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      1 /*
      2 ******************************************************************************
      3 * Copyright (C) 2003-2008, International Business Machines Corporation
      4 * and others. All Rights Reserved.
      5 ******************************************************************************
      6 *
      7 * File HEBRWCAL.CPP
      8 *
      9 * Modification History:
     10 *
     11 *   Date        Name        Description
     12 *   12/03/2003  srl         ported from java HebrewCalendar
     13 *****************************************************************************
     14 */
     15 
     16 #include "hebrwcal.h"
     17 
     18 #if !UCONFIG_NO_FORMATTING
     19 
     20 #include "umutex.h"
     21 #include <float.h>
     22 #include "gregoimp.h" // Math
     23 #include "astro.h" // CalendarAstronomer
     24 #include "uhash.h"
     25 #include "ucln_in.h"
     26 
     27 // Hebrew Calendar implementation
     28 
     29 /**
     30 * The absolute date, in milliseconds since 1/1/1970 AD, Gregorian,
     31 * of the start of the Hebrew calendar.  In order to keep this calendar's
     32 * time of day in sync with that of the Gregorian calendar, we use
     33 * midnight, rather than sunset the day before.
     34 */
     35 //static const double EPOCH_MILLIS = -180799862400000.; // 1/1/1 HY
     36 
     37 static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
     38     // Minimum  Greatest    Least  Maximum
     39     //           Minimum  Maximum
     40     {        0,        0,        0,        0}, // ERA
     41     { -5000000, -5000000,  5000000,  5000000}, // YEAR
     42     {        0,        0,       12,       12}, // MONTH
     43     {        1,        1,       51,       56}, // WEEK_OF_YEAR
     44     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
     45     {        1,        1,       29,       30}, // DAY_OF_MONTH
     46     {        1,        1,      353,      385}, // DAY_OF_YEAR
     47     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
     48     {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
     49     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
     50     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
     51     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
     52     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
     53     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
     54     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
     55     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
     56     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
     57     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
     58     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
     59     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
     60     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
     61     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
     62     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
     63 };
     64 
     65 /**
     66 * The lengths of the Hebrew months.  This is complicated, because there
     67 * are three different types of years, or six if you count leap years.
     68 * Due to the rules for postponing the start of the year to avoid having
     69 * certain holidays fall on the sabbath, the year can end up being three
     70 * different lengths, called "deficient", "normal", and "complete".
     71 */
     72 static const int8_t MONTH_LENGTH[][3] = {
     73     // Deficient  Normal     Complete
     74     {   30,         30,         30     },           //Tishri
     75     {   29,         29,         30     },           //Heshvan
     76     {   29,         30,         30     },           //Kislev
     77     {   29,         29,         29     },           //Tevet
     78     {   30,         30,         30     },           //Shevat
     79     {   30,         30,         30     },           //Adar I (leap years only)
     80     {   29,         29,         29     },           //Adar
     81     {   30,         30,         30     },           //Nisan
     82     {   29,         29,         29     },           //Iyar
     83     {   30,         30,         30     },           //Sivan
     84     {   29,         29,         29     },           //Tammuz
     85     {   30,         30,         30     },           //Av
     86     {   29,         29,         29     },           //Elul
     87 };
     88 
     89 /**
     90 * The cumulative # of days to the end of each month in a non-leap year
     91 * Although this can be calculated from the MONTH_LENGTH table,
     92 * keeping it around separately makes some calculations a lot faster
     93 */
     94 
     95 static const int16_t MONTH_START[][3] = {
     96     // Deficient  Normal     Complete
     97     {    0,          0,          0  },          // (placeholder)
     98     {   30,         30,         30  },          // Tishri
     99     {   59,         59,         60  },          // Heshvan
    100     {   88,         89,         90  },          // Kislev
    101     {  117,        118,        119  },          // Tevet
    102     {  147,        148,        149  },          // Shevat
    103     {  147,        148,        149  },          // (Adar I placeholder)
    104     {  176,        177,        178  },          // Adar
    105     {  206,        207,        208  },          // Nisan
