Will Ramadan begin on Wednesday or Thursday this year?

Dubai: Most Muslim countries are expected to attempt to sight the crescent moon marking the start of Ramadan on Tuesday, February 17, but astronomers say the sighting will be astronomically impossible or unfeasible across the Arab and Islamic world, making Thursday, February 19, the most likely first day of the holy month for the majority of countries that rely on confirmed moon sighting.

According to astronomical analyses based on all internationally recognised crescent-visibility criteria, the moon on Tuesday will not have moved sufficiently from conjunction to form a visible crescent, whether by the naked eye, telescope or even advanced astronomical imaging techniques, the International Astronomical Center (IAC) said. 

These conclusions are consistent across multiple peer-reviewed visibility standards, including those developed by Ibn Tariq, Fotheringham, Maunder, Bruin, Mohamed Ilyas, the South African Astronomical Observatory (SAAO), Yallop and Odeh. All indicate that crescent visibility on Tuesday evening is either impossible or not achievable anywhere in the Arab or wider Islamic world.

As a result, countries that require an authenticated crescent sighting to declare the start of the lunar month are expected to complete 30 days of Shaaban on Wednesday, with Ramadan beginning on Thursday, 19 February. Some countries that apply alternative criteria may declare Ramadan a day earlier, on Wednesday, 18 February, though this is expected to be limited.

Astronomers explain that the crescent’s invisibility on Tuesday is due to the moon’s position relative to the sun at sunset. In eastern parts of the Islamic world, the moon will set before the sun. In central regions, it will set simultaneously, while in western areas it will set only minutes after sunset, far too brief a window for the crescent to form and be observed.

Crucially, calculations in this case are based on the lower edge of the lunar disc, where the crescent would appear, rather than the upper edge commonly used in moonset calculations. This provides a more accurate measure of how long the crescent itself remains above the horizon.

In Jakarta, the moon will set six minutes before sunset. In the UAE, it will set one minute before sunset, while in Riyadh the lower edge of the moon will disappear 42 seconds before sunset. In Tabuk, where the moon’s presence will be longest in Saudi Arabia, it will set exactly at sunset, with a surface age of just one hour and 49 minutes, and a separation from the sun of only one degree. Similar conditions will be seen in Amman.

In Cairo, the moon will set two minutes after sunset, with a sun-moon separation of just 1.3 degrees, while in Algiers it will remain visible for only six minutes after sunset.

Under such conditions, sighting the crescent is ruled out by the Danjon limit, established by the French astronomer André Danjon, which demonstrates that the crescent cannot be seen, even with optical aid, if the angular distance between the moon and the sun is less than about seven degrees. All regions on Tuesday fall well below this threshold.

Even the most advanced crescent-imaging techniques, which use high-sensitivity astronomical cameras and real-time image processing capable of detecting the crescent in daylight, will not be effective on Tuesday. At best, the moon’s separation from the sun at sunset in the Arab world will be around two degrees, far below what is required for detection.

Historical records support this conclusion: there has never been a confirmed naked-eye sighting of the crescent at a separation below 7.6 degrees, nor a confirmed telescopic sighting below six degrees.

Adding further confirmation, the Earth will witness an annular solar eclipse on Tuesday afternoon, visible from southern Africa and Antarctica, coinciding with sunset across large parts of Asia. A solar eclipse is a visible conjunction of the sun and moon, and its occurrence underscores the impossibility of crescent visibility at that time or shortly afterwards.

Astronomers have therefore urged caution against false sighting claims that may emerge on Tuesday. Venus will be visible low in the western sky near the moon’s position, increasing the risk of misidentification, a phenomenon reported in past lunar observation campaigns.

Several countries, including Bangladesh, Pakistan, Iran, Morocco, Mauritania and parts of non-Arab Africa, will observe the crescent on Wednesday, 18 February, as it will be their 29th day of Shaaban. In these countries, Ramadan is expected to begin on either Thursday 19 February or Friday 20 February, depending on local sightings and weather conditions.

On Wednesday evening, conditions will be significantly more favourable. In Abu Dhabi, the moon will remain above the horizon for 58 minutes after sunset, with an age of 24 hours and 29 minutes. In Mecca, it will set after 59 minutes, aged 25 hours and 37 minutes. In Amman and Jerusalem, the moon will stay visible for 65 minutes, while in Cairo it will remain for 64 minutes. In Rabat, the moon will stay above the horizon for 73 minutes, with an age of nearly 30 hours.

Under these conditions, astronomers say the crescent should be easily visible to the naked eye in much of the Arab world, provided skies are clear.

For context, the shortest lunar stay above the horizon ever recorded for a confirmed naked-eye sighting is 29 minutes, while the youngest crescent ever seen was 15 hours and 33 minutes old. Even then, visibility depends on additional factors such as altitude above the horizon and atmospheric clarity.

Astronomers and jurists note that there is no religious obligation to attempt crescent sighting in regions where calculations show the moon has already set before sunset. This position was endorsed at the Second Emirates Astronomical Conference, which concluded that when astronomy definitively establishes the moon’s absence from the sky, attempting to sight it serves no practical or religious purpose.

This view has also been supported by prominent scholars, including Sheikh Abdullah bin Mani’, a member of Saudi Arabia’s Council of Senior Scholars, who has long argued that definitive astronomical knowledge should be taken into account in such cases.