2 unstable releases

0.5.0 Jan 12, 2021
0.4.2 Jan 21, 2019

#21 in Date and time

MIT license

105KB
2K SLoC

Salah

Build Status Crate.io Docs

Usage

Add the following to your Cargo.toml file under the [dependencies] section:

[dependencies]
salah = "0.5.0"

To get prayer times, use the PrayerSchedule struct passing in coordinates, date, and calculation parameters.

use salah::prelude::*;

let new_york_city = Coordinates::new(40.7128, -74.0059);
let date          = Utc.ymd(2019, 1, 25);
let params        = Configuration::with(Method::NorthAmerica, Madhab::Hanafi);
let prayers       = PrayerSchedule::new()
                      .on(date)
                      .for_location(new_york_city)
                      .with_configuration(params)
                      .calculate();

Initialization parameters

Coordinates

Create a Coordinates struct with the latitude and longitude for the location you want prayer times for.

let coordinates = Coordinates::new(40.7128, -74.0059);

Date

To avoid confusion with timezones the date parameter passed in should be an instance of Date<Utc>. The year, month, and day components need to be populated. All other components will be ignored.

let date = Utc.ymd(2019, 1, 25);

Configuration

The calculation of the prayer times requires certain pieces of information. These can configured using the Configuration struct, a builder for the underlaying Parameters struct. This struct can be initialized by passing one of the Method enum variants (see below for the available variants) along with the one of the Madhab enum variants. You can then further customize the calculation parameters if needed.

let params = Configuration::with(Method::NorthAmerica, Madhab::Hanafi);
Parameter Description
method Member of Method enum
fajr_angle Angle of the sun used to calculate Fajr
isha_angle Angle of the sun used to calculate Isha
isha_interval Minutes after Maghrib (if set, the time for Isha will be Maghrib plus isha_interval)
madhab Member of the Madhab enum, used to calculate Asr
high_latitude_rule Member of the HighLatitudeRule enum, used to set a minimum time for Fajr and a max time for Isha
time_adjustments TimeAdjustment struct with adjustment based on the selected Method.
custom_time_adjustments TimeAdjustment struct with custom prayer time adjustments in minutes for each prayer time. By default, all values are 0.

Method

Provides preset configuration for a few authorities for calculating prayer times.

Value Description
MuslimWorldLeague Muslim World League. Fajr angle: 18, Isha angle: 17
Egyptian Egyptian General Authority of Survey. Fajr angle: 19.5, Isha angle: 17.5
Karachi University of Islamic Sciences, Karachi. Fajr angle: 18, Isha angle: 18
UmmAlQura Umm al-Qura University, Makkah. Fajr angle: 18.5, Isha interval: 90. Note: you should add a +30 minute custom adjustment for Isha during Ramadan.
Dubai Method used in UAE. Fajr angle: 18.2, Isha angle: 18.2.
Qatar Modified version of Umm al-Qura used in Qatar. Fajr angle: 18, Isha interval: 90.
Kuwait Method used by the country of Kuwait. Fajr angle: 18, Isha angle: 17.5
MoonsightingCommittee Moonsighting Committee. Fajr angle: 18, Isha angle: 18. Also uses seasonal adjustment values.
Singapore Method used by Singapore. Fajr angle: 20, Isha angle: 18.
NorthAmerica Referred to as the ISNA method. Fajr angle: 15, Isha angle: 15
Other Fajr angle: 0, Isha angle: 0. This is the default value for when manually initializing the Parameters struct.

Madhab

Setting for the Asr prayer time. For Hanafi madhab, the Asr is bit later than that of the Shafi madhab.

Value Description
Shafi Earlier Asr time
Hanafi Later Asr time

HighLatitudeRule

Rule for approximating Fajr and Isha at high latitudes.

Value Description
MiddleOfTheNight Fajr will never be earlier than the middle of the night and Isha will never be later than the middle of the night
SeventhOfTheNight Fajr will never be earlier than the beginning of the last seventh of the night and Isha will never be later than the end of the first seventh of the night
TwilightAngle Similar to SeventhOfTheNight, but instead of 1/7, the fraction of the night used is fajr_angle/60 and isha_angle/60

Prayer Schedule

The PrayerSchedule struct is a builder for the the PrayerTimes struct. Once the calculate() method is invoked on it, a PrayerTime struct will be initialized and it will contain fields for all five prayer times, the time for sunrise, and for the Qiyam prayer.