    106     {  235,        236,        237  },          // Iyar
    107     {  265,        266,        267  },          // Sivan
    108     {  294,        295,        296  },          // Tammuz
    109     {  324,        325,        326  },          // Av
    110     {  353,        354,        355  },          // Elul
    111 };
    112 
    113 /**
    114 * The cumulative # of days to the end of each month in a leap year
    115 */
    116 static const int16_t  LEAP_MONTH_START[][3] = {
    117     // Deficient  Normal     Complete
    118     {    0,          0,          0  },          // (placeholder)
    119     {   30,         30,         30  },          // Tishri
    120     {   59,         59,         60  },          // Heshvan
    121     {   88,         89,         90  },          // Kislev
    122     {  117,        118,        119  },          // Tevet
    123     {  147,        148,        149  },          // Shevat
    124     {  177,        178,        179  },          // Adar I
    125     {  206,        207,        208  },          // Adar II
    126     {  236,        237,        238  },          // Nisan
    127     {  265,        266,        267  },          // Iyar
    128     {  295,        296,        297  },          // Sivan
    129     {  324,        325,        326  },          // Tammuz
    130     {  354,        355,        356  },          // Av
    131     {  383,        384,        385  },          // Elul
    132 };
    133 
    134 static U_NAMESPACE_QUALIFIER CalendarCache *gCache =  NULL;
    135 
    136 U_CDECL_BEGIN
    137 static UBool calendar_hebrew_cleanup(void) {
    138     delete gCache;
    139     gCache = NULL;
    140     return TRUE;
    141 }
    142 U_CDECL_END
    143 
    144 U_NAMESPACE_BEGIN
    145 //-------------------------------------------------------------------------
    146 // Constructors...
    147 //-------------------------------------------------------------------------
    148 
    149 /**
    150 * Constructs a default <code>HebrewCalendar</code> using the current time
    151 * in the default time zone with the default locale.
    152 * @internal
    153 */
    154 HebrewCalendar::HebrewCalendar(const Locale& aLocale, UErrorCode& success)
    155 :   Calendar(TimeZone::createDefault(), aLocale, success)
    156 
    157 {
    158     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
    159 }
    160 
    161 
    162 HebrewCalendar::~HebrewCalendar() {
    163 }
    164 
    165 const char *HebrewCalendar::getType() const {
    166     return "hebrew";
    167 }
    168 
    169 Calendar* HebrewCalendar::clone() const {
    170     return new HebrewCalendar(*this);
    171 }
    172 
    173 HebrewCalendar::HebrewCalendar(const HebrewCalendar& other) : Calendar(other) {
    174 }
    175 
    176 
    177 //-------------------------------------------------------------------------
    178 // Rolling and adding functions overridden from Calendar
    179 //
    180 // These methods call through to the default implementation in IBMCalendar
    181 // for most of the fields and only handle the unusual ones themselves.
    182 //-------------------------------------------------------------------------
    183 
    184 /**
    185 * Add a signed amount to a specified field, using this calendar's rules.
    186 * For example, to add three days to the current date, you can call
    187 * <code>add(Calendar.DATE, 3)</code>.
    188 * <p>
    189 * When adding to certain fields, the values of other fields may conflict and
    190 * need to be changed.  For example, when adding one to the {@link #MONTH MONTH} field
    191 * for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
    192 * must be adjusted so that the result is "29 Elul 5758" rather than the invalid
    193 * "30 Elul 5758".
    194 * <p>
    195 * This method is able to add to
    196 * all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
    197 * and {@link #ZONE_OFFSET ZONE_OFFSET}.
    198 * <p>
    199 * <b>Note:</b> You should always use {@link #roll roll} and add rather
    200 * than attempting to perform arithmetic operations directly on the fields
    201 * of a <tt>HebrewCalendar</tt>.  Since the {@link #MONTH MONTH} field behaves
    202 * discontinuously in non-leap years, simple arithmetic can give invalid results.
    203 * <p>
    204 * @param field     the time field.
    205 * @param amount    the amount to add to the field.
    206 *
    207 * @exception   IllegalArgumentException if the field is invalid or refers
    208 *              to a field that cannot be handled by this method.
    209 * @internal
    210 */
    211 void HebrewCalendar::add(UCalendarDateFields field, int32_t amount, UErrorCode& status)
    212 {
    213     if(U_FAILURE(status)) {
    214         return;
    215     }
    216     switch (field) {
    217   case UCAL_MONTH:
    218       {
    219           // We can't just do a set(MONTH, get(MONTH) + amount).  The
    220           // reason is ADAR_1.  Suppose amount is +2 and we land in
    221           // ADAR_1 -- then we have to bump to ADAR_2 aka ADAR.  But
    222           // if amount is -2 and we land in ADAR_1, then we have to
    223           // bump the other way -- down to SHEVAT.  - Alan 11/00
    224           int32_t month = get(UCAL_MONTH, status);
    225           int32_t year = get(UCAL_YEAR, status);
    226           UBool acrossAdar1;
    227           if (amount > 0) {
    228               acrossAdar1 = (month < ADAR_1); // started before ADAR_1?
