sharshi / kosherzmanim

Port of the KosherJava zmanim library to TypeScript

This project is at an alpha stage.

Things will break, and APIs might change. Be cautious using this in production. Additionally, not all methods have been tested for accuracy.

Introduction

Kosher Zmanim is a TS/JS port of the KosherJava library.

Installation

NPM:

npm install kosher-zmanim

UMD (browser):

<script src="https://unpkg.com/kosher-zmanim/dist/kosher-zmanim.min.js"></script>

It is highly recommended that you pin the version (e.g. https://unpkg.com/[email protected]/dist/kosher-zmanim.min.js), so updates don't break your app.

Usage and Documentation

Importing

ES6 modules / Typescript:

import * as KosherZmanim from "kosher-zmanim";

Or:

import { ComplexZmanimCalendar, getZmanimJson } from "kosher-zmanim";

CommonJS modules:

const KosherZmanim = require("kosher-zmanim");

Or:

const { ComplexZmanimCalendar, getZmanimJson } = require("kosher-zmanim");

UMD (browser):

For UMD, a global KosherZmanim object is exposed.

Library Usage:

The KosherJava library has been ported to JS, following the original API as close as possible. The classes are exposed as named exports. You can instantiate or extend those classes as necessary, the same way you would in Java.

const zmanimCalendar = new KosherZmanim.ZmanimCalendar();

See the KosherJava API documentation for more details.

Simple usage

Alternatively, there is a getZmanimJson() utility method.

const zmanim = KosherZmanim.getZmanimJson(options);

Check out the demo, and look at the code to see an example of how it's used.

options object

The options object has the following structure:

{
    date: Date | string | number;
    timeZoneId: string;
    locationName?: string;
    latitude: number;
    longitude: number;
    elevation?: number;
    complexZmanim?: boolean
}

Note about how zmanim are calculated

This library uses Luxon as a date/time library, since Javascript's Date object does not support setting timezones other than the system timezone. All class methods that return a DateTime object will be in UTC.

Breaking changes from KosherJava

• AstronomicalCalendar.getTemporalHour() returns null instead of Long.MIN_VALUE if the calculations cannot be completed.
• JS/TS does not have a parallel to Java's Long.MIN_VALUE, so Long_MIN_VALUE is set to NaN.
• The following methods are not supported:
  • AstronomicalCalendar.toString()
  • AstronomicalCalendar.toJSON() (Use ZmanimFormatter.toJSON(astronomicalCalendar) instead).
  • AstronomicalCalculator.getDefault() (Use new NOAACalculator() instead).
  • JewishCalendar.getDafYomiBavli() (Use YomiCalculator.getDafYomiBavli(jewishCalendar) instead).
  • JewishCalendar.getDafYomiYerushalmi() (Use YerushalmiYomiCalculator.getDafYomiYerushalmi(jewishCalendar) instead).
  • Time.toString() (Use new ZmanimFormatter(TimeZone.getTimeZone("UTC")).format(time) instead).
  • ZmanimFormatter.toXML()
• Some method signatures are different, due to the differences between Java and JS.