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php-src/ext/calendar/jewish.c
Peter Kokot 92ac598aab Remove local variables 
This patch removes the so called local variables defined per
file basis for certain editors to properly show tab width, and
similar settings. These are mainly used by Vim and Emacs editors
yet with recent changes the once working definitions don't work
anymore in Vim without custom plugins or additional configuration.
Neither are these settings synced across the PHP code base.

A simpler and better approach is EditorConfig and fixing code
using some code style fixing tools in the future instead.

This patch also removes the so called modelines for Vim. Modelines
allow Vim editor specifically to set some editor configuration such as
syntax highlighting, indentation style and tab width to be set in the
first line or the last 5 lines per file basis. Since the php test
files have syntax highlighting already set in most editors properly and
EditorConfig takes care of the indentation settings, this patch removes
these as well for the Vim 6.0 and newer versions.

With the removal of local variables for certain editors such as
Emacs and Vim, the footer is also probably not needed anymore when
creating extensions using ext_skel.php script.

Additionally, Vim modelines for setting php syntax and some editor
settings has been removed from some *.phpt files.  All these are
mostly not relevant for phpt files neither work properly in the
middle of the file.
2019-02-03 21:03:00 +01:00

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/* $selId: jewish.c,v 2.0 1995/10/24 01:13:06 lees Exp $
* Copyright 1993-1995, Scott E. Lee, all rights reserved.
* Permission granted to use, copy, modify, distribute and sell so long as
* the above copyright and this permission statement are retained in all
* copies. THERE IS NO WARRANTY - USE AT YOUR OWN RISK.
*/
/**************************************************************************
*
* These are the externally visible components of this file:
*
* void
* SdnToJewish(
* long int sdn,
* int *pYear,
* int *pMonth,
* int *pDay);
*
* Convert a SDN to a Jewish calendar date. If the input SDN is before the
* first day of year 1, the three output values will all be set to zero,
* otherwise *pYear will be > 0; *pMonth will be in the range 1 to 13
* inclusive; *pDay will be in the range 1 to 30 inclusive. Note that Adar
* II is assigned the month number 7 and Elul is always 13.
*
* long int
* JewishToSdn(
* int year,
* int month,
* int day);
*
* Convert a Jewish calendar date to a SDN. Zero is returned when the
* input date is detected as invalid or out of the supported range. The
* return value will be > 0 for all valid, supported dates, but there are
* some invalid dates that will return a positive value. To verify that a
* date is valid, convert it to SDN and then back and compare with the
* original.
*
* char *JewishMonthName[14];
*
* Convert a Jewish month number (1 to 13) to the name of the Jewish month
* (null terminated). An index of zero will return a zero length string.
*
* VALID RANGE
*
* Although this software can handle dates all the way back to the year
* 1 (3761 B.C.), such use may not be meaningful.
*
* The Jewish calendar has been in use for several thousand years, but
* in the early days there was no formula to determine the start of a
* month. A new month was started when the new moon was first
* observed.
*
* It is not clear when the current rule based calendar replaced the
* observation based calendar. According to the book "Jewish Calendar
* Mystery Dispelled" by George Zinberg, the patriarch Hillel II
* published these rules in 358 A.D. But, according to The
* Encyclopedia Judaica, Hillel II may have only published the 19 year
* rule for determining the occurrence of leap years.
*
* I have yet to find a specific date when the current set of rules
* were known to be in use.
*
* CALENDAR OVERVIEW
*
* The Jewish calendar is based on lunar as well as solar cycles. A
* month always starts on or near a new moon and has either 29 or 30
* days (a lunar cycle is about 29 1/2 days). Twelve of these
* alternating 29-30 day months gives a year of 354 days, which is
* about 11 1/4 days short of a solar year.
*
* Since a month is defined to be a lunar cycle (new moon to new moon),
* this 11 1/4 day difference cannot be overcome by adding days to a
* month as with the Gregorian calendar, so an entire month is
* periodically added to the year, making some years 13 months long.