The prayer time will be an instance of DateTime<Utc> and as such will refer to a fixed point in universal time. To display these times for the local timezone you will need to format them with the appropriate local time zone.

This struct provides convenience methods for the prayer times to ease their usage and display.

PrayerTime

Method Description
name() Returns the name of the payer transliterated in English.
time(prayer: Prayer) Returns the time of the prayer as a DateTime<Utc>. See the DateTime documentation for manipulating the return value.
current() Returns the current prayer as the Prayer type.
next() Returns the next prayer as the Prayer type.
time_remaining() Returns a tuple with the hours as its first element, and minutes as its second element. The value is always in the context of the current prayer.

Prayer

This is an enum and has variants for all prayers, including, sunrise and Qiyam. This is single method available for this type called, name(), that will return the name of the prayer transliterated into English.

Full Example

use salah::prelude::*;

let new_york_city = Coordinates::new(40.7128, -74.0059);
let date          = Utc.ymd(2019, 1, 25);
let params        = Configuration::with(Method::NorthAmerica, Madhab::Hanafi);
let prayers       = PrayerSchedule::new()
                        .on(date)
                        .for_location(new_york_city)
                        .with_configuration(params)
                        .calculate();

match prayers
{
    Ok(prayer) => {
        println!("{}: {}", Prayer::Fajr.name(), prayer.time(Prayer::Fajr).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Sunrise.name(), prayer.time(Prayer::Sunrise).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Dhuhr.name(), prayer.time(Prayer::Dhuhr).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Asr.name(), prayer.time(Prayer::Asr).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Maghrib.name(), prayer.time(Prayer::Maghrib).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Isha.name(), prayer.time(Prayer::Isha).format("%-l:%M %p").to_string());
        println!("{}: {}", Prayer::Qiyam.name(), prayer.time(Prayer::Qiyam).format("%-l:%M %p").to_string());
    },
    Err(error) => println!("Could not calculate prayer times: {}", error)
}

The output will be (in UTC):

Fajr: 10:53 AM
Sunrise: 12:12 PM
Dhuhr: 5:09 PM
Asr: 8:24 PM
Maghrib: 10:05 PM
Isha: 11:24 PM
Qiyam: 6:37 AM

Convenience Utilities

The PrayerTimes struct has functions for getting the current prayer and the next prayer. You can also get the time for a specified prayer, making it easier to dynamically show countdowns until the next prayer.

...
let prayers = PrayerSchedule::new()
                .on(date)
                .for_location(new_york_city)
                .with_configuration(params)
                .calculate();
let (hours, minutes) = prayers.current().time_remaining();

println!("Current: {} ({}:{})", prayers.current().name, hours, minutes);
println!("Next prayer is {} at {}.", prayers.next().name, prayers.time(prayer.next()).format("%-l:%M %p").to_string()));

Qibla Direction

Get the direction, in degrees from North, of the Qibla from a given set of coordinates.

let new_york_city   = Coordinates::new(40.7128, -74.0059);
let qibla_direction = Qibla::new(coordinates: new_york_city);

println!("Qiblah: {:?}", qibla_direction); //  Outputs: Qiblah: 58.4817

Contributing

Please see the CONTRIBUTING.md file for more information.

Code of Conduct

Our contributor code of conduct can be found in the code-of-conduct.md file.

Acknowledgement

This library is based on the Adhan library by Batoul Apps. All astronomical calculations are high precision equations directly from the book Astronomical Algorithms by Jean Meeus.

License

Salah is licensed under a three clause BSD License. It basically means: do whatever you want with it as long as the copyright in Salah sticks around, the conditions are not modified and the disclaimer is present. Furthermore you must not use the names of the authors to promote derivatives of the software without written consent.

The full license text can be found in the LICENSE file.

Dependencies

~1MB
~12K SLoC