While the Jews adopted an algorithm-based lunar calendar at least a millennium ago, the Muslim world still finds the idea deeply polarising. Pak’s venture is interesting
On May 25, Pakistan launched its first official moon sighting website pakmoonsighting.pk. This came days after Pakistan released its first calculation-based Hijri calendar for the next five years, prepared by its Ministry of Science and Technology. Federal Minister Fawad Chaudhry has plans to launch a mobile application for moon sighting soon in line with several international apps on the subject.
The object of developing a calculation- based lunar calendar was to make the beginnings and ends of Hijri months independent of visibility of the new moon. Though the moon sighting stays in the news only thrice every year — the beginning of the Ramzan (the 9th and holiest month of Islam), end of Ramzan, and beginning of Dhul Hijjah (the 12th and final month in which both Hajj and Eid-ul-Adha take place) — it actually affects the beginning and end of every Hijri month. An Islamic republic like Pakistan diverts disproportionate amount of resources to fix those loose ends.
Pakistan’s meteorological department has 288 observatories, most of them located in rural and sequestered areas with the advantage of a clearer sky. These, apart from gathering meteorological data, also collect data on moonrise and setting. The department employs theodolite for observing the new moon. A theodolite is a precision instrument fitted with a movable telescope, which could turn in both vertical and horizontal directions. It can record the azimuth and altitude of the moon. But, as a study revealed, there was no case where theodolite had demonstrated proven advantage over naked eye.
The data on lunar visibility is passed over to Ruet-e-Hilal Committee (estd.1974), Pakistan’s official though non-statutory body, authorised to determine the beginning and end of a Islamic month based on evidence of moon-sighting. The committee is organised at three levels — national, zonal and district. Every 29th of a lunar month, the zonal/district committees meet at the camp offices of the Pakistan Meteorological Department. The main meetings happen for key events. For the rest of the year, their members join the meetings of zonal/district committees (vide answer to Oral Question No.13, Pakistan National Assembly, January 14, 2019). The committee also admits evidences from private persons in Pakistan on moon-sighting. Decisions are taken in accordance with the Islamic law.
The slender crescent of the new moon visible to the naked eye days after the conjunction is called Hilal in Arabic. Its visibility marks the beginning of a new Hijri month. The naked eye viewing (ruya in Arabic) nowadays includes optically-aided viewing, for instance, by telescope. It is not uncommon to see muftis and maulanas hunting for the moon on the western horizon immediately after sunset with their trendy telescopes. But this often leads to contrary decisions and split verdicts. The visibility, itself, is subject to a host of conditions like width of the crescent, position of the moon on its orbit round the earth which affects its apparent size, brightness of the background, meteorological conditions, altitude of the location and so on.
The time lag between the sunset and moonset, depending upon the season, varies between one to one-and-a- half hours, without the advantage of the night sky under any situation. The crepuscular game of moon-hunting is long over before the night sets in. There is no separate moonrise because during conjunction (amavasya) the positions of sun and moon on the celestial longitude coincide. In the days that follow, the angular distance between the two celestial bodies is extremely narrow. The moon is still lost in the glare of the sun. The 29th day of a Hijri month coincides with dwitiya tithi when the chances of lunar visibility are dicey. If the crescent is not visible that evening, a Hijri month is extended by one day, whereupon it automatically ends. The crescent not visible on 29th Ramadan means that Eid-ul-Fitr is delayed by another day. Days in Hijri calendar are either of 29 days or 30 days.
However, moon-sighting in Islamic nations is more of a religious than astronomical issue. This is evident from the proceedings of several moonsighting conferences, which this author has had the opportunity to pursue. For Pakistan’s new calendar, therefore, to pass the muster at the Council of Islamic Ideology (CII), a constitutional body was founded in 1962, which advises the government on whether a certain law is repugnant to the principles of Islam. The CII has already begun a consultation process but its chairperson Dr Qibla Ayaz has played his cards diplomatically by saying that the role of Ruet-e-Hilal, the official body on moon-sighting, should not be undermined. With many of the top Muslim clerics in Pakistan gone for Umra in Mecca, no decision is likely to be forthcoming soon.
The observation-based beginning of a lunar month was originally a Judaic practice. Prior to 70 AD, when ancient Israel existed, the Jewish grand council called Sanhedrin took a decision on the beginning of a new month based on evidence from various private persons. The Misnah Torah, a post-Biblical sacred book of the Jews, describes the process of rigorous examination of the witnesses who presented themselves at the Sanhedrin. The decision then used to be relayed to Jewish communities living in various parts of the eastern Mediterranean. But following the destruction of ancient Israel and dispersion of Jews across various lands, the old system of fixing dates became unviable. This finally led to growth of a perpetual Jewish lunar calendar based on algorithm. The tradition has it that the same was developed by Rabbi Hilel, the Jewish patriarch, in the middle of the fourth century AD. However, Prof Sacha Stern of University College (London), a contemporary authority on Jewish religious history, affirms that it dates back only to 10th or 11th century AD.
A key feature of this perpetual calendar is molad, literally meaning renewal or rejuvenation in Hebrew. It implies the new moon was mathematically derived, which replaced the system of observation.
However, the length of the lunation adopted by the founders of the calendar is fixed, whereas in reality the length of lunation varies due to eccentricity of moon’s motion. The mean length of synodic motion of moon is 29 d. 12 h. 44 m. 2.87s or 29.53059 days though its actual length can vary up to 13 hours on account of eccentricities and perturbations of the orbits of moon around the earth, and earth around the sun.
While the Jews made a smarter choice on lunar calendar at least one millennium ago, the Islamic world remains caught in a time warp. Determining new moon by observation is characteristic of elementary level of astronomy. It makes the whole calendar uncertain. Even when this practice was formalised in Islam, astronomy in the ancient world had advanced far enough to predict tithis and eclipses based on calculation. Today, we have GPS-enabled mobile apps like MoonCalc etc which places accurate data on lunar movement, position, phases, meridian crossing time on our very palms. There have been several attempts in the Muslim world to develop a calculation-based calendar, for instance, the Makkah Calendar. But these have only polarised the Islamic world. Pakistan’s calendrical venture needs to be watched with interest.
(The author is an independent researcher based in New Delhi. He is currently working on a book on calendar reforms. Views expressed are personal.)