*
* For astronomical as well as ceremonial reasons, the start of a new
* year may be delayed until a day or two after the new moon causing
* years to vary in length. Leap years can be from 383 to 385 days and
* common years can be from 353 to 355 days. These are the months of
* the year and their possible lengths:
*
* COMMON YEAR LEAP YEAR
* 1 Tishri 30 30 30 30 30 30
* 2 Heshvan 29 29 30 29 29 30 (variable)
* 3 Kislev 29 30 30 29 30 30 (variable)
* 4 Tevet 29 29 29 29 29 29
* 5 Shevat 30 30 30 30 30 30
* 6 Adar I -- -- -- 30 30 30 (optional)
* 7 Adar (II) 29 29 29 29 29 29
* 8 Nisan 30 30 30 30 30 30
* 9 Iyyar 29 29 29 29 29 29
* 10 Sivan 30 30 30 30 30 30
* 11 Tammuz 29 29 29 29 29 29
* 12 Av 30 30 30 30 30 30
* 13 Elul 29 29 29 29 29 29
* --- --- --- --- --- ---
* 353 354 355 383 384 385
*
* Note that the month names and other words that appear in this file
* have multiple possible spellings in the Roman character set. I have
* chosen to use the spellings found in the Encyclopedia Judaica.
*
* Adar I, the month added for leap years, is sometimes referred to as
* the 13th month, but I have chosen to assign it the number 6 to keep
* the months in chronological order. This may not be consistent with
* other numbering schemes.
*
* Leap years occur in a fixed pattern of 19 years called the metonic
* cycle. The 3rd, 6th, 8th, 11th, 14th, 17th and 19th years of this
* cycle are leap years. The first metonic cycle starts with Jewish
* year 1, or 3761/60 B.C. This is believed to be the year of
* creation.
*
* To construct the calendar for a year, you must first find the length
* of the year by determining the first day of the year (Tishri 1, or
* Rosh Ha-Shanah) and the first day of the following year. This
* selects one of the six possible month length configurations listed
* above.
*
* Finding the first day of the year is the most difficult part.
* Finding the date and time of the new moon (or molad) is the first
* step. For this purpose, the lunar cycle is assumed to be 29 days 12
* hours and 793 halakim. A halakim is 1/1080th of an hour or 3 1/3
* seconds. (This assumed value is only about 1/2 second less than the
* value used by modern astronomers -- not bad for a number that was
* determined so long ago.) The first molad of year 1 occurred on
* Sunday at 11:20:11 P.M. This would actually be Monday, because the
* Jewish day is considered to begin at sunset.
*
* Since sunset varies, the day is assumed to begin at 6:00 P.M. for
* calendar calculation purposes. So, the first molad was 5 hours 793
* halakim after the start of Tishri 1, 0001 (which was Monday
* September 7, 4761 B.C. by the Gregorian calendar). All subsequent
* molads can be calculated from this starting point by adding the
* length of a lunar cycle.
*
* Once the molad that starts a year is determined the actual start of
* the year (Tishri 1) can be determined. Tishri 1 will be the day of
* the molad unless it is delayed by one of the following four rules
* (called dehiyyot). Each rule can delay the start of the year by one
* day, and since rule #1 can combine with one of the other rules, it
* can be delayed as much as two days.
*
* 1. Tishri 1 must never be Sunday, Wednesday or Friday. (This
* is largely to prevent certain holidays from occurring on the
* day before or after the Sabbath.)
*
* 2. If the molad occurs on or after noon, Tishri 1 must be
* delayed.
*
* 3. If it is a common (not leap) year and the molad occurs on
* Tuesday at or after 3:11:20 A.M., Tishri 1 must be delayed.
*
* 4. If it is the year following a leap year and the molad occurs
* on Monday at or after 9:32:43 and 1/3 sec, Tishri 1 must be
* delayed.
*
* GLOSSARY
*
* dehiyyot The set of 4 rules that determine when the new year
* starts relative to the molad.
*
* halakim 1/1080th of an hour or 3 1/3 seconds.
*
* lunar cycle The period of time between mean conjunctions of the
* sun and moon (new moon to new moon). This is
* assumed to be 29 days 12 hours and 793 halakim for
* calendar purposes.
