Khalid Chraibi

16 August 2008

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The sun and the moon follow courses (exactly) computed;” (Koran, Ar-Rahman, 55 : 5)

It is He Who made the sun to be a shining glory and the moon to be a light (of beauty), and measured out stages for it; that ye might know the number of years and the count (of time).” (Koran, Yunus, 10 : 5)

The ulamas do not have the monopoly of interpretation of the shariah. Of course, their advice must be sought in the first place on shariah matters. (But) they do no make religious law, in the same way that it is not the law professors who make the law, but parliaments.” (Ahmed Khamlichi, Point de vue n° 4)

Issue # 1: Why do Muslims observe the new moon to determine the beginning of months?

When the Messenger was asked by his Companions for a method to determine the beginning of the month of fasting, he told them to begin fasting with the observation of the new moon (on the evening of the 29th day of sha’aban) and to end fasting with the new moon (of the month of shawal). “If the crescent is not visible (because of the clouds), count to 30 days”. (1)

At that time, the Bedouins didn’t know how to write or how to count. They knew nothing about astronomy. But, they were used to observe the stars, at night, in order to find their way in the desert, and to observe the birth of the new moon to determine the beginning of months. The Messenger’s recommendation fitted perfectly with the specifics of their situation.

Issue # 2: Why is the new moon visible, after its birth, in some regions of the world only?

The new lunar month begins, for astronomers, with the monthly “conjunction”, when the Moon is located on a straight line between the Earth and the Sun. At that moment, the Moon is invisible. The lunar crescent begins to be visible only some 18 hours after the “conjunction”, and only subject to the existence of a number of favourable conditions relative to weather, time, geographic location, as well as various astronomical parameters (number of hours after conjunction; relative positions of the Sun, the lunar crescent and the observer; altitude of the moon at sunset; site of observation; limits of vision of the human eye…). (2)

Each month, the new Moon will be visible, at first, at some specific sites on Earth, before it can be seen elsewhere.

Issue # 3: Can we identify in advance the most favourable sites for the observation of each new moon?

Renowned Muslim astronomers, such as Ibn Tariq (8th c.), Al-Khawarizmi (780 ?- 863), Al-Battani (850-929), Al-Bayrouni (973-1048), Tabari (11th c.), Ibn Yunus (11th c.), Nassir al-Din Al-Tousi (1258-1274 ?), etc. devoted much attention to the study of the criteria of visibility of the new moon, with the objective of developing efficient techniques of forecasting of the beginning of a new month.

But, it’s only in recent times that some astronomers and information systems experts succeeded in developing procedures which make it possible to identify in advance, each month, the areas on Earth in which favourable conditions will exist for the observation of the new moon. Thus, in 1984, a physicist from Malaysia, Mohamed Ilyas, succeeded in drawing on the Earth map a “line of lunar date”, at whose west the crescent will be visible on the evening of the new month, whereas it won’t be seen, East of this line, until the next evening. (2) Today, detailed maps of the areas of visibility of the new moon are monthly drawn, well in advance, and published in such sites as « ». (3)

Issue # 4: Shouldn’t the observation of the new moon, wherever it is carried out, mark the beginning of a new month for all Muslims?

In theory, when the new moon is observed, this indicates the beginning of a new month for all Muslims in the areas in which the information is received. At the time of Revelation, when communications from one region to another were difficult, this rule applied essentially to the geographic areas which were proximate to the site of observation. But, today, with modern communication means, and instant transmission of news throughout the world, the area in which the rule could apply is much wider. (4) (5)

However, in order to demonstrate their sovereignty, most Islamic States generally proceed with their own monthly observation of the new moon (or, failing that, await the completion of 30 days) before declaring the beginning of a new month on their territory. Each State has defined its own applicable parameters and procedures in this matter, thereby adding to the complexity of the situation. (6)

Issue # 5: Since the lunar month can only have 29 days or 30 days, why is there a difference of two days (and sometimes even three days) in the celebration of the beginning of Ramadan or of eid al-Fitr in different countries?

Logically speaking, either a State will observe the new moon on the evening of the 29th day, or it will complete a count of 30 days. So, the beginning of a new month should differ by only 24 hours between the countries of the world.

But this is not verified, in practice. Thus, the 1st Ramadan 1428 corresponded to Wednesday 12 September 2007 in 2 countries; to Thursday 13 September in 40 countries; and to Friday 14 September in 9 countries. (7)

Similarly, the 1st Shawwal 1428, date of celebration of Eid al-Fitr, corresponded to Thursday 11 October 2007 in 1 country; to Friday 12 October in 33 countries; to Saturday 13 October in 23 countries; and to Sunday 14 October in 3 countries. (8)

Since different Muslim States determine different days for the beginning of the same month, they also reach the 30th day of the month on different days. Political and geostrategic considerations, as well as human errors in the observation of the new moon, also explain some discrepancies.

