Ramadan is determined by sighting of crescent moon. For the moon to be visible, the moon must set after the moon When is the first crescent moon? Three methods: - calculation of ijtima ( sun moon geocentric conjunction) - time of sunset - position of sun - position of moon at sunset In the book Kitab ad-Dur al-Aniq (by KH. Ahmad Ghozali ) is included in the category of the tahqiqi bi at-tadqiq method with a very long algorithm and several corrections so that it gets very accurate results. 2 Rukyat (observation) 2023: 2020: 2018: Crescent moon watch How to sight new crescent moon RMG Yallop visibility IMCCE for 2023 Aljazeera Lembago New criteria Hukumonline using Jean meeus algorithms Implement astronomical algorithms Hisab awal bulan hijriyah metode kitab ad-durr al aniq Prayer times Sciencedirect UTHM BRIN @OIFUMSU brunei astronomy brunei Darussalam FB Astrotalk Islam calendar backg...