Fasting Time Calculator

Calculate the daily fasting duration for Islamic fasting (sawm). Enter your location coordinates and date to determine when fasting begins (Fajr), when it ends (Maghrib/Iftar), and the total duration.

Solar Calculations: Fasting Period: Start: Fajr (pre-dawn) End: Maghrib (sunset) Duration = Maghrib time - Fajr time Fajr Calculation: Fajr occurs when sun is 18 deg below horizon (MWL method) Other methods: ISNA (15 deg), Umm al-Qura (18.5 deg), Egyptian (19.5 deg) Hour Angle for Fajr: cos(H) = (sin(-alpha) - sin(phi)*sin(delta)) / (cos(phi)*cos(delta)) Where: ? alpha = Fajr angle (typically 18 deg) ? phi = latitude ? delta = solar declination ? H = hour angle Fajr time = Solar noon - (H / 15) Maghrib (Sunset): Sunset angle = -0.833 deg (accounts for refraction + solar disc) Maghrib time = Solar noon + (sunset hour angle / 15) Solar Noon: Noon = 12 - (longitude / 15) - (equation of time / 60) Declination (delta): Changes daily based on Earth's tilt and orbital position Varies from -23.44 deg (winter solstice) to +23.44 deg (summer) Equation of Time: Accounts for Earth's elliptical orbit and axial tilt Varies +-16 minutes throughout the year Duration: Hours = Maghrib - Fajr Varies by latitude and season: ? Equator: ~12-13 hours year-round ? 40 deg N/S: 11-16 hours (seasonal variation) ? 60 deg N/S: 6-21 hours (extreme variation)
Example 1 (New York, Summer): Location: 40.7128 deg N, -74.0060 deg W Date: June 15, 2024 Fajr Angle: 18 deg (MWL) Results: Fajr (start): 03:30 Sunrise: 05:25 Maghrib (Iftar): 20:30 Duration: 17h 00m This is near summer solstice - longest fasting day. Example 2 (New York, Winter): Location: 40.7128 deg N, -74.0060 deg W Date: December 15, 2024 Fajr Angle: 18 deg (MWL) Results: Fajr (start): 05:45 Sunrise: 07:15 Maghrib (Iftar): 16:35 Duration: 10h 50m Winter solstice - shortest fasting day. Example 3 (Mecca, Saudi Arabia): Location: 21.4225 deg N, 39.8262 deg E Date: April 15, 2024 Fajr Angle: 18.5 deg (Umm al-Qura) Results: Fajr (start): 04:35 Sunrise: 05:55 Maghrib (Iftar): 18:30 Duration: 13h 55m Near equator - moderate, consistent fasting times. Example 4 (London, Summer): Location: 51.5074 deg N, -0.1278 deg W Date: June 20, 2024 Fajr Angle: 18 deg (MWL) Results: Fajr (start): 02:45 Sunrise: 04:45 Maghrib (Iftar): 21:20 Duration: 18h 35m High latitude - very long summer fasting. Example 5 (Jakarta, Indonesia): Location: -6.2088 deg S, 106.8456 deg E Date: March 15, 2024 Fajr Angle: 18 deg (MWL) Results: Fajr (start): 04:30 Sunrise: 05:55 Maghrib (Iftar): 18:10 Duration: 13h 40m Equatorial region - consistent 13-14 hour fasting. Example 6 (Istanbul, Turkey): Location: 41.0082 deg N, 28.9784 deg E Date: May 1, 2024 Fajr Angle: 18 deg (MWL) Results: Fajr (start): 04:15 Sunrise: 06:00 Maghrib (Iftar): 19:45 Duration: 15h 30m Mid-latitude spring - moderate fasting duration. Note: This calculator demonstrates the concept. For religious observance, use verified local timetables or trusted Islamic apps with proper calculation methods.

What are the fasting hours in Islam?

Islamic fasting (sawm) during Ramadan is from Fajr (pre-dawn) to Maghrib (sunset). Muslims abstain from food, drink, and other specific activities from the break of dawn until the sun sets. The exact times vary by location and date.

When does fasting start (Fajr)?

Fasting begins at Fajr, which is the pre-dawn prayer time. This occurs when the first light appears on the eastern horizon (true dawn or "Fajr al-Sadiq"), approximately 1.5-2 hours before sunrise. The exact time depends on latitude and calculation method.

When does fasting end (Maghrib)?

Fasting ends at Maghrib, which is sunset when the sun's disc completely disappears below the horizon. This is the time for breaking the fast (Iftar) and performing the Maghrib prayer. It occurs when the sun is 0.833 deg below the horizon (accounting for refraction).

How is Fajr time calculated?

Fajr is calculated when the sun is at a specific angle below the horizon, typically 15-18 deg depending on the calculation method. Common methods: MWL (18 deg), ISNA (15 deg), Umm al-Qura (18.5 deg), Egyptian (19.5 deg). This calculator uses a simplified 18 deg angle.

Why do fasting hours vary by location?

Fasting hours depend on sunrise and sunset times, which vary by latitude, longitude, and season. Near the equator, days are roughly 12 hours year-round. In higher latitudes, summer days can be very long (16+ hours) and winter days short (8 hours).

How do I calculate fasting duration?

Fasting duration = time from Fajr to Maghrib. Calculate both times for your location and date, then find the difference. For example, if Fajr is 4:30 AM and Maghrib is 7:45 PM, fasting duration is 15 hours 15 minutes.

What about extreme latitudes?

In far northern/southern regions, summer days may be extremely long or never have true night (midnight sun). Islamic scholars provide guidance for such locations, often recommending following times of nearest normal location or fixed durations (e.g., Mecca times).

Does fasting time change during Ramadan?

Yes, because Ramadan spans 29-30 days and the Islamic calendar shifts 10-11 days earlier each solar year. Daily sunrise/sunset times also change throughout the month. Fasting gets longer or shorter depending on whether Ramadan is in summer or winter.

What is Suhoor and Iftar?

Suhoor is the pre-dawn meal eaten before Fajr begins. Iftar is the meal to break fast at Maghrib. Suhoor should end a few minutes before Fajr (to be safe). Iftar begins immediately at Maghrib, traditionally with dates and water.

Do I need exact times?

Yes, precise prayer times are important for valid fasting. Using calculated times ensures you begin fasting after true dawn and break at proper sunset. However, this simplified calculator demonstrates concepts - use verified local timetables or Islamic apps for actual religious observance.

🧮
Ramadan Calendar Calculator
🧮
Iftar Time Calculator
🧮
Prayer Times Calculator
🧮
Qibla Finder