*
* metonic cycle A 19 year cycle which determines which years are
* leap years and which are common years. The 3rd,
* 6th, 8th, 11th, 14th, 17th and 19th years of this
* cycle are leap years.
*
* molad The date and time of the mean conjunction of the
* sun and moon (new moon). This is the approximate
* beginning of a month.
*
* Rosh Ha-Shanah The first day of the Jewish year (Tishri 1).
*
* Tishri The first month of the Jewish year.
*
* ALGORITHMS
*
* SERIAL DAY NUMBER TO JEWISH DATE
*
* The simplest approach would be to use the rules stated above to find
* the molad of Tishri before and after the given day number. Then use
* the molads to find Tishri 1 of the current and following years.
* From this the length of the year can be determined and thus the
* length of each month. But this method is used as a last resort.
*
* The first 59 days of the year are the same regardless of the length
* of the year. As a result, only the day number of the start of the
* year is required.
*
* Similarly, the last 6 months do not change from year to year. And
* since it can be determined whether the year is a leap year by simple
* division, the lengths of Adar I and II can be easily calculated. In
* fact, all dates after the 3rd month are consistent from year to year
* (once it is known whether it is a leap year).
*
* This means that if the given day number falls in the 3rd month or on
* the 30th day of the 2nd month the length of the year must be found,
* but in no other case.
*
* So, the approach used is to take the given day number and round it
* to the closest molad of Tishri (first new moon of the year). The
* rounding is not really to the *closest* molad, but is such that if
* the day number is before the middle of the 3rd month the molad at
* the start of the year is found, otherwise the molad at the end of
* the year is found.
*
* Only if the day number is actually found to be in the ambiguous
* period of 29 to 31 days is the other molad calculated.
*
* JEWISH DATE TO SERIAL DAY NUMBER
*
* The year number is used to find which 19 year metonic cycle contains
* the date and which year within the cycle (this is a division and
* modulus). This also determines whether it is a leap year.
*
* If the month is 1 or 2, the calculation is simple addition to the
* first of the year.
*
* If the month is 8 (Nisan) or greater, the calculation is simple
* subtraction from beginning of the following year.
*
* If the month is 4 to 7, it is considered whether it is a leap year
* and then simple subtraction from the beginning of the following year
* is used.
*
* Only if it is the 3rd month is both the start and end of the year
* required.
*
* TESTING
*
* This algorithm has been tested in two ways. First, 510 dates from a
* table in "Jewish Calendar Mystery Dispelled" were calculated and
* compared to the table. Second, the calculation algorithm described
* in "Jewish Calendar Mystery Dispelled" was coded and used to verify
* all dates from the year 1 (3761 B.C.) to the year 13760 (10000
* A.D.).
*
* The source code of the verification program is included in this
* package.
*
* REFERENCES
*
* The Encyclopedia Judaica, the entry for "Calendar"
*
* The Jewish Encyclopedia
*
* Jewish Calendar Mystery Dispelled by George Zinberg, Vantage Press,
* 1963
*
* The Comprehensive Hebrew Calendar by Arthur Spier, Behrman House
*
* The Book of Calendars [note that this work contains many typos]
*
**************************************************************************/
#if defined(PHP_WIN32)
#pragma setlocale("english")
#endif
#include "sdncal.h"
#define HALAKIM_PER_HOUR 1080
#define HALAKIM_PER_DAY 25920
#define HALAKIM_PER_LUNAR_CYCLE ((29 * HALAKIM_PER_DAY) + 13753)
