPP
10 *
11 * Modification History:
12 *
13 * Date Name Description
14 * 02/05/97 clhuang Creation.
15 * 03/28/97 aliu Made highly questionable fix to computeFields to
16 * handle DST correctly.
17 * 04/22/97 aliu Cleaned up code drastically. Added monthLength().
18 * Finished unimplemented parts of computeTime() for
19 * week-based date determination. Removed quetionable
20 * fix and wrote correct fix for computeFields() and
21 * daylight time handling. Rewrote inDaylightTime()
22 * and computeFields() to handle sensitive Daylight to
23 * Standard time transitions correctly.
24 * 05/08/97 aliu Added code review changes. Fixed isLeapYear() to
25 * not cutover.
26 * 08/12/97 aliu Added equivalentTo. Misc other fixes. Updated
27 * add() from Java source.
28 * 07/28/98 stephen Sync up with JDK 1.2
29 * 09/14/98 stephen Changed type of kOneDay, kOneWeek to double.
30 * Fixed bug in roll()
31 * 10/15/99 aliu Fixed j31, incorrect WEEK_OF_YEAR computation.
32 * 10/15/99 aliu Fixed j32, cannot set date to Feb 29 2000 AD.
33 * {JDK bug 4210209 4209272}
34 * 11/15/99 weiv Added YEAR_WOY and DOW_LOCAL computation
35 * to timeToFields method, updated kMinValues, kMaxValues & kLeastMaxValues
36 * 12/09/99 aliu Fixed j81, calculation errors and roll bugs
37 * in year of cutover.
38 * 01/24/2000 aliu Revised computeJulianDay for YEAR YEAR_WOY WOY.
39 ********************************************************************************
40 */
41
42 #include "unicode/utypes.h"
43 #include <float.h>
44
45 #if !UCONFIG_NO_FORMATTING
46
47 #include "unicode/gregocal.h"
48 #include "gregoimp.h"
49 #include "umutex.h"
50 #include "uassert.h"
51
52 // *****************************************************************************
53 // class GregorianCalendar
54 // *****************************************************************************
55
56 /**
57 * Note that the Julian date used here is not a true Julian date, since
58 * it is measured from midnight, not noon. This value is the Julian
59 * day number of January 1, 1970 (Gregorian calendar) at noon UTC. [LIU]
60 */
61
62 static const int16_t kNumDays[]
63 = {0,31,59,90,120,151,181,212,243,273,304,334}; // 0-based, for day-in-year
64 static const int16_t kLeapNumDays[]
65 = {0,31,60,91,121,152,182,213,244,274,305,335}; // 0-based, for day-in-year
66 static const int8_t kMonthLength[]
67 = {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
68 static const int8_t kLeapMonthLength[]
69 = {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
70
71 // setTimeInMillis() limits the Julian day range to +/-7F000000.
72 // This would seem to limit the year range to:
73 // ms=+183882168921600000 jd=7f000000 December 20, 5828963 AD
74 // ms=-184303902528000000 jd=81000000 September 20, 5838270 BC
75 // HOWEVER, CalendarRegressionTest/Test4167060 shows that the actual
76 // range limit on the year field is smaller (~ +/-140000). [alan 3.0]
77
78 static const int32_t kGregorianCalendarLimits[UCAL_FIELD_COUNT][4] = {
79 // Minimum Greatest Least Maximum
80 // Minimum Maximum
81 { 0, 0, 1, 1}, // ERA
82 { 1, 1, 140742, 144683}, // YEAR
83 { 0, 0, 11, 11}, // MONTH
84 { 1, 1, 52, 53}, // WEEK_OF_YEAR
85 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
86 { 1, 1, 28, 31}, // DAY_OF_MONTH
87 { 1, 1, 365, 366}, // DAY_OF_YEAR
88 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
89 { -1, -1, 4, 5}, // DAY_OF_WEEK_IN_MONTH
90 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
91 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
92 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
93 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
94 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
95 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
96 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
97 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
98 { -140742, -140742, 140742, 144683}, // YEAR_WOY
99 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
100 { -140742, -140742, 140742, 144683}, // EXTENDED_YEAR
101 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
102 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
103 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
104 };
105
106 /*
107 * <pre>
108 * Greatest Least
109 * Field name Minimum Minimum Maximum Maximum
110 * ---------- ------- ------- ------- -------
111 * ERA 0 0 1 1
112 * YEAR 1 1 140742 144683
113 * MONTH 0 0 11 11
114 * WEEK_OF_YEAR 1 1 52 53
115 * WEEK_OF_MONTH 0 0 4 6
116 * DAY_OF_MONTH 1 1 28 31
117 * DAY_OF_YEAR 1 1 365 366
118 * DAY_OF_WEEK 1 1 7 7
119 * DAY_OF_WEEK_IN_MONTH -1 -1 4 5
120 * AM_PM 0 0 1 1
121 * HOUR 0 0 11 11
122 * HOUR_OF_DAY 0 0 23 23
123 * MINUTE 0 0 59 59
124 * SECOND 0 0 59 59
125 * MILLISECOND 0 0 999 999
126 * ZONE_OFFSET -12* -12* 12* 12*
127 * DST_OFFSET 0 0 1* 1*
128 * YEAR_WOY 1 1 140742 144683
129 * DOW_LOCAL 1 1 7 7
130 * </pre>
131 * (*) In units of one-hour
132 */
133
134 #if defined( U_DEBUG_CALSVC ) || defined (U_DEBUG_CAL)
135 #include <stdio.h>
136 #endif
137
138 U_NAMESPACE_BEGIN
139
140 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(GregorianCalendar)
141
142 // 00:00:00 UTC, October 15, 1582, expressed in ms from the epoch.
