Aug 10 2010
The dating of the Islamic year was introduced by the second caliph, `Umar ibn al-Khattab, in 638 CE (16AH). He set the hijrah – the flight of the Prophet from Makkah to Madinah – as the most significant reference for the new Islamic era.
The Islamic calendar is lunar, thus its year is ten or eleven days fewer than the Gregorian year. This means that Muslim months fall in different seasons. For example, Ramadan and Hajj can fall in the summer as well as in the winter. It takes about 33 years for the Islamic dates to rotate through the solar seasons. So, for example, if Ramadan starts in October this year, it will be another 33 years before it starts in October again.
The first day of the lunar month is identified by the sighting of the waxing crescent, after sunset on the twenty-ninth or the thirtieth day of the foregoing month. Of particular concern to Muslims is the beginning of the fasting month of Ramadan and the month of Hajj, the pilgrimage season.
The moon is the earth’s dark satellite, visible only by reflecting the light of the sun. The visible area of the moon changes daily according to the angle formed by the line between the sun, the earth and the moon, which results in the cycle of lunar phases. The motion of the moon can now be calculated with great precision, but the beginning of every new lunar month remains a problem. Historically, however, communication constraints (ie. no satellite dishes) meant there was no controversy across the vast Muslim lands.
The two main Issues: Issue One: Calculation: According to Islamic rulings, to establish the beginning of the new lunar month, the crescent must be sighted by the naked eye under specific conditions. The sighting may, however, be influenced by a number of factors. For example, the age and size of the crescent and the angle it forms with the sun; the height of the crescent relative to the horizon line at the time of sunset, the distance between the earth and the moon, and, of course, weather conditions and the degree of visibility. The main criterion for hilaal (crescent) visibility is the angular separation between the sun and the moon at sunset.
All relevant traditions suggest that sighting the moon with the naked eye was the only method available back then. The naked-eye method is perfectly acceptable when conditions of clear visibility are available. But if otherwise, things get complicated.
Accurate calculations for the position of the moon have been around for thousands of years. Knowledge of solar and lunar eclipses was often used. The calculation of the visibility of the new crescent moon has only become significantly accurate over the last 20 years. Usually, the moon needs to be 20-25 hours old before the crescent is visible.
Calculations can be refined with the help of accurate observations around the world, for example moonsighting.com, International Crescent Observation Project and the Jordanian Astronomical Society. The best test of an authentic sighting is: “When the crescent moon is visible somewhere on earth, it must be visible at all points west of it with a clear horizon.” (www.moonsighting.com)
There are three major opinions of Muslim jurists on the use of calculations: 1. Calculations cannot be used to determine the new month (and therefore insists on the actual physical hilaal sighting without the use of astronomical tools and calculations). 2. Calculations can be used to reject false crescent-sightings. 3. Calculations can be used to determine the new month (ie. it is sufficient to follow the calculated dates which may have used modern astronomical tools and predictions).
Calculations are an extremely useful way of helping one to be in the right place at the right time in order to physically see the new crescent moon. However, those who accept the use of calculations to predict the new moon have another issue: there are many types of calculations. The calculations need to be done using the visible crescent, and not using the dark invisible astronomical new moon, which is typically one day before the hilaal. The main criterion for hilaal visibility is the angular separation between the sun and the moon at sunset.
Issue Two: the ‘Time Zone’: For people living outside of the Hejaz, there are even bigger problems. The world being a globe, any place round the world (on the same latitude) should over time be equally likely to be the first place to sight the hilaal. Hence, for some years the sighting in the USA should be before a sighting in Saudi Arabia. Actually the chances of seeing the hilaal in North America one day before seeing it in Saudi Arabia are quite high. It can be roughly calculated as follows:
The time difference between Saudi Arabia and California is 11 hours. The total time around the world is 24 hours. Thus the chances that the curve for first visibility of hilaal falling between Saudi and California is approximately 11/24 = 45%. Thus for little less than half of the occasions, California should sight the hilaal one day before Saudi.
People look at the flat map of the earth and assume that Saudi being East of North America should always see the hilaal before North America. But the earth is not flat! It is a globe as we know. East and West are only relative. Typically having Eid on two dates (but within about 24 hours for much of the populated earth) is natural and only in rare cases (like January 2005) can we expect the entire globe to celebrate Eid on the same date. Although no surprise, we didn’t!
This leads to the big dilemma: Should we fast and end our fast according to the sighting of the new moon in Saudi Arabia or should we do it according to the sighting of the new moon in the country we’re in? There are as many as six different opinions amongst the scholars concerning this issue, however, there are two main points of view. Dominant view: Ikhtilaf al-matali’ (multiple horizons) where the crescent sighting applies only ‘locally’.
This first opinion is that people should sight the moon in their own country and those countries where the moon rises at the same time should follow them. The reason for this is that the time at which the moon rises varies from place to place. Ikhtilaf al-matali’ is supported by science and the spherical geometry of earth implies multiple horizons. If the earth were flat – then Ittihaad al-matali’ would be valid and there would be only one horizon. But then we would also pray – say the zuhr (mid-day) salah at the same time all over the globe (no time zones). Since the earth is spherical, the countries east of the place of the first hilaal sighting (which shifts every month) have to wait till the next day before their hilaal sighting. This also provides a test of an authentic sighting: “When the crescent moon is visible somewhere on earth, it must be visible at all points west of it with a clear horizon.”
Alternative view: Ittihaad al-matali’ (unified horizons) where a single sighting applies for the whole (Muslim) world.
This second opinion is that the beginning of the new month need only be confirmed in any one of the Muslim countries. If the sighting of the new moon is confirmed in any Muslim country, it is then obligatory for all Muslims to use that sighting to begin the fast of Ramadan or end it. Therefore, if the new month is confirmed in Saudi Arabia, it is obligatory upon all Muslims, in all parts of the world, to fast if it is the beginning of Ramadan and to end their fast if it is the beginning of Shawwaal. Note, that if the earth was flat instead of spherical we would then see the hilaal at the same time everywhere.
A bit of history… For centuries the Muslim world had no way of knowing the exact date of Hajj in Saudi Arabia until the pilgrims returned home, perhaps months later. Muslims celebrated Eid by local sighting.