1 /*
2 *******************************************************************************
3 * Copyright (C) 1997-2012, International Business Machines Corporation and *
4 * others. All Rights Reserved. *
5 *******************************************************************************
6 *
7 * File GREGOCAL.CPP
8 *
9 * Modification History:
10 *
11 * Date Name Description
12 * 02/05/97 clhuang Creation.
13 * 03/28/97 aliu Made highly questionable fix to computeFields to
14 * handle DST correctly.
15 * 04/22/97 aliu Cleaned up code drastically. Added monthLength().
16 * Finished unimplemented parts of computeTime() for
17 * week-based date determination. Removed quetionable
18 * fix and wrote correct fix for computeFields() and
19 * daylight time handling. Rewrote inDaylightTime()
20 * and computeFields() to handle sensitive Daylight to
21 * Standard time transitions correctly.
22 * 05/08/97 aliu Added code review changes. Fixed isLeapYear() to
23 * not cutover.
24 * 08/12/97 aliu Added equivalentTo. Misc other fixes. Updated
25 * add() from Java source.
26 * 07/28/98 stephen Sync up with JDK 1.2
27 * 09/14/98 stephen Changed type of kOneDay, kOneWeek to double.
28 * Fixed bug in roll()
29 * 10/15/99 aliu Fixed j31, incorrect WEEK_OF_YEAR computation.
30 * 10/15/99 aliu Fixed j32, cannot set date to Feb 29 2000 AD.
31 * {JDK bug 4210209 4209272}
32 * 11/15/99 weiv Added YEAR_WOY and DOW_LOCAL computation
33 * to timeToFields method, updated kMinValues, kMaxValues & kLeastMaxValues
34 * 12/09/99 aliu Fixed j81, calculation errors and roll bugs
35 * in year of cutover.
36 * 01/24/2000 aliu Revised computeJulianDay for YEAR YEAR_WOY WOY.
37 ********************************************************************************
38 */
39
40 #include "unicode/utypes.h"
41 #include <float.h>
42
43 #if !UCONFIG_NO_FORMATTING
44
45 #include "unicode/gregocal.h"
46 #include "gregoimp.h"
47 #include "umutex.h"
48 #include "uassert.h"
49
50 // *****************************************************************************
51 // class GregorianCalendar
52 // *****************************************************************************
53
54 /**
55 * Note that the Julian date used here is not a true Julian date, since
56 * it is measured from midnight, not noon. This value is the Julian
57 * day number of January 1, 1970 (Gregorian calendar) at noon UTC. [LIU]
58 */
59
60 static const int16_t kNumDays[]
61 = {0,31,59,90,120,151,181,212,243,273,304,334}; // 0-based, for day-in-year
62 static const int16_t kLeapNumDays[]
63 = {0,31,60,91,121,152,182,213,244,274,305,335}; // 0-based, for day-in-year
64 static const int8_t kMonthLength[]
65 = {31,28,31,30,31,30,31,31,30,31,30,31}; // 0-based
66 static const int8_t kLeapMonthLength[]
67 = {31,29,31,30,31,30,31,31,30,31,30,31}; // 0-based
68
69 // setTimeInMillis() limits the Julian day range to +/-7F000000.
70 // This would seem to limit the year range to:
71 // ms=+183882168921600000 jd=7f000000 December 20, 5828963 AD
72 // ms=-184303902528000000 jd=81000000 September 20, 5838270 BC
73 // HOWEVER, CalendarRegressionTest/Test4167060 shows that the actual
74 // range limit on the year field is smaller (~ +/-140000). [alan 3.0]
75
76 static const int32_t kGregorianCalendarLimits[UCAL_FIELD_COUNT][4] = {
77 // Minimum Greatest Least Maximum
78 // Minimum Maximum
79 { 0, 0, 1, 1}, // ERA
80 { 1, 1, 140742, 144683}, // YEAR
81 { 0, 0, 11, 11}, // MONTH
82 { 1, 1, 52, 53}, // WEEK_OF_YEAR
83 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
84 { 1, 1, 28, 31}, // DAY_OF_MONTH
85 { 1, 1, 365, 366}, // DAY_OF_YEAR
86 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
87 { -1, -1, 4, 5}, // DAY_OF_WEEK_IN_MONTH
88 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
89 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
90 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
91 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
92 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
93 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
94 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
95 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
96 { -140742, -140742, 140742, 144683}, // YEAR_WOY
97 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
98 { -140742, -140742, 140742, 144683}, // EXTENDED_YEAR
99 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
100 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
101 {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
102 };
103
104 /*
105 * <pre>
106 * Greatest Least
107 * Field name Minimum Minimum Maximum Maximum
108 * ---------- ------- ------- ------- -------
109 * ERA 0 0 1 1
110 * YEAR 1 1 140742 144683
111 * MONTH 0 0 11 11
112 * WEEK_OF_YEAR 1 1 52 53
113 * WEEK_OF_MONTH 0 0 4 6
114 * DAY_OF_MONTH 1 1 28 31
115 * DAY_OF_YEAR 1 1 365 366
116 * DAY_OF_WEEK 1 1 7 7
117 * DAY_OF_WEEK_IN_MONTH -1 -1 4 5
118 * AM_PM 0 0 1 1
119 * HOUR 0 0 11 11
120 * HOUR_OF_DAY 0 0 23 23
121 * MINUTE 0 0 59 59
122 * SECOND 0 0 59 59
123 * MILLISECOND 0 0 999 999
124 * ZONE_OFFSET -12* -12* 12* 12*
125 * DST_OFFSET 0 0 1* 1*
126 * YEAR_WOY 1 1 140742 144683
127 * DOW_LOCAL 1 1 7 7
128 * </pre>
129 * (*) In units of one-hour
130 */
131
132 #if defined( U_DEBUG_CALSVC ) || defined (U_DEBUG_CAL)
133 #include <stdio.h>
134 #endif
135
136 U_NAMESPACE_BEGIN
137
138 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(GregorianCalendar)
139
140 // 00:00:00 UTC, October 15, 1582, expressed in ms from the epoch.
