Today is Hari Raya Aidil Adha or Hari Raya Haji as we Bruneians call it. Some also called it Hari Raya Korban which is predominantly used also in Singapore, Malaysia, Indonesia and the Philippines. According to Wiki, it is Eid el-Kbir in Morocco, Egypt and Libya; Tfaska Tamoqqart (see if you can pronounce that) in the Berber language of Jerba; and Tabaski or Tobaski in some parts of Africa; Babbar Sallah in Nigeria and West Africa; "Ciidwayneey" in Somalia and Somali speaking regions of Kenya and Ethiopia. In India, Afghanistan, and Pakistan it is also called Eid ul-Azha, and commonly referred to as Bakr-Eid "Goat Eid" as goat is the major sacrificial animal in those countries. In Bangladesh it is called either Id-ul-Azha or Korbani Id. In Turkey it is often referred to as the Kurban Bayramı or "Sacrifice Feast". Similarly, in Bosnia and Herzegovina and Albania it is referred as Kurban Bajram. In Kazakhstan, it is referred to as Kurban Ait.
In Saudi Arabia, we all know that this year's Ukuf at Arafah was on Friday thus making it Haji Akbar which will give a multiple 70 times 'pahala' to the lucky pilgrims this year. Haji Akbar is special because on the day of the ukuf is the meeting of two special days - the ukuf as the day when the door to forgiveness from Allah is open and the day of Friday which is the leader of all days (penghulu segala hari). Thus in Saudi, the Hari Raya Aidil Adha prayer was yesterday.
This is always the question - why is it that in Saudi, the day for Hari Raya or Hari Raya Haji can be off from Brunei by more than one day? Even with our neighbouring countries, there is that one day difference. Obviously the answer to that is the moon sighting. Traditionally, the first day of each month was the day (beginning at sunset) of the first sighting of the new moon shortly after sunset. If the new moon is not sighted immediately after the 29th day of a month, then the day that began at that sunset was the 30th.
But the calendar used in Saudi uses a very different astronomical method which uses the age or rather the hours of the new moon. Before 1999, in Saudi, if the moon's age at sunset in Riyadh was at least 12 hours, then the day ending at that sunset was the first day of the month. In our calendar, the new month begins when we sight the new moon regardless of how old or rather how many hours the new moon is supposed to be. Because of this major difference, the Hari Raya prayers can be off by ours by about two or three days in the past. In 1970s, the difference can be off by four days in some countries.
From 1999 onwards, the Saudi changed to another method which is if the moonset occurred after sunset at Mecca, then the day beginning at that sunset was the first day of a Saudi month which makes it the same rule used by Brunei. During the new moon, the moonset can only be for a few minutes, so that's why it requires precise judgment to see the new moon.
From 2002, the rule was further clarified (when I read this, I had to laugh because I got more confused - but you read on) by requiring the geocentric conjunction of the sun and moon to occur before sunset, in addition to requiring moonset to occur after sunset at Mecca. This ensures that the moon has moved past the sun by sunset, even though the sky may still be too bright immediately before moonset to actually see the crescent.
But because the moon sets progressively later than the sun for locations further west, thus western Muslim countries are more likely to celebrate some holy day one day earlier than eastern Muslim countries. Whatever method, the more western the Muslim countries such as Saudi, the earlier will be the beginning of their new month. I am not an astronomer or a religious expert - the Brunei method looked much easier, sight the new moon - that's the new month.
There is also an added non-technical explanation as to why the beginning of the new month in Saudi can be off by a couple of days. Apparently the religious authorities of Saudi Arabia also allow the sighting of the new moon testimony of amateur observers even when no other official groups can sight the new moon. I have been told that sighting the new moon is very difficult and if one is not an experienced or trained sighters, it can be very difficult. So there is the possibility that the amateur observers may not be as accurate in their sightings.
I also wrote about the issue of identifying the beginning of the new Muslim month sometime in September entitled Moon Sighter versus Scientists detailing the argument between moon sighters and scientists about whether to use the moon sighting or to use calculations when a new month should begin.
In the meantime, Selamat Hari Raya Aidil Adha to all Muslim readers.