Ramadan

Ramadan is the clearest demonstration of what a purely lunar calendar does, and the mechanism is worth stating exactly.

The Islamic year is twelve lunar months and comes to 354 or 355 days. The solar year is about 365.24. The difference is roughly eleven days, and because the Islamic calendar contains no intercalation whatever, that difference is never corrected. Ramadan therefore falls about eleven days earlier in the Gregorian calendar each year, and works its way through the entire seasonal cycle in about 33 years.

This is not an oversight. Intercalation, nasi, was practised in pre-Islamic Arabia, and it is prohibited in the Quran at 9:37, which describes it as an increase in unbelief by which those who disbelieve are led astray, making a month lawful one year and forbidden the next. The verse is understood as forbidding the manipulation of the sacred months, and the effect is a calendar that is purely lunar by design.

The practical consequences are considerable and are the reason Muslims frequently mention them. When Ramadan falls in a northern summer, the fast from dawn to sunset can run to eighteen or nineteen hours in Britain or Scandinavia and does not end at all above the Arctic circle in some weeks, for which jurists have issued rulings directing the use of the timings of Mecca or of the nearest moderate latitude. When it falls in winter it may be nine or ten hours. Over a lifetime a Muslim fasts in every season, which is often described within the tradition as an equalising feature rather than an inconvenience.

The month begins when the new crescent is seen, and who has to see it, from where, and whether calculation may substitute, are questions that produce visible annual disagreement.

Classical practice requires observation of the hilal, the new crescent, by credible witnesses, reported to an authority who declares the month begun. Because the crescent's visibility depends on the observer's longitude, on the moon's altitude and elongation at sunset, and on atmospheric conditions, two places can legitimately differ by a day.

Two positions then divide jurists. One holds that a sighting anywhere in the Muslim world obliges everyone, global sighting. The other holds that each region follows its own, local sighting. Both have classical support. Different countries follow different rules, some countries follow Saudi announcements and others do not, and communities within a single Western city routinely begin and end the month on different days because they follow different authorities.

Calculation has been increasingly accepted. The Fiqh Council of North America adopted an astronomical criterion in 2006 and the European Council for Fatwa and Research followed in 2007, both arguing that the requirement is knowledge of the month's beginning, for which the classical method was the available instrument rather than the object. Others hold that the sighting is itself the requirement.

The resulting variation is up to about two days globally. Eid, ending the month, is affected the same way, which means families and mosques in one city can celebrate on different days, a recurrent and much-discussed source of friction.