ISLAMIC CALENDAR DEVELOPMENT
IN NORTH AMERICA

Syed Khalid Shaukat

Every calendar except one, at any time in the entire history of the world, has had to make corrections by either adding or subtracting time. The Jewish, Chinese, or Hindu calendars add a thirteenth month periodically, to bring the lunar calendar in line with the solar calendar. This is called "intercalation" or "Nasi" (in Arabic). Two kinds of Nasi were in practice at the time of Prophet Muhammad (PBUH). One was inserting a thirteenth month, and the other was transposing a sacred month with another for certain social or political advantages. During the Prophet's farewell message, two revelations regarding the Islamic calendar were given to humankind.

(Qur'an, 9:36): "Number of months in sight of Allah is twelve (in a year). So ordained by Him, the day He created the heavens and the earth."

(Qur'an, 9:37): "Verily the transposition (of a prohibited month or intercalation) is an addition to Unbelief."

This indicates that the use of a calendar with intercalation is against nature and disliked by Allah (SWT). Intercalation of a month is used by the Jewish, Chinese, and Hindu calendars, while Gregorian calendar uses intercalation of days in several months to increase the number of days to 30 or 31. The one calendar that does not add or subtract time is the Islamic calendar. Despite the figures presented by some calendars, the reality is that among all the prevailing calendars in the world the Islamic calendar is the oldest in practice in its original form without any correction or modification. The year 5757 of Jewish calendar or the year 1997 of the Gregorian calendar should not mislead one. These calendars have had adjustments of adding or subtracting days or months. The Gregorian calendar was last corrected replacing the Julian calendar by dropping ten days in the year 1582 CE in the Catholic world, or by dropping 13 days in the year 1752 CE in England, and its colonies including the United States.

The Islamic calendar, because of its inherent cycles of the visible crescent, does not require any corrections, and has remained intact in its principle since it was given to mankind by Allah (SWT) through His Messenger, Prophet Muhammad (PBUH). Thus, there is a definite need to develop an Islamic calendar. The guidance regarding the reckoning of time, comes from Qur'an, and Hadith. The Qur'an says:

(Qur'an, 10:5): "It is He who made the sun a radiance and the moon a light and determined their stations that you might know the number of years and reckoning of time."

(Qur'an, 36:39): "Neither the sun may reach the moon nor night will precede the day...each in special orbit is swimming around according to its law."

(Qur'an, 2:189): "They ask you about the crescent moons, say: they are signs to mark fixed periods of time for the people and for pilgrimage."

Thus, in the Islamic calendar the visible waxing crescent moon marks the beginning of each new month, and there are 12 months in a year. The year count started from the year of the Messenger's migration to Madinah. According to Abu Hurayra, the Messenger said: "Fast to its sighting (ru'yah) and break your fast to its sighting, and if it is obscured to you by clouds, then count the month to thirty days." (Bokhari and Muslim). The word ru'yah has been used in the language of the Qur'an for "vision" by knowledge.

This is evident (Qur'an, 105:1): "See thou not how thy Lord had dealt with the people of the elephant?" and (Qur'an, 99:6): "See thou not how thy Lord dealt with the 'Ad people?" Here, Allah is questioning the Messenger; "Do you not know?" "Are you not aware of?" etc., while the Messenger was not even born at the time of the people of the elephant or the people of 'Ad. Therefore, the Hadith may mean "Fast to the vision (by eye or by knowledge) of the new crescent." Moreover, the same concept (absolute knowledge) is precisely what Muslims have used for centuries to determine the daily prayer times by calculations, despite the fact that in the past Muslims used direct vision of the sun, the simplest and only method available at the time, to ascertain the prayer times. However, with the advent of the clock and wristwatch, no longer does a Muslim go out to check whether an object's shadow has reached its length or whether the sun has gone below horizon. Instead, he simply looks at his watch and uses prayer times (calculated years in advance). Thus, observation by direct vision was not the criterion; rather, it was merely a means of attaining certainty. In other words, the method has changed (the use of calculation) while the basis for prayer times (the solar position) has not. All the Muslims accept this methodology without hesitation or argumentation.

The same principle may be applied to the precise orbit and rotation of the moon since both the sun and the moon move with sufficiently known precision. Furthermore, the Messenger warned his companions that they were unlettered people who could "neither read nor count" (Hadith, Muslim) and that they must therefore prefer to sight the moon rather than calculate its position although if the day were cloudy, they could calculate it by counting 30 days from the previous crescent. Later, when the Islamic civilization flourished. Muslims could do more than count and write. They invented spherical astronomy and with the advances in astronomy and computer technology Muslims are now able to calculate the dates when a new crescent could be sighted, and when it is impossible to sight the moon. When sighting was more reliable than calculation, the Ummah was told to rely on sighting. Today calculation is more reliable than sighting, hence, that should be used.

Lunar Crescent Visibility

Muslim astronomers have worked on this subject from 700 CE to the present.

