Crate rust_zmanim 

rust-zmanim

rust-zmanim calculates solar events (such as sunrise, sunset, and twilight) and Jewish zmanim built on those events.

Modules

• astronomical_calculator: Low-level astronomical calculations.
• zmanim_calculator: Core zmanim building blocks.
• complex_zmanim_calendar: Stateful convenience API with many predefined zmanim.

Examples

zmanim_calculator: Hanetz (sunrise)

use jiff::{tz::TimeZone, Zoned};
use rust_zmanim::prelude::*;

let date = Zoned::now().date();
let location = GeoLocation {
    latitude: 31.778,
    longitude: 35.234,
    elevation: 754.0,
    timezone: TimeZone::get("Asia/Jerusalem").unwrap(),
};

let hanetz = zmanim_calculator::hanetz(&date, &location, false).unwrap();
println!("Hanetz: {}", hanetz.strftime("%H:%M:%S %Z"));

zmanim_calculator: Shkia (sunset)

let shkia = zmanim_calculator::shkia(&date, &location, false).unwrap();
println!("Shkia: {}", shkia.strftime("%H:%M:%S %Z"));

zmanim_calculator: Chatzos (Solar Noon)

let chatzos = zmanim_calculator::chatzos(&date, &location).unwrap();
println!("Chatzos: {}", chatzos.strftime("%H:%M:%S %Z"));

zmanim_calculator: Alos with a Minutes Offset

let alos_72 =
    zmanim_calculator::alos(&date, &location, false, &ZmanOffset::Minutes(72.0)).unwrap();
println!("Alos (72 min): {}", alos_72.strftime("%H:%M:%S %Z"));

zmanim_calculator: Tzeis with a Degrees Offset

let tzeis_4_5 =
    zmanim_calculator::tzeis(&date, &location, false, &ZmanOffset::Degrees(4.5)).unwrap();
println!("Tzeis (4.5 deg): {}", tzeis_4_5.strftime("%H:%M:%S %Z"));

zmanim_calculator: Sof Zman Shema (MGA) using zmanis-based Alos and Tzeis

let hanetz = zmanim_calculator::hanetz(&date, &location, false).unwrap();
let shkia = zmanim_calculator::shkia(&date, &location, false).unwrap();
// this is a GRA shaah zmanis, based on sunrise and sunset
let shaah_zmanis_gra = zmanim_calculator::shaah_zmanis(&hanetz, &shkia);

// the offset used for alos and tzeis will be based on shaos zmaniyos
let offset_50_zmanis = ZmanOffset::MinutesZmaniyos {
    minutes_zmaniyos: 50.0,
    shaah_zmanis: shaah_zmanis_gra,
};
let alos_50_zmanis =
    zmanim_calculator::alos(&date, &location, false, &offset_50_zmanis).unwrap();
let tzeis_50_zmanis =
    zmanim_calculator::tzeis(&date, &location, false, &offset_50_zmanis).unwrap();

// calculate Sof Zman Shema according to the Magen Avraham, that it is
// calculated from alos to tzeis
let szks = zmanim_calculator::sof_zman_shema(&alos_50_zmanis, &tzeis_50_zmanis);
println!(
    "Sof Zman Shema (MGA 50 min zmaniyos): {}",
    szks.strftime("%H:%M:%S %Z")
);

ComplexZmanimCalendar: Build Once, Reuse Many Times

let czc = ComplexZmanimCalendar {
    geo_location: location,
    date,
    use_elevation: UseElevation::No,
};

println!("Hanetz: {}", czc.hanetz().unwrap().strftime("%H:%M:%S %Z"));
println!("Shkia: {}", czc.shkia().unwrap().strftime("%H:%M:%S %Z"));

ComplexZmanimCalendar: Premade 72-Minute Alos

println!("Alos (72 min): {}", czc.alos_72_minutes().unwrap().strftime("%H:%M:%S %Z"));

ComplexZmanimCalendar: Generic Tzeis with Custom Offset

let tzeis_7_083 = czc.tzeis(&ZmanOffset::Degrees(7.083)).unwrap();
println!("Tzeis (7.083 deg): {}", tzeis_7_083.strftime("%H:%M:%S %Z"));

ComplexZmanimCalendar: Tzeis 90 Minutes Zmaniyos After Sunset

let tzeis_90_zmanis = czc.tzeis_90_minutes_zmanis().unwrap();
println!(
    "Tzeis (90 min zmaniyos): {}",
    tzeis_90_zmanis.strftime("%H:%M:%S %Z")
);

ComplexZmanimCalendar: Elevation Modes

let sea_level = ComplexZmanimCalendar {
    geo_location: location.clone(),
    date,
    use_elevation: UseElevation::No,
};

let elevated = ComplexZmanimCalendar {
    geo_location: location,
    date,
    use_elevation: UseElevation::HanetzShkia,
};

let sea_level_hanetz = sea_level.hanetz().unwrap();
let elevated_hanetz = elevated.hanetz().unwrap();
println!("Sea-level hanetz: {}", sea_level_hanetz.strftime("%H:%M:%S %Z"));
println!("Elevated hanetz:  {}", elevated_hanetz.strftime("%H:%M:%S %Z"));

Notes

• Most APIs return Option<Zoned>. A result of None means the requested event does not occur for the requested date/location (common in high latitudes or for deep-twilight calculations).
• This crate uses NOAA-based algorithms. Returned values can be highly precise, but real-world observations vary with atmospheric conditions, temperature, pressure, etc.
• For religious practice (halacha lemaaseh), consult competent halachic guidance.
• Elevation based zmanim (even sunrise and sunset) should not be used lekula without the guidance of a posek. According to Rabbi Dovid Yehudah Bursztyn in his Zmanim Kehilchasam, 7th edition chapter 2, section 7 (pages 181-182) and section 9 (pages 186-187), no zmanim besides sunrise and sunset should use elevation. However, Rabbi Yechiel Avrahom Zilber in the Birur Halacha Vol. 6 Ch. 58 Pages 34 and 42 is of the opinion that elevation should be accounted for in zmanim calculations. Related to this, Rabbi Yaakov Karp in Shimush Zekeinim, Ch. 1, page 17 states that obstructing horizons should be factored into zmanim calculations.

Background

This crate is a Rust port which reuses a lot of code and documentation from:

• KosherJava
• python-zmanim

See the KosherJava website for additional background on zmanim.

Modules

astronomical_calculator

Astronomical calculations for sunrise, sunset, twilight, and solar transit times.

complex_zmanim_calendar

The ComplexZmanimCalendar struct is stateful and has many premade zmanim calculations, both conveniences built on the zmanim_calculator API.

prelude

A convenience module for glob imports. use rust_zmanim::prelude::*;

util

Utility modules for the Zmanim API.

zmanim_calculator

Core zmanim calculations built on astronomical sunrise/sunset events.

Macros

zmanim_for_offset