How prayer times are calculated: the 18° angle, Hanafi Asr and district differences

Prayer times follow the sun, so for a given place and date they can be worked out in advance. For questions of religious ruling, follow your local mosque or the Islamic Foundation; this guide covers only the calculation.

What the six times mean

• Fajr: first light at dawn (subh sadiq); in the calculation, the sun 18° below the horizon. It lasts until sunrise.
• Sunrise: the sun’s first edge appears. Not a prayer time; it marks the end of Fajr.
• Dhuhr: the sun has passed its highest point; here, one minute after solar noon.
• Asr: an afternoon shadow reaches a set length (see below).
• Maghrib: the sun has fully set.
• Isha: the evening glow has gone; in the calculation, the sun 18° below the horizon.

The prayer times on bdrate.fyi are calculated for each of the 64 district headquarters with the Karachi method (University of Islamic Sciences, Karachi), the one in common use in Bangladesh, Pakistan, India and Afghanistan.

What 18° and Hanafi Asr mean

The sun 18° below the horizon is the edge of astronomical twilight; beyond it the sky is, in practice, fully dark. So in Bangladesh Fajr comes about 1¼ to 1½ hours before sunrise, and Isha the same after Maghrib. Some methods use 15° or 19.5°; a smaller angle means a later Fajr and an earlier Isha.

Asr is about shadows. Even at noon a 1-metre stick casts a short shadow, say 0.3 m.

• Shafi’i, Maliki and Hanbali view (often labelled “standard”): Asr begins when the shadow is the stick’s length plus the noon shadow, 1.3 m.
• Hanafi view: twice the stick’s length plus the noon shadow, 2.3 m.

Most Muslims in Bangladesh follow the Hanafi school, so the site shows Hanafi Asr. The gap is large: in Dhaka on 5 November 2026, Hanafi Asr is at 3:41 pm, the other at 2:54 pm. It ranges from about 45 minutes in winter to about 80 in summer.

Between districts: earlier in the east

The earth turns 360° in 24 hours, 4 minutes per degree of longitude, so the sun rises and sets earlier further east. Bangladesh spans 88°01’ to 92°41’ east, about 4.7°, so its two ends are about 19 minutes apart. Chapainawabganj is the westernmost district headquarters and Bandarban the easternmost. On 5 November 2026:

Latitude matters too: winter days are a little shorter further north, so Sylhet’s Maghrib comes before Bandarban’s. And at this latitude a degree of longitude is about 100 km, so within a district times shift roughly a minute for every 25 km east or west.

Through the seasons

Dhaka in 2026 (other years are almost the same):

The earliest Maghrib and latest Fajr miss the shortest day because solar noon itself drifts: the earth’s tilt and elliptical orbit put it about 16 minutes ahead of its average in early November and 14 minutes behind in February.

Why a mosque or the Islamic Foundation may differ

• Jamaat: a timetable shows when each prayer’s time begins; the azan and jamaat usually come later, set by each mosque.
• Place: the site calculates for the district headquarters. For Ramadan 2026 the Islamic Foundation issued separate timetables for the 64 districts, setting sehri by each district’s eastern edge and the Fajr azan and iftar by its western edge. So its sehri is a little earlier and its iftar a little later: in Dhaka on 19 February 2026 it gave sehri ending at 5:12 and iftar at 5:58, against this site’s Fajr 5:13 and Maghrib 5:56.
• Precaution: the Foundation’s timetables used to end sehri 3 minutes before subh sadiq, start Fajr 3 minutes after it and put iftar 3 minutes after sunset. In February 2025 it said the new timetable drops these extra minutes, and anyone may add caution on their own account. Older printed calendars can therefore differ by a few minutes.

Sehri and iftar

The Foundation says the end of sehri in its timetable is essentially the start of Fajr. Iftar is at Maghrib, that is, sunset. So each district page under prayer times shows Fajr as the end of sehri and Maghrib as iftar, with a table for all of Ramadan. Its dates follow the Umm al-Qura calendar; in Bangladesh Ramadan may start a day later, depending on the moon sighting. To be safe, finish sehri a few minutes early.

Sources

• Banglapedia: Bangladesh (latitude and longitude)
• PrayTimes.org: how prayer times are calculated, and the two Asr views
• Wikipedia: Salah times (definitions and the Karachi method)
• Wikipedia: Islam in Bangladesh
• US National Weather Service: definitions of twilight
• AMSI: longitude and time and Wikipedia: Longitude
• EarthSky: the equation of time
• Desh Rupantor: the Islamic Foundation on its sehri and iftar timetable (27 February 2025, in Bangla)
• Desh Rupantor: Ramadan sehri and iftar timetable published (22 January 2026, in Bangla)
• Khobor Sangjog: sehri and iftar timetable published (26 January 2026, in Bangla)
• Ittefaq: this year’s Ramadan sehri and iftar timetable (19 February 2026, in Bangla)
• Islamic Foundation Bangladesh
• Times for specific dates: this site’s own calculation (Karachi method, Hanafi Asr, district headquarters)