From 83ee626bd05a102c560b3004ab0244ec6fa19444 Mon Sep 17 00:00:00 2001
From: "Michael J. Radwin" <michael@radwin.org>
Date: Sat, 9 Nov 2024 18:28:03 -0800
Subject: [PATCH] Add options.yizkor (default false) to CalOptions

---
 src/CalOptions.ts   | 11 +++++++++++
 src/calendar.ts     | 19 +++++++++++++++++++
 src/event.ts        |  2 ++
 src/hebcal.ts       |  1 +
 test/hebcal.spec.ts | 32 ++++++++++++++++++++++++++++++++
 5 files changed, 65 insertions(+)

diff --git a/src/CalOptions.ts b/src/CalOptions.ts
index 566019e..d54e212 100644
--- a/src/CalOptions.ts
+++ b/src/CalOptions.ts
@@ -158,4 +158,15 @@ export type CalOptions = {
   dailyLearning?: {
     [x: string]: DailyLearningValue;
   };
+  /**
+   * Yizkor (Hebrew: יִזְכּוֹר) is an Ashkenazi Jewish memorial prayer service
+   * for the dead. Yizkor is recited in synagogue as part of the service
+   * during four holidays each year:
+   * 1. Yom Kippur
+   * 2. Shmini Atzeret
+   * 3. The final day of Passover (8th day Pesach in Diaspora, 7th day
+   *    Pesach in Israel)
+   * 4. Shavuot (2nd day Shavuot in Diaspora)
+   */
+  yizkor?: boolean;
 };
diff --git a/src/calendar.ts b/src/calendar.ts
index e20cf08..25d397a 100644
--- a/src/calendar.ts
+++ b/src/calendar.ts
@@ -55,6 +55,7 @@ import {Location} from './location';
  * * Shabbat Mevarchim HaChodesh on Saturday before Rosh Chodesh (`options.shabbatMevarchim`)
  * * Molad announcement on Saturday before Rosh Chodesh (`options.molad`)
  * * Yom Kippur Katan (`options.yomKippurKatan`)
+ * * Yizkor (`options.yizkor`)
  *
  * Daily Study of texts are supported by the
  * {@link https://github.com/hebcal/hebcal-learning @hebcal/learning} package,
@@ -233,6 +234,18 @@ export function calendar(options: CalOptions = {}): Event[] {
     if (candlesEv) {
       evts.push(candlesEv);
     }
+    if (options.yizkor) {
+      const mm = hd.getMonth();
+      const dd = hd.getDate();
+      if (
+        (mm === months.TISHREI && (dd === 10 || dd === 22)) ||
+        (mm === NISAN && dd === (il ? 21 : 22)) ||
+        (mm === SIVAN && dd === (il ? 6 : 7))
+      ) {
+        const ev = new Event(hd, 'Yizkor', flags.YIZKOR, {emoji: '🕯️'});
+        evts.push(ev);
+      }
+    }
     if (
       options.addHebrewDates ||
       (options.addHebrewDatesForEvents && prevEventsLength !== evts.length)
@@ -277,6 +290,7 @@ const MINOR_HOLIDAY = flags.MINOR_HOLIDAY;
 const EREV = flags.EREV;
 const CHOL_HAMOED = flags.CHOL_HAMOED;
 const YOM_KIPPUR_KATAN = flags.YOM_KIPPUR_KATAN;
+const YIZKOR = flags.YIZKOR;
 
 type StringIntMap = {
   [x: string]: number;
@@ -315,6 +329,7 @@ const RECOGNIZED_OPTIONS: StringIntMap = {
   hour12: 1,
   dailyLearning: 1,
   useElevation: 1,
+  yizkor: 1,
 } as const satisfies Record<keyof CalOptions, 1>;
 
 /**
@@ -490,6 +505,9 @@ function getMaskFromOptions(options: CalOptions): number {
   if (options.yomKippurKatan) {
     mask |= YOM_KIPPUR_KATAN;
   }
+  if (options.yizkor) {
+    mask |= YIZKOR;
+  }
   if (options.dailyLearning) {
     const dailyLearning = options.dailyLearning;
     if (dailyLearning.dafYomi) {
@@ -542,6 +560,7 @@ function setOptionsFromMask(options: CalOptions): number {
   if (m & OMER_COUNT) options.omer = true;
   if (m & SHABBAT_MEVARCHIM) options.shabbatMevarchim = true;
   if (m & YOM_KIPPUR_KATAN) options.yomKippurKatan = true;
+  if (m & YIZKOR) options.yizkor = true;
   return m;
 }
 
diff --git a/src/event.ts b/src/event.ts
index 8e2ff25..b3596b5 100644
--- a/src/event.ts
+++ b/src/event.ts
@@ -62,6 +62,8 @@ export const flags = {
   NACH_YOMI: 0x2000000,
   /** Daily Learning */
   DAILY_LEARNING: 0x4000000,
+  /** Yizkor */
+  YIZKOR: 0x8000000,
 } as const;
 
 const flagToCategory = [
diff --git a/src/hebcal.ts b/src/hebcal.ts
index 455a1d7..55de259 100644
--- a/src/hebcal.ts
+++ b/src/hebcal.ts
@@ -79,6 +79,7 @@ export class HebrewCalendar {
    * * Shabbat Mevarchim HaChodesh on Saturday before Rosh Chodesh (`options.shabbatMevarchim`)
    * * Molad announcement on Saturday before Rosh Chodesh (`options.molad`)
    * * Yom Kippur Katan (`options.yomKippurKatan`)
+   * * Yizkor (`options.yizkor`)
    *
    * Daily Study of texts are supported by the
    * {@link https://github.com/hebcal/hebcal-learning @hebcal/learning} package,
diff --git a/test/hebcal.spec.ts b/test/hebcal.spec.ts
index 4ffd2da..de3267b 100644
--- a/test/hebcal.spec.ts
+++ b/test/hebcal.spec.ts
@@ -713,3 +713,35 @@ test('Eruv Tavshilin', () => {
   expect(HebrewCalendar.eruvTavshilin(new HDate(20, 'Cheshvan', 5785), false)).toBe(false);
   expect(HebrewCalendar.eruvTavshilin(new HDate(20, 'Cheshvan', 5785), true)).toBe(false);
 });
+
+test('yikzor', () => {
+  const options: CalOptions = {
+    isHebrewYear: true,
+    year: 5786,
+    noHolidays: true,
+    yizkor: true,
+    il: true,
+  };
+  const events = HebrewCalendar.calendar(options);
+  expect(events.length).toBe(4);
+  const actualIL = events.map(eventISODateDesc);
+  const expectedIL = [
+    { date: '2025-10-02', desc: 'Yizkor' },
+    { date: '2025-10-14', desc: 'Yizkor' },
+    { date: '2026-04-08', desc: 'Yizkor' },
+    { date: '2026-05-22', desc: 'Yizkor' }
+  ];
+  expect(actualIL).toEqual(expectedIL);
+
+  options.il = false;
+  const diaspora = HebrewCalendar.calendar(options);
+  expect(diaspora.length).toBe(4);
+  const actualD = diaspora.map(eventISODateDesc);
+  const expectedD = [
+    { date: '2025-10-02', desc: 'Yizkor' },
+    { date: '2025-10-14', desc: 'Yizkor' },
+    { date: '2026-04-09', desc: 'Yizkor' },
+    { date: '2026-05-23', desc: 'Yizkor' }
+  ];
+  expect(actualD).toEqual(expectedD);
+});