143 // Note that only Italy and other Catholic countries actually
144 // observed this cutover. Most other countries followed in
145 // the next few centuries, some as late as 1928. [LIU]
146 // in Java, -12219292800000L
147 //const UDate GregorianCalendar::kPapalCutover = -12219292800000L;
148 static const uint32_t kCutoverJulianDay = 2299161;
149 static const UDate kPapalCutover = (2299161.0 - kEpochStartAsJulianDay) * U_MILLIS_PER_DAY;
150 //static const UDate kPapalCutoverJulian = (2299161.0 - kEpochStartAsJulianDay);
151
152 // -------------------------------------
153
GregorianCalendar(UErrorCode & status)154 GregorianCalendar::GregorianCalendar(UErrorCode& status)
155 : Calendar(status),
156 fGregorianCutover(kPapalCutover),
157 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
158 fIsGregorian(TRUE), fInvertGregorian(FALSE)
159 {
160 setTimeInMillis(getNow(), status);
161 }
162
163 // -------------------------------------
164
GregorianCalendar(TimeZone * zone,UErrorCode & status)165 GregorianCalendar::GregorianCalendar(TimeZone* zone, UErrorCode& status)
166 : Calendar(zone, Locale::getDefault(), status),
167 fGregorianCutover(kPapalCutover),
168 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
169 fIsGregorian(TRUE), fInvertGregorian(FALSE)
170 {
171 setTimeInMillis(getNow(), status);
172 }
173
174 // -------------------------------------
175
GregorianCalendar(const TimeZone & zone,UErrorCode & status)176 GregorianCalendar::GregorianCalendar(const TimeZone& zone, UErrorCode& status)
177 : Calendar(zone, Locale::getDefault(), status),
178 fGregorianCutover(kPapalCutover),
179 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
180 fIsGregorian(TRUE), fInvertGregorian(FALSE)
181 {
182 setTimeInMillis(getNow(), status);
183 }
184
185 // -------------------------------------
186
GregorianCalendar(const Locale & aLocale,UErrorCode & status)187 GregorianCalendar::GregorianCalendar(const Locale& aLocale, UErrorCode& status)
188 : Calendar(TimeZone::forLocaleOrDefault(aLocale), aLocale, status),
189 fGregorianCutover(kPapalCutover),
190 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
191 fIsGregorian(TRUE), fInvertGregorian(FALSE)
192 {
193 setTimeInMillis(getNow(), status);
194 }
195
196 // -------------------------------------
197
GregorianCalendar(TimeZone * zone,const Locale & aLocale,UErrorCode & status)198 GregorianCalendar::GregorianCalendar(TimeZone* zone, const Locale& aLocale,
199 UErrorCode& status)
200 : Calendar(zone, aLocale, status),
201 fGregorianCutover(kPapalCutover),
202 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
203 fIsGregorian(TRUE), fInvertGregorian(FALSE)
204 {
205 setTimeInMillis(getNow(), status);
206 }
207
208 // -------------------------------------
209
GregorianCalendar(const TimeZone & zone,const Locale & aLocale,UErrorCode & status)210 GregorianCalendar::GregorianCalendar(const TimeZone& zone, const Locale& aLocale,
211 UErrorCode& status)
212 : Calendar(zone, aLocale, status),
213 fGregorianCutover(kPapalCutover),
214 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
215 fIsGregorian(TRUE), fInvertGregorian(FALSE)
216 {
217 setTimeInMillis(getNow(), status);
218 }
219
220 // -------------------------------------
221
GregorianCalendar(int32_t year,int32_t month,int32_t date,UErrorCode & status)222 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
223 UErrorCode& status)
224 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
225 fGregorianCutover(kPapalCutover),
226 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
227 fIsGregorian(TRUE), fInvertGregorian(FALSE)
228 {
229 set(UCAL_ERA, AD);
230 set(UCAL_YEAR, year);
231 set(UCAL_MONTH, month);
232 set(UCAL_DATE, date);
233 }
234
235 // -------------------------------------
236
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,UErrorCode & status)237 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
238 int32_t hour, int32_t minute, UErrorCode& status)
239 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
240 fGregorianCutover(kPapalCutover),
241 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
242 fIsGregorian(TRUE), fInvertGregorian(FALSE)
243 {
244 set(UCAL_ERA, AD);
245 set(UCAL_YEAR, year);
246 set(UCAL_MONTH, month);
247 set(UCAL_DATE, date);
248 set(UCAL_HOUR_OF_DAY, hour);
249 set(UCAL_MINUTE, minute);
250 }
251
252 // -------------------------------------
253
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,int32_t second,UErrorCode & status)254 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
255 int32_t hour, int32_t minute, int32_t second,
256 UErrorCode& status)
257 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
258 fGregorianCutover(kPapalCutover),
259 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
260 fIsGregorian(TRUE), fInvertGregorian(FALSE)
261 {
262 set(UCAL_ERA, AD);
263 set(UCAL_YEAR, year);
264 set(UCAL_MONTH, month);
265 set(UCAL_DATE, date);
266 set(UCAL_HOUR_OF_DAY, hour);
267 set(UCAL_MINUTE, minute);
268 set(UCAL_SECOND, second);
269 }
270
271 // -------------------------------------
272
~GregorianCalendar()273 GregorianCalendar::~GregorianCalendar()
274 {
275 }
276
277 // -------------------------------------
278
GregorianCalendar(const GregorianCalendar & source)279 GregorianCalendar::GregorianCalendar(const GregorianCalendar &source)
280 : Calendar(source),
281 fGregorianCutover(source.fGregorianCutover),
282 fCutoverJulianDay(source.fCutoverJulianDay), fNormalizedGregorianCutover(source.fNormalizedGregorianCutover), fGregorianCutoverYear(source.fGregorianCutoverYear),
283 fIsGregorian(source.fIsGregorian), fInvertGregorian(source.fInvertGregorian)
284 {
285 }
286
287 // -------------------------------------
288
clone() const289 GregorianCalendar* GregorianCalendar::clone() const
290 {
291 return new GregorianCalendar(*this);
292 }
293
294 // -------------------------------------
295
296 GregorianCalendar &
operator =(const GregorianCalendar & right)297 GregorianCalendar::operator=(const GregorianCalendar &right)
298 {
299 if (this != &right)
300 {
301 Calendar::operator=(right);
302 fGregorianCutover = right.fGregorianCutover;
303 fNormalizedGregorianCutover = right.fNormalizedGregorianCutover;
304 fGregorianCutoverYear = right.fGregorianCutoverYear;
305 fCutoverJulianDay = right.fCutoverJulianDay;
306 }
307 return *this;
308 }
309
310 // -------------------------------------
311
isEquivalentTo(const Calendar & other) const312 UBool GregorianCalendar::isEquivalentTo(const Calendar& other) const
313 {
314 // Calendar override.
315 return Calendar::isEquivalentTo(other) &&
316 fGregorianCutover == ((GregorianCalendar*)&other)->fGregorianCutover;
317 }
318
319 // -------------------------------------
320
321 void
setGregorianChange(UDate date,UErrorCode & status)322 GregorianCalendar::setGregorianChange(UDate date, UErrorCode& status)
323 {
324 if (U_FAILURE(status))
325 return;
326
327 // Precompute two internal variables which we use to do the actual
328 // cutover computations. These are the normalized cutover, which is the
329 // midnight at or before the cutover, and the cutover year. The
330 // normalized cutover is in pure date milliseconds; it contains no time
331 // of day or timezone component, and it used to compare against other
332 // pure date values.
333 double cutoverDay = ClockMath::floorDivide(date, (double)kOneDay);
334
335 // Handle the rare case of numeric overflow where the user specifies a time
336 // outside of INT32_MIN .. INT32_MAX number of days.