    229               month += amount;
    230               for (;;) {
    231                   if (acrossAdar1 && month>=ADAR_1 && !isLeapYear(year)) {
    232                       ++month;
    233                   }
    234                   if (month <= ELUL) {
    235                       break;
    236                   }
    237                   month -= ELUL+1;
    238                   ++year;
    239                   acrossAdar1 = TRUE;
    240               }
    241           } else {
    242               acrossAdar1 = (month > ADAR_1); // started after ADAR_1?
    243               month += amount;
    244               for (;;) {
    245                   if (acrossAdar1 && month<=ADAR_1 && !isLeapYear(year)) {
    246                       --month;
    247                   }
    248                   if (month >= 0) {
    249                       break;
    250                   }
    251                   month += ELUL+1;
    252                   --year;
    253                   acrossAdar1 = TRUE;
    254               }
    255           }
    256           set(UCAL_MONTH, month);
    257           set(UCAL_YEAR, year);
    258           pinField(UCAL_DAY_OF_MONTH, status);
    259           break;
    260       }
    261 
    262   default:
    263       Calendar::add(field, amount, status);
    264       break;
    265     }
    266 }
    267 
    268 /**
    269 * @deprecated ICU 2.6 use UCalendarDateFields instead of EDateFields
    270 */
    271 void HebrewCalendar::add(EDateFields field, int32_t amount, UErrorCode& status)
    272 {
    273     add((UCalendarDateFields)field, amount, status);
    274 }
    275 
    276 /**
    277 * Rolls (up/down) a specified amount time on the given field.  For
    278 * example, to roll the current date up by three days, you can call
    279 * <code>roll(Calendar.DATE, 3)</code>.  If the
    280 * field is rolled past its maximum allowable value, it will "wrap" back
    281 * to its minimum and continue rolling.
    282 * For example, calling <code>roll(Calendar.DATE, 10)</code>
    283 * on a Hebrew calendar set to "25 Av 5758" will result in the date "5 Av 5758".
    284 * <p>
    285 * When rolling certain fields, the values of other fields may conflict and
    286 * need to be changed.  For example, when rolling the {@link #MONTH MONTH} field
    287 * upward by one for the date "30 Av 5758", the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
    288 * must be adjusted so that the result is "29 Elul 5758" rather than the invalid
    289 * "30 Elul".
    290 * <p>
    291 * This method is able to roll
    292 * all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
    293 * and {@link #ZONE_OFFSET ZONE_OFFSET}.  Subclasses may, of course, add support for
    294 * additional fields in their overrides of <code>roll</code>.
    295 * <p>
    296 * <b>Note:</b> You should always use roll and {@link #add add} rather
    297 * than attempting to perform arithmetic operations directly on the fields
    298 * of a <tt>HebrewCalendar</tt>.  Since the {@link #MONTH MONTH} field behaves
    299 * discontinuously in non-leap years, simple arithmetic can give invalid results.
    300 * <p>
    301 * @param field     the time field.
    302 * @param amount    the amount by which the field should be rolled.
    303 *
    304 * @exception   IllegalArgumentException if the field is invalid or refers
    305 *              to a field that cannot be handled by this method.
    306 * @internal
    307 */
    308 void HebrewCalendar::roll(UCalendarDateFields field, int32_t amount, UErrorCode& status)
    309 {
    310     if(U_FAILURE(status)) {
    311         return;
    312     }
    313     switch (field) {
    314   case UCAL_MONTH:
    315       {
    316           int32_t month = get(UCAL_MONTH, status);
    317           int32_t year = get(UCAL_YEAR, status);
    318 
    319           UBool leapYear = isLeapYear(year);
    320           int32_t yearLength = monthsInYear(year);
    321           int32_t newMonth = month + (amount % yearLength);
    322           //
    323           // If it's not a leap year and we're rolling past the missing month
    324           // of ADAR_1, we need to roll an extra month to make up for it.