#define HALAKIM_PER_METONIC_CYCLE (HALAKIM_PER_LUNAR_CYCLE * (12 * 19 + 7))
#define JEWISH_SDN_OFFSET 347997
#define JEWISH_SDN_MAX 324542846L /* 12/13/887605, greater value raises integer overflow */
#define NEW_MOON_OF_CREATION 31524
#define SUNDAY 0
#define MONDAY 1
#define TUESDAY 2
#define WEDNESDAY 3
#define THURSDAY 4
#define FRIDAY 5
#define SATURDAY 6
#define NOON (18 * HALAKIM_PER_HOUR)
#define AM3_11_20 ((9 * HALAKIM_PER_HOUR) + 204)
#define AM9_32_43 ((15 * HALAKIM_PER_HOUR) + 589)
const int monthsPerYear[19] =
{
12, 12, 13, 12, 12, 13, 12, 13, 12, 12, 13, 12, 12, 13, 12, 12, 13, 12, 13
};
static const int yearOffset[19] =
{
0, 12, 24, 37, 49, 61, 74, 86, 99, 111, 123,
136, 148, 160, 173, 185, 197, 210, 222
};
/* names for leap (13-month) year */
const char * const JewishMonthNameLeap[14] =
{
"",
"Tishri",
"Heshvan",
"Kislev",
"Tevet",
"Shevat",
"Adar I",
"Adar II",
"Nisan",
"Iyyar",
"Sivan",
"Tammuz",
"Av",
"Elul"
};
/* names for regular year */
const char * const JewishMonthName[14] =
{
"",
"Tishri",
"Heshvan",
"Kislev",
"Tevet",
"Shevat",
"",
"Adar",
"Nisan",
"Iyyar",
"Sivan",
"Tammuz",
"Av",
"Elul"
};
/* names for leap (13-month) year */
const char * const JewishMonthHebNameLeap[14] =
{
"",
"\xFA\xF9\xF8\xE9",
"\xE7\xF9\xE5\xEF",
"\xEB\xF1\xEC\xE5",
"\xE8\xE1\xFA",
"\xF9\xE1\xE8",
"\xE0\xE3\xF8 \xE0'",
"\xE0\xE3\xF8 \xE1'",
"\xF0\xE9\xF1\xEF",
"\xE0\xE9\xE9\xF8",
"\xF1\xE9\xe5\xEF",
"\xFA\xEE\xE5\xE6",
"\xE0\xE1",
"\xE0\xEC\xE5\xEC"
};
/* names for regular year */
const char * const JewishMonthHebName[14] =
{
"",
"\xFA\xF9\xF8\xE9",
"\xE7\xF9\xE5\xEF",
"\xEB\xF1\xEC\xE5",
"\xE8\xE1\xFA",
"\xF9\xE1\xE8",
"",
"\xE0\xE3\xF8",
"\xF0\xE9\xF1\xEF",
"\xE0\xE9\xE9\xF8",
"\xF1\xE9\xE5\xEF",
"\xFA\xEE\xE5\xE6",
"\xE0\xE1",
"\xE0\xEC\xE5\xEC"
};
/************************************************************************
* Given the year within the 19 year metonic cycle and the time of a molad
* (new moon) which starts that year, this routine will calculate what day
* will be the actual start of the year (Tishri 1 or Rosh Ha-Shanah). This
* first day of the year will be the day of the molad unless one of 4 rules
* (called dehiyyot) delays it. These 4 rules can delay the start of the
* year by as much as 2 days.
*/
static zend_long Tishri1(
int metonicYear,
zend_long moladDay,
zend_long moladHalakim)
{
zend_long tishri1;
int dow;
int leapYear;
int lastWasLeapYear;
tishri1 = moladDay;
dow = tishri1 % 7;
leapYear = metonicYear == 2 || metonicYear == 5 || metonicYear == 7
|| metonicYear == 10 || metonicYear == 13 || metonicYear == 16
|| metonicYear == 18;
lastWasLeapYear = metonicYear == 3 || metonicYear == 6
|| metonicYear == 8 || metonicYear == 11 || metonicYear == 14
|| metonicYear == 17 || metonicYear == 0;
/* Apply rules 2, 3 and 4. */
if ((moladHalakim >= NOON) ||
((!leapYear) && dow == TUESDAY && moladHalakim >= AM3_11_20) ||
(lastWasLeapYear && dow == MONDAY && moladHalakim >= AM9_32_43)) {
tishri1++;
dow++;
if (dow == 7) {
dow = 0;
}
}
/* Apply rule 1 after the others because it can cause an additional
* delay of one day. */
if (dow == WEDNESDAY || dow == FRIDAY || dow == SUNDAY) {
tishri1++;
}
return (tishri1);
}
/************************************************************************
* Given a metonic cycle number, calculate the date and time of the molad
* (new moon) that starts that cycle. Since the length of a metonic cycle
* is a constant, this is a simple calculation, except that it requires an
* intermediate value which is bigger that 32 bits. Because this
* intermediate value only needs 36 to 37 bits and the other numbers are
* constants, the process has been reduced to just a few steps.
