What you need know about sighting crescent in Islam

Egypt Today

08-04-2025

Crescent Moon- CC via Steffen und Christina
CAIRO – 3 April 2025: The moonsighting for Eid Al-Fitr (the Feast of Breaking the Fast) this year sparked controversy among Arab nations, especially on social media, after disagreements regarding the visibility of the crescent of Shawwal—the tenth month of the Islamic calendar.
Egypt, along with countries like Jordan and Syria, declared that the crescent of Shawwal was not sighted on March 29, meaning the first day of Shawwal would fall on March 30. This moonsighting marks the beginning of the four-day Eid al-Fitr celebrations.
Meanwhile, Saudi Arabia, other Gulf states, and Palestine announced that the crescent was sighted on March 29, declaring March 30 as the first day of Eid al-Fitr. Saudi Arabia relied on naked-eye observations at ten different sites, as reported by Al-Arabiya Net on March 29.
The disagreement among Arab countries sparked controversy over which side was more accurate. This raised questions about how moonsighting should be accurately calculated, and why different countries have their own systems for observing the crescent. This confusion stands in contrast to the widespread practice of other nations following Saudi Arabia's moonsighting for Eid al-Adha (the Sacrifice Feast).
In Islam, the start of a new Islamic (Hijri) month is determined by the sighting of the crescent at the sunset of the twenty-ninth day of the preceding Hijri month. To mark the beginning of the new month, two conditions must be met: First, the crescent moon must have been born at least four hours before sunset on that day. Second, the new crescent must remain visible above the horizon for no less than five minutes. This practice is followed by the Egyptian Survey Authority (ESA), the official body responsible for calculating the start of the Hijri months, according to Amir Hussein Hassan, professor in the National Research Institute of Astronomy and Geophysics, in comments to Egypt Today. He further explained that in Islam, a day begins at sunset and lasts until sunset of the following day, encompassing a full night and a full day.
Visually or scientifically?
Some countries, like Saudi Arabia, rely mainly on naked-eye sightings of the crescent, adhering to the approach practiced during the era of Prophet Muhammad (Peace and Blessings Be Upon Him), while other countries depend on scientific astronomical calculations. This difference in approach has given rise to questions regarding methods of sighting the new crescent.
Prominent scientists from the past century argue that when visual sighting conflicts with scientific calculations, the latter should be prioritized. This is because eye-naked sighting can be speculative, influenced by various obstacles such as natural and industrial pollutants, whereas scientific calculation is definitive, Hassan clarified.
"As for the so-called 'eye-witnessing' method, it should only be applied when there is no reliable scientific method available to calculate the start of the months," he continued. Hassan said the basis for the moonsighting is to rely on astronomical calculations in accordance with evidence from Quran and Sunnah (Prophet Muhammad's sayings, and deeds [PBUH]). He elaborated that Islam does not restrict moonsighting to visual observations, but encourages the use of science and calculations. He explained that the practice of visual sighting was used at the beginning of Islam because the Arabs at that time did not have the advanced astronomical knowledge they possess today.
As Muslims became more aware of scientific advancements, he said, it became essential to prioritize the use of such advancements, as supported by a hadith in Sahih Muslim, where the Prophet Muhammad (PBUH) said: 'Do not fast until you see the crescent, and do not break your fast until you see it. If it is obscured from you, then calculate for it.' Hassan also referenced a Quranic verse from Surah Ar-Rahman, where Allah says: 'The sun and the moon follow courses that are exactly computed.'
He continued that the Noble Quran has several verses about astronomically-based calculation and how it works precisely. Allah says in Surah Younus (Jonah) 'He is the One who rendered the sun radiant, and the moon a light, and He designed its phases that you may learn to count the years and to calculate. GOD did not create all this, except for a specific purpose. He explains the revelations for people who know,' -Khalifa's translation of the meaning of Noble Quran.
Furthermore, Hassan cited a report by former Egyptian Judge Mohamed Ahmed Shaker on the Islamic months, which emphasized that scientific calculations are definitive and reliable, unlike the naked-eye observations. He stressed that scientific calculations should be applied in the moonsighting process, noting that this method helps avoid errors caused by factors like air pollution.
Unified Islamic Calendar
The recent disagreement among Arab countries has reignited discussions about the possibility of a unified Islamic calendar among Muslim nations.
Hassan stated that while the idea of a unified Islamic calendar for moon sighting is a positive initiative, it is quite difficult to implement. He explained that Islamic countries are located on opposite sides of the Earth, with each country lying at different latitudes and longitudes. "A unified Islamic calendar is challenging and may even be impossible," he said. Additionally, some countries may observe the moon below the horizon at sunset on the 29th day of the lunar month, while others may see it above the horizon.
In the Hijri year 1446, the moon was sighted above the horizon in some countries, such as those in the Middle East, while it was below the horizon in other countries, such as Indonesia and Malaysia. "The difference in these sightings is acceptable," Hassan explained. However, he pointed out that the real issue lies in the disagreement that may occur among countries that have observed the moon above the horizon, so this disagreement is unacceptable.
"Calculations remain the foundation of the process, and it will continue to be applied," Dr. Hassan concluded.