Fixed Islamic Dates – Astronomy of Moon-sighting
By Dr. Omar Afzal
Committee for Crescent Observation Intl.

Fixed Islamic dates are the need of the hour.
Who does not want that the dates of Ramadan, Eids and the Hajj be precisely known so that the Muslims can plan their rituals ahead of time? The present chaos and waiting till midnight to know if to pray Taraweeh, or rent a place for large congregational Eid prayers, taking a day off from schools, colleges, businesses or professional jobs are not only unbearable but also make the Muslims a butt of ridicule.
The attempt to find a solution started long ago. Almost every Muslim astronomer from the tenth century on attempted some theoretical model to predict the moon’s earliest visibility. However, the zone of uncertainty between “the “Possible” and “Not Possible” was so wide that success eluded all.
Data carefully collected during the last hundred years provided very valuable information. Now we can calculate the probable Islamic lunar dates for various parts of the world. However, lunar calculations do not predict moon’s visibility with 100% certainty. Abdali (1979) suggested computing broad visibility of the crescent moon. Kahf (1980) proposed “News” from any Muslim country.” ISNA Fiqh Council (10 June, 2006) has proposed purely calculable fixed Islamic dates, based on the “conjunction before 12:00Noon at GMT”, eliminating the visibility altogether.
The Qur’an (2:189) makes “Ahilla” (visible crescent moons) the “Mawaqeet” (determinant of the beginning of the Islamic month).
The Messenger (SAW) put Allah’s command into practice. He was aware of the Jewish calendar used by the Jewish tribes in Medina and the accuracy of its calculation. (The Jewish calendar was calculated by the conjunction around Jerusalem, with some crucial adjustments and Nasi - adding an extra month every three years.) But the Prophet (PBUH) asked the Muslims to use a different method to fix their dates.
To be sure about the Ramadan and Eid dates he carefully looked for the Sh’aban moon. He began Ramadan 29 or 30 days later. He instructed the Muslims to begin Ramadan only after a sighting of the Ramadan moon, and not start it a day earlier on the “suspected date” (yaum al-shakk). To avoid Eid al-Fitr on the last day of Ramadan, he instructed us to stop fasting only when the Shawwal moon was sighted at the end of the fasting period. In case the clouds or haze obstruct the moon’s visibility on the 29th day then the Muslims complete the month to thirty days. A moon is always visible on the 30th evening.
His Khulafa and the companions kept his practice. As the need grew the Muslim jurists came up with detailed solutions, according to their knowledge of the geographical facts and the trends in reporting moon’s visibility. Some required only one or two witnesses from a town and others went for 50. When some jurists noticed deliberate mistakes, they increased the number to five hundred in the same town to attain certainty about fixing these religious observances. None of them ever discarded the moon’s naked-eye, local visibility. All agreed that:
1. Ahillah are the “visible crescent moons.”
2. “Ru’yah” is to “perceive with the eye” after looking at an object.
3.“Ghumma” means “overcast”(in the context of the Hadith).
Any suggestion that the word “Ra’a” means mere “knowledge of the moon in the sky”, or that the Hilal means “a black invisible moon” was not known a few decades ago and rejected almost unanimously. Extending the local horizon of sighting was rejected by Ibn Abbas and others, and allowed to some distance not exceeding the distance between Damascus and Median. Extending the Matla backwards was unheard of. All these suggestions are denying the very core of the Fiqh and astronomy of moon-sighting.
Any classical Arabic dictionary will provide the detailed usage of these terms. All explanatory note on these Ahadith support the assertion that the Prophet (PBUH) proposed the simplest, practical solution to a contested issue between the “Ummi” Muslims of Medina, and followers of the accurate but “conjunction-based” Jewish calendar there. “Go look for the moon. If you see it then fast/celebrate Eid.” If the moon is hidden behind the clouds or haze then complete fasting to 30 days.
This is how the Muslims practiced the words of the Prophet (PBUH) for the last 1427 years.
