Astronomical Islamic Prayer Times & Solar Telemetry Engine

✦ ASTRONOMICAL SOLAR ALGORITHMS

Sub-Arcsecond Solar Telemetry

Traditional Islamic timekeeping relies on the observable position of the Sun. Prayer transforms these celestial observations into mathematical code executed 100% on your device.

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Fajr & Sunrise

Calculated precisely at astronomical twilight when the first white thread of dawn appears horizontally across the eastern horizon (sub-solar angle between 15° and 19.5° based on chosen fiqh).

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Dhuhr & Zawal

Marks solar noon when the Sun crosses the local celestial meridian. Prayer automatically incorporates a mandatory 2-to-5 minute precautionary margin (temkin) after zenith.

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Asr Shadow Ratios

Switch seamlessly between the Shafi'i/Maliki/Hanbali standard (shadow equals object length + noon shadow) and the Hanafi standard (shadow equals twice object length + noon shadow).

Calculation Authority	Region	Fajr Angle	Isha Angle / Offset	Fiqh Alignment
Diyanet İşleri Başkanlığı	Turkey & Europe	18.0°	17.0° (Temkin Adjusted)	Hanafi / Shafi'i Consensus
Muslim World League (MWL)	Global / Europe	18.0°	17.0°	Ahl al-Sunnah Standard
Islamic Society of North America (ISNA)	USA & Canada	15.0°	15.0°	North American Fiqh Council
Umm al-Qura University	Saudi Arabia & Arabian Peninsula	18.5°	90 min (120 min Ramadan)	Hanbali Tradition
University of Islamic Sciences, Karachi	Pakistan, India, Bangladesh	18.0°	18.0°	Hanafi School Standard
Egyptian General Authority of Survey	Egypt, Africa, Levant	19.5°	17.5°	Maliki / Shafi'i Tradition
University of Tehran / Leva Institute	Iran & Shia Communities	17.7° / 16.0°	14.0°	Ja'fari / Shia Ithna-Ashari

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High Latitude Adjustments

During summer in northern latitudes (above 48° N), twilight persists throughout the night without reaching the theoretical astronomical angles. Prayer implements mathematically sound angle-based, midnight-split, and seventh-of-the-night adjustments approved by contemporary fatwa councils.

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100% On-Device Privacy

Unlike commercial prayer apps that harvest your GPS coordinates to sell to advertising data brokers, Prayer processes all mathematical calculations in device RAM. Your location never touches a server, cloud bucket, or analytics SDK.

Frequently Asked Questions

Everything you need to know about astronomical calculations and adhan reliability.

How does Prayer calculate prayer times without an internet connection? ▼

Prayer incorporates high-precision Jean Meeus astronomical algorithms directly into its local engine. By using your device's latitude, longitude, and elevation, it computes the sun's declination, equation of time, and zenith angles locally on your phone's processor. Zero network requests are made, guaranteeing absolute offline reliability and complete privacy.

Which calculation authorities and twilight angles are supported? ▼

Prayer supports all major Islamic fiqh calculation authorities worldwide: Diyanet İşleri Başkanlığı (Turkey 18°/17° with Temkin offsets), Muslim World League (18°/17°), ISNA (North America 15°/15°), Umm al-Qura University (Makkah 18.5° / 90 min), University of Islamic Sciences Karachi (18°/18° with Hanafi Asr), Egyptian General Authority of Survey (19.5°/17.5°), and Shia Ithna-Ashari / University of Tehran.

How does the app handle prayer times in extreme northern or southern latitudes? ▼

In high-latitude locations (such as the UK, Scandinavia, and Canada) where astronomical twilight does not vanish during summer months, Prayer automatically provides three established fiqh solutions: Angle-Based rule, Middle of the Night rule, and One-Seventh of the Night rule to ensure valid, balanced prayer schedules.

Will Adhan notifications ring reliably if my phone is in battery-saver or Doze mode? ▼

Yes. On Android, Prayer utilizes an Exact AlarmManager implementation paired with a persistent foreground service to bypass Doze mode battery optimizations. On iOS, critical background audio notifications and scheduled notifications ensure the Adhan rings precisely on time, every time.