141 // Note that only Italy and other Catholic countries actually
142 // observed this cutover. Most other countries followed in
143 // the next few centuries, some as late as 1928. [LIU]
144 // in Java, -12219292800000L
145 //const UDate GregorianCalendar::kPapalCutover = -12219292800000L;
146 static const uint32_t kCutoverJulianDay = 2299161;
147 static const UDate kPapalCutover = (2299161.0 - kEpochStartAsJulianDay) * U_MILLIS_PER_DAY;
148 //static const UDate kPapalCutoverJulian = (2299161.0 - kEpochStartAsJulianDay);
149
150 // -------------------------------------
151
GregorianCalendar(UErrorCode & status)152 GregorianCalendar::GregorianCalendar(UErrorCode& status)
153 : Calendar(status),
154 fGregorianCutover(kPapalCutover),
155 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
156 fIsGregorian(TRUE), fInvertGregorian(FALSE)
157 {
158 setTimeInMillis(getNow(), status);
159 }
160
161 // -------------------------------------
162
GregorianCalendar(TimeZone * zone,UErrorCode & status)163 GregorianCalendar::GregorianCalendar(TimeZone* zone, UErrorCode& status)
164 : Calendar(zone, Locale::getDefault(), status),
165 fGregorianCutover(kPapalCutover),
166 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
167 fIsGregorian(TRUE), fInvertGregorian(FALSE)
168 {
169 setTimeInMillis(getNow(), status);
170 }
171
172 // -------------------------------------
173
GregorianCalendar(const TimeZone & zone,UErrorCode & status)174 GregorianCalendar::GregorianCalendar(const TimeZone& zone, UErrorCode& status)
175 : Calendar(zone, Locale::getDefault(), status),
176 fGregorianCutover(kPapalCutover),
177 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
178 fIsGregorian(TRUE), fInvertGregorian(FALSE)
179 {
180 setTimeInMillis(getNow(), status);
181 }
182
183 // -------------------------------------
184
GregorianCalendar(const Locale & aLocale,UErrorCode & status)185 GregorianCalendar::GregorianCalendar(const Locale& aLocale, UErrorCode& status)
186 : Calendar(TimeZone::createDefault(), aLocale, status),
187 fGregorianCutover(kPapalCutover),
188 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
189 fIsGregorian(TRUE), fInvertGregorian(FALSE)
190 {
191 setTimeInMillis(getNow(), status);
192 }
193
194 // -------------------------------------
195
GregorianCalendar(TimeZone * zone,const Locale & aLocale,UErrorCode & status)196 GregorianCalendar::GregorianCalendar(TimeZone* zone, const Locale& aLocale,
197 UErrorCode& status)
198 : Calendar(zone, aLocale, status),
199 fGregorianCutover(kPapalCutover),
200 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
201 fIsGregorian(TRUE), fInvertGregorian(FALSE)
202 {
203 setTimeInMillis(getNow(), status);
204 }
205
206 // -------------------------------------
207
GregorianCalendar(const TimeZone & zone,const Locale & aLocale,UErrorCode & status)208 GregorianCalendar::GregorianCalendar(const TimeZone& zone, const Locale& aLocale,
209 UErrorCode& status)
210 : Calendar(zone, aLocale, status),
211 fGregorianCutover(kPapalCutover),
212 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
213 fIsGregorian(TRUE), fInvertGregorian(FALSE)
214 {
215 setTimeInMillis(getNow(), status);
216 }
217
218 // -------------------------------------
219
GregorianCalendar(int32_t year,int32_t month,int32_t date,UErrorCode & status)220 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
221 UErrorCode& status)
222 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
223 fGregorianCutover(kPapalCutover),
224 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
225 fIsGregorian(TRUE), fInvertGregorian(FALSE)
226 {
227 set(UCAL_ERA, AD);
228 set(UCAL_YEAR, year);
229 set(UCAL_MONTH, month);
230 set(UCAL_DATE, date);
231 }
232
233 // -------------------------------------
234
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,UErrorCode & status)235 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
236 int32_t hour, int32_t minute, UErrorCode& status)
237 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
238 fGregorianCutover(kPapalCutover),
239 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
240 fIsGregorian(TRUE), fInvertGregorian(FALSE)
241 {
242 set(UCAL_ERA, AD);
243 set(UCAL_YEAR, year);
244 set(UCAL_MONTH, month);
245 set(UCAL_DATE, date);
246 set(UCAL_HOUR_OF_DAY, hour);
247 set(UCAL_MINUTE, minute);
248 }
249
250 // -------------------------------------
251
GregorianCalendar(int32_t year,int32_t month,int32_t date,int32_t hour,int32_t minute,int32_t second,UErrorCode & status)252 GregorianCalendar::GregorianCalendar(int32_t year, int32_t month, int32_t date,
253 int32_t hour, int32_t minute, int32_t second,
254 UErrorCode& status)
255 : Calendar(TimeZone::createDefault(), Locale::getDefault(), status),
256 fGregorianCutover(kPapalCutover),
257 fCutoverJulianDay(kCutoverJulianDay), fNormalizedGregorianCutover(fGregorianCutover), fGregorianCutoverYear(1582),
258 fIsGregorian(TRUE), fInvertGregorian(FALSE)
259 {
260 set(UCAL_ERA, AD);
261 set(UCAL_YEAR, year);
262 set(UCAL_MONTH, month);
263 set(UCAL_DATE, date);
264 set(UCAL_HOUR_OF_DAY, hour);
265 set(UCAL_MINUTE, minute);
266 set(UCAL_SECOND, second);
267 }
268
269 // -------------------------------------
270
~GregorianCalendar()271 GregorianCalendar::~GregorianCalendar()
272 {
273 }
274
275 // -------------------------------------
276
GregorianCalendar(const GregorianCalendar & source)277 GregorianCalendar::GregorianCalendar(const GregorianCalendar &source)
278 : Calendar(source),
279 fGregorianCutover(source.fGregorianCutover),
280 fCutoverJulianDay(source.fCutoverJulianDay), fNormalizedGregorianCutover(source.fNormalizedGregorianCutover), fGregorianCutoverYear(source.fGregorianCutoverYear),
281 fIsGregorian(source.fIsGregorian), fInvertGregorian(source.fInvertGregorian)
282 {
283 }
284
285 // -------------------------------------
286
clone() const287 Calendar* GregorianCalendar::clone() const
288 {
289 return new GregorianCalendar(*this);
290 }
291
292 // -------------------------------------
293
294 GregorianCalendar &
operator =(const GregorianCalendar & right)295 GregorianCalendar::operator=(const GregorianCalendar &right)
296 {
297 if (this != &right)
298 {
299 Calendar::operator=(right);
300 fGregorianCutover = right.fGregorianCutover;
301 fNormalizedGregorianCutover = right.fNormalizedGregorianCutover;
302 fGregorianCutoverYear = right.fGregorianCutoverYear;
303 fCutoverJulianDay = right.fCutoverJulianDay;
304 }
305 return *this;
306 }
307
308 // -------------------------------------
309
isEquivalentTo(const Calendar & other) const310 UBool GregorianCalendar::isEquivalentTo(const Calendar& other) const
311 {
312 // Calendar override.
313 return Calendar::isEquivalentTo(other) &&
314 fGregorianCutover == ((GregorianCalendar*)&other)->fGregorianCutover;
315 }
316
317 // -------------------------------------
318
319 void
setGregorianChange(UDate date,UErrorCode & status)320 GregorianCalendar::setGregorianChange(UDate date, UErrorCode& status)
321 {
322 if (U_FAILURE(status))
323 return;
324
325 fGregorianCutover = date;
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 int32_t cutoverDay = (int32_t)ClockMath::floorDivide(fGregorianCutover, (double)kOneDay);
334 fNormalizedGregorianCutover = cutoverDay * kOneDay;
335
336 // Handle the rare case of numeric overflow. If the user specifies a
337 // change of UDate(Long.MIN_VALUE), in order to get a pure Gregorian
338 // calendar, then the epoch day is -106751991168, which when multiplied
339 // by ONE_DAY gives 9223372036794351616 -- the negative value is too
340 // large for 64 bits, and overflows into a positive value. We correct
341 // this by using the next day, which for all intents is semantically
342 // equivalent.
