mirror of https://github.com/acamarata/luxon-hijri.git synced 2026-06-30 18:54:28 +00:00

Aric Camarata eea0bc808d test: align day-boundary tests and docs with hijri-core's UTC-day contract

Convert all LOCAL-noon Date anchors (new Date(y, m, d, 12)) to UTC-explicit
anchors (new Date(Date.UTC(y, m-1, d))) in test.mjs and test-cjs.cjs.
Add UAQ default-engine round-trip regression suite (5 cases).
Extend FCNA round-trips; update vitest header comment.

README: add "Day boundaries and time zones" section explaining the UTC-day
contract, the correct pattern for zone-aware Luxon DateTimes, and ISO-string
parsing behaviour. Quick Start examples updated to use Date.UTC.

CHANGELOG: document inherited UTC-day fix under [Unreleased].

Lock-step dependency: requires hijri-core fix (commit 3419378,
branch fix/utc-day-boundary). Both packages release together per ADR-013.

Verified: TZ={UTC,America/New_York,Pacific/Auckland} × {test.mjs,
test-cjs.cjs, test-crossval.mjs, vitest} — all pass (88+26+120+15 tests).

2026-06-10 16:38:29 -04:00

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luxon-hijri

Hijri/Gregorian date conversion and formatting for Luxon users. Thin adapter over hijri-core. Supports the Umm al-Qura calendar (1318-1500 AH, table-based) and the FCNA/ISNA calendar (astronomical, all Hijri years).

Installation

pnpm add luxon-hijri luxon hijri-core
# or
npm install luxon-hijri luxon hijri-core

Quick Start

import { toHijri, toGregorian, formatHijriDate } from 'luxon-hijri';

// Gregorian to Hijri (Umm al-Qura, default) — use Date.UTC for cross-host consistency
const h = toHijri(new Date(Date.UTC(2023, 2, 23)));
// { hy: 1444, hm: 9, hd: 1 }

// Hijri to Gregorian
const g = toGregorian(1444, 9, 1);
// Date: 2023-03-23T00:00:00.000Z

// Format a Hijri date
formatHijriDate({ hy: 1444, hm: 9, hd: 1 }, 'iEEEE, iD iMMMM iYYYY ioooo');
// "Yawm al-Khamis, 1 Ramadan 1444 AH"

// FCNA/ISNA calendar
toHijri(new Date(Date.UTC(2025, 2, 1)), { calendar: 'fcna' });

Day boundaries and time zones

toHijri(date) reads the UTC calendar day of the Date you pass. toGregorian(hy, hm, hd) returns a Date at UTC midnight on the corresponding Gregorian day. Round-trips are therefore exact and produce identical results on any machine regardless of local timezone.

Converting a zone-aware Luxon DateTime. Pass the DateTime's calendar fields, not .toJSDate(), unless the DateTime is already pinned to UTC:

import { DateTime } from 'luxon';
import { toHijri } from 'luxon-hijri';

const dt = DateTime.now().setZone('America/New_York');

// Correct — reads the calendar date in the DateTime's own zone
const h = toHijri(new Date(Date.UTC(dt.year, dt.month - 1, dt.day)));

// Wrong if dt is not UTC-anchored — toJSDate() produces local-zone midnight,
// which may land on the previous UTC day for western timezones
// const h = toHijri(dt.toJSDate());

ISO string parsing. new Date("2025-03-01") parses as UTC midnight — that is exactly the right input for a calendar-day conversion and will produce the correct Hijri date.

Note: determining when the Hijri day begins at local sunset is out of scope for this library.

TypeScript

import { toHijri, toGregorian, formatHijriDate, isValidHijriDate } from 'luxon-hijri';
import type { HijriDate, CalendarSystem, ConversionOptions } from 'luxon-hijri';

Documentation

Full API reference, format token guide, calendar background, and architecture notes: GitHub Wiki

hijri-core: The underlying calendar engine
pray-calc: Islamic prayer times
nrel-spa: NREL Solar Position Algorithm

Acknowledgments

The Umm al-Qura table is derived from data published by KACST (King Abdulaziz City for Science and Technology). The FCNA new moon algorithm follows Jean Meeus, "Astronomical Algorithms," 2nd ed., Chapter 49.

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