First Visibility and Prediction of the Lunar Crescent Brunei Darussalam

By Hazarry bin Haji Ali Ahmad | Powered by BruneiAstronomy.org

Hijri Year (e.g., 1447)

Or Gregorian Year

Parameters to Display:

CONSTELLATION SIGHTABILITY LONGITUDE DIFF. AZIMUTH DIFF. MOON DISTANCE MOON SEMI-DIAMETER V VALUE V ZONE

Default

First Visibility and Prediction of Hilal (Gregorian Year: 2026)

Location: Bandar Seri Begawan, Brunei Darussalam
(Latitude: 4°53'25.26", Longitude: 114°56'24.22", Altitude: 10m, Timezone: BNT)

HIJRAH YEAR	HIJRAH MONTH	NEW MOON / CONJUNC.	SUNSET	MOONSET	MOON AGE	MOON ALT	ELON.Geo	VISIBILITY ODEH 2005	neo-MABIMS
1447 H	Syaaban	Mon 19-Jan-2026 03:53:56	18:27:42.18	18:56:10.34	14:33:45.73	5°53'06.66"	7°33'32.09"	Optical Aid Only	Yes
1447 H	Ramadhan	Tue 17-Feb-2026 20:03:59	18:33:58.34	19:16:06.91	22:29:59.46	9°32'38.97"	11°31'04.90"	Optical / Naked Eye	Yes
1447 H	Syawal	Thu 19-Mar-2026 09:27:05	18:31:37.10	17:44:21.92	09:04:31.61	2°37'09.51"	5°25'03.20"	Not Visible	No
1447 H	Zulkaedah	Fri 17-Apr-2026 19:55:24	18:27:12.07	19:12:37.69	22:31:47.66	9°43'17.54"	13°46'28.03"	Naked Eye	Yes
1447 H	Zulhijjah	Sun 17-May-2026 04:04:07	18:27:30.81	18:59:05.40	14:23:23.78	6°16'19.37"	9°52'55.70"	Optical Aid Only	Yes
1448 H	Muharram	Mon 15-Jun-2026 10:56:48	18:33:16.50	18:51:05.13	07:36:28.83	3°21'18.33"	6°21'38.84"	Not Visible	No
1448 H	Safar	Tue 14-Jul-2026 17:45:40	18:37:56.74	18:39:08.52	00:52:16.99	0°11'22.28"	3°12'40.39"	Not Visible	No
1448 H	Rabiul Awal	Thu 13-Aug-2026 01:37:55	18:34:06.82	19:06:07.85	16:56:12.29	7°10'38.44"	9°26'46.47"	Optical / Naked Eye	Yes
1448 H	Rabiul Akhir	Fri 11-Sep-2026 11:27:25	18:22:10.77	18:27:32.36	06:54:45.69	1°05'58.06"	4°10'31.16"	Not Visible	No
1448 H	Jamadil Awal	Sat 10-Oct-2026 23:50:14	18:08:19.85	18:29:55.00	18:18:06.06	4°41'14.88"	10°03'51.68"	Optical Aid Only	Yes
1448 H	Jamadil Akhir	Mon 09-Nov-2026 15:02:36	18:02:00.37	17:55:33.15	02:59:24.65	-1°06'14.60"	5°07'00.21"	Not Visible	No
1448 H	Rejab	Wed 09-Dec-2026 08:53:05	18:08:21.55	18:19:33.64	09:15:16.32	2°05'25.12"	6°04'50.01"	Not Visible	No

This web application is an astronomical calculation tool designed for determining Hijri calendar months and assessing new moon (hilal / anak bulan) visibility. It will generate a timetable with the most comprehensive lunar crescent visibility predictions for Brunei Darussalam. It is based on complex astronomical calculations which provides detailed information on projected dates when the hilal (lunar crescent) is first expected to be seen from Brunei’s skies on the day of conjunction. Each lunation includes prediction on the new crescent’s visibility probability, V, developed by Mohammad Shawkat Odeh (2005). The neo-MABIMS (takwim Imkanur-Rukyah) visibility criteria (Alt ≥ 3°, Elong ≥6.4°) is also indicated by Y (satisfies) and N (does not meet).

Table Parameter Definitions

HIJRAH YEAR: The Islamic lunar calendar year being evaluated (e.g., 1447 H).
HIJRAH MONTH: The specific Islamic month corresponding to the lunation.
NEW MOON / CONJUNC.: The date and exact local time of the astronomical new moon (conjunction) when the Earth, Moon, and Sun align.
SUNSET: The local time the Sun drops below the horizon on the date of new moon observation.
MOONSET: The local time the Moon drops below the horizon on the date of new moon observation.
CONST (CONSTELLATION): The zodiac constellation in which the Moon is positioned when it sets.
SIGHT (SIGHTABILITY): The lag time (hh:mm:ss) that the lunar crescent remains above the horizon after sunset.
dLONG (LONGITUDE DIFF.): The difference in ecliptic longitude between the Moon and the Sun.
MOON AGE: The amount of time passed between the exact moment of conjunction and local sunset.
MOON ALT (MOON ALTITUDE): The apparent topocentric angular height of the Moon above the horizon at the exact moment of sunset.
dAZ (AZIMUTH DIFF.): The difference in azimuth (horizontal compass direction) between the Sun and the Moon at sunset.
ELON.Geo: The geocentric elongation, or apparent angular distance between the centers of the Sun and the Moon.
MOON DIST: The geocentric distance from the observer to the Moon, measured in kilometers.
SD (MOON SEMI-DIAMETER): The apparent angular radius of the Moon's disk.
V (V VALUE): A numerical value calculated using Odeh's 2005 visibility model, factoring in crescent width and arc of vision.
V ZONE: A categorization (A, B, C, or D) based on the V Value indicating the probability and method required to see the crescent.
VISIBILITY ODEH 2005: The descriptive prediction corresponding to the V Zone (e.g., "Naked Eye", "Optical Aid Only").
neo-MABIMS: Indicates "Yes" or "No" based on whether the crescent satisfies the regional visibility criteria (minimum altitude of 3° and elongation of 6.4°).

By default, first visibility dates and hilal parameters are generated for the current year. For other dates using Hijrah Year, first clear both input boxes, enter the respective input year and click "Generate & Apply". Current month is highlighted is green, and the next observation date from today is highlighted in yellow row.

This First Visibility and Prediction of the Lunar Crescent Brunei Darussalam webapp is developed by Hazarry bin Haji Ali Ahmad (webmaster@bruneiastronomy.org)

For detailed astronomical calculations, lunar crescent visibility analyses, and graphical Hilal simulation outputs, please refer to the Hilal Calculator.

Note: All dates are based on scientific modeling and do not replace official moon sighting declarations by government authorities.

Generated by bruneiastronomy.org/hilalcalc (Engine version 202611.12)