337
338 if (cutoverDay <= INT32_MIN) {
339 cutoverDay = INT32_MIN;
340 fGregorianCutover = fNormalizedGregorianCutover = cutoverDay * kOneDay;
341 } else if (cutoverDay >= INT32_MAX) {
342 cutoverDay = INT32_MAX;
343 fGregorianCutover = fNormalizedGregorianCutover = cutoverDay * kOneDay;
344 } else {
345 fNormalizedGregorianCutover = cutoverDay * kOneDay;
346 fGregorianCutover = date;
347 }
348
349 // Normalize the year so BC values are represented as 0 and negative
350 // values.
351 GregorianCalendar *cal = new GregorianCalendar(getTimeZone(), status);
352 /* test for NULL */
353 if (cal == 0) {
354 status = U_MEMORY_ALLOCATION_ERROR;
355 return;
356 }
357 if(U_FAILURE(status))
358 return;
359 cal->setTime(date, status);
360 fGregorianCutoverYear = cal->get(UCAL_YEAR, status);
361 if (cal->get(UCAL_ERA, status) == BC)
362 fGregorianCutoverYear = 1 - fGregorianCutoverYear;
363 fCutoverJulianDay = (int32_t)cutoverDay;
364 delete cal;
365 }
366
367
handleComputeFields(int32_t julianDay,UErrorCode & status)368 void GregorianCalendar::handleComputeFields(int32_t julianDay, UErrorCode& status) {
369 int32_t eyear, month, dayOfMonth, dayOfYear, unusedRemainder;
370
371
372 if(U_FAILURE(status)) {
373 return;
374 }
375
376 #if defined (U_DEBUG_CAL)
377 fprintf(stderr, "%s:%d: jd%d- (greg's %d)- [cut=%d]\n",
378 __FILE__, __LINE__, julianDay, getGregorianDayOfYear(), fCutoverJulianDay);
379 #endif
380
381
382 if (julianDay >= fCutoverJulianDay) {
383 month = getGregorianMonth();
384 dayOfMonth = getGregorianDayOfMonth();
385 dayOfYear = getGregorianDayOfYear();
386 eyear = getGregorianYear();
387 } else {
388 // The Julian epoch day (not the same as Julian Day)
389 // is zero on Saturday December 30, 0 (Gregorian).
390 int32_t julianEpochDay = julianDay - (kJan1_1JulianDay - 2);
391 eyear = (int32_t) ClockMath::floorDivide((4.0*julianEpochDay) + 1464.0, (int32_t) 1461, unusedRemainder);
392
393 // Compute the Julian calendar day number for January 1, eyear
394 int32_t january1 = 365*(eyear-1) + ClockMath::floorDivide(eyear-1, (int32_t)4);
395 dayOfYear = (julianEpochDay - january1); // 0-based
396
397 // Julian leap years occurred historically every 4 years starting
398 // with 8 AD. Before 8 AD the spacing is irregular; every 3 years
399 // from 45 BC to 9 BC, and then none until 8 AD. However, we don't
400 // implement this historical detail; instead, we implement the
401 // computationally cleaner proleptic calendar, which assumes
402 // consistent 4-year cycles throughout time.
403 UBool isLeap = ((eyear&0x3) == 0); // equiv. to (eyear%4 == 0)
404
405 // Common Julian/Gregorian calculation
406 int32_t correction = 0;
407 int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
408 if (dayOfYear >= march1) {
409 correction = isLeap ? 1 : 2;
410 }
411 month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
412 dayOfMonth = dayOfYear - (isLeap?kLeapNumDays[month]:kNumDays[month]) + 1; // one-based DOM
413 ++dayOfYear;
414 #if defined (U_DEBUG_CAL)
415 // fprintf(stderr, "%d - %d[%d] + 1\n", dayOfYear, isLeap?kLeapNumDays[month]:kNumDays[month], month );
416 // fprintf(stderr, "%s:%d: greg's HCF %d -> %d/%d/%d not %d/%d/%d\n",
417 // __FILE__, __LINE__,julianDay,
418 // eyear,month,dayOfMonth,
419 // getGregorianYear(), getGregorianMonth(), getGregorianDayOfMonth() );
420 fprintf(stderr, "%s:%d: doy %d (greg's %d)- [cut=%d]\n",
421 __FILE__, __LINE__, dayOfYear, getGregorianDayOfYear(), fCutoverJulianDay);
422 #endif
423
424 }
425
426 // [j81] if we are after the cutover in its year, shift the day of the year
427 if((eyear == fGregorianCutoverYear) && (julianDay >= fCutoverJulianDay)) {
428 //from handleComputeMonthStart
429 int32_t gregShift = Grego::gregorianShift(eyear);
430 #if defined (U_DEBUG_CAL)
431 fprintf(stderr, "%s:%d: gregorian shift %d ::: doy%d => %d [cut=%d]\n",
432 __FILE__, __LINE__,gregShift, dayOfYear, dayOfYear+gregShift, fCutoverJulianDay);
433 #endif
434 dayOfYear += gregShift;
435 }
436
437 internalSet(UCAL_MONTH, month);
438 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
439 internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
440 internalSet(UCAL_EXTENDED_YEAR, eyear);
441 int32_t era = AD;
442 if (eyear < 1) {
443 era = BC;
444 eyear = 1 - eyear;
445 }
446 internalSet(UCAL_ERA, era);
447 internalSet(UCAL_YEAR, eyear);
448 }
449
450
451 // -------------------------------------
452
453 UDate
getGregorianChange() const454 GregorianCalendar::getGregorianChange() const
455 {
456 return fGregorianCutover;
457 }
458
459 // -------------------------------------
460
461 UBool
isLeapYear(int32_t year) const462 GregorianCalendar::isLeapYear(int32_t year) const
463 {
464 // MSVC complains bitterly if we try to use Grego::isLeapYear here
465 // NOTE: year&0x3 == year%4
466 return (year >= fGregorianCutoverYear ?
467 (((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
468 ((year&0x3) == 0)); // Julian
469 }
470
471 // -------------------------------------
472
handleComputeJulianDay(UCalendarDateFields bestField)473 int32_t GregorianCalendar::handleComputeJulianDay(UCalendarDateFields bestField)
474 {
475 fInvertGregorian = FALSE;
476
477 int32_t jd = Calendar::handleComputeJulianDay(bestField);
478
479 if((bestField == UCAL_WEEK_OF_YEAR) && // if we are doing WOY calculations, we are counting relative to Jan 1 *julian*
480 (internalGet(UCAL_EXTENDED_YEAR)==fGregorianCutoverYear) &&
481 jd >= fCutoverJulianDay) {
482 fInvertGregorian = TRUE; // So that the Julian Jan 1 will be used in handleComputeMonthStart
483 return Calendar::handleComputeJulianDay(bestField);
484 }
485
486
487 // The following check handles portions of the cutover year BEFORE the
488 // cutover itself happens.