*/
static void MoladOfMetonicCycle(
int metonicCycle,
zend_long *pMoladDay,
zend_long *pMoladHalakim)
{
register zend_ulong r1, r2, d1, d2;
/* Start with the time of the first molad after creation. */
r1 = NEW_MOON_OF_CREATION;
/* Calculate metonicCycle * HALAKIM_PER_METONIC_CYCLE. The upper 32
* bits of the result will be in r2 and the lower 16 bits will be
* in r1. */
r1 += metonicCycle * (HALAKIM_PER_METONIC_CYCLE & 0xFFFF);
r2 = r1 >> 16;
r2 += metonicCycle * ((HALAKIM_PER_METONIC_CYCLE >> 16) & 0xFFFF);
/* Calculate r2r1 / HALAKIM_PER_DAY. The remainder will be in r1, the
* upper 16 bits of the quotient will be in d2 and the lower 16 bits
* will be in d1. */
d2 = r2 / HALAKIM_PER_DAY;
r2 -= d2 * HALAKIM_PER_DAY;
r1 = (r2 << 16) | (r1 & 0xFFFF);
d1 = r1 / HALAKIM_PER_DAY;
r1 -= d1 * HALAKIM_PER_DAY;
*pMoladDay = (d2 << 16) | d1;
*pMoladHalakim = r1;
}
/************************************************************************
* Given a day number, find the molad of Tishri (the new moon at the start
* of a year) which is closest to that day number. It's not really the
* *closest* molad that we want here. If the input day is in the first two
* months, we want the molad at the start of the year. If the input day is
* in the fourth to last months, we want the molad at the end of the year.
* If the input day is in the third month, it doesn't matter which molad is
* returned, because both will be required. This type of "rounding" allows
* us to avoid calculating the length of the year in most cases.
*/
static void FindTishriMolad(
zend_long inputDay,
int *pMetonicCycle,
int *pMetonicYear,
zend_long *pMoladDay,
zend_long *pMoladHalakim)
{
zend_long moladDay;
zend_long moladHalakim;
int metonicCycle;
int metonicYear;
/* Estimate the metonic cycle number. Note that this may be an under
* estimate because there are 6939.6896 days in a metonic cycle not
* 6940, but it will never be an over estimate. The loop below will
* correct for any error in this estimate. */
metonicCycle = (inputDay + 310) / 6940;
/* Calculate the time of the starting molad for this metonic cycle. */
MoladOfMetonicCycle(metonicCycle, &moladDay, &moladHalakim);
/* If the above was an under estimate, increment the cycle number until
* the correct one is found. For modern dates this loop is about 98.6%
* likely to not execute, even once, because the above estimate is
* really quite close. */
while (moladDay < inputDay - 6940 + 310) {
metonicCycle++;
moladHalakim += HALAKIM_PER_METONIC_CYCLE;
moladDay += moladHalakim / HALAKIM_PER_DAY;
moladHalakim = moladHalakim % HALAKIM_PER_DAY;
}
/* Find the molad of Tishri closest to this date. */
for (metonicYear = 0; metonicYear < 18; metonicYear++) {
if (moladDay > inputDay - 74) {
break;
}
moladHalakim += HALAKIM_PER_LUNAR_CYCLE * monthsPerYear[metonicYear];
moladDay += moladHalakim / HALAKIM_PER_DAY;
moladHalakim = moladHalakim % HALAKIM_PER_DAY;
}
*pMetonicCycle = metonicCycle;
*pMetonicYear = metonicYear;
*pMoladDay = moladDay;
*pMoladHalakim = moladHalakim;
}
/************************************************************************
* Given a year, find the number of the first day of that year and the date
* and time of the starting molad.