343 if (cutoverDay < 0 && fNormalizedGregorianCutover > 0) {
344 fNormalizedGregorianCutover = (cutoverDay + 1) * kOneDay;
345 }
346
347 // Normalize the year so BC values are represented as 0 and negative
348 // values.
349 GregorianCalendar *cal = new GregorianCalendar(getTimeZone(), status);
350 /* test for NULL */
351 if (cal == 0) {
352 status = U_MEMORY_ALLOCATION_ERROR;
353 return;
354 }
355 if(U_FAILURE(status))
356 return;
357 cal->setTime(date, status);
358 fGregorianCutoverYear = cal->get(UCAL_YEAR, status);
359 if (cal->get(UCAL_ERA, status) == BC)
360 fGregorianCutoverYear = 1 - fGregorianCutoverYear;
361 fCutoverJulianDay = cutoverDay;
362 delete cal;
363 }
364
365
handleComputeFields(int32_t julianDay,UErrorCode & status)366 void GregorianCalendar::handleComputeFields(int32_t julianDay, UErrorCode& status) {
367 int32_t eyear, month, dayOfMonth, dayOfYear, unusedRemainder;
368
369
370 if(U_FAILURE(status)) {
371 return;
372 }
373
374 #if defined (U_DEBUG_CAL)
375 fprintf(stderr, "%s:%d: jd%d- (greg's %d)- [cut=%d]\n",
376 __FILE__, __LINE__, julianDay, getGregorianDayOfYear(), fCutoverJulianDay);
377 #endif
378
379
380 if (julianDay >= fCutoverJulianDay) {
381 month = getGregorianMonth();
382 dayOfMonth = getGregorianDayOfMonth();
383 dayOfYear = getGregorianDayOfYear();
384 eyear = getGregorianYear();
385 } else {
386 // The Julian epoch day (not the same as Julian Day)
387 // is zero on Saturday December 30, 0 (Gregorian).
388 int32_t julianEpochDay = julianDay - (kJan1_1JulianDay - 2);
389 eyear = (int32_t) ClockMath::floorDivide((4.0*julianEpochDay) + 1464.0, (int32_t) 1461, unusedRemainder);
390
391 // Compute the Julian calendar day number for January 1, eyear
392 int32_t january1 = 365*(eyear-1) + ClockMath::floorDivide(eyear-1, (int32_t)4);
393 dayOfYear = (julianEpochDay - january1); // 0-based
394
395 // Julian leap years occurred historically every 4 years starting
396 // with 8 AD. Before 8 AD the spacing is irregular; every 3 years
397 // from 45 BC to 9 BC, and then none until 8 AD. However, we don't
398 // implement this historical detail; instead, we implement the
399 // computatinally cleaner proleptic calendar, which assumes
400 // consistent 4-year cycles throughout time.
401 UBool isLeap = ((eyear&0x3) == 0); // equiv. to (eyear%4 == 0)
402
403 // Common Julian/Gregorian calculation
404 int32_t correction = 0;
405 int32_t march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
406 if (dayOfYear >= march1) {
407 correction = isLeap ? 1 : 2;
408 }
409 month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
410 dayOfMonth = dayOfYear - (isLeap?kLeapNumDays[month]:kNumDays[month]) + 1; // one-based DOM
411 ++dayOfYear;
412 #if defined (U_DEBUG_CAL)
413 // fprintf(stderr, "%d - %d[%d] + 1\n", dayOfYear, isLeap?kLeapNumDays[month]:kNumDays[month], month );
414 // fprintf(stderr, "%s:%d: greg's HCF %d -> %d/%d/%d not %d/%d/%d\n",
415 // __FILE__, __LINE__,julianDay,
416 // eyear,month,dayOfMonth,
417 // getGregorianYear(), getGregorianMonth(), getGregorianDayOfMonth() );
418 fprintf(stderr, "%s:%d: doy %d (greg's %d)- [cut=%d]\n",
419 __FILE__, __LINE__, dayOfYear, getGregorianDayOfYear(), fCutoverJulianDay);
420 #endif
421
422 }
423
424 // [j81] if we are after the cutover in its year, shift the day of the year
425 if((eyear == fGregorianCutoverYear) && (julianDay >= fCutoverJulianDay)) {
426 //from handleComputeMonthStart
427 int32_t gregShift = Grego::gregorianShift(eyear);
428 #if defined (U_DEBUG_CAL)
429 fprintf(stderr, "%s:%d: gregorian shift %d ::: doy%d => %d [cut=%d]\n",
430 __FILE__, __LINE__,gregShift, dayOfYear, dayOfYear+gregShift, fCutoverJulianDay);
431 #endif
432 dayOfYear += gregShift;
433 }
434
435 internalSet(UCAL_MONTH, month);
436 internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
437 internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
438 internalSet(UCAL_EXTENDED_YEAR, eyear);
439 int32_t era = AD;
440 if (eyear < 1) {
441 era = BC;
442 eyear = 1 - eyear;
443 }
444 internalSet(UCAL_ERA, era);
445 internalSet(UCAL_YEAR, eyear);
446 }
447
448
449 // -------------------------------------
450
451 UDate
getGregorianChange() const452 GregorianCalendar::getGregorianChange() const
453 {
454 return fGregorianCutover;
455 }
456
457 // -------------------------------------
458
459 UBool
isLeapYear(int32_t year) const460 GregorianCalendar::isLeapYear(int32_t year) const
461 {
462 // MSVC complains bitterly if we try to use Grego::isLeapYear here
463 // NOTE: year&0x3 == year%4
464 return (year >= fGregorianCutoverYear ?
465 (((year&0x3) == 0) && ((year%100 != 0) || (year%400 == 0))) : // Gregorian
466 ((year&0x3) == 0)); // Julian
467 }
468
469 // -------------------------------------
470
handleComputeJulianDay(UCalendarDateFields bestField)471 int32_t GregorianCalendar::handleComputeJulianDay(UCalendarDateFields bestField)
472 {
473 fInvertGregorian = FALSE;
474
475 int32_t jd = Calendar::handleComputeJulianDay(bestField);
476
477 if((bestField == UCAL_WEEK_OF_YEAR) && // if we are doing WOY calculations, we are counting relative to Jan 1 *julian*
478 (internalGet(UCAL_EXTENDED_YEAR)==fGregorianCutoverYear) &&
479 jd >= fCutoverJulianDay) {
480 fInvertGregorian = TRUE; // So that the Julian Jan 1 will be used in handleComputeMonthStart
481 return Calendar::handleComputeJulianDay(bestField);
482 }
483
484
485 // The following check handles portions of the cutover year BEFORE the
486 // cutover itself happens.