489 //if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
490 if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
491 #if defined (U_DEBUG_CAL)
492 fprintf(stderr, "%s:%d: jd [invert] %d\n",
493 __FILE__, __LINE__, jd);
494 #endif
495 fInvertGregorian = TRUE;
496 jd = Calendar::handleComputeJulianDay(bestField);
497 #if defined (U_DEBUG_CAL)
498 fprintf(stderr, "%s:%d: fIsGregorian %s, fInvertGregorian %s - ",
499 __FILE__, __LINE__,fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
500 fprintf(stderr, " jd NOW %d\n",
501 jd);
502 #endif
503 } else {
504 #if defined (U_DEBUG_CAL)
505 fprintf(stderr, "%s:%d: jd [==] %d - %sfIsGregorian %sfInvertGregorian, %d\n",
506 __FILE__, __LINE__, jd, fIsGregorian?"T":"F", fInvertGregorian?"T":"F", bestField);
507 #endif
508 }
509
510 if(fIsGregorian && (internalGet(UCAL_EXTENDED_YEAR) == fGregorianCutoverYear)) {
511 int32_t gregShift = Grego::gregorianShift(internalGet(UCAL_EXTENDED_YEAR));
512 if (bestField == UCAL_DAY_OF_YEAR) {
513 #if defined (U_DEBUG_CAL)
514 fprintf(stderr, "%s:%d: [DOY%d] gregorian shift of JD %d += %d\n",
515 __FILE__, __LINE__, fFields[bestField],jd, gregShift);
516 #endif
517 jd -= gregShift;
518 } else if ( bestField == UCAL_WEEK_OF_MONTH ) {
519 int32_t weekShift = 14;
520 #if defined (U_DEBUG_CAL)
521 fprintf(stderr, "%s:%d: [WOY/WOM] gregorian week shift of %d += %d\n",
522 __FILE__, __LINE__, jd, weekShift);
523 #endif
524 jd += weekShift; // shift by weeks for week based fields.
525 }
526 }
527
528 return jd;
529 }
530
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const531 int32_t GregorianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month,
532
533 UBool /* useMonth */) const
534 {
535 GregorianCalendar *nonConstThis = (GregorianCalendar*)this; // cast away const
536
537 // If the month is out of range, adjust it into range, and
538 // modify the extended year value accordingly.
539 if (month < 0 || month > 11) {
540 eyear += ClockMath::floorDivide(month, 12, month);
541 }
542
543 UBool isLeap = eyear%4 == 0;
544 int64_t y = (int64_t)eyear-1;
545 int64_t julianDay = 365*y + ClockMath::floorDivide(y, (int64_t)4) + (kJan1_1JulianDay - 3);
546
547 nonConstThis->fIsGregorian = (eyear >= fGregorianCutoverYear);
548 #if defined (U_DEBUG_CAL)
549 fprintf(stderr, "%s:%d: (hcms%d/%d) fIsGregorian %s, fInvertGregorian %s\n",
550 __FILE__, __LINE__, eyear,month, fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
551 #endif
552 if (fInvertGregorian) {
553 nonConstThis->fIsGregorian = !fIsGregorian;
554 }
555 if (fIsGregorian) {
556 isLeap = isLeap && ((eyear%100 != 0) || (eyear%400 == 0));
557 // Add 2 because Gregorian calendar starts 2 days after
558 // Julian calendar
559 int32_t gregShift = Grego::gregorianShift(eyear);
560 #if defined (U_DEBUG_CAL)
561 fprintf(stderr, "%s:%d: (hcms%d/%d) gregorian shift of %d += %d\n",
562 __FILE__, __LINE__, eyear, month, julianDay, gregShift);
563 #endif
564 julianDay += gregShift;
565 }
566
567 // At this point julianDay indicates the day BEFORE the first
568 // day of January 1, <eyear> of either the Julian or Gregorian
569 // calendar.
570
571 if (month != 0) {
572 julianDay += isLeap?kLeapNumDays[month]:kNumDays[month];
573 }
574
575 return static_cast<int32_t>(julianDay);
576 }
577
handleGetMonthLength(int32_t extendedYear,int32_t month) const578 int32_t GregorianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const
579 {
580 // If the month is out of range, adjust it into range, and
581 // modify the extended year value accordingly.
582 if (month < 0 || month > 11) {
583 extendedYear += ClockMath::floorDivide(month, 12, month);
584 }
585
586 return isLeapYear(extendedYear) ? kLeapMonthLength[month] : kMonthLength[month];
587 }
588
handleGetYearLength(int32_t eyear) const589 int32_t GregorianCalendar::handleGetYearLength(int32_t eyear) const {
590 return isLeapYear(eyear) ? 366 : 365;
591 }
592
593
594 int32_t
monthLength(int32_t month) const595 GregorianCalendar::monthLength(int32_t month) const
596 {
597 int32_t year = internalGet(UCAL_EXTENDED_YEAR);
598 return handleGetMonthLength(year, month);
599 }
600
601 // -------------------------------------
602
603 int32_t
monthLength(int32_t month,int32_t year) const604 GregorianCalendar::monthLength(int32_t month, int32_t year) const
605 {
606 return isLeapYear(year) ? kLeapMonthLength[month] : kMonthLength[month];
607 }
608
609 // -------------------------------------
610
611 int32_t
yearLength(int32_t year) const612 GregorianCalendar::yearLength(int32_t year) const
613 {
614 return isLeapYear(year) ? 366 : 365;
615 }
616
617 // -------------------------------------
618
619 int32_t
yearLength() const620 GregorianCalendar::yearLength() const
621 {
622 return isLeapYear(internalGet(UCAL_YEAR)) ? 366 : 365;
623 }
624
625 // -------------------------------------
626
627 /**
628 * After adjustments such as add(MONTH), add(YEAR), we don't want the
629 * month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
630 * 3, we want it to go to Feb 28. Adjustments which might run into this
631 * problem call this method to retain the proper month.
632 */
633 void
pinDayOfMonth()634 GregorianCalendar::pinDayOfMonth()
635 {
636 int32_t monthLen = monthLength(internalGet(UCAL_MONTH));
637 int32_t dom = internalGet(UCAL_DATE);
638 if(dom > monthLen)
639 set(UCAL_DATE, monthLen);
640 }
641
642 // -------------------------------------
643
644
645 UBool
validateFields() const646 GregorianCalendar::validateFields() const
647 {
648 for (int32_t field = 0; field < UCAL_FIELD_COUNT; field++) {
649 // Ignore DATE and DAY_OF_YEAR which are handled below
650 if (field != UCAL_DATE &&
651 field != UCAL_DAY_OF_YEAR &&
652 isSet((UCalendarDateFields)field) &&
653 ! boundsCheck(internalGet((UCalendarDateFields)field), (UCalendarDateFields)field))
654 return FALSE;
655 }
656
657 // Values differ in Least-Maximum and Maximum should be handled
658 // specially.
