FAQ: Different Parshas Hashavua in Eretz Yisrael Than Chutz La’aretz

Zmanim API FAQ

Question:

Why does the KosherJava Zmanim API seem to sometimes return the incorrect parshas hashavua in Israel?

Answer:

I have had a number of inquiries this year about the incorrect Parshas Hashavua being returned by the API. In all cases this has been a complaint for Eretz Yisrael and not Chutz La’aretz. The explanation is pretty simple and covered in the API documentation for the JewishCalendar class, but may not be clear to all. When the first day of Pesach occurs on a Shabbos, as it did this year (5775), the last day of Pesach in Eretz Yisrael is on a Friday. The following day is a regular Shabbos in Eretz Yisrael with the usual krias hatorah, but in chutz la’aretz it is the 8th day of Pesach, resulting in Pesach kriah. The following weeks will have different krias hatorah in Eretz Yisrael vs chutz la’aretz, and this will continue for a number of weeks until a double parsha in chutz laaretz is added to equalize the parsha. This last occurred in 2012 (before the release of the calendar functionality in the Zmanim 1.3 release), and will occur again next year. If you are coding to display the Parshas Hashavuah for use in Israel, it is important to set the inIsrael flag (it defaults to false).

JewishDate.setInIsrael(true);

A fuller example showing how to set the indicator and showing the comparison of Eretz Yisrael and Chutz Laaretz this year can be seen in this example.

JewishCalendar israelCalendar = new JewishCalendar(5775, JewishDate.NISSAN, 7);
israelCalendar.setInIsrael(true); //set the calendar to Israel
JewishCalendar chutsLaaretzCalendar = new JewishCalendar(5775, JewishDate.NISSAN, 7);
chutsLaaretzCalendar.setInIsrael(false); //not really needed since the API defaults to false
HebrewDateFormatter hdf = new HebrewDateFormatter();
System.out.println("Date\tChutz Laaretz / Eretz Yisrael"));
for(int i = 0; i < 57; i++){
	israelCalendar.forward(); //roll the date forward a day
	chutsLaaretzCalendar.forward(); //roll the date forward a day
	if(chutsLaaretzCalendar.getDayOfWeek() == 7){ //ignore weekdays
		System.out.println(hdf.formatParsha(chutsLaaretzCalendar) + "\t" + hdf.formatParsha(israelCalendar) + " \\ " + hdf.format(chutsLaaretzCalendar));
	}
}

the output of this is

Date               Chutz Laaretz / Eretz Yisrael
8 Nissan, 5775     Tzav / Tzav
15 Nissan, 5775     / 
22 Nissan, 5775     / Shmini
29 Nissan, 5775    Shmini / Tazria Metzora
6 Iyar, 5775       Tazria Metzora / Achrei Mos Kedoshim
13 Iyar, 5775      Achrei Mos Kedoshim / Emor
20 Iyar, 5775      Emor / Behar
27 Iyar, 5775      Behar Bechukosai / Bechukosai
5 Sivan, 5775      Bamidbar / Bamidbar

It should be noted that this discrepancy is not rare and happens about 25% of the calendar years.

FAQ: Calculating the Baal Hatanya’s Shkiah

Zmanim API FAQ

Question:

How do I calculate the Baal Hatanya’s Zman for Shkiah?

Answer:

The Baal Hatanya’s opinion is that shkiah (halachic sunset) is 4 minutes after civil sunset. I was recently asked how to calculate this zman using the API. The technique is identical to the way getTzais72() would be calculated. The source of that method is

public Date getTzais72() {
    return getTimeOffset(getSeaLevelSunset(), 72 * MINUTE_MILLIS);
}

The getTimeOffset(Date time, double offset) method in the base class AstronomicalCalendar is very simple:

public Date getTimeOffset(Date time, long offset) {
    if (time == null || offset == Long.MIN_VALUE) {
        return null;
    }
    return new Date(time.getTime() + offset);
}

The getTimeOffset method simply adds the number of milliseconds of the offset to the raw time of the zman and returns it as a date. While using the API itself is not needed for such a simple calculation, here is how it would be used:

String locationName = "Jerusalem";
double latitude = 31.778; // Har habayis
double longitude = 35.2354;// Har Habayis
double elevation = 0;
TimeZone timeZone = TimeZone.getTimeZone("Asia/Jerusalem");
GeoLocation location = new GeoLocation(locationName, latitude, longitude, elevation, timeZone);
ZmanimCalendar zc = new ZmanimCalendar(location);
Date baalHatanyaShkiah = zc.getTimeOffset(zc.getSeaLevelSunset(), 4 * 60000);
System.out.println("Baal Hatanya Shkiah: " + baalHatanyaShkiah);

Adding it to the API itself would be even simpler:

public Date getShkiahBaalHatanya() {
    return getTimeOffset(getSeaLevelSunset(), 4 * MINUTE_MILLIS);
}

At some point in the future I may add this time to the API itself. The zman is not commonly used, and the Chabad calendars that I have seen all use regular sunset.

Forensic Zmanim Calculations

Claude Monet's Cliff at Etretat, Sunset
Claude Monet’s Cliff at Etretat, Sunset
Unrelated to practical zmanim calculations, it is fascinating to see that with enough work, astronomers were able to pinpoint the exact date and time that Claude Monet painted the Cliff at Etretat, Sunset painting based on the position of the sun at sunset. Researchers from Texas State University published information showing that the masterpiece was painted (or more accurately, visualized in Claude Monet's mind) at 4:53PM on February 5th, 1883.
The picture of the Kosel below was taken by my grandfather Sidney (Nesanel) Siegfried. While I can’t pinpoint the exact time the picture was taken, I do know that it was taken in the early afternoon on Aug 1st, 1932 כ״ח תמוז תרצ״ב. I leave it to the readers of this post to try and calculate the exact time the picture was taken based on the shadows.
Picture of the Kosel taken by Sidney (Nesanel) Siegfried on Aug 1, 1932 כ״ח תמוז תרצ״ב
Picture of the Kosel taken by Sidney (Nesanel) Siegfried on Aug 1, 1932 כ״ח תמוז תרצ״ב

Using the Zmanim API 1.3.0 Jewish Calendar Code

Java CalendarThe recently released Zmanim API 1.3.0 added Jewish calendar support to the API. Previously, the API had zmanim support, but no Jewish calendar support. While the calendar code is in beta mode and is subject to API changes, below are some simple code examples using the current 1.3.0 release. These examples of the use of the JewishCalendar and HebrewDateFormatter classes do not fully cover the functionality available in the Zmanim API. Please read the JavaDocs and experiment. Please let me know if there are any calendar related items that you feel should change or be added to the API.

Setting and outputting formatted dates

JewishCalendar jd = new JewishCalendar(); // current date 23 Nissan, 5773
HebrewDateFormatter hdf = new HebrewDateFormatter();
System.out.println(jd); // prints hebrew date in English chars - 23 Nissan, 5773
hdf.setHebrewFormat(true); // change formatting to Hebrew
System.out.println(hdf.format(jd)); // date formatted in Hebrew
jd.setJewishDate(5729, JewishDate.SHEVAT, 21); // set the date to 21 Shevat, 5729
System.out.println(hdf.format(jd)); // date formatted in Hebrew
jd.setJewishDate(5772, JewishDate.NISSAN, 18); // set date to third day of Pesach
System.out.println(hdf.format(jd));
System.out.println(hdf.formatYomTov(jd)); //output Chol Hamoed Pesach in Hebrew
hdf.setHebrewFormat(false); // change formatting to default
System.out.println(hdf.format(jd)); // prints Hebrew date in English chars - 18 Nissan, 5772
System.out.println(hdf.formatYomTov(jd)); //output Chol Hamoed Pesach

Output:

23 Nissan, 5773
כ״ג ניסן תשע״ג
כ״א שבט תשכ״ט
י״ח ניסן תשע״ב
חול המועד פסח
18 Nissan, 5772
Chol Hamoed Pesach

Parshas Hashavua

Please note that the parsha will only input if the date is a Shabbos. This is something that may change down the line.