    325           //
    326           if (!leapYear) {
    327               if (amount > 0 && month < ADAR_1 && newMonth >= ADAR_1) {
    328                   newMonth++;
    329               } else if (amount < 0 && month > ADAR_1 && newMonth <= ADAR_1) {
    330                   newMonth--;
    331               }
    332           }
    333           set(UCAL_MONTH, (newMonth + 13) % 13);
    334           pinField(UCAL_DAY_OF_MONTH, status);
    335           return;
    336       }
    337   default:
    338       Calendar::roll(field, amount, status);
    339     }
    340 }
    341 
    342 void HebrewCalendar::roll(EDateFields field, int32_t amount, UErrorCode& status) {
    343     roll((UCalendarDateFields)field, amount, status);
    344 }
    345 
    346 //-------------------------------------------------------------------------
    347 // Support methods
    348 //-------------------------------------------------------------------------
    349 
    350 // Hebrew date calculations are performed in terms of days, hours, and
    351 // "parts" (or halakim), which are 1/1080 of an hour, or 3 1/3 seconds.
    352 static const int32_t HOUR_PARTS = 1080;
    353 static const int32_t DAY_PARTS  = 24*HOUR_PARTS;
    354 
    355 // An approximate value for the length of a lunar month.
    356 // It is used to calculate the approximate year and month of a given
    357 // absolute date.
    358 static const int32_t  MONTH_DAYS = 29;
    359 static const int32_t MONTH_FRACT = 12*HOUR_PARTS + 793;
    360 static const int32_t MONTH_PARTS = MONTH_DAYS*DAY_PARTS + MONTH_FRACT;
    361 
    362 // The time of the new moon (in parts) on 1 Tishri, year 1 (the epoch)
    363 // counting from noon on the day before.  BAHARAD is an abbreviation of
    364 // Bet (Monday), Hey (5 hours from sunset), Resh-Daled (204).
    365 static const int32_t BAHARAD = 11*HOUR_PARTS + 204;
    366 
    367 /**
    368 * Finds the day # of the first day in the given Hebrew year.
    369 * To do this, we want to calculate the time of the Tishri 1 new moon
    370 * in that year.
    371 * <p>
    372 * The algorithm here is similar to ones described in a number of
    373 * references, including:
    374 * <ul>
    375 * <li>"Calendrical Calculations", by Nachum Dershowitz & Edward Reingold,
    376 *     Cambridge University Press, 1997, pages 85-91.
    377 *
    378 * <li>Hebrew Calendar Science and Myths,
    379 *     <a href="http://www.geocities.com/Athens/1584/">
    380 *     http://www.geocities.com/Athens/1584/</a>
    381 *
    382 * <li>The Calendar FAQ,
    383 *      <a href="http://www.faqs.org/faqs/calendars/faq/">
    384 *      http://www.faqs.org/faqs/calendars/faq/</a>
    385 * </ul>
    386 */
    387 int32_t HebrewCalendar::startOfYear(int32_t year, UErrorCode &status)
    388 {
    389     ucln_i18n_registerCleanup(UCLN_I18N_HEBREW_CALENDAR, calendar_hebrew_cleanup);
    390     int32_t day = CalendarCache::get(&gCache, year, status);
    391 
    392     if (day == 0) {
    393         int32_t months = (235 * year - 234) / 19;           // # of months before year
    394 
    395         int64_t frac = (int64_t)months * MONTH_FRACT + BAHARAD;  // Fractional part of day #
    396         day  = months * 29 + (int32_t)(frac / DAY_PARTS);        // Whole # part of calculation
    397         frac = frac % DAY_PARTS;                        // Time of day
    398 
    399         int32_t wd = (day % 7);                        // Day of week (0 == Monday)
    400 
    401         if (wd == 2 || wd == 4 || wd == 6) {
    402             // If the 1st is on Sun, Wed, or Fri, postpone to the next day
    403             day += 1;
    404             wd = (day % 7);
    405         }
    406         if (wd == 1 && frac > 15*HOUR_PARTS+204 && !isLeapYear(year) ) {
    407             // If the new moon falls after 3:11:20am (15h204p from the previous noon)
    408             // on a Tuesday and it is not a leap year, postpone by 2 days.
    409             // This prevents 356-day years.