659 if (isSet(UCAL_DATE)) {
660 int32_t date = internalGet(UCAL_DATE);
661 if (date < getMinimum(UCAL_DATE) ||
662 date > monthLength(internalGet(UCAL_MONTH))) {
663 return FALSE;
664 }
665 }
666
667 if (isSet(UCAL_DAY_OF_YEAR)) {
668 int32_t days = internalGet(UCAL_DAY_OF_YEAR);
669 if (days < 1 || days > yearLength()) {
670 return FALSE;
671 }
672 }
673
674 // Handle DAY_OF_WEEK_IN_MONTH, which must not have the value zero.
675 // We've checked against minimum and maximum above already.
676 if (isSet(UCAL_DAY_OF_WEEK_IN_MONTH) &&
677 0 == internalGet(UCAL_DAY_OF_WEEK_IN_MONTH)) {
678 return FALSE;
679 }
680
681 return TRUE;
682 }
683
684 // -------------------------------------
685
686 UBool
boundsCheck(int32_t value,UCalendarDateFields field) const687 GregorianCalendar::boundsCheck(int32_t value, UCalendarDateFields field) const
688 {
689 return value >= getMinimum(field) && value <= getMaximum(field);
690 }
691
692 // -------------------------------------
693
694 UDate
getEpochDay(UErrorCode & status)695 GregorianCalendar::getEpochDay(UErrorCode& status)
696 {
697 complete(status);
698 // Divide by 1000 (convert to seconds) in order to prevent overflow when
699 // dealing with UDate(Long.MIN_VALUE) and UDate(Long.MAX_VALUE).
700 double wallSec = internalGetTime()/1000 + (internalGet(UCAL_ZONE_OFFSET) + internalGet(UCAL_DST_OFFSET))/1000;
701
702 return ClockMath::floorDivide(wallSec, kOneDay/1000.0);
703 }
704
705 // -------------------------------------
706
707
708 // -------------------------------------
709
710 /**
711 * Compute the julian day number of the day BEFORE the first day of
712 * January 1, year 1 of the given calendar. If julianDay == 0, it
713 * specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
714 * or Gregorian).
715 */
computeJulianDayOfYear(UBool isGregorian,int32_t year,UBool & isLeap)716 double GregorianCalendar::computeJulianDayOfYear(UBool isGregorian,
717 int32_t year, UBool& isLeap)
718 {
719 isLeap = year%4 == 0;
720 int32_t y = year - 1;
721 double julianDay = 365.0*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
722
723 if (isGregorian) {
724 isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
725 // Add 2 because Gregorian calendar starts 2 days after Julian calendar
726 julianDay += Grego::gregorianShift(year);
727 }
728
729 return julianDay;
730 }
731
732 // /**
733 // * Compute the day of week, relative to the first day of week, from
734 // * 0..6, of the current DOW_LOCAL or DAY_OF_WEEK fields. This is
735 // * equivalent to get(DOW_LOCAL) - 1.
736 // */
737 // int32_t GregorianCalendar::computeRelativeDOW() const {
738 // int32_t relDow = 0;
739 // if (fStamp[UCAL_DOW_LOCAL] > fStamp[UCAL_DAY_OF_WEEK]) {
740 // relDow = internalGet(UCAL_DOW_LOCAL) - 1; // 1-based
741 // } else if (fStamp[UCAL_DAY_OF_WEEK] != kUnset) {
742 // relDow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
743 // if (relDow < 0) relDow += 7;
744 // }
745 // return relDow;
746 // }
747
748 // /**
749 // * Compute the day of week, relative to the first day of week,
750 // * from 0..6 of the given julian day.
751 // */
752 // int32_t GregorianCalendar::computeRelativeDOW(double julianDay) const {
753 // int32_t relDow = julianDayToDayOfWeek(julianDay) - getFirstDayOfWeek();
754 // if (relDow < 0) {
755 // relDow += 7;
756 // }
757 // return relDow;
758 // }
759
760 // /**
761 // * Compute the DOY using the WEEK_OF_YEAR field and the julian day
762 // * of the day BEFORE January 1 of a year (a return value from
763 // * computeJulianDayOfYear).
764 // */
765 // int32_t GregorianCalendar::computeDOYfromWOY(double julianDayOfYear) const {
766 // // Compute DOY from day of week plus week of year
767
768 // // Find the day of the week for the first of this year. This
769 // // is zero-based, with 0 being the locale-specific first day of
770 // // the week. Add 1 to get first day of year.
771 // int32_t fdy = computeRelativeDOW(julianDayOfYear + 1);
772
773 // return
774 // // Compute doy of first (relative) DOW of WOY 1
775 // (((7 - fdy) < getMinimalDaysInFirstWeek())
776 // ? (8 - fdy) : (1 - fdy))
777
778 // // Adjust for the week number.
779 // + (7 * (internalGet(UCAL_WEEK_OF_YEAR) - 1))
780
781 // // Adjust for the DOW
782 // + computeRelativeDOW();
783 // }
784
785 // -------------------------------------
786
787 double
millisToJulianDay(UDate millis)788 GregorianCalendar::millisToJulianDay(UDate millis)
789 {
790 return (double)kEpochStartAsJulianDay + ClockMath::floorDivide(millis, (double)kOneDay);
791 }
792
793 // -------------------------------------
794
795 UDate
julianDayToMillis(double julian)796 GregorianCalendar::julianDayToMillis(double julian)
797 {
798 return (UDate) ((julian - kEpochStartAsJulianDay) * (double) kOneDay);
799 }
800
801 // -------------------------------------
802
803 int32_t
aggregateStamp(int32_t stamp_a,int32_t stamp_b)804 GregorianCalendar::aggregateStamp(int32_t stamp_a, int32_t stamp_b)
805 {
806 return (((stamp_a != kUnset && stamp_b != kUnset)
807 ? uprv_max(stamp_a, stamp_b)
808 : (int32_t)kUnset));
809 }
810
811 // -------------------------------------
812
813 /**
814 * Roll a field by a signed amount.
