Lunar Crescent Marathon

Here’s our cosmic idea for school holiday activities – Lunar Crescent Marathon!

Go out to look for the daily changing moon crescent in early morning, before sunrise, on May 27 until Jun 02 2019 for the Waning and Old Crescent in the Eastern sky. Continue your observation on evening of June 04 until June 10 2019, shortly after sunset, for the New and Waxing Crescent in the Western sky.

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New Lunar Crescent of Syawal 1437 seen from Brunei

Bandar Seri Begawan – July 05, 2016. A group of members of the Astronomical Society of Brunei Darussalam was at the Agok Hill in Tutong for the moonsighting to observe the new moon of Syawal 1437H. The western sky was partly cloudy especially new the horizon with the sun set behind the clouds on that evening. At about 15 minutes after sunset, at the clouds break, the 24 hour old hilal was firstly visible through telescopes and CCD Camera at around 6.52 pm. Continue reading “New Lunar Crescent of Syawal 1437 seen from Brunei”

Basis for Using the Rukyah Method for Determining the Arrival of Ramadan and Syawal in Brunei Darussalam

By Dr. Mohd Shukri Hanapi1 & Dr. Shahir Akram Hassan

Source: Journal of Islamic Studies and Culture December 2015, Vol. 3, No. 2, pp. 13-22 ISSN: 2333-5904 (Print), 2333-5912 (Online) Copyright © The Author(s). All Rights Reserved. Published by American Research Institute for Policy Development DOI: 10.15640/jisc.v3n2a2 URL:


There are various methods used to determine the arrival of Ramadan (fasting) and Syawal in South East Asia. Malaysia and Indonesia use the rukyah (sighting of the moon) and hisab (mathematical calculations), Singapore uses the hisab while Brunei only uses the rukyah method. These differences are due to the different basis for using a certain method to determine the arrival of Ramadan and Syawal. The basis here refers to religious references and forms of istidlal (inferences). The question is, what religious references are used to substantiate the adoption of the rukyah method in Brunei? What is their form of istidlal based on the religious references? To answer all these questions this study has two objectives. Firstly, it intends to determine the religious references that act as the basis for using the rukyah method in Brunei. Secondly, to analyse the different forms of istidlal based on the religious references. In order to achieve these objectives, this qualitative study used library research and expert interview methods for collecting data. All the data were analysed using the content analysis method. Lastly, this study concluded that religious references from the al-Qur’an and Hadith used as a basis for applying the rukyah method in Brunei is similar to the religious references used as a basis for applying rukyah and hisab in other South East Asian countries. The only difference is the various forms of istidlal.

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First Sightings of Lunar Crescent 2015-2019 for Brunei Darussalam

First Sightings of Lunar Crescent 2015-2019 for Brunei
First Sightings of Lunar Crescent 2015-2019 for Brunei (Click on the image for a larger version)

The table above provides the dates and concise data to hunt for the youngest possible lunar crescent in this country, which is a very challenging activity.

First sighting of the new crescent moon is used as the basis of various calendars to signal the start of the new month. For instance, Islam requires that the sighting of the the new crescent moon should be made with the naked eye.

Predicting the first sighting of the new crescent moon has been attempted since the time of the Babylonians. These ancient methods relied on the age of the Moon and the time difference between moonset and sunset. More modern methods use the angular separation of the Sun and Moon, the altitude difference between the Sun and Moon, their relative azimuths and the width of the crescent.

Guidelines on using the table.
Guidelines on using the table.

The following table shows the dates of possible first sighting of new moon crescent (in Arabic known as hilal) for Brunei Darussalam. These dates are colour-coded based on the moon altitude and a crude prediction of the new moon sighting can be related as follow:

1. Red that indicates the moon altitude which is less than 2°. A very slim chance of visibility due to low altitude.
2. Orange that signifies the moon altitude between 2° and 5.5°. There is a slim chance of crescent visibility. However visibility might be improved with the use of optical aids and excellent atmospheric conditions.
3. Yellow that the moon is at altitude between 5.5° and 7.5°. There is a good chance that the crescent is visible to the naked eyes under excellent atmospheric conditions.
4. Green that shows the moon’s altitude is more than 7.5°. The lunar crescent is positioned reasonably high above the horizon making it easily visible to the naked eye.

If you manage to sight the crescent on the dates provided, please share your experience and photos via

More info: Jadual Kenampakan Pertama Anak Bulan Di Negara Brunei Darussalam 2000 – 2099