By the Astronomical Society of Brunei Darussalam | Powered by BruneiAstronomy.org
| Date | Day | Imsak | Subuh | Sunrise | Doha | Zuhur | Asar | Maghrib | Isyak | Midnight |
|---|
Note: Generated times are based on astronomical formula as well as your location. For official prayer times (Waktu Sembahyang), please consult the relevant religious authority.
Calculation method and astronomical corrections: This application uses the high-accuracy procedure described in the supplied literature, Calculations of Prayer Times. The method states that, for high-accuracy prayer times, Fajr is calculated at a solar zenith angle of 108°, Sunrise and Maghrib use the Sun's semidiameter, atmospheric refraction, horizon dip and horizontal parallax, Dhuhr is obtained from the equation of time and longitude, Asar uses the variable Asar zenith angle together with the refraction correction, and Isyak is calculated at 108°.
Sunrise, Sunset and Maghrib: The zenith angle is calculated as: 90° + solar semidiameter + atmospheric refraction + elevation correction − horizontal parallax. The solar semidiameter is calculated from the Sun-Earth distance using the Appendix II expression, 0.2666° / R. Atmospheric refraction uses Equation [7], based on atmospheric pressure (mbar) and temperature (°C). The elevation correction uses Equation [8], D = 0.035333° × √h, and the horizontal parallax value of 0.0024° is included.
Asar: The Asar zenith angle is first obtained from the shadow-length factor (Standard/Shafi'i = 1; Hanafi = 2). Refraction then applies the altitude-dependent refraction calculation in Equations [6a] and [6b], and adds the resulting refraction to the Asar zenith angle using Equation [6c].
Solar position and iteration: The Sun's declination and equation of time are calculated using the Appendix II low-precision solar-coordinate equations. The calculation is iterated so that the solar declination is refined at the approximate prayer time. The literature notes that its Appendix II solar-coordinate formulas provide better than 1 arcminute precision for approximately year 1950–2050 AD.
Atmospheric inputs: Pressure and temperature are user inputs because refraction varies directly with atmospheric pressure and inversely with temperature. Default values are 1010 mbar and 27°C and may be changed to represent local observing conditions.
Doha: Select either Sun altitude above horizon (default 4.5°) or Sunrise + ⅓ (Sunrise − Subuh). The latter calculates Doha as one-third of the interval from Subuh to Sunrise, added to Sunrise.
Important: The literature gives 18° as the astronomical Fajr and Isyak criterion. The existing Brunei Darussalam calculation setting in this application is retained at Subuh 20° / Isyak 18°
Reference: Calculations of Prayer Times by Mohammad Shawkat Odeh, 2024 (revised 17th December 2024), with revisions, including Section 3 (Prayer Time Calculations), Section 4 (Factors Affecting Prayer Times), Section 5 (Summary of Prayer Time Calculations), and Appendix II (Computing Approximate Solar Coordinates and Equation of Time).
This prayer time web application is proudly developed by Hazarry Hj Ali Ahmad (webmaster@bruneiastronomy.org)