815 * Note: This will be made public later. [LIU]
816 */
817
818 void
roll(EDateFields field,int32_t amount,UErrorCode & status)819 GregorianCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
820 roll((UCalendarDateFields) field, amount, status);
821 }
822
823 void
roll(UCalendarDateFields field,int32_t amount,UErrorCode & status)824 GregorianCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status)
825 {
826 if((amount == 0) || U_FAILURE(status)) {
827 return;
828 }
829
830 // J81 processing. (gregorian cutover)
831 UBool inCutoverMonth = FALSE;
832 int32_t cMonthLen=0; // 'c' for cutover; in days
833 int32_t cDayOfMonth=0; // no discontinuity: [0, cMonthLen)
834 double cMonthStart=0.0; // in ms
835
836 // Common code - see if we're in the cutover month of the cutover year
837 if(get(UCAL_EXTENDED_YEAR, status) == fGregorianCutoverYear) {
838 switch (field) {
839 case UCAL_DAY_OF_MONTH:
840 case UCAL_WEEK_OF_MONTH:
841 {
842 int32_t max = monthLength(internalGet(UCAL_MONTH));
843 UDate t = internalGetTime();
844 // We subtract 1 from the DAY_OF_MONTH to make it zero-based, and an
845 // additional 10 if we are after the cutover. Thus the monthStart
846 // value will be correct iff we actually are in the cutover month.
847 cDayOfMonth = internalGet(UCAL_DAY_OF_MONTH) - ((t >= fGregorianCutover) ? 10 : 0);
848 cMonthStart = t - ((cDayOfMonth - 1) * kOneDay);
849 // A month containing the cutover is 10 days shorter.
850 if ((cMonthStart < fGregorianCutover) &&
851 (cMonthStart + (cMonthLen=(max-10))*kOneDay >= fGregorianCutover)) {
852 inCutoverMonth = TRUE;
853 }
854 }
855 break;
856 default:
857 ;
858 }
859 }
860
861 switch (field) {
862 case UCAL_WEEK_OF_YEAR: {
863 // Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
864 // week. Also, rolling the week of the year can have seemingly
865 // strange effects simply because the year of the week of year
866 // may be different from the calendar year. For example, the
867 // date Dec 28, 1997 is the first day of week 1 of 1998 (if
868 // weeks start on Sunday and the minimal days in first week is
869 // <= 3).
870 int32_t woy = get(UCAL_WEEK_OF_YEAR, status);
871 // Get the ISO year, which matches the week of year. This
872 // may be one year before or after the calendar year.
873 int32_t isoYear = get(UCAL_YEAR_WOY, status);
874 int32_t isoDoy = internalGet(UCAL_DAY_OF_YEAR);
875 if (internalGet(UCAL_MONTH) == UCAL_JANUARY) {
876 if (woy >= 52) {
877 isoDoy += handleGetYearLength(isoYear);
878 }
879 } else {
880 if (woy == 1) {
881 isoDoy -= handleGetYearLength(isoYear - 1);
882 }
883 }
884 woy += amount;
885 // Do fast checks to avoid unnecessary computation:
886 if (woy < 1 || woy > 52) {
887 // Determine the last week of the ISO year.
888 // We do this using the standard formula we use
889 // everywhere in this file. If we can see that the
890 // days at the end of the year are going to fall into
891 // week 1 of the next year, we drop the last week by
892 // subtracting 7 from the last day of the year.
893 int32_t lastDoy = handleGetYearLength(isoYear);
894 int32_t lastRelDow = (lastDoy - isoDoy + internalGet(UCAL_DAY_OF_WEEK) -
895 getFirstDayOfWeek()) % 7;
896 if (lastRelDow < 0) lastRelDow += 7;
897 if ((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) lastDoy -= 7;
898 int32_t lastWoy = weekNumber(lastDoy, lastRelDow + 1);
899 woy = ((woy + lastWoy - 1) % lastWoy) + 1;
900 }
901 set(UCAL_WEEK_OF_YEAR, woy);
902 set(UCAL_YEAR_WOY,isoYear);
903 return;
904 }
905
906 case UCAL_DAY_OF_MONTH:
907 if( !inCutoverMonth ) {
908 Calendar::roll(field, amount, status);
909 return;
910 } else {
911 // [j81] 1582 special case for DOM
912 // The default computation works except when the current month
913 // contains the Gregorian cutover. We handle this special case
914 // here. [j81 - aliu]
915 double monthLen = cMonthLen * kOneDay;
916 double msIntoMonth = uprv_fmod(internalGetTime() - cMonthStart +
917 amount * kOneDay, monthLen);
918 if (msIntoMonth < 0) {
919 msIntoMonth += monthLen;
920 }
921 #if defined (U_DEBUG_CAL)
922 fprintf(stderr, "%s:%d: roll DOM %d -> %.0lf ms \n",
923 __FILE__, __LINE__,amount, cMonthLen, cMonthStart+msIntoMonth);
924 #endif
925 setTimeInMillis(cMonthStart + msIntoMonth, status);
926 return;
927 }
928
929 case UCAL_WEEK_OF_MONTH:
930 if( !inCutoverMonth ) {
931 Calendar::roll(field, amount, status);
932 return;
933 } else {
934 #if defined (U_DEBUG_CAL)
935 fprintf(stderr, "%s:%d: roll WOM %d ??????????????????? \n",
936 __FILE__, __LINE__,amount);
937 #endif
938 // NOTE: following copied from the old
939 // GregorianCalendar::roll( WEEK_OF_MONTH ) code
940
941 // This is tricky, because during the roll we may have to shift
942 // to a different day of the week. For example:
943
944 // s m t w r f s
945 // 1 2 3 4 5
946 // 6 7 8 9 10 11 12
947
948 // When rolling from the 6th or 7th back one week, we go to the
949 // 1st (assuming that the first partial week counts). The same
950 // thing happens at the end of the month.
951
952 // The other tricky thing is that we have to figure out whether
953 // the first partial week actually counts or not, based on the
954 // minimal first days in the week. And we have to use the
955 // correct first day of the week to delineate the week
956 // boundaries.
957
958 // Here's our algorithm. First, we find the real boundaries of
959 // the month. Then we discard the first partial week if it
960 // doesn't count in this locale. Then we fill in the ends with
961 // phantom days, so that the first partial week and the last
962 // partial week are full weeks. We then have a nice square
963 // block of weeks. We do the usual rolling within this block,
964 // as is done elsewhere in this method. If we wind up on one of
965 // the phantom days that we added, we recognize this and pin to
966 // the first or the last day of the month. Easy, eh?
967
968 // Another wrinkle: To fix jitterbug 81, we have to make all this
969 // work in the oddball month containing the Gregorian cutover.
970 // This month is 10 days shorter than usual, and also contains
971 // a discontinuity in the days; e.g., the default cutover month
972 // is Oct 1582, and goes from day of month 4 to day of month 15.
973
974 // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
975 // in this locale. We have dow in 0..6.
