إثبات دخول الشهر القمري برؤية الهلال أو بالحساب الفلكي؟

Proof of the start of the lunar month; By sighting the crescent or by astronomical calculation?

Abstract

In Islamic Sharia, many worships are associated with lunar dates, such as Ramadan fasting, Eids and Hajj. To determine the time of these worships, it is necessary to determine the beginning of the lunar month. In ancient times, the beginning of the lunar month was determined only by sighting the moon, but in modern times, as science has progressed in all other fields, it has progressed in astronomy to the extent that Before the moon rise, it is even known when the moon will be born and when it will appear on the sky of any country. It can be said about most of countries that sighting the moon will be possible on their sky on this date.

This is an issue that we come across several times a year. In days of Ramadan and Eids, it becomes a burning issue whether the beginning of the Islamic month should be determined by sighting the moon or a calendar should be arranged according to the opinion of astronomers in which the dates of Ramadan and Eids etc are fixed.

The following article explains in detail which of the two is the correct opinion. Can a calendar arranged by astronomers be adopted for determining the beginning of the lunar month? If so, to what extent? And what are the things where it is necessary for us to see the moon instead of following this calendar?