The Muslim astronomers who proceeded, in recent years, with in-depth studies of these issues reached the conclusion that the beginning of months that were announced by Islamic States over a period of several decades was often erroneous, for a number of reasons. (2) (9)

Issue # 6: Is the lunar calendar based on calculations a satisfactory alternative to the observation of the new moon?

The lunar calendar based on astronomical calculations has been in existence for some four millennia. It was already used by the Babylonians in the 18th c. B.C. Each lunar month begins, as was stated, at the time of the monthly “conjunction”, when the Moon is located on a straight line between the Earth and the Sun. The month is defined as the average duration of a rotation of the Moon around the Earth (29.53 days).

The lunation (period of time between two successive new moons) varies within a zone whose limits are 29.27 days at the Summer solstice and 29.84 days at the Winter solstice, giving for the 12 months’ year an average length of 354.37 days.

From an astronomical point of view, lunar months do not alternate between a length of 30 days and 29 days in succession. There are, at times, short series of 29 d, and at other times short series of 30 d, as illustrated by the length (in days) of the following 24 lunar months, corresponding to the period 2007-2008 :

« 30, 29, 30, 29, 29, 30, 29, 29, 30, 30, 29, 30, 30, 30, 29, 30, 29, 29, 30, 29, 29, 30, 29, 30 »

The astronomers formulated the convention, over two thousands years ago, that months of 30 days and 29 days would succeed each other, in order for two successive months to add up to 59 full days. This left only a small monthly variation of 44 minutes to account for, which added up to a total of 24 hours (i.e. the equivalent of one full day) in 2.73 years. To settle accounts, it was sufficient to add one day every three years to the lunar calendar, in the same way that one adds one day to the Gregorian calendar, every four years. The “tabular calendar” thus obtained includes 11 “abundant” years, with a duration of 355 d each, within a cycle of 30 years (years # 2, 5, 7, 10, 13, 16, 18, 21, 24, 26 and 29), whereas there are 19 « common » years, with a duration of 354 d each. (10)

Issue # 7: Why don’t Muslims use the lunar calendar based on calculations?

The Koran does not prohibit the use of astronomical calculations for the establishment of the calendar. At the methodological level, it merely specifies that the lunar year has only 12 months. (11)

But, based on the Messenger’s recommendation to the Bedouins to start and to end the fast of the month of Ramadan with the observation of the new moon, the Ulamas (Muslim jurists) developed a consensus to reject the use of calculations, based on the postulate that one shouldn’t go against the teachings of the Messenger (12). This consensus has lasted for 14 centuries.

The only exceptions were a handful of theologians, in the early years of Islam, who saw no contradiction between the Messenger’s teachings and the use of astronomical calculations to determine the beginnings of lunar months. (13) At the institutional level, the (shi’ite) dynasty of Fatimids in Egypt was the only State to use a pre-calculated calendar, over a period of two centuries, between the 10th and 12th centuries, before a change of political regime reactivated the procedure of observation of the new moon. (14)

Issue # 8: Does the hadith of the Messenger concerning the observation of the new moon establish an immutable rule of law?

Since the beginning of the 20th century, many Islamic thinkers have questioned the arguments presented against the use of calculations.

They consider that the Messenger’s recommendation to the faithful was merely adapted to the culture of the times, and should not be confused with the acts of worship (‘ibada). In their opinion, the hadith about observation did not establish an immutable rule of law, no more than it forbade the use of a calendar based on astronomical calculations. (4) (15)

They note that, over long periods of Islamic history, the hadith under discussion was not interpreted to mean the visual observation of a new moon, but only the acquisition of information, according to credible sources, that the month had begun. (16) This opens entirely different vistas in the discussion of this question.

They observe that Saudi Arabia’s Umm al Qura calendar (which is used for administrative purposes only) has been prepared for years based on the calculation of the schedules of sunset and moonset at the coordinates of Mecca, on the evening of the 29th day of each month. By convention, if the “conjunction” takes place before sunset at the coordinates of Mecca, and if the sun sets before the moon, this signals the beginning of a new month. Otherwise, the new month will begin on the next evening, after the completion of 30 days. (17) This procedure has little to do with the observation of the new moon.