976 int32_t dow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
977 if (dow < 0)
978 dow += 7;
979
980 // Find the day of month, compensating for cutover discontinuity.
981 int32_t dom = cDayOfMonth;
982
983 // Find the day of the week (normalized for locale) for the first
984 // of the month.
985 int32_t fdm = (dow - dom + 1) % 7;
986 if (fdm < 0)
987 fdm += 7;
988
989 // Get the first day of the first full week of the month,
990 // including phantom days, if any. Figure out if the first week
991 // counts or not; if it counts, then fill in phantom days. If
992 // not, advance to the first real full week (skip the partial week).
993 int32_t start;
994 if ((7 - fdm) < getMinimalDaysInFirstWeek())
995 start = 8 - fdm; // Skip the first partial week
996 else
997 start = 1 - fdm; // This may be zero or negative
998
999 // Get the day of the week (normalized for locale) for the last
1000 // day of the month.
1001 int32_t monthLen = cMonthLen;
1002 int32_t ldm = (monthLen - dom + dow) % 7;
1003 // We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
1004
1005 // Get the limit day for the blocked-off rectangular month; that
1006 // is, the day which is one past the last day of the month,
1007 // after the month has already been filled in with phantom days
1008 // to fill out the last week. This day has a normalized DOW of 0.
1009 int32_t limit = monthLen + 7 - ldm;
1010
1011 // Now roll between start and (limit - 1).
1012 int32_t gap = limit - start;
1013 int32_t newDom = (dom + amount*7 - start) % gap;
1014 if (newDom < 0)
1015 newDom += gap;
1016 newDom += start;
1017
1018 // Finally, pin to the real start and end of the month.
1019 if (newDom < 1)
1020 newDom = 1;
1021 if (newDom > monthLen)
1022 newDom = monthLen;
1023
1024 // Set the DAY_OF_MONTH. We rely on the fact that this field
1025 // takes precedence over everything else (since all other fields
1026 // are also set at this point). If this fact changes (if the
1027 // disambiguation algorithm changes) then we will have to unset
1028 // the appropriate fields here so that DAY_OF_MONTH is attended
1029 // to.
1030
1031 // If we are in the cutover month, manipulate ms directly. Don't do
1032 // this in general because it doesn't work across DST boundaries
1033 // (details, details). This takes care of the discontinuity.
1034 setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
1035 return;
1036 }
1037
1038 default:
1039 Calendar::roll(field, amount, status);
1040 return;
1041 }
1042 }
1043
1044 // -------------------------------------
1045
1046
1047 /**
1048 * Return the minimum value that this field could have, given the current date.
1049 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1050 * @param field the time field.
1051 * @return the minimum value that this field could have, given the current date.
1052 * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.
1053 */
getActualMinimum(EDateFields field) const1054 int32_t GregorianCalendar::getActualMinimum(EDateFields field) const
1055 {
1056 return getMinimum((UCalendarDateFields)field);
1057 }
1058
getActualMinimum(EDateFields field,UErrorCode &) const1059 int32_t GregorianCalendar::getActualMinimum(EDateFields field, UErrorCode& /* status */) const
1060 {
1061 return getMinimum((UCalendarDateFields)field);
1062 }
1063
1064 /**
1065 * Return the minimum value that this field could have, given the current date.
1066 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1067 * @param field the time field.
1068 * @return the minimum value that this field could have, given the current date.
1069 * @draft ICU 2.6.
1070 */
getActualMinimum(UCalendarDateFields field,UErrorCode &) const1071 int32_t GregorianCalendar::getActualMinimum(UCalendarDateFields field, UErrorCode& /* status */) const
1072 {
1073 return getMinimum(field);
1074 }
1075
1076
1077 // ------------------------------------
1078
1079 /**
1080 * Old year limits were least max 292269054, max 292278994.
1081 */
1082
1083 /**
1084 * @stable ICU 2.0
1085 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const1086 int32_t GregorianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
1087 return kGregorianCalendarLimits[field][limitType];
1088 }
1089
1090 /**
1091 * Return the maximum value that this field could have, given the current date.
1092 * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1093 * maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar,
1094 * for some years the actual maximum for MONTH is 12, and for others 13.
1095 * @stable ICU 2.0
1096 */
getActualMaximum(UCalendarDateFields field,UErrorCode & status) const1097 int32_t GregorianCalendar::getActualMaximum(UCalendarDateFields field, UErrorCode& status) const
1098 {
1099 /* It is a known limitation that the code here (and in getActualMinimum)
1100 * won't behave properly at the extreme limits of GregorianCalendar's
1101 * representable range (except for the code that handles the YEAR
1102 * field). That's because the ends of the representable range are at
1103 * odd spots in the year. For calendars with the default Gregorian
1104 * cutover, these limits are Sun Dec 02 16:47:04 GMT 292269055 BC to Sun
1105 * Aug 17 07:12:55 GMT 292278994 AD, somewhat different for non-GMT
1106 * zones. As a result, if the calendar is set to Aug 1 292278994 AD,
1107 * the actual maximum of DAY_OF_MONTH is 17, not 30. If the date is Mar
1108 * 31 in that year, the actual maximum month might be Jul, whereas is
1109 * the date is Mar 15, the actual maximum might be Aug -- depending on
1110 * the precise semantics that are desired. Similar considerations
1111 * affect all fields. Nonetheless, this effect is sufficiently arcane
1112 * that we permit it, rather than complicating the code to handle such
1113 * intricacies. - liu 8/20/98
1114
1115 * UPDATE: No longer true, since we have pulled in the limit values on
1116 * the year. - Liu 11/6/00 */
1117
1118 switch (field) {
1119
1120 case UCAL_YEAR:
1121 /* The year computation is no different, in principle, from the
1122 * others, however, the range of possible maxima is large. In
1123 * addition, the way we know we've exceeded the range is different.
1124 * For these reasons, we use the special case code below to handle
1125 * this field.
1126 *
1127 * The actual maxima for YEAR depend on the type of calendar:
1128 *
1129 * Gregorian = May 17, 292275056 BC - Aug 17, 292278994 AD
1130 * Julian = Dec 2, 292269055 BC - Jan 3, 292272993 AD
1131 * Hybrid = Dec 2, 292269055 BC - Aug 17, 292278994 AD
1132 *
1133 * We know we've exceeded the maximum when either the month, date,
1134 * time, or era changes in response to setting the year. We don't
1135 * check for month, date, and time here because the year and era are
1136 * sufficient to detect an invalid year setting. NOTE: If code is
1137 * added to check the month and date in the future for some reason,
1138 * Feb 29 must be allowed to shift to Mar 1 when setting the year.
