Implikasi Penggunaan Sistem Perhitungan Aboge dalam Penetapan Awal Bulan Hijriah

This paper aims to examine the implications of using the Aboge calculation system for the determination of the beginning of the Hijri month, especially the beginning of the month of Ramadan, Syawal and Dzulhijjah with a comprehensive library research. Based on the analysis of the data obtained by the content analysis method, this paper found that the use of the Aboge calculation system has implications for 2 (two) aspects, namely from astronomical aspect and Islamic law aspect. From the astronomical aspect, it shows that the Aboge calculation system is a system of calculating the beginning of the Hijri month with the hisab urfi method which must make adjustments to match the calculation of the Hijri calendar, but this adjustment is not made so that it will have implications for a difference of 1 day every 120 years. It can even be up to a difference of 10 days over a period of 1200 years. As for the Islamic law aspect, the use of the Aboge calculation cannot be used as a basis for determining the beginning of the hijri month, because the calculation of Aboge is based on the average circulation of the Moon around the Earth. What can be used to determine the beginning of the hijri month is a calculation based on the actual circulation of the moon around the Earth.