487 //if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
488 if ((fIsGregorian==TRUE) != (jd >= fCutoverJulianDay)) { /* cutoverJulianDay)) { */
489 #if defined (U_DEBUG_CAL)
490 fprintf(stderr, "%s:%d: jd [invert] %d\n",
491 __FILE__, __LINE__, jd);
492 #endif
493 fInvertGregorian = TRUE;
494 jd = Calendar::handleComputeJulianDay(bestField);
495 #if defined (U_DEBUG_CAL)
496 fprintf(stderr, "%s:%d: fIsGregorian %s, fInvertGregorian %s - ",
497 __FILE__, __LINE__,fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
498 fprintf(stderr, " jd NOW %d\n",
499 jd);
500 #endif
501 } else {
502 #if defined (U_DEBUG_CAL)
503 fprintf(stderr, "%s:%d: jd [==] %d - %sfIsGregorian %sfInvertGregorian, %d\n",
504 __FILE__, __LINE__, jd, fIsGregorian?"T":"F", fInvertGregorian?"T":"F", bestField);
505 #endif
506 }
507
508 if(fIsGregorian && (internalGet(UCAL_EXTENDED_YEAR) == fGregorianCutoverYear)) {
509 int32_t gregShift = Grego::gregorianShift(internalGet(UCAL_EXTENDED_YEAR));
510 if (bestField == UCAL_DAY_OF_YEAR) {
511 #if defined (U_DEBUG_CAL)
512 fprintf(stderr, "%s:%d: [DOY%d] gregorian shift of JD %d += %d\n",
513 __FILE__, __LINE__, fFields[bestField],jd, gregShift);
514 #endif
515 jd -= gregShift;
516 } else if ( bestField == UCAL_WEEK_OF_MONTH ) {
517 int32_t weekShift = 14;
518 #if defined (U_DEBUG_CAL)
519 fprintf(stderr, "%s:%d: [WOY/WOM] gregorian week shift of %d += %d\n",
520 __FILE__, __LINE__, jd, weekShift);
521 #endif
522 jd += weekShift; // shift by weeks for week based fields.
523 }
524 }
525
526 return jd;
527 }
528
handleComputeMonthStart(int32_t eyear,int32_t month,UBool) const529 int32_t GregorianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month,
530
531 UBool /* useMonth */) const
532 {
533 GregorianCalendar *nonConstThis = (GregorianCalendar*)this; // cast away const
534
535 // If the month is out of range, adjust it into range, and
536 // modify the extended year value accordingly.
537 if (month < 0 || month > 11) {
538 eyear += ClockMath::floorDivide(month, 12, month);
539 }
540
541 UBool isLeap = eyear%4 == 0;
542 int32_t y = eyear-1;
543 int32_t julianDay = 365*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
544
545 nonConstThis->fIsGregorian = (eyear >= fGregorianCutoverYear);
546 #if defined (U_DEBUG_CAL)
547 fprintf(stderr, "%s:%d: (hcms%d/%d) fIsGregorian %s, fInvertGregorian %s\n",
548 __FILE__, __LINE__, eyear,month, fIsGregorian?"T":"F", fInvertGregorian?"T":"F");
549 #endif
550 if (fInvertGregorian) {
551 nonConstThis->fIsGregorian = !fIsGregorian;
552 }
553 if (fIsGregorian) {
554 isLeap = isLeap && ((eyear%100 != 0) || (eyear%400 == 0));
555 // Add 2 because Gregorian calendar starts 2 days after
556 // Julian calendar
557 int32_t gregShift = Grego::gregorianShift(eyear);
558 #if defined (U_DEBUG_CAL)
559 fprintf(stderr, "%s:%d: (hcms%d/%d) gregorian shift of %d += %d\n",
560 __FILE__, __LINE__, eyear, month, julianDay, gregShift);
561 #endif
562 julianDay += gregShift;
563 }
564
565 // At this point julianDay indicates the day BEFORE the first
566 // day of January 1, <eyear> of either the Julian or Gregorian
567 // calendar.
568
569 if (month != 0) {
570 julianDay += isLeap?kLeapNumDays[month]:kNumDays[month];
571 }
572
573 return julianDay;
574 }
575
handleGetMonthLength(int32_t extendedYear,int32_t month) const576 int32_t GregorianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const
577 {
578 // If the month is out of range, adjust it into range, and
579 // modify the extended year value accordingly.
580 if (month < 0 || month > 11) {
581 extendedYear += ClockMath::floorDivide(month, 12, month);
582 }
583
584 return isLeapYear(extendedYear) ? kLeapMonthLength[month] : kMonthLength[month];
585 }
586
handleGetYearLength(int32_t eyear) const587 int32_t GregorianCalendar::handleGetYearLength(int32_t eyear) const {
588 return isLeapYear(eyear) ? 366 : 365;
589 }
590
591
592 int32_t
monthLength(int32_t month) const593 GregorianCalendar::monthLength(int32_t month) const
594 {
595 int32_t year = internalGet(UCAL_EXTENDED_YEAR);
596 return handleGetMonthLength(year, month);
597 }
598
599 // -------------------------------------
600
601 int32_t
monthLength(int32_t month,int32_t year) const602 GregorianCalendar::monthLength(int32_t month, int32_t year) const
603 {
604 return isLeapYear(year) ? kLeapMonthLength[month] : kMonthLength[month];
605 }
606
607 // -------------------------------------
608
609 int32_t
yearLength(int32_t year) const610 GregorianCalendar::yearLength(int32_t year) const
611 {
612 return isLeapYear(year) ? 366 : 365;
613 }
614
615 // -------------------------------------
616
617 int32_t
yearLength() const618 GregorianCalendar::yearLength() const
619 {
620 return isLeapYear(internalGet(UCAL_YEAR)) ? 366 : 365;
621 }
622
623 // -------------------------------------
624
625 /**
626 * After adjustments such as add(MONTH), add(YEAR), we don't want the
627 * month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
628 * 3, we want it to go to Feb 28. Adjustments which might run into this
629 * problem call this method to retain the proper month.
630 */
631 void
pinDayOfMonth()632 GregorianCalendar::pinDayOfMonth()
633 {
634 int32_t monthLen = monthLength(internalGet(UCAL_MONTH));
635 int32_t dom = internalGet(UCAL_DATE);
636 if(dom > monthLen)
637 set(UCAL_DATE, monthLen);
638 }
639
640 // -------------------------------------
641
642
643 UBool
validateFields() const644 GregorianCalendar::validateFields() const
645 {
646 for (int32_t field = 0; field < UCAL_FIELD_COUNT; field++) {
647 // Ignore DATE and DAY_OF_YEAR which are handled below
648 if (field != UCAL_DATE &&
649 field != UCAL_DAY_OF_YEAR &&
650 isSet((UCalendarDateFields)field) &&
651 ! boundsCheck(internalGet((UCalendarDateFields)field), (UCalendarDateFields)field))
652 return FALSE;
653 }
654
655 // Values differ in Least-Maximum and Maximum should be handled
656 // specially.