1139 */
1140 {
1141 if(U_FAILURE(status)) return 0;
1142 Calendar *cal = clone();
1143 if(!cal) {
1144 status = U_MEMORY_ALLOCATION_ERROR;
1145 return 0;
1146 }
1147
1148 cal->setLenient(TRUE);
1149
1150 int32_t era = cal->get(UCAL_ERA, status);
1151 UDate d = cal->getTime(status);
1152
1153 /* Perform a binary search, with the invariant that lowGood is a
1154 * valid year, and highBad is an out of range year.
1155 */
1156 int32_t lowGood = kGregorianCalendarLimits[UCAL_YEAR][1];
1157 int32_t highBad = kGregorianCalendarLimits[UCAL_YEAR][2]+1;
1158 while ((lowGood + 1) < highBad) {
1159 int32_t y = (lowGood + highBad) / 2;
1160 cal->set(UCAL_YEAR, y);
1161 if (cal->get(UCAL_YEAR, status) == y && cal->get(UCAL_ERA, status) == era) {
1162 lowGood = y;
1163 } else {
1164 highBad = y;
1165 cal->setTime(d, status); // Restore original fields
1166 }
1167 }
1168
1169 delete cal;
1170 return lowGood;
1171 }
1172
1173 default:
1174 return Calendar::getActualMaximum(field,status);
1175 }
1176 }
1177
1178
handleGetExtendedYear()1179 int32_t GregorianCalendar::handleGetExtendedYear() {
1180 // the year to return
1181 int32_t year = kEpochYear;
1182
1183 // year field to use
1184 int32_t yearField = UCAL_EXTENDED_YEAR;
1185
1186 // There are three separate fields which could be used to
1187 // derive the proper year. Use the one most recently set.
1188 if (fStamp[yearField] < fStamp[UCAL_YEAR])
1189 yearField = UCAL_YEAR;
1190 if (fStamp[yearField] < fStamp[UCAL_YEAR_WOY])
1191 yearField = UCAL_YEAR_WOY;
1192
1193 // based on the "best" year field, get the year
1194 switch(yearField) {
1195 case UCAL_EXTENDED_YEAR:
1196 year = internalGet(UCAL_EXTENDED_YEAR, kEpochYear);
1197 break;
1198
1199 case UCAL_YEAR:
1200 {
1201 // The year defaults to the epoch start, the era to AD
1202 int32_t era = internalGet(UCAL_ERA, AD);
1203 if (era == BC) {
1204 year = 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
1205 } else {
1206 year = internalGet(UCAL_YEAR, kEpochYear);
1207 }
1208 }
1209 break;
1210
1211 case UCAL_YEAR_WOY:
1212 year = handleGetExtendedYearFromWeekFields(internalGet(UCAL_YEAR_WOY), internalGet(UCAL_WEEK_OF_YEAR));
1213 #if defined (U_DEBUG_CAL)
1214 // if(internalGet(UCAL_YEAR_WOY) != year) {
1215 fprintf(stderr, "%s:%d: hGEYFWF[%d,%d] -> %d\n",
1216 __FILE__, __LINE__,internalGet(UCAL_YEAR_WOY),internalGet(UCAL_WEEK_OF_YEAR),year);
1217 //}
1218 #endif
1219 break;
1220
1221 default:
1222 year = kEpochYear;
1223 }
1224 return year;
1225 }
1226
handleGetExtendedYearFromWeekFields(int32_t yearWoy,int32_t woy)1227 int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy)
1228 {
1229 // convert year to extended form
1230 int32_t era = internalGet(UCAL_ERA, AD);
1231 if(era == BC) {
1232 yearWoy = 1 - yearWoy;
1233 }
1234 return Calendar::handleGetExtendedYearFromWeekFields(yearWoy, woy);
1235 }
1236
1237
1238 // -------------------------------------
1239
1240 UBool
inDaylightTime(UErrorCode & status) const1241 GregorianCalendar::inDaylightTime(UErrorCode& status) const
1242 {
1243 if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
1244 return FALSE;
1245
1246 // Force an update of the state of the Calendar.
1247 ((GregorianCalendar*)this)->complete(status); // cast away const
1248
1249 return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
1250 }
1251
1252 // -------------------------------------
1253
1254 /**
1255 * Return the ERA. We need a special method for this because the
1256 * default ERA is AD, but a zero (unset) ERA is BC.
1257 */
1258 int32_t
internalGetEra() const1259 GregorianCalendar::internalGetEra() const {
1260 return isSet(UCAL_ERA) ? internalGet(UCAL_ERA) : (int32_t)AD;
1261 }
1262
1263 const char *
getType() const1264 GregorianCalendar::getType() const {
1265 //static const char kGregorianType = "gregorian";
1266
1267 return "gregorian";
1268 }
1269
1270 /**
1271 * The system maintains a static default century start date and Year. They are
1272 * initialized the first time they are used. Once the system default century date
1273 * and year are set, they do not change.
1274 */
1275 static UDate gSystemDefaultCenturyStart = DBL_MIN;
1276 static int32_t gSystemDefaultCenturyStartYear = -1;
1277 static icu::UInitOnce gSystemDefaultCenturyInit = U_INITONCE_INITIALIZER;
1278
1279
haveDefaultCentury() const1280 UBool GregorianCalendar::haveDefaultCentury() const
1281 {
1282 return TRUE;
1283 }
1284
1285 static void U_CALLCONV
initializeSystemDefaultCentury()1286 initializeSystemDefaultCentury()
1287 {
1288 // initialize systemDefaultCentury and systemDefaultCenturyYear based
1289 // on the current time. They'll be set to 80 years before
1290 // the current time.
1291 UErrorCode status = U_ZERO_ERROR;
1292 GregorianCalendar calendar(status);
1293 if (U_SUCCESS(status)) {
1294 calendar.setTime(Calendar::getNow(), status);
1295 calendar.add(UCAL_YEAR, -80, status);
1296
1297 gSystemDefaultCenturyStart = calendar.getTime(status);
1298 gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
1299 }
1300 // We have no recourse upon failure unless we want to propagate the failure
1301 // out.
1302 }
1303
defaultCenturyStart() const1304 UDate GregorianCalendar::defaultCenturyStart() const {
1305 // lazy-evaluate systemDefaultCenturyStart
1306 umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
1307 return gSystemDefaultCenturyStart;
1308 }
1309
defaultCenturyStartYear() const1310 int32_t GregorianCalendar::defaultCenturyStartYear() const {
1311 // lazy-evaluate systemDefaultCenturyStartYear
1312 umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
1313 return gSystemDefaultCenturyStartYear;
1314 }
1315
1316 U_NAMESPACE_END
1317
1318 #endif /* #if !UCONFIG_NO_FORMATTING */
1319
1320 //eof
1321