Hijri Month Determination in Southeast Asia: An Illustration Between Religion, Science, and Cultural Background.

This paper investigates the procedure for determining the new Hijri Month between Brunei, Indonesia, Malaysia, and Singapore. It endeavours to understand the reason for dissimilarity in terms of practice between these four nations in commencing Hijri Month of and despite sharing the same lunar crescent visibility criterion. This study is conducted through the examination of literature with regards to regulations of the lunar crescent visibility criterion between these countries.

Alteration of twilight sky brightness profile by light pollution.

The phenomenon of twilight has been stipulated as naturally dependent on the variables of solar depression, aerosol concentration and ozone composition. The unique color spectrum of twilight is attributed by ozone layer and aerosol, whereas its brightness is heavily relying on the altitude of sun below horizon. While all the natural dependence is being researched extensively, the impact of light pollution on the brightness of the twilight is not being explored thoroughly.