    410             day += 2;
    411         }
    412         else if (wd == 0 && frac > 21*HOUR_PARTS+589 && isLeapYear(year-1) ) {
    413             // If the new moon falls after 9:32:43 1/3am (21h589p from yesterday noon)
    414             // on a Monday and *last* year was a leap year, postpone by 1 day.
    415             // Prevents 382-day years.
    416             day += 1;
    417         }
    418         CalendarCache::put(&gCache, year, day, status);
    419     }
    420     return day;
    421 }
    422 
    423 /**
    424 * Find the day of the week for a given day
    425 *
    426 * @param day   The # of days since the start of the Hebrew calendar,
    427 *              1-based (i.e. 1/1/1 AM is day 1).
    428 */
    429 int32_t HebrewCalendar::absoluteDayToDayOfWeek(int32_t day)
    430 {
    431     // We know that 1/1/1 AM is a Monday, which makes the math easy...
    432     return (day % 7) + 1;
    433 }
    434 
    435 /**
    436 * Returns the the type of a given year.
    437 *  0   "Deficient" year with 353 or 383 days
    438 *  1   "Normal"    year with 354 or 384 days
    439 *  2   "Complete"  year with 355 or 385 days
    440 */
    441 int32_t HebrewCalendar::yearType(int32_t year) const
    442 {
    443     int32_t yearLength = handleGetYearLength(year);
    444 
    445     if (yearLength > 380) {
    446         yearLength -= 30;        // Subtract length of leap month.
    447     }
    448 
    449     int type = 0;
    450 
    451     switch (yearLength) {
    452   case 353:
    453       type = 0; break;
    454   case 354:
    455       type = 1; break;
    456   case 355:
    457       type = 2; break;
    458   default:
    459       //throw new RuntimeException("Illegal year length " + yearLength + " in year " + year);
    460       type = 1;
    461     }
    462     return type;
    463 }
    464 
    465 /**
    466 * Determine whether a given Hebrew year is a leap year
    467 *
    468 * The rule here is that if (year % 19) == 0, 3, 6, 8, 11, 14, or 17.
    469 * The formula below performs the same test, believe it or not.
    470 */
    471 UBool HebrewCalendar::isLeapYear(int32_t year) {
    472     //return (year * 12 + 17) % 19 >= 12;
    473     int32_t x = (year*12 + 17) % 19;
    474     return x >= ((x < 0) ? -7 : 12);
    475 }
    476 
    477 int32_t HebrewCalendar::monthsInYear(int32_t year) {
    478     return isLeapYear(year) ? 13 : 12;
    479 }
    480 
    481 //-------------------------------------------------------------------------
    482 // Calendar framework
    483 //-------------------------------------------------------------------------
    484 
    485 /**
    486 * @internal
    487 */
    488 int32_t HebrewCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
    489     return LIMITS[field][limitType];
    490 }
    491 
    492 /**
    493 * Returns the length of the given month in the given year
    494 * @internal
    495 */
    496 int32_t HebrewCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
    497     // Resolve out-of-range months.  This is necessary in order to
    498     // obtain the correct year.  We correct to
    499     // a 12- or 13-month year (add/subtract 12 or 13, depending
    500     // on the year) but since we _always_ number from 0..12, and
    501     // the leap year determines whether or not month 5 (Adar 1)
    502     // is present, we allow 0..12 in any given year.
    503     while (month < 0) {
    504         month += monthsInYear(--extendedYear);
    505     }
    506     // Careful: allow 0..12 in all years
    507     while (month > 12) {
    508         month -= monthsInYear(extendedYear++);
    509     }
    510 
    511     switch (month) {
    512     case HESHVAN:
    513     case KISLEV:
    514       // These two month lengths can vary
    515       return MONTH_LENGTH[month][yearType(extendedYear)];
    516 
    517     default:
    518       // The rest are a fixed length
    519       return MONTH_LENGTH[month][0];
    520     }
    521 }
    522 
    523 /**
    524 * Returns the number of days in the given Hebrew year
    525 * @internal
    526 */
    527 int32_t HebrewCalendar::handleGetYearLength(int32_t eyear) const {
    528     UErrorCode status = U_ZERO_ERROR;
    529     return startOfYear(eyear+1, status) - startOfYear(eyear, status);
    530 }
    531 
    532 //-------------------------------------------------------------------------
    533 // Functions for converting from milliseconds to field values
    534 //-------------------------------------------------------------------------
    535 
    536 /**
    537 * Subclasses may override this method to compute several fields
    538 * specific to each calendar system.  These are:
    539 *
    540 * <ul><li>ERA
    541 * <li>YEAR
    542 * <li>MONTH
    543 * <li>DAY_OF_MONTH
    544 * <li>DAY_OF_YEAR
    545 * <li>EXTENDED_YEAR</ul>
    546 *
    547 * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields,
    548 * which will be set when this method is called.  Subclasses can
    549 * also call the getGregorianXxx() methods to obtain Gregorian
    550 * calendar equivalents for the given Julian day.
