prediction of holidays based on the Muslim Calendar
provides additional information needed to better understand how Muslim holidays
dates were predicted in our database of
national public, bank and legal holidays. When looking at the dates of Muslim
various countries, it is important to bear in mind the following points :
The dates of
the Muslim holidays for many countries of this website are based on the Umm al-Qura
Calendar which is the Muslim
calendar used in Saudi Arabia. This a reasonable choice
conceptually, since Saudi Arabia is the
birthplace of Islam, and the only country in the world to use the Islamic
calendar for day-to-day civil matters (as opposed to
other countries that only use it for religious matters). Most
other countries in the
Arabian peninsula also follow the Saudi calendar.
Since AH 1423, the Saudi criterion for
determining if the day after the 29th day of a lunar month is the 30th day of
that same month or the first day of the next month, is that the next day is the
first day of the new lunar month, if on the 29th day of the lunar month the two
following conditions are satisfied : a) the geocentric conjunctiona between the
Sun and the Moon occurs before sunset, and b) the Moon sets after the Sun. Both
moonset and sunset are calculated for the geographical location of Mecca.
country uses a specific Islamic Calendar, then this is noted in the footnotes
section at the bottom of that country's page of public holidays (see, for
example, the footnotes for Singapore).
Other countries tend to rely on human sighting of the first crescent of the Moon
(some accept sighting reports from anywhere in the world, and some insist on
sightings made within their national borders), meaning
that dates in these countries can vary by a day with respect to the Saudi
Arabian dates (their holidays, when different, are usually one day later
than the Saudi ones) and, most importantly are subject to change until the Moon
crescent for the current Islamic month is actually sighted.
Many of the Muslim holidays, especially
the Eids, last between 3 and 4 days.
Finally, it is important to note that the
Muslim day starts at sunset, and not at midnight. Therefore all holidays
presented here actually begin the evening before the displayed date (for
example, if a holiday is displayed as occurring on March 4th, then it actually
began at sunset the evening before, on March 3rd).
More details on lunar crescent visibility
and Muslim dates in general, can be found at :
If you have questions or comments, please
do not hesitate to contact us.
a The geocentric conjunction between the
Sun and the Moon is the same as the New Moon, but as observed by a
hypothetical observer located at the centre of the Earth (not by an observer
located on the surface of the Earth).