657 if (isSet(UCAL_DATE)) {
658 int32_t date = internalGet(UCAL_DATE);
659 if (date < getMinimum(UCAL_DATE) ||
660 date > monthLength(internalGet(UCAL_MONTH))) {
661 return FALSE;
662 }
663 }
664
665 if (isSet(UCAL_DAY_OF_YEAR)) {
666 int32_t days = internalGet(UCAL_DAY_OF_YEAR);
667 if (days < 1 || days > yearLength()) {
668 return FALSE;
669 }
670 }
671
672 // Handle DAY_OF_WEEK_IN_MONTH, which must not have the value zero.
673 // We've checked against minimum and maximum above already.
674 if (isSet(UCAL_DAY_OF_WEEK_IN_MONTH) &&
675 0 == internalGet(UCAL_DAY_OF_WEEK_IN_MONTH)) {
676 return FALSE;
677 }
678
679 return TRUE;
680 }
681
682 // -------------------------------------
683
684 UBool
boundsCheck(int32_t value,UCalendarDateFields field) const685 GregorianCalendar::boundsCheck(int32_t value, UCalendarDateFields field) const
686 {
687 return value >= getMinimum(field) && value <= getMaximum(field);
688 }
689
690 // -------------------------------------
691
692 UDate
getEpochDay(UErrorCode & status)693 GregorianCalendar::getEpochDay(UErrorCode& status)
694 {
695 complete(status);
696 // Divide by 1000 (convert to seconds) in order to prevent overflow when
697 // dealing with UDate(Long.MIN_VALUE) and UDate(Long.MAX_VALUE).
698 double wallSec = internalGetTime()/1000 + (internalGet(UCAL_ZONE_OFFSET) + internalGet(UCAL_DST_OFFSET))/1000;
699
700 return ClockMath::floorDivide(wallSec, kOneDay/1000.0);
701 }
702
703 // -------------------------------------
704
705
706 // -------------------------------------
707
708 /**
709 * Compute the julian day number of the day BEFORE the first day of
710 * January 1, year 1 of the given calendar. If julianDay == 0, it
711 * specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
712 * or Gregorian).
713 */
computeJulianDayOfYear(UBool isGregorian,int32_t year,UBool & isLeap)714 double GregorianCalendar::computeJulianDayOfYear(UBool isGregorian,
715 int32_t year, UBool& isLeap)
716 {
717 isLeap = year%4 == 0;
718 int32_t y = year - 1;
719 double julianDay = 365.0*y + ClockMath::floorDivide(y, 4) + (kJan1_1JulianDay - 3);
720
721 if (isGregorian) {
722 isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
723 // Add 2 because Gregorian calendar starts 2 days after Julian calendar
724 julianDay += Grego::gregorianShift(year);
725 }
726
727 return julianDay;
728 }
729
730 // /**
731 // * Compute the day of week, relative to the first day of week, from
732 // * 0..6, of the current DOW_LOCAL or DAY_OF_WEEK fields. This is
733 // * equivalent to get(DOW_LOCAL) - 1.
734 // */
735 // int32_t GregorianCalendar::computeRelativeDOW() const {
736 // int32_t relDow = 0;
737 // if (fStamp[UCAL_DOW_LOCAL] > fStamp[UCAL_DAY_OF_WEEK]) {
738 // relDow = internalGet(UCAL_DOW_LOCAL) - 1; // 1-based
739 // } else if (fStamp[UCAL_DAY_OF_WEEK] != kUnset) {
740 // relDow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
741 // if (relDow < 0) relDow += 7;
742 // }
743 // return relDow;
744 // }
745
746 // /**
747 // * Compute the day of week, relative to the first day of week,
748 // * from 0..6 of the given julian day.
749 // */
750 // int32_t GregorianCalendar::computeRelativeDOW(double julianDay) const {
751 // int32_t relDow = julianDayToDayOfWeek(julianDay) - getFirstDayOfWeek();
752 // if (relDow < 0) {
753 // relDow += 7;
754 // }
755 // return relDow;
756 // }
757
758 // /**
759 // * Compute the DOY using the WEEK_OF_YEAR field and the julian day
760 // * of the day BEFORE January 1 of a year (a return value from
761 // * computeJulianDayOfYear).
762 // */
763 // int32_t GregorianCalendar::computeDOYfromWOY(double julianDayOfYear) const {
764 // // Compute DOY from day of week plus week of year
765
766 // // Find the day of the week for the first of this year. This
767 // // is zero-based, with 0 being the locale-specific first day of
768 // // the week. Add 1 to get first day of year.
769 // int32_t fdy = computeRelativeDOW(julianDayOfYear + 1);
770
771 // return
772 // // Compute doy of first (relative) DOW of WOY 1
773 // (((7 - fdy) < getMinimalDaysInFirstWeek())
774 // ? (8 - fdy) : (1 - fdy))
775
776 // // Adjust for the week number.
777 // + (7 * (internalGet(UCAL_WEEK_OF_YEAR) - 1))
778
779 // // Adjust for the DOW
780 // + computeRelativeDOW();
781 // }
782
783 // -------------------------------------
784
785 double
millisToJulianDay(UDate millis)786 GregorianCalendar::millisToJulianDay(UDate millis)
787 {
788 return (double)kEpochStartAsJulianDay + ClockMath::floorDivide(millis, (double)kOneDay);
789 }
790
791 // -------------------------------------
792
793 UDate
julianDayToMillis(double julian)794 GregorianCalendar::julianDayToMillis(double julian)
795 {
796 return (UDate) ((julian - kEpochStartAsJulianDay) * (double) kOneDay);
797 }
798
799 // -------------------------------------
800
801 int32_t
aggregateStamp(int32_t stamp_a,int32_t stamp_b)802 GregorianCalendar::aggregateStamp(int32_t stamp_a, int32_t stamp_b)
803 {
804 return (((stamp_a != kUnset && stamp_b != kUnset)
805 ? uprv_max(stamp_a, stamp_b)
806 : (int32_t)kUnset));
807 }
808
809 // -------------------------------------
810
811 /**
812 * Roll a field by a signed amount.
813 * Note: This will be made public later. [LIU]
814 */
815
816 void
roll(EDateFields field,int32_t amount,UErrorCode & status)817 GregorianCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
818 roll((UCalendarDateFields) field, amount, status);
819 }
820
821 void
roll(UCalendarDateFields field,int32_t amount,UErrorCode & status)822 GregorianCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status)
823 {
824 if((amount == 0) || U_FAILURE(status)) {
825 return;
826 }
827
828 // J81 processing. (gregorian cutover)
829 UBool inCutoverMonth = FALSE;
830 int32_t cMonthLen=0; // 'c' for cutover; in days
831 int32_t cDayOfMonth=0; // no discontinuity: [0, cMonthLen)
832 double cMonthStart=0.0; // in ms
833
834 // Common code - see if we're in the cutover month of the cutover year
835 if(get(UCAL_EXTENDED_YEAR, status) == fGregorianCutoverYear) {
836 switch (field) {
837 case UCAL_DAY_OF_MONTH:
838 case UCAL_WEEK_OF_MONTH:
839 {
840 int32_t max = monthLength(internalGet(UCAL_MONTH));
841 UDate t = internalGetTime();
842 // We subtract 1 from the DAY_OF_MONTH to make it zero-based, and an
843 // additional 10 if we are after the cutover. Thus the monthStart
844 // value will be correct iff we actually are in the cutover month.