They also note that Muslims find it perfectly licit to use the Gregorian calendar to manage all their activities, and have been doing so for centuries, without having any misgivings about it. Why should the use of the solar Gregorian calendar, based on astronomical calculations, be considered as licit, whereas the use of the lunar Islamic calendar, based on the same astronomical calculations, would violate Islamic religious prescriptions?

Issue # 9: Is it licit to use a calendar based on calculations?

Egyptian cadi Ahmad Muhammad Shakir (18) is the spokesman and the theoretician of this school of thought. He is a distinguished jurist of the first half of the 20th century, who was to become President of the Egyptian Supreme Court of the Shariah at the end of his career, and who remains to this day an author of reference in the field of hadith (19). He published, in 1939, a detailed legal opinion on the subject of the Islamic calendar, entitled: “The beginning of arab months… is it licit to determine it using astronomical calculations?” (20)

According to him, the Messenger took into account the fact that the Muslim community of his time was « illiterate, not knowing how to write nor how to count. » So, he recommended to its members to observe the new moon to carry out their religious duties at the time of fasting and hajj. But the community evolved considerably over time, and some of its members even became experts in astronomy.

According to the principle of Muslim law which states that « a rule is no longer applicable, when the factor which justified its existence has disappeared », the Messenger’s recommendation didn’t apply anymore to the Muslims, after they had learned to write and count and had ceased being illiterate.

Therefore, according to Shakir, contemporary ulamas commit an error of interpretation when they give to the Messenger’s hadith the same interpretation that applied at the time of Revelation, as if the hadith prescribed immutable rules. But, it has stopped being applicable to the Muslim community long ago, based on the principles of the shari’ah themselves.

Furthermore, Shakir refers to the principle of Muslim law according to which « what is relative cannot refute what is absolute, nor can it be preferred to it, according to the consensus of the ulamas. » The observation of the new moon with the naked eye is relative, and can be the subject of error, whereas the knowledge of the beginning of lunar months, based on astronomical calculations, is absolute, and belongs to the domain of certainty.

He observes that numerous distinguished Muslim jurists have taken into account astronomical calculations data in reaching their decisions. He concludes that there is nothing in the shari’ah which opposes the use of calculations to determine the beginning of all lunar months, in all circumstances, and not only in special situations, as had been recommended by some ulamas.

For Shakir, there can exist only one lunar month applicable in all countries of the world, based on astronomical calculations. This precludes the possibility that the beginning of the month should differ from one country to another. He adds that the use of the same pre-calculated calendar in all Muslim countries will give them an opportunity to celebrate all major Islamic events on the same day, throughout the world, thereby increasing their feeling of solidarity and unity as an “ummah”.

It should be noted that Shakir’s reasoning parallels some of Ibn Taymiyyah’s (1263-1328) own observations on this subject, developed centuries earlier. In a discussion of the hadith of the Messenger according to which the Bedouins can neither write nor count, and must thus avoid using (astronomical) calculations, Ibn Taymiya observes that the argument may have been justified at the beginning of the 7th century, but he questions whether it could still apply to Muslims centuries later, after they had been at the vanguard of development of scientific knowledge, including in the field of astronomy. (21)

In recent years, Yusuf al-Qaradawi, a distinguished jurist, who is also President of the European Council for Fatwa and Research (ECFR) became another well-known representative of this line of thinking. In 2004, he published an article entitled: “Astronomical calculations and determination of the beginning of months” (22) in which he expressed his full support for the use of calculations in the establishment of the Islamic calendar. Throughout his analysis, he quoted extensively and approvingly the major legal arguments developed by cadi Shakir in his 1939 study.

The advocates of the use of calculations gained in strength, in the last few years, when the « Islamic Society of North America » (ISNA), the « Fiqh Council of North America » (FCNA) and the « European Council for Fatwa and Research » (ECFR) announced, in 2006 and 2007 respectively, their decision to use, from then on, a calendar based on calculations. (23) They justified their decision using the same type of legal reasoning which was pioneered by Shakir and further developed by al-Qaradawi in their respective studies. (24) (25)

