Tefila Rules Added to KosherJava Zmanim Library

Kosel Picture 1932
Davening at the Kosel. This picture was taken by my grandfather Sidney (Nesanel) Siegfried on Aug 1, 1932 כ״ח תמוז תרצ״ב. This article was posted exactly 90 years to the day (Gregorian date) after the picture was taken.
The new TefilaRules class has been added to the KosherJava Zmanim Library. This will be included in the upcoming v2.4.0 release. The TefilaRules class was added in an effort to help zmanim calendar authors who sometimes require knowing if תחנון tachanun is recited on a specific day in order to set tefila times (such as mincha starting X minutes before shkiah, and a few minutes later if tachanun is not recited). It is also useful for siddur app creators. With many different minhagim (mostly chasidishe) about when tachanun is recited, the class currently supports 12 different options that can allow setting the rules for a majority of minhagim.
Yahrzeits such as 7 Adar, (Moshe Rabbeinu’s yahrzeit) or holidays celebrated by specific communities such as Purim Mezhbizh (Medzhybizh) celebrated on 11 Teves or Purim Saragossa celebrated on the 17th of Shevat (the Wikipedia date seems to be in error), are not (and likely never will be) supported by this class.
Other tefila related rules such as the existing Mashiv Haruach etc. rules were moved over from the JewishCalendar class to this new class where they have a more natural fit. The methods that were migrated over, were deprecated in the JewishCalendar class and will be removed in v3.0.0.

Key Methods in the TefilaRules Class

The following are the key methods in the new TefilaRules class.

Sample Code

TefilaRules tr = new TefilaRules();
JewishCalendar jCal = new JewishCalendar();
HebrewDateFormatter hdf = new HebrewDateFormatter();
hdf.setHebrewFormat(true); // Hebrew formatting
jCal.setJewishDate(5783, JewishDate.TISHREI, 1); // Rosh Hashana
System.out.println(hdf.format(jCal) + " - Is tachanun recited: " + tr.isTachanunRecitedShacharis(jCal));
jCal.setJewishDate(5729, JewishDate.SHEVAT, 21);
System.out.println(hdf.format(jCal) + " - is mashiv haruch recited: " + tr.isMashivHaruachRecited(jCal));
jCal.setJewishDate(5783, JewishDate.ADAR, 17);
System.out.println(hdf.format(jCal) + " - Is tachanun recited: " + tr.isTachanunRecitedShacharis(jCal));
tr.setTachanunRecitedWeekOfPurim(false); //default is true
System.out.println(hdf.format(jCal) + " - Is tachanun recited: " + tr.isTachanunRecitedShacharis(jCal));

Output:

א׳ תשרי תשפ״ג - Is tachanun recited: false
כ״א שבט תשכ״ט - is mashiv haruch recited: true
י״ז אדר תשפ״ג - Is tachanun recited: true
י״ז אדר תשפ״ג - Is tachanun recited: false

Zmanim API 2.3.0 Released


The KosherJava Zmanim API version 2.3.0 was released on Dec 7th, 2021 ג׳ טבת תשפ״ב in Maven and GitHub. While there have been numerous releases over the years, this is the first release-related post since the v1.3.0 release in 2013. If you have not updated since that time, you can expect some changes. The most significant changes (besides a lot of new functionality) are the simple to fix breaking changes listed below.

New in Version 2.3.0

The list of significant changes in this and previous releases can be seen in the KosherJava Zmanim API changelog.

Breaking Changes since v1.3

The Yereim’s Bein Hashmashos

Rabbi Eliezer of Metz (known by his acronym The רא״ם Re’em), a disciple of Rabbeinu Tam, in his Sefer Yereim ספר יראים chapter 274, states that bein hashmashos starts the time it takes to walk three quarters of a mil before sunset, and ends at sunset.

פירוש משתשקע החמה דר׳ יהודה ור׳ נחמיה משמתחלת לשקוע שנוטה מעט ומכירים העולם שרוצה להכנס בעובי הרקיע … ולשון משתשקע משמע הקדמה … וכן נראה לי עיקר דמשתשקע החמה הוא קודם שקיעת החמה דעולא ולא כדברי רבינו יעקב … ואין להקפיד על צאת הככבים … אע״ף שאין הכוכבים נראים … שלילה גמור הוא כפירושי.