845 cDayOfMonth = internalGet(UCAL_DAY_OF_MONTH) - ((t >= fGregorianCutover) ? 10 : 0);
846 cMonthStart = t - ((cDayOfMonth - 1) * kOneDay);
847 // A month containing the cutover is 10 days shorter.
848 if ((cMonthStart < fGregorianCutover) &&
849 (cMonthStart + (cMonthLen=(max-10))*kOneDay >= fGregorianCutover)) {
850 inCutoverMonth = TRUE;
851 }
852 }
853 default:
854 ;
855 }
856 }
857
858 switch (field) {
859 case UCAL_WEEK_OF_YEAR: {
860 // Unlike WEEK_OF_MONTH, WEEK_OF_YEAR never shifts the day of the
861 // week. Also, rolling the week of the year can have seemingly
862 // strange effects simply because the year of the week of year
863 // may be different from the calendar year. For example, the
864 // date Dec 28, 1997 is the first day of week 1 of 1998 (if
865 // weeks start on Sunday and the minimal days in first week is
866 // <= 3).
867 int32_t woy = get(UCAL_WEEK_OF_YEAR, status);
868 // Get the ISO year, which matches the week of year. This
869 // may be one year before or after the calendar year.
870 int32_t isoYear = get(UCAL_YEAR_WOY, status);
871 int32_t isoDoy = internalGet(UCAL_DAY_OF_YEAR);
872 if (internalGet(UCAL_MONTH) == UCAL_JANUARY) {
873 if (woy >= 52) {
874 isoDoy += handleGetYearLength(isoYear);
875 }
876 } else {
877 if (woy == 1) {
878 isoDoy -= handleGetYearLength(isoYear - 1);
879 }
880 }
881 woy += amount;
882 // Do fast checks to avoid unnecessary computation:
883 if (woy < 1 || woy > 52) {
884 // Determine the last week of the ISO year.
885 // We do this using the standard formula we use
886 // everywhere in this file. If we can see that the
887 // days at the end of the year are going to fall into
888 // week 1 of the next year, we drop the last week by
889 // subtracting 7 from the last day of the year.
890 int32_t lastDoy = handleGetYearLength(isoYear);
891 int32_t lastRelDow = (lastDoy - isoDoy + internalGet(UCAL_DAY_OF_WEEK) -
892 getFirstDayOfWeek()) % 7;
893 if (lastRelDow < 0) lastRelDow += 7;
894 if ((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) lastDoy -= 7;
895 int32_t lastWoy = weekNumber(lastDoy, lastRelDow + 1);
896 woy = ((woy + lastWoy - 1) % lastWoy) + 1;
897 }
898 set(UCAL_WEEK_OF_YEAR, woy);
899 set(UCAL_YEAR_WOY,isoYear);
900 return;
901 }
902
903 case UCAL_DAY_OF_MONTH:
904 if( !inCutoverMonth ) {
905 Calendar::roll(field, amount, status);
906 return;
907 } else {
908 // [j81] 1582 special case for DOM
909 // The default computation works except when the current month
910 // contains the Gregorian cutover. We handle this special case
911 // here. [j81 - aliu]
912 double monthLen = cMonthLen * kOneDay;
913 double msIntoMonth = uprv_fmod(internalGetTime() - cMonthStart +
914 amount * kOneDay, monthLen);
915 if (msIntoMonth < 0) {
916 msIntoMonth += monthLen;
917 }
918 #if defined (U_DEBUG_CAL)
919 fprintf(stderr, "%s:%d: roll DOM %d -> %.0lf ms \n",
920 __FILE__, __LINE__,amount, cMonthLen, cMonthStart+msIntoMonth);
921 #endif
922 setTimeInMillis(cMonthStart + msIntoMonth, status);
923 return;
924 }
925
926 case UCAL_WEEK_OF_MONTH:
927 if( !inCutoverMonth ) {
928 Calendar::roll(field, amount, status);
929 return;
930 } else {
931 #if defined (U_DEBUG_CAL)
932 fprintf(stderr, "%s:%d: roll WOM %d ??????????????????? \n",
933 __FILE__, __LINE__,amount);
934 #endif
935 // NOTE: following copied from the old
936 // GregorianCalendar::roll( WEEK_OF_MONTH ) code
937
938 // This is tricky, because during the roll we may have to shift
939 // to a different day of the week. For example:
940
941 // s m t w r f s
942 // 1 2 3 4 5
943 // 6 7 8 9 10 11 12
944
945 // When rolling from the 6th or 7th back one week, we go to the
946 // 1st (assuming that the first partial week counts). The same
947 // thing happens at the end of the month.
948
949 // The other tricky thing is that we have to figure out whether
950 // the first partial week actually counts or not, based on the
951 // minimal first days in the week. And we have to use the
952 // correct first day of the week to delineate the week
953 // boundaries.
954
955 // Here's our algorithm. First, we find the real boundaries of
956 // the month. Then we discard the first partial week if it
957 // doesn't count in this locale. Then we fill in the ends with
958 // phantom days, so that the first partial week and the last
959 // partial week are full weeks. We then have a nice square
960 // block of weeks. We do the usual rolling within this block,
961 // as is done elsewhere in this method. If we wind up on one of
962 // the phantom days that we added, we recognize this and pin to
963 // the first or the last day of the month. Easy, eh?
964
965 // Another wrinkle: To fix jitterbug 81, we have to make all this
966 // work in the oddball month containing the Gregorian cutover.
967 // This month is 10 days shorter than usual, and also contains
968 // a discontinuity in the days; e.g., the default cutover month
969 // is Oct 1582, and goes from day of month 4 to day of month 15.
970
971 // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
972 // in this locale. We have dow in 0..6.
973 int32_t dow = internalGet(UCAL_DAY_OF_WEEK) - getFirstDayOfWeek();
974 if (dow < 0)
975 dow += 7;
976
977 // Find the day of month, compensating for cutover discontinuity.
978 int32_t dom = cDayOfMonth;
979
980 // Find the day of the week (normalized for locale) for the first
981 // of the month.
982 int32_t fdm = (dow - dom + 1) % 7;
983 if (fdm < 0)
984 fdm += 7;
985
986 // Get the first day of the first full week of the month,
987 // including phantom days, if any. Figure out if the first week
988 // counts or not; if it counts, then fill in phantom days. If
989 // not, advance to the first real full week (skip the partial week).
990 int32_t start;
991 if ((7 - fdm) < getMinimalDaysInFirstWeek())
992 start = 8 - fdm; // Skip the first partial week
993 else
994 start = 1 - fdm; // This may be zero or negative
995
996 // Get the day of the week (normalized for locale) for the last
997 // day of the month.