    551 *
    552 * <p>In addition, subclasses should compute any subclass-specific
    553 * fields, that is, fields from BASE_FIELD_COUNT to
    554 * getFieldCount() - 1.
    555 * @internal
    556 */
    557 void HebrewCalendar::handleComputeFields(int32_t julianDay, UErrorCode &status) {
    558     int32_t d = julianDay - 347997;
    559     double m = ((d * (double)DAY_PARTS)/ (double) MONTH_PARTS);         // Months (approx)
    560     int32_t year = (int32_t)( ((19. * m + 234.) / 235.) + 1.);     // Years (approx)
    561     int32_t ys  = startOfYear(year, status);                   // 1st day of year
    562     int32_t dayOfYear = (d - ys);
    563 
    564     // Because of the postponement rules, it's possible to guess wrong.  Fix it.
    565     while (dayOfYear < 1) {
    566         year--;
    567         ys  = startOfYear(year, status);
    568         dayOfYear = (d - ys);
    569     }
    570 
    571     // Now figure out which month we're in, and the date within that month
    572     int32_t type = yearType(year);
    573     UBool isLeap = isLeapYear(year);
    574 
    575     int32_t month = 0;
    576     int32_t momax = sizeof(MONTH_START) / (3 * sizeof(MONTH_START[0][0]));
    577     while (month < momax && dayOfYear > (  isLeap ? LEAP_MONTH_START[month][type] : MONTH_START[month][type] ) ) {
    578         month++;
    579     }
    580     if (month >= momax || month<=0) {
    581         // TODO: I found dayOfYear could be out of range when
    582         // a large value is set to julianDay.  I patched startOfYear
    583         // to reduce the chace, but it could be still reproduced either
    584         // by startOfYear or other places.  For now, we check
    585         // the month is in valid range to avoid out of array index
    586         // access problem here.  However, we need to carefully review
    587         // the calendar implementation to check the extreme limit of
    588         // each calendar field and the code works well for any values
    589         // in the valid value range.  -yoshito
    590         status = U_ILLEGAL_ARGUMENT_ERROR;
    591         return;
    592     }
    593     month--;
    594     int dayOfMonth = dayOfYear - (isLeap ? LEAP_MONTH_START[month][type] : MONTH_START[month][type]);
    595 
    596     internalSet(UCAL_ERA, 0);
    597     internalSet(UCAL_YEAR, year);
    598     internalSet(UCAL_EXTENDED_YEAR, year);
    599     internalSet(UCAL_MONTH, month);
    600     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
    601     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
    602 }
    603 
    604 //-------------------------------------------------------------------------
    605 // Functions for converting from field values to milliseconds
    606 //-------------------------------------------------------------------------
    607 
    608 /**
    609 * @internal
    610 */
    611 int32_t HebrewCalendar::handleGetExtendedYear() {
    612     int32_t year;
    613     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
    614         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
    615     } else {
    616         year = internalGet(UCAL_YEAR, 1); // Default to year 1
    617     }
    618     return year;
    619 }
    620 
    621 /**
    622 * Return JD of start of given month/year.
    623 * @internal
    624 */
    625 int32_t HebrewCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /*useMonth*/) const {
    626     UErrorCode status = U_ZERO_ERROR;
    627     // Resolve out-of-range months.  This is necessary in order to
    628     // obtain the correct year.  We correct to
    629     // a 12- or 13-month year (add/subtract 12 or 13, depending
    630     // on the year) but since we _always_ number from 0..12, and
    631     // the leap year determines whether or not month 5 (Adar 1)
    632     // is present, we allow 0..12 in any given year.