*/
static void FindStartOfYear(
int year,
int *pMetonicCycle,
int *pMetonicYear,
zend_long *pMoladDay,
zend_long *pMoladHalakim,
int *pTishri1)
{
*pMetonicCycle = (year - 1) / 19;
*pMetonicYear = (year - 1) % 19;
MoladOfMetonicCycle(*pMetonicCycle, pMoladDay, pMoladHalakim);
*pMoladHalakim += HALAKIM_PER_LUNAR_CYCLE * yearOffset[*pMetonicYear];
*pMoladDay += *pMoladHalakim / HALAKIM_PER_DAY;
*pMoladHalakim = *pMoladHalakim % HALAKIM_PER_DAY;
*pTishri1 = Tishri1(*pMetonicYear, *pMoladDay, *pMoladHalakim);
}
/************************************************************************
* Given a serial day number (SDN), find the corresponding year, month and
* day in the Jewish calendar. The three output values will always be
* modified. If the input SDN is before the first day of year 1, they will
* all be set to zero, otherwise *pYear will be > 0; *pMonth will be in the
* range 1 to 13 inclusive; *pDay will be in the range 1 to 30 inclusive.
*/
void SdnToJewish(
zend_long sdn,
int *pYear,
int *pMonth,
int *pDay)
{
zend_long inputDay;
zend_long day;
zend_long halakim;
int metonicCycle;
int metonicYear;
int tishri1;
int tishri1After;
int yearLength;
if (sdn <= JEWISH_SDN_OFFSET || sdn > JEWISH_SDN_MAX) {
*pYear = 0;
*pMonth = 0;
*pDay = 0;
return;
}
inputDay = sdn - JEWISH_SDN_OFFSET;
FindTishriMolad(inputDay, &metonicCycle, &metonicYear, &day, &halakim);
tishri1 = Tishri1(metonicYear, day, halakim);
if (inputDay >= tishri1) {
/* It found Tishri 1 at the start of the year. */
*pYear = metonicCycle * 19 + metonicYear + 1;
if (inputDay < tishri1 + 59) {
if (inputDay < tishri1 + 30) {
*pMonth = 1;
*pDay = inputDay - tishri1 + 1;
} else {
*pMonth = 2;
*pDay = inputDay - tishri1 - 29;
}
return;
}
/* We need the length of the year to figure this out, so find
* Tishri 1 of the next year. */
halakim += HALAKIM_PER_LUNAR_CYCLE * monthsPerYear[metonicYear];
day += halakim / HALAKIM_PER_DAY;
halakim = halakim % HALAKIM_PER_DAY;
tishri1After = Tishri1((metonicYear + 1) % 19, day, halakim);
} else {
/* It found Tishri 1 at the end of the year. */
*pYear = metonicCycle * 19 + metonicYear;
if (inputDay >= tishri1 - 177) {
/* It is one of the last 6 months of the year. */
if (inputDay > tishri1 - 30) {
*pMonth = 13;
*pDay = inputDay - tishri1 + 30;
} else if (inputDay > tishri1 - 60) {
*pMonth = 12;
*pDay = inputDay - tishri1 + 60;
} else if (inputDay > tishri1 - 89) {
*pMonth = 11;
*pDay = inputDay - tishri1 + 89;
} else if (inputDay > tishri1 - 119) {
*pMonth = 10;
*pDay = inputDay - tishri1 + 119;
} else if (inputDay > tishri1 - 148) {
*pMonth = 9;
*pDay = inputDay - tishri1 + 148;
} else {
*pMonth = 8;
*pDay = inputDay - tishri1 + 178;
}
return;
} else {
if (monthsPerYear[(*pYear - 1) % 19] == 13) {
*pMonth = 7;
*pDay = inputDay - tishri1 + 207;
if (*pDay > 0)
return;
(*pMonth)--;
(*pDay) += 30;
if (*pDay > 0)
return;
(*pMonth)--;
(*pDay) += 30;
} else {
*pMonth = 7;
*pDay = inputDay - tishri1 + 207;
if (*pDay > 0)
return;
(*pMonth) -= 2;
(*pDay) += 30;
}
if (*pDay > 0)
return;
(*pMonth)--;
(*pDay) += 29;
if (*pDay > 0)
return;
/* We need the length of the year to figure this out, so find
* Tishri 1 of this year. */
tishri1After = tishri1;
FindTishriMolad(day - 365,
&metonicCycle, &metonicYear, &day, &halakim);
tishri1 = Tishri1(metonicYear, day, halakim);
}
}
yearLength = tishri1After - tishri1;
day = inputDay - tishri1 - 29;
if (yearLength == 355 || yearLength == 385) {
/* Heshvan has 30 days */
if (day <= 30) {
*pMonth = 2;
*pDay = day;
return;
}
day -= 30;
} else {
/* Heshvan has 29 days */
if (day <= 29) {
*pMonth = 2;
*pDay = day;
return;
}
day -= 29;
}
/* It has to be Kislev. */
*pMonth = 3;
*pDay = day;
}
/************************************************************************
* Given a year, month and day in the Jewish calendar, find the
* corresponding serial day number (SDN). Zero is returned when the input
* date is detected as invalid. The return value will be > 0 for all valid
* dates, but there are some invalid dates that will return a positive
* value. To verify that a date is valid, convert it to SDN and then back
* and compare with the original.