998 int32_t monthLen = cMonthLen;
999 int32_t ldm = (monthLen - dom + dow) % 7;
1000 // We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
1001
1002 // Get the limit day for the blocked-off rectangular month; that
1003 // is, the day which is one past the last day of the month,
1004 // after the month has already been filled in with phantom days
1005 // to fill out the last week. This day has a normalized DOW of 0.
1006 int32_t limit = monthLen + 7 - ldm;
1007
1008 // Now roll between start and (limit - 1).
1009 int32_t gap = limit - start;
1010 int32_t newDom = (dom + amount*7 - start) % gap;
1011 if (newDom < 0)
1012 newDom += gap;
1013 newDom += start;
1014
1015 // Finally, pin to the real start and end of the month.
1016 if (newDom < 1)
1017 newDom = 1;
1018 if (newDom > monthLen)
1019 newDom = monthLen;
1020
1021 // Set the DAY_OF_MONTH. We rely on the fact that this field
1022 // takes precedence over everything else (since all other fields
1023 // are also set at this point). If this fact changes (if the
1024 // disambiguation algorithm changes) then we will have to unset
1025 // the appropriate fields here so that DAY_OF_MONTH is attended
1026 // to.
1027
1028 // If we are in the cutover month, manipulate ms directly. Don't do
1029 // this in general because it doesn't work across DST boundaries
1030 // (details, details). This takes care of the discontinuity.
1031 setTimeInMillis(cMonthStart + (newDom-1)*kOneDay, status);
1032 return;
1033 }
1034
1035 default:
1036 Calendar::roll(field, amount, status);
1037 return;
1038 }
1039 }
1040
1041 // -------------------------------------
1042
1043
1044 /**
1045 * Return the minimum value that this field could have, given the current date.
1046 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1047 * @param field the time field.
1048 * @return the minimum value that this field could have, given the current date.
1049 * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field) instead.
1050 */
getActualMinimum(EDateFields field) const1051 int32_t GregorianCalendar::getActualMinimum(EDateFields field) const
1052 {
1053 return getMinimum((UCalendarDateFields)field);
1054 }
1055
getActualMinimum(EDateFields field,UErrorCode &) const1056 int32_t GregorianCalendar::getActualMinimum(EDateFields field, UErrorCode& /* status */) const
1057 {
1058 return getMinimum((UCalendarDateFields)field);
1059 }
1060
1061 /**
1062 * Return the minimum value that this field could have, given the current date.
1063 * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1064 * @param field the time field.
1065 * @return the minimum value that this field could have, given the current date.
1066 * @draft ICU 2.6.
1067 */
getActualMinimum(UCalendarDateFields field,UErrorCode &) const1068 int32_t GregorianCalendar::getActualMinimum(UCalendarDateFields field, UErrorCode& /* status */) const
1069 {
1070 return getMinimum(field);
1071 }
1072
1073
1074 // ------------------------------------
1075
1076 /**
1077 * Old year limits were least max 292269054, max 292278994.
1078 */
1079
1080 /**
1081 * @stable ICU 2.0
1082 */
handleGetLimit(UCalendarDateFields field,ELimitType limitType) const1083 int32_t GregorianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
1084 return kGregorianCalendarLimits[field][limitType];
1085 }
1086
1087 /**
1088 * Return the maximum value that this field could have, given the current date.
1089 * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1090 * maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar,
1091 * for some years the actual maximum for MONTH is 12, and for others 13.
1092 * @stable ICU 2.0
1093 */
getActualMaximum(UCalendarDateFields field,UErrorCode & status) const1094 int32_t GregorianCalendar::getActualMaximum(UCalendarDateFields field, UErrorCode& status) const
1095 {
1096 /* It is a known limitation that the code here (and in getActualMinimum)
1097 * won't behave properly at the extreme limits of GregorianCalendar's
1098 * representable range (except for the code that handles the YEAR
1099 * field). That's because the ends of the representable range are at
1100 * odd spots in the year. For calendars with the default Gregorian
1101 * cutover, these limits are Sun Dec 02 16:47:04 GMT 292269055 BC to Sun
1102 * Aug 17 07:12:55 GMT 292278994 AD, somewhat different for non-GMT
1103 * zones. As a result, if the calendar is set to Aug 1 292278994 AD,
1104 * the actual maximum of DAY_OF_MONTH is 17, not 30. If the date is Mar
1105 * 31 in that year, the actual maximum month might be Jul, whereas is
1106 * the date is Mar 15, the actual maximum might be Aug -- depending on
1107 * the precise semantics that are desired. Similar considerations
1108 * affect all fields. Nonetheless, this effect is sufficiently arcane
1109 * that we permit it, rather than complicating the code to handle such
1110 * intricacies. - liu 8/20/98
1111
1112 * UPDATE: No longer true, since we have pulled in the limit values on
1113 * the year. - Liu 11/6/00 */
1114
1115 switch (field) {
1116
1117 case UCAL_YEAR:
1118 /* The year computation is no different, in principle, from the
1119 * others, however, the range of possible maxima is large. In
1120 * addition, the way we know we've exceeded the range is different.
1121 * For these reasons, we use the special case code below to handle
1122 * this field.
1123 *
1124 * The actual maxima for YEAR depend on the type of calendar:
1125 *
1126 * Gregorian = May 17, 292275056 BC - Aug 17, 292278994 AD
1127 * Julian = Dec 2, 292269055 BC - Jan 3, 292272993 AD
1128 * Hybrid = Dec 2, 292269055 BC - Aug 17, 292278994 AD
1129 *
1130 * We know we've exceeded the maximum when either the month, date,
1131 * time, or era changes in response to setting the year. We don't
1132 * check for month, date, and time here because the year and era are
1133 * sufficient to detect an invalid year setting. NOTE: If code is
1134 * added to check the month and date in the future for some reason,
1135 * Feb 29 must be allowed to shift to Mar 1 when setting the year.
1136 */
1137 {
1138 if(U_FAILURE(status)) return 0;
1139 Calendar *cal = clone();
1140 if(!cal) {
1141 status = U_MEMORY_ALLOCATION_ERROR;
1142 return 0;
1143 }
1144
1145 cal->setLenient(TRUE);
1146
1147 int32_t era = cal->get(UCAL_ERA, status);
1148 UDate d = cal->getTime(status);
1149
1150 /* Perform a binary search, with the invariant that lowGood is a
1151 * valid year, and highBad is an out of range year.