The Yereim’s opinion is brought down by other Rishonim including the Mordechai and Rav Alexander Suslin HaKohen in his Sefer Agudah. The Yereim is mentioned by the Bach as a reason for the minhag of starting Shabbos early. The Yereim’s times are not brought down by the poskim lehalacha.

The Time to Walk a Mil

The time to walk a mil is based on the Gemara in Pesachim 93b – 94a. The time ranges in the poskim and includes 18, 22.5 and 24 minutes. Three quarters of these mil times would be 13.5, 16.875 and 18 minutes. It should be noted that the Yereim is of the opinion that a mil is 24 minutes. The above mentioned Mordechai who quoted the Yereim is also of the same opinion. We will hopefully discuss in detail the various opinions on the time to walk a mil in a future article.

The Addition of the Yereim’s Times to the KosherJava Zmanim Library

As of the 2.1.0 release of the KosherJava zmanim library, the Yereim’s bein hashmashos times have been added to the KosherJava zmanim library/API. There are six variants of these zmanim that were added. These include the three exact minute offsets mentioned above, as well as the conversion of these three times to degrees (elevation angle, or solar zenith angle). The only prior degree based time for the Yereim that I am aware of is in Rabbi Yedidya Manet’s Zmanei Halacha Lema’aseh (זמני ההלכה למעשה מהרב ידידיה מנת). The Zmanei Halacha Lema’aseh charts calculate bein hashmashos in degrees based on the 18 minute (3/4 of a 24 minute mil, see p. 27 in the 4th ed. published in 2005), but does not clarify the degrees used. At Rabbi Yaakov Shakow’s recommendation, I used the refraction value of 31/60 or 0.516° that exists in Israel, as opposed to the global average of 0.566°. This more stringent refraction is mentioned in the Zmanei Halacha Lema’aseh (p. 11) and used in the לוח עתים לבינה Luach Itim Lebinah. I also slightly rounded the times. These small tweaks resulted in a trivial maximum 19 second chumra vs the non-rounded global average refraction. The resulting degrees of elevation angle for the Yereim’s bein hashmashos are 2.1°, 2.8° and 3.05°. Solar zenith angles are traditionally calculated using the sun’s position without adjusting for refraction and without accounting for the solar radius (i.e. it is the position of the center of the sun in a vacuum). This does not impact the calculated time, it is simply the convention used. In the upcoming 8th edition of הרב דוד יהודה בורשטין Rabbi Yehuda Burstein’s זמנים כהלכתם / Zmanim Kehilchasam he mentions that

הזמן הנ״ל של 18 דקות לפני השקיעה המישורית הוא הזמן רק במרכז א״י ביום הבינוני כנ״ל, ובכל מקום בכל יום מחשבין זאת לפי שיטת המעלות, דהיינו דבודקים כמה מעלות מעל האופק נמצאת השמש במרכז א״י ביום הבינוני 18 דקות לפני השקיעה המישורית, ואותו מספר מעלות של השמש מעל האופק בכל מקום בכל יום הוא הזמן של ״היראם״. ועוד יש להוסיף זמן ל״תוספת שבת״, ובזה יוצא ידי כל שיטות הראשונים ואשרי חלקו.

A future article will address the proper date to use for converting minute-based times to degrees below (or above) the horizon and show how to use the KosherJava Zmanim code to calculate this.
I would like to thank Rabbi Yaakov Shakow for his help and suggestions.

Sample Code

Below are code examples for all six variants of the Yereim’s Bein Hashmashos (spelled BainHashmashos in the code).