*/
zend_long JewishToSdn(
int year,
int month,
int day)
{
zend_long sdn;
int metonicCycle;
int metonicYear;
int tishri1;
int tishri1After;
zend_long moladDay;
zend_long moladHalakim;
int yearLength;
int lengthOfAdarIAndII;
if (year <= 0 || day <= 0 || day > 30) {
return (0);
}
switch (month) {
case 1:
case 2:
/* It is Tishri or Heshvan - don't need the year length. */
FindStartOfYear(year, &metonicCycle, &metonicYear,
&moladDay, &moladHalakim, &tishri1);
if (month == 1) {
sdn = tishri1 + day - 1;
} else {
sdn = tishri1 + day + 29;
}
break;
case 3:
/* It is Kislev - must find the year length. */
/* Find the start of the year. */
FindStartOfYear(year, &metonicCycle, &metonicYear,
&moladDay, &moladHalakim, &tishri1);
/* Find the end of the year. */
moladHalakim += HALAKIM_PER_LUNAR_CYCLE * monthsPerYear[metonicYear];
moladDay += moladHalakim / HALAKIM_PER_DAY;
moladHalakim = moladHalakim % HALAKIM_PER_DAY;
tishri1After = Tishri1((metonicYear + 1) % 19, moladDay, moladHalakim);
yearLength = tishri1After - tishri1;
if (yearLength == 355 || yearLength == 385) {
sdn = tishri1 + day + 59;
} else {
sdn = tishri1 + day + 58;
}
break;
case 4:
case 5:
case 6:
/* It is Tevet, Shevat or Adar I - don't need the year length. */
FindStartOfYear(year + 1, &metonicCycle, &metonicYear,
&moladDay, &moladHalakim, &tishri1After);
if (monthsPerYear[(year - 1) % 19] == 12) {
lengthOfAdarIAndII = 29;
} else {
lengthOfAdarIAndII = 59;
}
if (month == 4) {
sdn = tishri1After + day - lengthOfAdarIAndII - 237;
} else if (month == 5) {
sdn = tishri1After + day - lengthOfAdarIAndII - 208;
} else {
sdn = tishri1After + day - lengthOfAdarIAndII - 178;
}
break;
default:
/* It is Adar II or later - don't need the year length. */
FindStartOfYear(year + 1, &metonicCycle, &metonicYear,
&moladDay, &moladHalakim, &tishri1After);
switch (month) {
case 7:
sdn = tishri1After + day - 207;
break;
case 8:
sdn = tishri1After + day - 178;
break;
case 9:
sdn = tishri1After + day - 148;
break;
case 10:
sdn = tishri1After + day - 119;
break;
case 11:
sdn = tishri1After + day - 89;
break;
case 12:
sdn = tishri1After + day - 60;
break;
case 13:
sdn = tishri1After + day - 30;
break;
default:
return (0);
}
}
return (sdn + JEWISH_SDN_OFFSET);
}
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