1152 */
1153 int32_t lowGood = kGregorianCalendarLimits[UCAL_YEAR][1];
1154 int32_t highBad = kGregorianCalendarLimits[UCAL_YEAR][2]+1;
1155 while ((lowGood + 1) < highBad) {
1156 int32_t y = (lowGood + highBad) / 2;
1157 cal->set(UCAL_YEAR, y);
1158 if (cal->get(UCAL_YEAR, status) == y && cal->get(UCAL_ERA, status) == era) {
1159 lowGood = y;
1160 } else {
1161 highBad = y;
1162 cal->setTime(d, status); // Restore original fields
1163 }
1164 }
1165
1166 delete cal;
1167 return lowGood;
1168 }
1169
1170 default:
1171 return Calendar::getActualMaximum(field,status);
1172 }
1173 }
1174
1175
handleGetExtendedYear()1176 int32_t GregorianCalendar::handleGetExtendedYear() {
1177 // the year to return
1178 int32_t year = kEpochYear;
1179
1180 // year field to use
1181 int32_t yearField = UCAL_EXTENDED_YEAR;
1182
1183 // There are three separate fields which could be used to
1184 // derive the proper year. Use the one most recently set.
1185 if (fStamp[yearField] < fStamp[UCAL_YEAR])
1186 yearField = UCAL_YEAR;
1187 if (fStamp[yearField] < fStamp[UCAL_YEAR_WOY])
1188 yearField = UCAL_YEAR_WOY;
1189
1190 // based on the "best" year field, get the year
1191 switch(yearField) {
1192 case UCAL_EXTENDED_YEAR:
1193 year = internalGet(UCAL_EXTENDED_YEAR, kEpochYear);
1194 break;
1195
1196 case UCAL_YEAR:
1197 {
1198 // The year defaults to the epoch start, the era to AD
1199 int32_t era = internalGet(UCAL_ERA, AD);
1200 if (era == BC) {
1201 year = 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
1202 } else {
1203 year = internalGet(UCAL_YEAR, kEpochYear);
1204 }
1205 }
1206 break;
1207
1208 case UCAL_YEAR_WOY:
1209 year = handleGetExtendedYearFromWeekFields(internalGet(UCAL_YEAR_WOY), internalGet(UCAL_WEEK_OF_YEAR));
1210 #if defined (U_DEBUG_CAL)
1211 // if(internalGet(UCAL_YEAR_WOY) != year) {
1212 fprintf(stderr, "%s:%d: hGEYFWF[%d,%d] -> %d\n",
1213 __FILE__, __LINE__,internalGet(UCAL_YEAR_WOY),internalGet(UCAL_WEEK_OF_YEAR),year);
1214 //}
1215 #endif
1216 break;
1217
1218 default:
1219 year = kEpochYear;
1220 }
1221 return year;
1222 }
1223
handleGetExtendedYearFromWeekFields(int32_t yearWoy,int32_t woy)1224 int32_t GregorianCalendar::handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy)
1225 {
1226 // convert year to extended form
1227 int32_t era = internalGet(UCAL_ERA, AD);
1228 if(era == BC) {
1229 yearWoy = 1 - yearWoy;
1230 }
1231 return Calendar::handleGetExtendedYearFromWeekFields(yearWoy, woy);
1232 }
1233
1234
1235 // -------------------------------------
1236
1237 UBool
inDaylightTime(UErrorCode & status) const1238 GregorianCalendar::inDaylightTime(UErrorCode& status) const
1239 {
1240 if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
1241 return FALSE;
1242
1243 // Force an update of the state of the Calendar.
1244 ((GregorianCalendar*)this)->complete(status); // cast away const
1245
1246 return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
1247 }
1248
1249 // -------------------------------------
1250
1251 /**
1252 * Return the ERA. We need a special method for this because the
1253 * default ERA is AD, but a zero (unset) ERA is BC.
1254 */
1255 int32_t
internalGetEra() const1256 GregorianCalendar::internalGetEra() const {
1257 return isSet(UCAL_ERA) ? internalGet(UCAL_ERA) : (int32_t)AD;
1258 }
1259
1260 const char *
getType() const1261 GregorianCalendar::getType() const {
1262 //static const char kGregorianType = "gregorian";
1263
1264 return "gregorian";
1265 }
1266
1267 const UDate GregorianCalendar::fgSystemDefaultCentury = DBL_MIN;
1268 const int32_t GregorianCalendar::fgSystemDefaultCenturyYear = -1;
1269
1270 UDate GregorianCalendar::fgSystemDefaultCenturyStart = DBL_MIN;
1271 int32_t GregorianCalendar::fgSystemDefaultCenturyStartYear = -1;
1272
1273
haveDefaultCentury() const1274 UBool GregorianCalendar::haveDefaultCentury() const
1275 {
1276 return TRUE;
1277 }
1278
defaultCenturyStart() const1279 UDate GregorianCalendar::defaultCenturyStart() const
1280 {
1281 return internalGetDefaultCenturyStart();
1282 }
1283
defaultCenturyStartYear() const1284 int32_t GregorianCalendar::defaultCenturyStartYear() const
1285 {
1286 return internalGetDefaultCenturyStartYear();
1287 }
1288
1289 UDate
internalGetDefaultCenturyStart() const1290 GregorianCalendar::internalGetDefaultCenturyStart() const
1291 {
1292 // lazy-evaluate systemDefaultCenturyStart
1293 UBool needsUpdate;
1294 UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
1295
1296 if (needsUpdate) {
1297 initializeSystemDefaultCentury();
1298 }
1299
1300 // use defaultCenturyStart unless it's the flag value;
1301 // then use systemDefaultCenturyStart
1302
1303 return fgSystemDefaultCenturyStart;
1304 }
1305
1306 int32_t
internalGetDefaultCenturyStartYear() const1307 GregorianCalendar::internalGetDefaultCenturyStartYear() const
1308 {
1309 // lazy-evaluate systemDefaultCenturyStartYear
1310 UBool needsUpdate;
1311 UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
1312
1313 if (needsUpdate) {
1314 initializeSystemDefaultCentury();
1315 }
1316
1317 // use defaultCenturyStart unless it's the flag value;
1318 // then use systemDefaultCenturyStartYear
1319
1320 return fgSystemDefaultCenturyStartYear;
1321 }
1322
1323 void
initializeSystemDefaultCentury()1324 GregorianCalendar::initializeSystemDefaultCentury()
1325 {
1326 // initialize systemDefaultCentury and systemDefaultCenturyYear based
1327 // on the current time. They'll be set to 80 years before
1328 // the current time.
1329 UErrorCode status = U_ZERO_ERROR;
1330 Calendar *calendar = new GregorianCalendar(status);
1331 if (calendar != NULL && U_SUCCESS(status))
1332 {
1333 calendar->setTime(Calendar::getNow(), status);
1334 calendar->add(UCAL_YEAR, -80, status);
1335
1336 UDate newStart = calendar->getTime(status);
1337 int32_t newYear = calendar->get(UCAL_YEAR, status);
1338 umtx_lock(NULL);
1339 if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury)
1340 {
1341 fgSystemDefaultCenturyStartYear = newYear;
1342 fgSystemDefaultCenturyStart = newStart;
1343 }
1344 umtx_unlock(NULL);
1345 delete calendar;
1346 }
1347 // We have no recourse upon failure unless we want to propagate the failure
1348 // out.
1349 }
1350
1351
1352 U_NAMESPACE_END
1353
1354 #endif /* #if !UCONFIG_NO_FORMATTING */
1355
1356 //eof
1357