GeoLocation yerushalayim = new GeoLocation("Jerusalem, Israel", 31.778, 35.2354, 0, TimeZone.getTimeZone("Asia/Jerusalem"));
ComplexZmanimCalendar czc = new ComplexZmanimCalendar(yerushalayim);
Date bh18Min = czc.getBainHasmashosYereim18Minutes();
Date bh3Pt05Deg = czc.getBainHasmashosYereim3Point05Degrees();
Date bh16Pt875Min = czc.getBainHasmashosYereim16Point875Minutes();
Date bh2Pt8Deg = czc.getBainHasmashosYereim2Point8Degrees();
Date bh13Pt5Min = czc.getBainHasmashosYereim13Point5Minutes();
Date bh2Pt1Deg = czc.getBainHasmashosYereim2Point1Degrees();

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd h:mm:ss a z"); //set the output format
sdf.setTimeZone(czc.getGeoLocation().getTimeZone()); //set the formatter's time zone
System.out.println("Bein Hashmashos 18 min:     " + sdf.format(bh18Min));
System.out.println("Bein Hashmashos 3.05°:      " + sdf.format(bh3Pt05Deg));
System.out.println("Bein Hashmashos 16.875 min: " + sdf.format(bh16Pt875Min));
System.out.println("Bein Hashmashos 2.8°:       " + sdf.format(bh2Pt8Deg));
System.out.println("Bein Hashmashos 13.5 min:   " + sdf.format(bh13Pt5Min));
System.out.println("Bein Hashmashos 2.1°:       " + sdf.format(bh2Pt1Deg));

The output of the above code (assuming that the calendar was set to March 16, 2020).

Bein Hashmashos 18 min:     2020-03-16 5:29:58 PM IST
Bein Hashmashos 3.05°:      2020-03-16 5:29:40 PM IST
Bein Hashmashos 16.875 min: 2020-03-16 5:31:05 PM IST
Bein Hashmashos 2.8°:       2020-03-16 5:30:51 PM IST
Bein Hashmashos 13.5 min:   2020-03-16 5:34:28 PM IST
Bein Hashmashos 2.1°:       2020-03-16 5:34:09 PM IST

KosherJava Zmanim Library Package Name and Build Process Update


The KosherJava zmanim library originally went live in 2004. There was an existing C/C++ zmanim project by Ken Bloom hosted on SourceForge (that was at the time the equivalent of what GitHub is today). The Java package structure name net.sourceforge.zmanim was based on the one used by Ken’s project (despite not being hosted there), and remained that way for 16 years.
On August 3, 2020, Eli Julian modernized the library’s build process from the previously used Ant, to Maven & Gradle. This change simplified the workflow for many developers using the zmanim API. As part of the change, the package name was updated to com.kosherjava.zmanim. The KosherJava zmanim Maven / Gradle artifacts are available at the KosherJava zmanim Maven Central page. A direct Jar download is available at Maven Central (see the KosherJava Downloads page for instructions). The old code was branched into zmanim-1.5 and will allow people who do not want to upgrade to continue to use the old structure (and Ant build process) while continuing to receive emergency bug fixes. This will allow the codebase to use more modern Java language features, without impacting users who want to remain on the legacy code. The new code has a minimum Java 8 requirement (a version released in March 2014). Releases based on the new build process will use SemVer (Semantic Versioning) to make things simpler for developers.
The upgraded build process also allowed automated GitHub’s CodeQL vulnerability scanning for the KosherJava Zmanim project.
You can add the KosherJava zmanim library as a Maven or Gradle dependency. For Maven add the following to your pom.xml.

<dependency>
  <groupId>com.kosherjava</groupId>
  <artifactId>zmanim</artifactId>
  <version>2.0.3</version>
</dependency>

For Gradle, add the following to your build.gradle file.

implementation group: 'com.kosherjava', name: 'zmanim', version: '2.0.3'

Parsha Code Restored to the KosherJava Zmanim Calendar API

Sunrise CalendarIn the Parsha Code Removed from KosherJava Zmanim Calendar API article posted two years ago, I documented the removal of the parsha code from the KosherJava Zmanim API due to licensing issues. I would like to announce that thanks to Yechiel Paricher, the zmanim library now supports a clean LGPL implementation. Yechiel’s Jan 17, 2019 pull request that was a port of his C libzmanim code, was finally merged on August 22nd, and over the past day, the old formatting code for parshiyos was restored after being changed to work with the new code. The new code not only restores the old functionality, but adds support for the special parshiyos of Shekalim, Zachor, Parah and Hachodesh. It also added support for Shabbos Mevorchim and Machar Chodesh.