Different Criteria, One Problem

The Middle East countries, Saudi Arabia and UAE make use of advanced optical devices to sight very young new waxing crescents which shall otherwise be impossible for professionals/ sky gazers to pick with naked eyes. In contrast, the moon sighting committees in the countries of Indian subcontinent use the shariah-compliant method of physical sighting of the new waxing crescent, with unaided eyes, or with the help of minor optical aid, to declare the commencement of a new lunar month. The result of this practice of using different methods for the same problem-solving by Muslim countries is utter state of confusion as the same lunar month starts on two different Gregorian dates in different Muslim countries. The commencement of Ramadhan-1446 AH/2025 CE is the best example to illustrate the point.

Babylonian criterion for physical sighting of new waxing crescent

Around 500 B.C., the Babylonians had developed a simple criterion for the earliest sighting of new crescent and it stands highly useful even today. The criterion makes use of the following two astronomical thresholds for possible moon sighting:

1. That, at the time of local sunset, the age of the waxing crescent is 24 hours or more and
2. That the moon sets minimum 48 minutes after the local sunset.

Let us workout the commencement of Ramadhan-2025 in various subcontinental and middle eastern countries using the Babylonian Criterion.

Conclusion: For all the subcontinental cities projected above, the two critical parameters required for a successful naked eye sighting of young waxing crescent i.e. age of crescent and moonset-after-sunset time lag are both well below the requisite values of 12 hours and 48 minutes respectively. Hence the crescent shall not be sighted in the evening of 28.02.2025 in all these cities and Ramadhan-2025 shall not start on 01.03.2025. The holy month shall start a day later on 02.03.2025.