The proposed “conjunction before 12:00 noon GMT” is a slippery solution. Does it mean calculating “one second after the conjunction” or “a week after the conjunction and for what part of the world? What about the revolving length of the month? There are scores of issues that have to be solved for a global fixed Islamic calendar.
Now we can easily calculate a “sighted-moon” based Hijri calendar but only for a large area like the United States. In most cases, the calculated date would be verified by the actual visibility if we use MoonCal’s “A” curve. Thus fixed dates will give us the level of certainty as high as 90% and eliminate fasting on “Yam al-Shakk” and Eid on the last day of Ramadan. The “zone of uncertainty” causes problems on a limited number of dates every years. The calculated fixed dates should be use as a guide to be verified by subsequent confirmed sightings. They also eliminate false witnesses claiming from “B or C” zone that could not be corroborated by observations at places located west of the claimed sighting.
The real issue is at what point after the birth of the New Moon (conjunction) the "Visibility of a Hilal" starts for every person with the normal vision, and from which point on earth?
Muslim experts, when attempting to fix Islamic dates, must take into consideration the minimum threshold of moon's visibility, the shape of the globe, as well as calendar making rules besides the intricacies of the Shariah rules. For example, for Eid al-Fitr 2006, the moon by some calculation might become visible in southern Indian Ocean, but not in S. Arabia though it is hundreds of miles west of the initial sighting. Could the sighting in the east be used to celebrate Eid in S. Arabia although a crescent moon is not visible there? However, the Muslims will never accept any attempt to DISCARD the visible Hilal phase totally.
Astronomy of Lunar Dates
A new solar date begins at180E (Intl. date line). However, the local date starts everywhere at 12:00 midnight. The day begins when the sun rises at the place of the observer.
The Matla of the sun for the solar date is counted from 180E. The earth rotates around the sun and it takes 24 hours for the sun to be visible over the globe.
Similarly, the moon rotates around the earth but its Hilal generally takes 24 -72 hours to be visible in most regions of the world. As the sun has only one Matla, so has the moon. The moon’s Matla is measured westward from where the Hilal was seen first. As the first visibility of the moon begins from a different point on earth and extends in a parabola instead of north south at any longitude there is no fixed international dateline. The local lunar date begins from the sunset, and the month begins after a Hilal is seen after the sunset.
For fixing the lunar date, we always count from where the moon is seen first. Any attempt to start a lunar date backwards, or in places where the moon could not be seen on that date is technically incorrect.
One should also take into account the fact that at "12:00 Noon GMT" the solar date at 180W (International Dateline) instantly changes to the next one. How can the Muslims in the US start the month when the moon would be seen on the next solar date?
The Prophet (SAW) was clearly told about the authentic calculation of the conjunction for the Jewish calendar. He followed it for his first Ashura fast. Why did Allah not ask Muslims to adopt the practice of the previous Shari’ah? Why did the Prophet (SAW) ask the Muslims use a different method of fixing the Islamic dates?
Only the “conjunction” is calculable, and it occurs at all times of day and night. No lunar calendar ever used exactly calculated conjunction for fixing its date. All had to adjust the conjunction day/date to a fixed point of time of the day and from a fixed place (Jerusalem, Ujjain, etc.)
There is no "authentic" calculation of the Hilal" even today after 1427 years. The calculations of the Hilal are only for a broader region and the dates are calculated to reduce mistakes, and not replace the actual sighting.
Recent attempts to provide Fiqhi justification for eliminating the visual sighting of the moon and extending the US horizons to the solar dateline do not appear to fulfill the basic requirements of the moon’s visibility in the United States. Ignoring calendar computation rules, and geographical facts has led a few to interpret crucial terms like Hilal, Matla’, Ru’yah, and Shahadah to negate what has been a unanimous understanding and practice of the Muslims for the last fifteen centuries. Our desire to solve a complicated calendar-making problem by some naive solution should not obstruct our reasoning to the core Shariah requirements.
We should also educate the Muslims to abide by the Shariah standards, and not by what some countries are doing. May Allah help us. Ameen.



Editor: Akhtar M. Faruqui
2004 . All Rights Reserved.