Happy (Islamic) New Year!

by Cindy

We have had several holidays lately, the most recent being the Islamic New Year. What is a bit confusing about the holidays is that they are almost all based on the Islamic calendar which is more lunar based (but not the same thing as a lunar calendar) than solar based, like the US calendar. From a practical point, it can be quite confusing because you never really know when a holiday will start. At the University, we have set days we will take off but most other schools wait until the night before to announce the holiday. For instance, this week students will get either Tuesday or Wednesday off, depending on the observation of the new moon. A few weeks ago we were trying to plan a lunch for this Wednesday and people could only tentatively commit. "If the kids are out of school then I can't come but if they have school on Wednesday then I can come." It is weird like that, you just don't know until the day of or really the night before.

Here are a few sentences from Wikipedia about the Islamic calendar:

The Islamic calendar, however, is based on a different set of conventions. Each month has either 29 or 30 days, but usually in no discernible order. Traditionally, the first day of each month is the day (beginning at sunset) of the first sighting of the hilal shortly after sunset. If the hilal is not observed immediately after the 29th day of a month (either because clouds block its view or because the western sky is still too bright when the moon sets...), then the day that begins at that sunset is the 30th. Such a sighting has to be made by one or more trustworthy men testifying before a committee of Muslim leaders. Determining the most likely day that the hilal could be observed was a motivation for Muslim interest in astronomy, which put Islam in the forefront of that science for many centuries.

This traditional practice is still followed in the overwhelming majority of Muslim countries. Each Islamic State proceeds with its own monthly observation of the new moon (or, failing that, awaits the completion of 30 days) before declaring the beginning of a new month on its territory. But, the lunar crescent becomes visible only some 15–18 hours after the conjunction, and only subject to the existence of a number of favourable conditions relative to weather, time, geographic location, as well as various astronomical parameters. Given the fact that the moon sets progressively later than the sun as one goes West, Western Muslim countries are likely to observe the new moon one day earlier than Eastern Muslim countries. Due to the interplay of all these factors, the beginning of each month differs from one Muslim country to another, and the information provided by the calendar in any country does not extend beyond the current month.

At any rate, Happy (Islamic) New Year!