Standardizing the Islamic Lunar Calendar

Recent attempts to standardize the Islamic lunar calendar (Washington Post: Aug. 11, 2006) is not something new. For the last fifty or so years several attempts have been made especially by Saudi calendar-makers and Muslim scientist like Dr. SK Abdali and Dr. M. Ilyas (Malaysia) without much success.

Muslim holy texts required a visible crescent moon to begin a month, and the discrepancy was noticed with the improvements in means of communication. Every year, for decades the Muslims all over the world start the fasting month, Ramadan on 3-4 different solar dates.  Similarly, they celebrate Eid festival on 3 or 4 different days.

Several conferences and meetings (the most recent one in Jeddah, Nov. 1998) have done little to ease the chaotic situation. The confusion will continue until the Muslim jurists and calendar experts agree on some basic principles for computing a lunar calendar and Muslim states agree to implement a global Islamic calendar.

The most sticking point is the ever-shifting visibility parabola. The lunar visibility extends in a parabola rather than on a north/south longitude. The moon’s earliest visibility starts from a different point on the globe and results in the same lunar month being both 29 and 30 days long.. Muslim experts have yet to recognize an international lunar dateline and wish to make Mecca the meridian.

Causes of Confusion

            The scientific advances in the lunar visibility theory made significant advances between 1977-1990 (4). The credit goes to both Dr. S. Kamal Abdali and M. Ilyas for their methodical rigor and meticulous efforts. B. D. Yallop (Royal Greenwich Observatory (UK)), L. E. Doggett (Naval Observatory (USA)), F. Bruin, B. E. Schaefer (NASA, Yale) and many others also contributed. With their help, Ithaca NY based, the Committee for Crescent Observation Intl. has maintained significant accuracy in predicting moon's earliest visibility in various parts of the world.  

Unfortunately, the official calendar-makers in various Muslim countries have kept their eyes closed to physical limitations, and continue to harp on the "unity of Muslim dates", instead of searching for solutions for complicated lunar calendar problems.

Some Suggestions

             The conjunction (New Moon) (and its variations) cannot be used as the criterion for a lunar calendar. The reasons are obvious. The New moon occurs at all times of day and night. Islamic day/date starts from the sunset, and from where the waxing crescent moon first became visible. Most Muslims like to keep some sort of moon’s earliest visibility in the criterion for global Islamic dates.

We suggested:

1.         The solar international dateline (IDL) should also be adopted as the lunar international dateline (LIDL) for most practical, and obvious reasons.

2.         If the conjunction occurs at, or before Mecca the date following the New Moon date should be counted as the first date of the Islamic lunar month from IDL at sunset.

Example: On April 5, 2000 the conjunction occurred approximately 13.5 hours before IDL. The Islamic month will begin from the sunset on April 6 from IDL.

3.         If the conjunction occurs after the sunset at Mecca then the first date of the Islamic month should begin at sunset on IDL two dates following the New Moon date.

Example: On July 1, 2000 the conjunction occurs approximately 12 ½ hours after the IDL. The Islamic month therefore will begin on July 3 at IDL.

This solution may not fulfill the strict ‘lunar visibility’ conditions for all places on the globe, and may require some minor adjustments, yet it appears the most practical. Other variations like “ moon’s age=12+ hours at Mecca” may be appealing to some but they create more complications, especially for areas east of Mecca.

 Without a fixed Lunar International Dateline at IDL the lunar month will always be 29 and 30 days long simultaneously, making a unified calendar an impossibility.

All calculations were to felicitate the crescent moon’s earliest visibility. ISNA Fiqh Council’s recent criterion of starting the lunar date from sunset in North America if the conjunction occurred “before 12:00 noon GMT” not only abandons the most crucial basis of “Sighted Crescent moon” for fixing the Islamic dates, but rejects the cumulative juristic reasoning and practices of the last fourteen centuries, and physical astronomical facts.