Calculation Methods ​

Overview ​

Calculation methods are sets of parameters and rules used to compute Islamic prayer times. These methods are often standardized by religious authorities or geographical regions. They define specific angles of the sun or time intervals, and other factors to accurately calculate the times for Fajr, Sunrise, Dhuhr, Asr, Maghrib, and Isha prayers.

Available Methods ​

We recommend using prayers-call pre-defined calculation methods, as they are endorsed by official religious authorities making them more accurate and consistent with the local community. These methods are available via the Method enum. However, if you need to, you can create your own custom method using the CustomMethod interface for that check the Building a Custom Method section.

Using the recommendMethod Helper Function ​

prayers-call offers the recommendMethod helper function, designed to suggest the most appropriate calculation methods for prayer times based on the country of a given location. The function accepts a CoordinatesObject returns an array of recommended methods, ranked by best guess or by the number of methods commonly used in that specific country. If no match is found, the function returns undefined. Here's an example:"

import { ReactiveCalculator, recommendMethod } from 'prayers-call'

const makkaCoordinates = { latitude: 21.3891, longitude: 39.8579 }

const recommendedMethod = recommendMethod(makkaCoordinates)[0] // 'UmmAlQura'

const reactiveCalculator = new ReactiveCalculator({
  latitude: makkaCoordinates.latitude,
  longitude: makkaCoordinates.longitude,
  method: recommendedMethod ? recommendedMethod : Methods.MUSLIM_WORLD_LEAGUE,
})

import { ReactiveCalculator, recommendMethod } from 'prayers-call'

const makkaCoordinates = { latitude: 21.3891, longitude: 39.8579 }

const recommendedMethod = recommendMethod(makkaCoordinates)[0] // 'UmmAlQura'

const reactiveCalculator = new ReactiveCalculator({
  latitude: makkaCoordinates.latitude,
  longitude: makkaCoordinates.longitude,
  method: recommendedMethod ? recommendedMethod : Methods.MUSLIM_WORLD_LEAGUE,
})

The following is a map projecting the recommended methods for each country. hover on a country to see the recommended methods.

Building a Custom Method ​

It is possible to use a custom calculation method by passing a CustomMethod object to the method property on the CalculationsConfig or the ReactiveCalculationsConfig.

The following parameters are available:

• fajrAngle: The angle of the sun, in degrees, used to calculate Fajr time. Default is 18 degrees.
• ishaAngle: The angle of the sun, in degrees, used to calculate Isha time. Default is 18 degrees.
• ishaInterval: The number of minutes after Maghrib for Isha. If set, ishaAngle is ignored. Default is 0 minutes.
• maghribAngle: The angle of the sun, in degrees, used to calculate Maghrib. This is specifically used by the Tehran method. Default is 0 degrees.
• methodAdjustments: Custom adjustments, in minutes, for each prayer time. Default adjustments are all zero.

Example usage ​

const MyCustomMethod: CustomMethod = {
  fajrAngle: 17,
  ishaAngle: 18,
  methodAdjustments: { fajr: 2, isha: 2 },
}

const calculator = new StaticCalculator({
  date: new Date(2022, 1, 1),
  latitude: 2.9213,
  longitude: 101.6559,
  method: MyCustomMethod,
  adjustments: { dhuhr: 3, asr: 3, isha: 2 },
})

const MyCustomMethod: CustomMethod = {
  fajrAngle: 17,
  ishaAngle: 18,
  methodAdjustments: { fajr: 2, isha: 2 },
}

const calculator = new StaticCalculator({
  date: new Date(2022, 1, 1),
  latitude: 2.9213,
  longitude: 101.6559,
  method: MyCustomMethod,
  adjustments: { dhuhr: 3, asr: 3, isha: 2 },
})

Community Note ​

This documentation and the methods provided are based on our best capacity of research and publicly available information. We welcome contributions from the community to improve and expand this data.

Future Plans ​

We're working on releasing an open-source tool that allows you to test, compare, and build calculation methods. Check our roadmap and stay tuned for updates.

Feel free to contribute and help us make this resource even better.