HebrewDateFormatter hdf = new HebrewDateFormatter();
JewishCalendar jd = new JewishCalendar(5773, JewishDate.NISSAN, 12);
System.out.println(hdf.formatParsha(jd));
hdf.setHebrewFormat(true);
System.out.println(hdf.formatParsha(jd));
jd.back();
System.out.println("Parsha on Friday [" + hdf.formatParsha(jd) + "]"); //no Parsha output on a non Shabbos
jd.setJewishDate(5773, JewishDate.TAMMUZ, 28); //double parsha
System.out.println(hdf.formatParsha(jd));

Output:

Tzav
צו
Parsha on Friday []
מטות מסעי

Rosh Chodesh

HebrewDateFormatter hdf = new HebrewDateFormatter();
JewishCalendar jd = new JewishCalendar(5773, JewishDate.NISSAN, 1);
if(jd.isRoshChodesh()){ //not necessary for formatter
	System.out.println(hdf.formatRoshChodesh(jd));
}
hdf.setHebrewFormat(true);
System.out.println(hdf.formatRoshChodesh(jd));
jd.forward();// roll calendar to second day of Nisan
System.out.println("output[" + hdf.formatRoshChodesh(jd) + "]"); //no output for Rosh Chodesh Formatting

Output:

Rosh Chodesh Nissan
ראש חודש ניסן
output[]

Daf Yomi

JewishCalendar jd = new JewishCalendar();
HebrewDateFormatter hdf = new HebrewDateFormatter();
System.out.println(hdf.format(jd)); //output current formatted date "13 Nissan, 5773"
Daf daf = jd.getDafYomiBavli(); //get the current daf
System.out.println(daf.getMasechtaTransliterated()); //outout transliterated masechta name "Eruvin"
System.out.println(daf.getDaf()); //output current daf (page) number "16"
System.out.println(hdf.formatDafYomiBavli(daf)); //outout the formatted date "Eruvin 16"
hdf.setHebrewFormat(true); //set formatted to Hebrew
System.out.println(hdf.format(jd)); //output date in Hebrew "י״ג ניסן תשע״ג"
System.out.println(daf.getMasechta()); // output masechta name in Hebrew "עירובין"
System.out.println(hdf.formatHebrewNumber(daf.getDaf()));//output the daf number formatted in Hebrew "ט״ז"
System.out.println(hdf.formatDafYomiBavli(daf)); //output daf and masechta in Hebrew "עירובין ט״ז"

Output:

13 Nissan, 5773
Eruvin
16
Eruvin 16
י״ג ניסן תשע״ג
עירובין
ט״ז
עירובין ט״ז

Chanukah

JewishCalendar jd = new JewishCalendar(5772, JewishDate.KISLEV, 25); //set date to first day of Chanukah
HebrewDateFormatter hdf = new HebrewDateFormatter();
System.out.println(jd);//output current transliterated date
System.out.println(jd.getDayOfChanukah()); //output #1
System.out.println(hdf.formatYomTov(jd)); //output Chanukah 1
hdf.setHebrewFormat(true); //set format to hebrew
System.out.println(hdf.formatHebrewNumber(jd.getDayOfChanukah())); //output 1 in Hebrew
System.out.println(hdf.formatYomTov(jd)); // output Chanukah 1 in hebrew

Output:

25 Kislev, 5772
1
Chanukah 1
א׳
א׳ חנוכה

Note, that there is no simple way at this point to output just Chanukah. This will likely change in the future to match Chanukah to the behavior of other Yomim Tovim.

Loop and output an entire year

JewishCalendar jc = new JewishCalendar(5773, JewishDate.TISHREI, 1);
jc.setInIsrael(false); //default false for clarity but not needed. Set to true for Israel
HebrewDateFormatter hdf = new HebrewDateFormatter();
hdf.setHebrewFormat(true);
HebrewDateFormatter hdfTransliterated = new HebrewDateFormatter();
String hebrewOutput = "";
String transliteratedOutput = "";
while(jc.getJewishYear() == 5773){
	hebrewOutput = hdf.format(jc);
	transliteratedOutput = hdfTransliterated.format(jc);
	if (jc.isYomTov() || jc.isTaanis()) {
		hebrewOutput += ", " + hdf.formatYomTov(jc);
		transliteratedOutput += ", " + hdfTransliterated.formatYomTov(jc);
	} else if(jc.getDayOfWeek() == 7){
		hebrewOutput += " - " + hdf.formatParsha(jc);
		transliteratedOutput += " - " + hdfTransliterated.formatParsha(jc);
	}
	if (jc.isChanukah()) {
		if (hebrewOutput.length() > 0) {
			hebrewOutput += ", ";
			transliteratedOutput += ", ";
		}
		hebrewOutput += hdf.formatYomTov(jc);
		transliteratedOutput  += hdfTransliterated.formatYomTov(jc);
	}
	if (jc.isRoshChodesh()) {
		if (hebrewOutput.length() > 0) {
			hebrewOutput += ", ";
			transliteratedOutput += ", ";
		}
		hebrewOutput += hdf.formatRoshChodesh(jc);
		transliteratedOutput += hdfTransliterated.formatRoshChodesh(jc);
	}
	if(jc.getDayOfOmer() > 0){
		hebrewOutput += ", ";
		transliteratedOutput += ", ";
		hebrewOutput += hdf.formatOmer(jc);
	}
	System.out.println(transliteratedOutput + " - " + hebrewOutput);
	jc.forward();
}

