@hebcal/core/dist/src/isAssurBemlacha.js

A perpetual Jewish Calendar API

import { HDate } from '@hebcal/hdate';
import { Zmanim } from './zmanim';
import { getHolidaysOnDate } from './holidays';
import { flags } from './event';
const LIGHT_CANDLES = flags.LIGHT_CANDLES | flags.LIGHT_CANDLES_TZEIS;
function isTomorrowShabbosOrYomTov(dow, events) {
    if (dow === 5) {
        return true;
    }
    const erev = events.find(ev => ev.getFlags() & LIGHT_CANDLES);
    if (erev) {
        return true;
    }
    return false;
}
/**
 * Returns true if it is <em>Shabbos</em> or if it is a <em>Yom Tov</em> day that has a <em>melacha</em> (work)  prohibition.
 *
 * @return if the day is a <em>Yom Tov</em> that is <em>assur bemlacha</em> or <em>Shabbos</em>
 */
function isTodayAssurBemelacha(dow, events) {
    if (dow === 6) {
        return true;
    }
    const chag = events.find(ev => ev.getFlags() & flags.CHAG);
    if (chag) {
        return true;
    }
    return false;
}
/**
 * Utility method to determine if the date and time has a <em>melacha</em> (work) prohibition.
 * Although there are many opinions on the time of <em>tzais</em>, for simplicity
 * this function uses solar depression of 8.5 degrees.
 *
 * @return `true` if <em>melacha</em> is prohibited or `false` if it is not.
 */
export function isAssurBemlacha(currentTime, location, useElevation) {
    const zmanim = new Zmanim(location, currentTime, useElevation);
    // erev shabbos, YT or YT sheni and after shkiah
    const sunset = zmanim.sunset();
    const sunsetMillis = sunset.getTime();
    if (isNaN(sunsetMillis)) {
        throw new Error('Could not determine sunset');
    }
    // erev shabbos, YT or YT sheni and after shkiah
    const il = location.getIsrael();
    const currentMillis = currentTime.getTime();
    const hd = new HDate(currentTime);
    const dow = hd.getDay();
    const events = getHolidaysOnDate(hd, il) || [];
    if (isTomorrowShabbosOrYomTov(dow, events) && currentMillis >= sunsetMillis) {
        return true;
    }
    // is shabbos or YT and it is before tzais
    if (isTodayAssurBemelacha(dow, events)) {
        const tzais = zmanim.tzeit();
        const tzaisMillis = tzais.getTime();
        return currentMillis <= tzaisMillis;
    }
    return false;
}