The phases of the Moon are formed independently of the Earth’s rotation on its axis. Even if the Earth were to stop rotating, as long as the Moon continues orbiting the Earth, the lunar phases would still occur. Thus, the lunar phases are, in essence, a global astronomical phenomenon. Meanwhile, the visibility of the crescent moon (hilal) is a local astronomical phenomenon, influenced by the Earth’s rotation. Read more https://en.muhammadiyah.or.id/scientific-arguments-of-the-unified-global-hijri-calendar/