Output (most days removed for brevity):

1 Tishrei, 5773, Rosh Hashana - א׳ תשרי תשע״ג, ראש השנה
2 Tishrei, 5773, Rosh Hashana - ב׳ תשרי תשע״ג, ראש השנה
3 Tishrei, 5773, Fast of Gedalyah - ג׳ תשרי תשע״ג, צום גדליה
4 Tishrei, 5773 - ד׳ תשרי תשע״ג
...
6 Tishrei, 5773 - Vayeilech - ו׳ תשרי תשע״ג - וילך
...
10 Tishrei, 5773, Yom Kippur - י׳ תשרי תשע״ג, יום כיפור
...
15 Tishrei, 5773, Succos - ט״ו תשרי תשע״ג, סוכות
16 Tishrei, 5773, Succos - ט״ז תשרי תשע״ג, סוכות
17 Tishrei, 5773, Chol Hamoed Succos - י״ז תשרי תשע״ג, חול המועד סוכות
18 Tishrei, 5773, Chol Hamoed Succos - י״ח תשרי תשע״ג, חול המועד סוכות
19 Tishrei, 5773, Chol Hamoed Succos - י״ט תשרי תשע״ג, חול המועד סוכות
20 Tishrei, 5773, Chol Hamoed Succos - כ׳ תשרי תשע״ג, חול המועד סוכות
21 Tishrei, 5773, Hoshana Rabbah - כ״א תשרי תשע״ג, הושענא רבה
22 Tishrei, 5773, Shemini Atzeres - כ״ב תשרי תשע״ג, שמיני עצרת
23 Tishrei, 5773, Simchas Torah - כ״ג תשרי תשע״ג, שמחת תורה
...
30 Tishrei, 5773, Rosh Chodesh Cheshvan - ל׳ תשרי תשע״ג, ראש חודש חשוון
1 Cheshvan, 5773, Rosh Chodesh Cheshvan - א׳ חשוון תשע״ג, ראש חודש חשוון
...
25 Kislev, 5773, Chanukah 1 - כ״ה כסלו תשע״ג, א׳ חנוכה
26 Kislev, 5773, Chanukah 2 - כ״ו כסלו תשע״ג, ב׳ חנוכה
27 Kislev, 5773, Chanukah 3 - כ״ז כסלו תשע״ג, ג׳ חנוכה
28 Kislev, 5773, Chanukah 4 - כ״ח כסלו תשע״ג, ד׳ חנוכה
29 Kislev, 5773, Chanukah 5 - כ״ט כסלו תשע״ג, ה׳ חנוכה
1 Teves, 5773, Chanukah 6, Rosh Chodesh Teves - א׳ טבת תשע״ג, ו׳ חנוכה, ראש חודש טבת
2 Teves, 5773 - Miketz, Chanukah 7 - ב׳ טבת תשע״ג - מקץ, ז׳ חנוכה
3 Teves, 5773, Chanukah 8 - ג׳ טבת תשע״ג, ח׳ חנוכה
...
10 Teves, 5773, Tenth of Teves - י׳ טבת תשע״ג, עשרה בטבת
...
15 Shevat, 5773, Tu B'Shvat - ט״ו שבט תשע״ג, ט״ו בשבט
...
21 Shevat, 5773 - כ״א שבט תשע״ג
...
11 Adar, 5773, Fast of Esther - י״א אדר תשע״ג, תענית אסתר
...
14 Adar, 5773, Purim - י״ד אדר תשע״ג, פורים
15 Adar, 5773, Shushan Purim - ט״ו אדר תשע״ג, פורים שושן
...
27 Adar, 5773 - Vayakhel Pekudei - כ״ז אדר תשע״ג - ויקהל פקודי
...
15 Nissan, 5773, Pesach - ט״ו ניסן תשע״ג, פסח
16 Nissan, 5773, Pesach,  - ט״ז ניסן תשע״ג, פסח, א׳ בעומר
17 Nissan, 5773, Chol Hamoed Pesach,  - י״ז ניסן תשע״ג, חול המועד פסח, ב׳ בעומר
18 Nissan, 5773, Chol Hamoed Pesach,  - י״ח ניסן תשע״ג, חול המועד פסח, ג׳ בעומר
19 Nissan, 5773, Chol Hamoed Pesach,  - י״ט ניסן תשע״ג, חול המועד פסח, ד׳ בעומר
20 Nissan, 5773, Chol Hamoed Pesach,  - כ׳ ניסן תשע״ג, חול המועד פסח, ה׳ בעומר
21 Nissan, 5773, Pesach,  - כ״א ניסן תשע״ג, פסח, ו׳ בעומר
22 Nissan, 5773, Pesach,  - כ״ב ניסן תשע״ג, פסח, ז׳ בעומר
23 Nissan, 5773,  - כ״ג ניסן תשע״ג, ח׳ בעומר
...
26 Nissan, 5773 - Shmini,  - כ״ו ניסן תשע״ג - שמיני, י״א בעומר
...
6 Sivan, 5773, Shavuos - ו׳ סיוון תשע״ג, שבועות
7 Sivan, 5773, Shavuos - ז׳ סיוון תשע״ג, שבועות
...
17 Tammuz, 5773, Seventeenth of Tammuz - י״ז תמוז תשע״ג, שבעה עשר בתמוז
...
9 Av, 5773, Tishah B'Av - ט׳ אב תשע״ג, תשעה באב
...
15 Av, 5773, Tu B'Av - ט״ו אב תשע״ג, ט״ו באב
...