Notes :
(1) Al-Bokhary, Hadiths (3/119)
(2) Karim Meziane et Nidhal Guessoum : La visibilité du croissant lunaire et le ramadan, La Recherche n° 316, janvier 1999, pp. 66-71
(4) Allal el Fassi : « Aljawab assahih wannass-hi al-khaliss ‘an nazilati fas wama yata’allaqo bimabda-i acchouhouri al-islamiyati al-arabiyah », a report prepared at the request of King Hassan II of Morocco, Rabat 1965 (36 p.), with no indication of editor
(5) Abi alfayd Ahmad al-Ghomari : Tawjih alandhar litaw-hidi almouslimin fi assawmi wal iftar, 160p, 1960, Dar al bayareq, Beyrouth, 2nd ed. 1999
(6) Procedure of observation of the new moon by country
(7) The observation of the new moon of Ramadan 1428 by country
(8) The observation of the new moon of Shawwal 1428 by country
(9) Nidhal Guessoum, Mohamed el Atabi and Karim Meziane: Ithbat acchouhour alhilaliya wa mouchkilate attawqiti alislami, 152p., Dar attali’a, Beyrouth, 2nd ed., 1997
(10) Emile Biémont, Rythmes du temps, Astronomie et calendriers, De Borck, 2000, 393p
(11) In pre-Islamic Arabia, the Bedouins used a lunar calendar based on a year of 12 months. But they added to it, beginning in 412, a movable 13th month (whose concept was borrowed from the Jewish calendar), in order to make the month of hajj correspond to the autumn season. After major abuses were associated with these adjustments, the Koran set the number of months in the year to 12 and prohibited the intercalation of a 13th month. The Koranic verses are as follows:
(Koran 9: 36) “The number of months in the sight of Allah is twelve (in a year), so ordained by Him the day He created the heavens and the earth; of them four are sacred: that is the straight usage. So wrong not yourselves therein, and fight the Pagans all together as they fight you all together. But know that Allah is with those who restrain themselves”.
(Koran 9: 37) “Verily the transposing (of a prohibited month) is an addition to Unbelief: the Unbelievers are led to wrong thereby: for they make it lawful one year, and forbidden another year, in order to adjust the number of months forbidden by Allah and make such forbidden ones lawful. The evil of their course seems pleasing to them. But Allah guideth not those who reject Faith”.
(12) Muhammad Mutawalla al-Shaârawi: Fiqh al-halal wal haram (édité par Ahmad Azzaâbi), Dar al-Qalam, Beyrouth, 2000, p. 88
(13) Abderrahman al-Haj: « The faqih, the politician and the determination of lunar months » (in Arabic)
(14) Helmer Aslaksen: The Islamic calendar
(15) Sheikh Abdul Muhsen Al-Obaikan, a Councilor in the Ministry of Justice of Saudi Arabia, is clearly favourable to the use of modern technology to determine the beginning of months. He says : « Using the naked eye to determine the beginning and end of Ramadan is primitive in an age of modern science and technology. There is no other way to put it. It’s pure backwardness.” » (Anver Saad, « The Untold Story of Ramadhan Moon Sighting » Daily muslims, October 07, 2005)
(16) Al-Ghazali: ‘Ihya’e ‘ouloum addine’, quoted in al-Ghomari, p 30
(17) Van Gent : The Umm al Qura calendar
(18) Ahmad Muhammad Shakir (biographical notice in Arabic)
(19) An author of reference in the science of hadith (in French)
(20) Ahmad Shakir: « The beginning of Arab months … is it licit to determine it using astronomical calculations? » (published in arabic in 1939) reproduced by the daily « Al-Madina », October 13, 2006 (n° 15878)
(21) Ibn Taymiyyah: Fiqh azzakat wa asseyyam, Dar al fikr al ‘arabi, Beyrouth, 1996, p. 133 ff. and p. 142 : Ibn Taymiyyah has a good knowledge of the astronomical facts. He rejects the use of a tabular calendar, in which months alternate between 30 days and 29 days in sequence, with the addition of a day every three years approximately. He explains that this calendar does not truthfully represent the astronomical facts, because it does not take into account the existence of series of two or three months of 30 days in a row, and at other times series of two or three months of 29 days in a row, as they happen, but only adjusts for them in the framework of a 30 year cycle. (p. 142)
(22) Yusuf al-Qaradawi: « Astronomical calculations and determination of the beginning of months » (in arabic)
(23) Fiqh Council of North America: Islamic lunar calendar
(24) Zulfikar Ali Shah: The astronomical calculations: a fiqhi discussion
(25) These developments were detailed in an article published by on July 23, 2008 entitled: Khalid Chraibi: Can the Umm al Qura calendar serve as a global Islamic calendar?

References :
Helmer Aslaksen: The Islamic calendar Selected articles on the Islamic calendar

Islamic Crescent’s Observation Project (ICOP): Selected articles on the Islamic calendar
Mohamed Odeh: The actual Saudi dating system
Khalid Chraibi: Can the Umm al Qura calendar serve as a global Islamic calendar?
Khalid Chraibi: It is time for the Islamic world to replace lunar uncertainty with scientific facts (, September 5, 2007)