Jewish Zmanim

A TypeScript library for calculating the daily halachic times (זמנים) that a Jewish app needs — alos hashachar, netz, sof zman krias shema and tefila, chatzos, mincha gedola, plag hamincha, shkiah, tzeis hakochavim, Rabbeinu Tam, and Shabbos candle-lighting / havdalah.

Built for Jewish developers who want accurate zmanim,computes the shaah zmanis in both the GRA and the Alter Rebbe / Magen Avraham shitos, and applies the right minhag defaults out of the box — 40 minutes candle-lighting in Yerushalayim, 30 minutes elsewhere in Eretz Yisrael, 18 minutes in chutz la'aretz, and the correct misheyakir degree for Israel vs. the diaspora.

Give it a built-in city or just GPS coordinates and it resolves the timezone and DST for you.

Installation

npm install jewish-zmanim
# or
yarn add jewish-zmanim

Usage

From a built-in city

import { Zmanim, cities } from 'jewish-zmanim';

const date = new Date('2026-02-08');
const z = Zmanim.fromCityRow(cities.israel.jerusalem, date);

const t = z.getTimes();
console.log(t.netzHachama);    // "6:27:37"  Sunrise (netz)
console.log(t.kriasShema);     // "9:10:33"  Latest Shema (GRA / Baal HaTanya)
console.log(t.chatzos);        // "11:53:31" Midday
console.log(t.shkiah);         // "17:19:25" Sunset (shkiah)
console.log(t.tzesHakochavim); // "17:56:56" Nightfall (8.5°)
console.log(t.shabbosEnter);   // "16:47:58" Candle lighting (40 min in Yerushalayim)

From GPS coordinates

Pass only latitude, longitude, and a date — the IANA timezone and DST are detected automatically:

import { Zmanim } from 'jewish-zmanim';

const z = Zmanim.fromCoordinates(31.7683, 35.2137, new Date('2026-07-15'));

console.log(z.timezoneInfo.timezoneName); // "Asia/Jerusalem"
console.log(z.timezoneInfo.offset);       // 3 (IDT — DST auto-detected)
console.log(z.timezoneInfo.dst);          // true

const t = z.getTimes();
console.log(t.netzHachama);  // Sunrise
console.log(t.shkiah);       // Sunset

Optionally override the timezone or tune the calculation:

Zmanim.fromCoordinates(31.7683, 35.2137, new Date('2026-02-08'), {
  timezoneName: 'Asia/Jerusalem', // IANA override (otherwise auto-detected)
  elevation: 800,                 // meters above sea level
  candleMinutes: 40,              // candle-lighting minutes before shkiah
  tefillinDeg: 11.5,              // misheyakir sun depression in degrees
});

Shabbat & Yom Tov status

getTimes() also returns two live boolean flags — isShabbat and isYomTov — powered by the jewish-holidays package. Unlike a plain calendar lookup, they are time-aware: they follow the halachic day, which runs from candle-lighting on the erev to tzeis (nightfall).

import { Zmanim, cities } from 'jewish-zmanim';

// Friday evening, after candle-lighting → already Shabbat
const erev = Zmanim.fromCityRow(cities.israel.jerusalem, new Date('2026-07-17T19:30:00'));
console.log(erev.getTimes().isShabbat); // true

// Saturday night, after tzeis → Shabbat is over
const motzash = Zmanim.fromCityRow(cities.israel.jerusalem, new Date('2026-07-18T23:00:00'));
console.log(motzash.getTimes().isShabbat); // false

• isShabbat — true on Shabbat before tzeis, and on Erev Shabbat once past candle-lighting (shabbosEnter).
• isYomTov — true on Yom Tov before tzeis, and on Erev Yom Tov once past candle-lighting. Multi-day festivals (e.g. the two days of Rosh Hashana, or diaspora second days) stay true through the intervening night and only end at tzeis on the final day. Israel vs. diaspora (isChutzLaaretz) is derived automatically from the city/coordinates.

The reference moment is the time-of-day of the Date you pass in. A date-only value (midnight) therefore reports the plain calendar-day status; pass a full timestamp (or new Date()) to get the exact live status.

Available cities

cities.israel.jerusalem   
cities.israel.telAviv      
cities.israel.haifa
cities.israel.safed       
cities.israel.beitShemesh  
cities.israel.modiin
cities.israel.maalehAdumim 
cities.israel.beerSheva   
cities.israel.eilat
cities.israel.kiryatMalachi
cities.unitedStates.newYork  
cities.unitedStates.brooklyn  
cities.unitedStates.miami
cities.france.paris          
cities.france.sarcelles
cities.unitedKingdom.london  
cities.australia.melbourne

or use any GPS coordinates

API

| Method | Returns | Description | |--------|---------|-------------| | Zmanim.fromCityRow(row, date) | Zmanim | Build from a built-in cities.* entry | | Zmanim.fromCoordinates(lat, lng, date, opts?) | Zmanim & { timezoneInfo } | Auto timezone + DST from coordinates | | z.getTimes() | ZmanimTimes | All halachic times for the day, fully typed |

ZmanimTimes fields

alosHashachar, tefillin (misheyakir), netzHachama (sunrise), sofZmanShemaMGA, kriasShema, tefila, chatzos, minchaGedola, plagHamincha, shkiah, shkiahElevated, tzesHakochavim, tzeisRT (Rabbeinu Tam), shabbosEnter / shabbosEnterUnix, shabbosExit / shabbosExitUnix, isShabbat, isYomTov, DST, date.

Times are returned as "H:MM:SS" strings in the location's local time; the *Unix fields are epoch seconds; isShabbat and isYomTov are booleans (see Shabbat & Yom Tov status).

Development

yarn test --run   # run the test suite (285 tests, 17 cities across 6 countries)
yarn typecheck    # type-check
yarn build        # bundle to dist/ (dual CJS + ESM)

Credits

Credit to Yitzhak Cohen for his great work, without him this would not be possible.

License

MIT