Zmanim API 1.3.0 Released

Zmanim API 1.3.0 ReleaseThe Zmanim API version 1.3.0 was released on March 4th, 2013 כ״א אדר תשע״ג. Various changes in the new release VS the previous version 1.2.1 that was released in May 2010 can be seen below. This release includes beta support for Jewish Calendar calculations as well as a number of updated zmanim and refactored code. The Jewish Calendar support in the Zmanim API is based on Avrom Finkelstien’s HebrewDate project released in 2002. Unlike the Zmanim code, the Jewish calendar interfaces may change significantly in the future (see Jay Gindin’s various changes that may make it into this API) and should therefore be considered beta.

Changes in the Zmanim API 1.3.0 release

Changes since March 23, 2011 have been in SVN and detailed changes can be seen there.

Zmanim Map 3.5 adds Date and Algorithm Selection

World mapThe Zmanim Map was recently updated to version 3.5. This new release adds a number of new features (listed below), and some technical changes over the previous Zmanim Map 3.0 release. With this release, the main focus of the map has shifted to the zmanim tabs. The direction to Yerushalayim tab with davening directions using both the rhumb line and great circle route to Yerushalayim is still present, but is no longer the default tab.

Zmanim Map v3.5

  • The date can now be selected by the user. In previous versions the date was always the current date on the user’s computer (though the map always supported passing the date on the URL using the undocumented date=1969-02-08 parameter). The current date is still the default, but the user can now change the date.
  • The calculation algorithm is now selectable. The Zmanim API supports both the USNO and NOAA algorithms. The map has always used the USNO algorithm, and this remains the default, but users can now use the NOAA algorithm.
  • The Zmanim tab is now the default tab. This reflects user feedback indicating that most people use the map for zmanim.
  • An About tab now provides a mini user guide and general information about the map.
  • The timezone look-up now uses the Google Timezone API. Previously the map had been using the Geo Names web service. Since the elevation service also uses Google, the change to a single stable source will hopefully result in fewer outages.
  • The currently selected tab persists across location changes, so if you were viewing zmanim for a location, and changed the location to see how the zmanim were affected, you will no longer have to change tabs after each move.
  • Candle Lighting was added for Fridays. Erev Yom Tov will not show candle lighting at this point.
  • Performance improvements, minor enhancements, bug fixes and refactoring