Among early Muslims the contributions made by Habash al-Haasib (740-840 CE). Muhammad ibn Musa al-Khwarizmi (830 CE), al-Farghani (850 CE), Muhammad ibn Gabir al-Battani (850-929 CE), and Abu Rayhan al-Biruni (11th century CE) are worth noting. In recent times, especially during the last three decades, scientists and astronomers both Muslims and non-Muslims have diligently worked to develop algorithms to calculate the expected dates for moon sighting. E.S. Kennedy (The lunar visibility theory of Ya'qub Ibn Tariq. Journal of Near Eastern Studies, 27, 126; 1968.) documented the work on the lunar visibility theory of Ya'qub Ibn Tariq of 8th century CE. F. Bruin, (The first visibility of the lunar crescent, Vistas in Astronomy, 21, 331-358, Pergamon Press, 1977) explained the first visibility of the lunar crescent, giving a good scientific perspective for the problem. S. K. Abdali, (On the crescent's visibility. Al-Ittihad, January-July 25-31, Muslim Students' Association, Plainfield IN, 1979) presented his views on crescent's visibility analyzing some of the work done by others. Dr. Muhammad Ilyas (A modern guide to astronomical calculations of Islamic calendar, times, and Qibla. Berita Publishing Sdn. Bhd., Kuala Lumpur, 1984) developed a few preliminary concepts for developing crescent visibility algorithm. D. A. King (Ibn Yunus on lunar crescent visibility. Journal of History Astronomy, 19, 155-168; 1988) wrote a paper on the work of Ibn Yunus on lunar crescent visibility. Ilyas (Astronomy of Islamic times for the twenty-first century. Mansell Publishers, London, 1989) presented his further work on lunar visibility and Islamic calendar. Yallop of Royal Greenwich Observatory (RGO) with his criterion of azimuth and altitude has been producing annually an RGO sheet showing the place of first visibility for every lunation. Ithaca, New York based Dr. Omar Afzal has been refining his criterion from 1979 onwards by collecting information on moon sighting from all over the world through the Committee for Crescent Observation.

With the benefit of the work done by these notable scientists, the author carried on this research further by compiling published crescent observation data from 1859 to 1990 CE, and data collected by the Committee for Crescent Observation from 1979 to the present. A database for crescent observation containing over 800 data points for sighting or non-sighting was analyzed with the algorithm developed by the author. All the important parameters that affect visibility were calculated for every single observation including arc of light (elongation), moon's topocentric altitude above horizon (which includes the effects of atmospheric refraction, the semi diameter of the moon, and the parallax correction), width of crescent, distance of the moon from the earth, and distance of the earth from the sun. Having calculated these parameters for all the analyzed data, a correlation was established for the threshold values that make a crescent visible. An algorithm (Shaukat's criterion) is thus developed (1988-1997 CE) to calculate visibility curve (Lunar Date Line) on the map of the world. This algorithm predicts the visibility of the new crescent better than the criteria developed by others (Yallop, Schaefer, Ilyas, Abdali and Afzal). Shaukat's criterion has proven to match with actual sighting every month since August 1992, as documented by an independent periodical "Islamic Perspectives," published monthly by Washington DC chapter of Islamic Circle of North America (ICNA), Shaukat (Moon sighting: Hand in hand with calculations. Islamic Horizons (January/February, 37, 1995) showed how did the calculations go hand in hand with actual sighting. In another article, Shaukat (1995) provided a review on a book written by Ilyas (New moon's visibility and International Islamic calendar for the American region. The American Journal of Islamic Social Sciences. 12 (2), 279-284), "New Moon's Visibility and International Islamic Calendar." Shaukat (Islamic Lunar calendar, Insight, a Quarterly Journal, 11 (2 & 3), 15-17. Islamic Foundation for Education & Welfare, Sydney, Australia. 1996) provided a sound basis for the development of an Islamic lunar calendar.

Development of Islamic Calendar

The continuous efforts by the author in the last two decades for refining the visibility criterion have reached to a point where sufficient agreement exists between actual sighting and calculations for sighting. This criterion can now be used to prepare Islamic calendar for a specific region. Thus, using this concept, a regional Islamic calendar for North America is calculated and presented here. In such calculations, there is a small percentage of uncertainty (about once a year on an average) when the visibility curve falls just west of California, in which case, a note can be added in the calendar indicating that although it is improbable to see the moon on that evening, there is a small chance that the moon could be sighted on West coast of North America on that day. Only for such a case, we have to wait for sighting confirmation; but for all other months the calculations of sighting are quite definite without ambiguity, and we do not have to wait for sighting, although the sighting would eventually be confirmed.

Table 1 shows Gregorian dates for the first day of Islamic months with the convention that Islamic date begins on the evening before the Gregorian date shown. This is based on the visible crescent moon assuming North America as one horizon (Matla').

Table 1

Islamic Calendar for North America

* very small chance that the first day of Islamic month may be on the day before.

In the modern age of communication, we all need to plan, schedule, and announce various religious occasions. Islamic calendar based on calculations of sighting that has proven to be sufficiently accurate for practical purposes would compel us to start the Islamic months correctly without chaos and confusion. Calculations for a visible crescent meet the intent of Shari'ah, and are effective means for producing an Islamic calendar for any defined Matla'. Benefits of developing such a calendar greatly surpass the chaotic consequences created by mistaken and erroneous claims of sighting, and having to wait past midnight to get the decision from authorities like Islamic Shura Council of North America, or the confirmed news of sighting.

Khalid Shaukat is an ISNA consultant on moon sighting

Reprinted from The MCC UPDATE, January 1998.

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