    633     while (month < 0) {
    634         month += monthsInYear(--eyear);
    635     }
    636     // Careful: allow 0..12 in all years
    637     while (month > 12) {
    638         month -= monthsInYear(eyear++);
    639     }
    640 
    641     int32_t day = startOfYear(eyear, status);
    642 
    643     if(U_FAILURE(status)) {
    644         return 0;
    645     }
    646 
    647     if (month != 0) {
    648         if (isLeapYear(eyear)) {
    649             day += LEAP_MONTH_START[month][yearType(eyear)];
    650         } else {
    651             day += MONTH_START[month][yearType(eyear)];
    652         }
    653     }
    654 
    655     return (int) (day + 347997);
    656 }
    657 
    658 UBool
    659 HebrewCalendar::inDaylightTime(UErrorCode& status) const
    660 {
    661     // copied from GregorianCalendar
    662     if (U_FAILURE(status) || !getTimeZone().useDaylightTime())
    663         return FALSE;
    664 
    665     // Force an update of the state of the Calendar.
    666     ((HebrewCalendar*)this)->complete(status); // cast away const
    667 
    668     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
    669 }
    670 
    671 // default century
    672 const UDate     HebrewCalendar::fgSystemDefaultCentury        = DBL_MIN;
    673 const int32_t   HebrewCalendar::fgSystemDefaultCenturyYear    = -1;
    674 
    675 UDate           HebrewCalendar::fgSystemDefaultCenturyStart       = DBL_MIN;
    676 int32_t         HebrewCalendar::fgSystemDefaultCenturyStartYear   = -1;
    677 
    678 
    679 UBool HebrewCalendar::haveDefaultCentury() const
    680 {
    681     return TRUE;
    682 }
    683 
    684 UDate HebrewCalendar::defaultCenturyStart() const
    685 {
    686     return internalGetDefaultCenturyStart();
    687 }
    688 
    689 int32_t HebrewCalendar::defaultCenturyStartYear() const
    690 {
    691     return internalGetDefaultCenturyStartYear();
    692 }
    693 
    694 UDate
    695 HebrewCalendar::internalGetDefaultCenturyStart() const
    696 {
    697     // lazy-evaluate systemDefaultCenturyStart
    698     UBool needsUpdate;
    699     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    700 
    701     if (needsUpdate) {
    702         initializeSystemDefaultCentury();
    703     }
    704 
    705     // use defaultCenturyStart unless it's the flag value;
    706     // then use systemDefaultCenturyStart
    707 
    708     return fgSystemDefaultCenturyStart;
    709 }
    710 
    711 int32_t
    712 HebrewCalendar::internalGetDefaultCenturyStartYear() const
    713 {
    714     // lazy-evaluate systemDefaultCenturyStartYear
    715     UBool needsUpdate;
    716     UMTX_CHECK(NULL, (fgSystemDefaultCenturyStart == fgSystemDefaultCentury), needsUpdate);
    717 
    718     if (needsUpdate) {
    719         initializeSystemDefaultCentury();
    720     }
    721 
    722     // use defaultCenturyStart unless it's the flag value;
    723     // then use systemDefaultCenturyStartYear
    724 
    725     return fgSystemDefaultCenturyStartYear;
    726 }
    727 
    728 void
    729 HebrewCalendar::initializeSystemDefaultCentury()
    730 {
    731     // initialize systemDefaultCentury and systemDefaultCenturyYear based
    732     // on the current time.  They'll be set to 80 years before
    733     // the current time.
    734     UErrorCode status = U_ZERO_ERROR;
    735     HebrewCalendar calendar(Locale("@calendar=hebrew"),status);
    736     if (U_SUCCESS(status))
    737     {
    738         calendar.setTime(Calendar::getNow(), status);
    739         calendar.add(UCAL_YEAR, -80, status);
    740         UDate    newStart =  calendar.getTime(status);
    741         int32_t  newYear  =  calendar.get(UCAL_YEAR, status);
    742         umtx_lock(NULL);
    743         if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
    744             fgSystemDefaultCenturyStartYear = newYear;
    745             fgSystemDefaultCenturyStart = newStart;
    746         }
    747         umtx_unlock(NULL);
    748     }
    749     // We have no recourse upon failure unless we want to propagate the failure
    750     // out.
    751 }
    752 
    753 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(HebrewCalendar)
    754 
    755 U_NAMESPACE_END
    756 
    757 #endif // UCONFIG_NO_FORMATTING
    758 
    759