Let’s contrast the above with Lakewood, NJ. With 0.107° of longitude from east to west, zmanim are 24 seconds later on the west side (the intersection of New Central Ave & N Hope Chapel Rd) than the east side (Shinn Cranes, 1600 Ocean Ave). New York City is larger, and from the western edge of Staten Island to the edge of Glen Oaks, the eastern edge of Queens there is a 2 minute and 11 second difference in zmanim.
See the Calculation of Zmanim VS Other Sites post for additional related material.
I thank Avraham David Gelbfish for generating the ZIP code longitude range for all 33,093 ZIP codes from the US Census Bureau ZIP code shape files.
Category: Software Dev
Parsha Code Removed from KosherJava Zmanim Calendar API
Due to licensing issues that were brought to my attention last year, the parsha code was removed from the Zmanim API on Aug 22, 2016. In the future I may release the parsha code as a standalone module under the GPL license, or create a new LGPL implementation. To understand this more clearly, the current Zmanim API is licensed under the LGPL, while the parsha code contained some GPL code that had to be removed in order to retain the LGPL license. I would welcome any code submission for parsha code that could be released under the LGPL.
Update: Parsha Code Restored
On November 17, 2019 – י״ט מרחשון תש״פ an updated post Parsha Code Restored to the KosherJava Zmanim Calendar API announced the restoration of the parsha functionality.
FAQ: Different Parshas Hashavua in Eretz Yisrael Than Chutz La’aretz
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 krias Hatorah for Pesach. 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(true) flag (it has a default of 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
Please see the more recent and updated article Baal Hatanya’s Zmanim Added to KosherJava Zmanim Library for more current information.
Question:
How do I calculate the בעל התניא Baal Hatanya’s Zman for Shkiah as 4 minutes after sunset using the KosherJava Zmanim API?
Answer:
I was recently asked how to use the Zmanim API to calculate the Baal Hatanya’s opinion is that shkiah (halachic sunset) is 4 minutes after civil sunset. The assumption that the Baal Hatanya’s shkiah is a fixed 4 minutes after sunset is not that simple and will require a separate post to clarify. This zman should not be used lehalacha without consulting a rov. This post shows how to us the API assuming that it is a fixed 4 minutes after sunset. The technique to calculate this with the API 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 (doubtful) 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.
Update on July 5, 2015 – י״ח תמוז תשע״ה: This article was updated to clarify that the Baal Hatanya’s opinion may not be a fixed 4 minutes, but that the post was showing how to use the API to calculate it based on the questioner’s assumption that it was a 4 minute zman.
Update on Dec 14, 2018 – ו׳ טבת תשע״ט: This article was superseded with the more recent and corrected article Baal Hatanya’s Zmanim Added to KosherJava Zmanim Library.
Zmanim API 1.3.0 Released
The 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
- Refactoring of zmanim calculations to allow more flexibility in generating custom zmanim. New generic methods that take an arbitrary start and end of day for many zmanim such as sofZmanShema and getPlagHamincha etc. This makes calculating atypical zmanim that I had not anticipated when creating the API. I receive such requests from time to time, and the changes greatly simplify these types of calculations. Examples of recent requests are:
- Zman krias Shema calculated from alos as 72 minutes before netz and tzais as 7.083 degrees
- Plag hamincha from alos 7.083° to tzais 7.083°
- Many rounds of general code refactoring to simplify and stabilize the code and make it easier to port. Thank you Jay Gindin for his many suggestions.
- The addition of Erev Pesach zmanim to the Zmanim API
- Added Tzais Geonim 3.676 degrees (18 minutes as calculated by Stanley Fishkind)
- Calculation of Kiddush Levana and molad times
- Hebrew calendar support (with formatters and Yom Tov calendar)
- Daf Yomi calendar
- A number of bug fixes including a fix to DST correction, and a calendar date correction
- Changing the license of the KosherJava Zmanim API from GPL 2 to LGPL 2.1
- Many additions and clarifications to the Zmanim API JavaDoc documentation. My thanks to Reb Feivel Muller for his valuable input.
- Removal of the deprecated (and inaccurate) JSuntimeCalculator.java class. This has been deprecated since 2008. The NOAACalculator replaced this class.
- Deprecation of the getSofZmanShmaKolEliyahu() method. Thank you to Rabbi Yisroel Boruch Twerski for pointing out that the Yisrael Vehazmanim was incorrect in including this zman. This is something he discussed with Rabbi Harfenes.
- Uniformly return zmanim based on sea level sunrise and sunset. Most zmanim had this fix a long time ago, but there were a few zmanim such as candle lighting time that were corrected.
- The getCandleLighting() method had a spelling correction (it had been getCandelLighting)
Changes since March 23, 2011 have been in SVN and detailed changes can be seen there.