pray-calc

The main PrayCalc prayer times engine. Built on NREL SPA for solar position, covering all 14 major calculation methods and a physics-grounded dynamic angle mode.

Overview

pray-calc computes the six daily Islamic prayer times (Fajr, Sunrise, Dhuhr, Asr, Maghrib, Isha) for any location on Earth, any date, and any standard calculation method.

14 standard methods (ISNA, MWL, Egypt, Umm al-Qura, Tehran, Karachi, and more)
Dynamic angle mode (DPC) for physics-grounded Fajr and Isha
Asr: Shafi'i (shadow = 1×) and Hanafi (shadow = 2×)
High latitude fallback rules (1/7 night, angle-based, nearest day)
TypeScript-first, full type exports
ESM + CommonJS builds
Zero runtime dependencies (NREL SPA bundled)

GitHub: github.com/acamarata/pray-calc

Installation

pnpm add pray-calc

Requires Node.js 20+.

getPrayerTimes

getPrayerTimes(options: PrayerTimesOptions): PrayerTimes

Options

Parameter	Type	Required	Description
`date`	`Date`	Yes	Date to compute times for
`latitude`	`number`	Yes	Observer latitude in decimal degrees
`longitude`	`number`	Yes	Observer longitude in decimal degrees
`timezone`	`string`	Yes	IANA timezone string (e.g. `'America/New_York'`)
`method`	`CalculationMethod`	No	Calculation method (default: `'MWL'`)
`asrMethod`	`'shafii' \| 'hanafi'`	No	Asr shadow multiplier (default: `'shafii'`)
`elevation`	`number`	No	Metres above sea level (default: `0`)
`pressure`	`number`	No	Millibars (default: `1013.25`)
`temperature`	`number`	No	Celsius (default: `15`)
`highLatRule`	`HighLatRule`	No	Fallback for extreme latitudes

Returns

{
  fajr: string        // "HH:MM" in local time
  sunrise: string
  dhuhr: string
  asr: string
  maghrib: string
  isha: string
  midnight: string
  date: string        // ISO 8601 date
  timezone: string
  method: string
}

Basic usage

import { getPrayerTimes } from 'pray-calc'

const times = getPrayerTimes({
  date: new Date(),
  latitude: 41.4993,
  longitude: -81.6944,
  timezone: 'America/New_York',
  method: 'ISNA',
})

console.log(times)
// {
//   fajr: "05:34",
//   sunrise: "06:52",
//   dhuhr: "13:02",
//   asr: "16:28",
//   maghrib: "19:47",
//   isha: "21:12",
//   ...
// }

Methods

All supported methods

import type { CalculationMethod } from 'pray-calc'

const methods: CalculationMethod[] = [
  'ISNA',        // 15°/15° — North America
  'MWL',         // 18°/17° — Muslim World League
  'EGYPT',       // 19.5°/17.5° — Egypt
  'UMM_AL_QURA', // 18°/90min — Saudi Arabia
  'TEHRAN',      // 17.7°/14° — Iran
  'KARACHI',     // 18°/18° — Pakistan
  'KUWAIT',      // 18°/17.5° — Kuwait
  'QATAR',       // 18°/90min — Qatar
  'SINGAPORE',   // 20°/18° — Singapore
  'FRANCE',      // 12°/12° — France
  'RUSSIA',      // 16°/15° — Russia
  'GULF',        // 19.5°/90min — Gulf states
  'FCNA',        // 15°/15° — North America (Fiqh Council)
  'JAKIM',       // 20°/18° — Malaysia
  'DPC',         // Dynamic PrayCalc — physics-grounded
]

Dynamic mode

Use method: 'DPC' to enable dynamic angle computation. The algorithm adapts Fajr and Isha depression angles based on latitude, day of year, Earth-Sun distance, and elevation.

Dynamic mode example

const times = getPrayerTimes({
  date: new Date(),
  latitude: 52.48,
  longitude: -1.90,
  timezone: 'Europe/London',
  method: 'DPC',  // dynamic angles
})

Dynamic mode is especially useful at latitudes above 45° or for applications where sky-accurate times are required. See Dynamic vs. Fixed Angles for the full explanation.

TypeScript types

Full type definitions

import type {
  PrayerTimesOptions,
  PrayerTimes,
  CalculationMethod,
  AsrMethod,
  HighLatRule,
} from 'pray-calc'

type HighLatRule =
  | 'seventh-of-night'   // 1/7 of the night
  | 'half-of-night'      // 1/2 of the night
  | 'angle-based'        // reduced angle fallback
  | 'nearest-day'        // nearest valid day