I. Introduction

As is well known, for any given place, the new Islamic month begins when the young crescent moon is visible in the evening sky. Traditionally, the sighting is approved by the community if it is reported by two reliable witnesses.

What is true in general is of course true for the holy city of Makkah. The calendar of Makkah is particularly important because of the annual pilgrimage of Hajj, centred on this town. This pilgrimage draws millions of people from almost every country in the world. Thus it is particularly incumbent on the Saudi Arabian authorities to fix an accurate date each year for Hajj. Because of the place Makkah occupies in the conscience of every pious Muslim, it is equally important to fix accurately the two other major feast days of Islam: the beginning and end of the fasting month of Ramadan.

In our project of establishing an accurate scientific islamic calendar for Makkah based on the calculated and predicted visibility of the new moon, we have enlarged upon the notion of visibility in Makkah around the sunset that follows the birth of the new moon. Invisible at conjunction, the crescent cannot be seen until at least ten hours after this recurrent monthly event. However, instead of trying to spot the crescent in Makkah around sunset, it is perfectly legitimate to allow oneself more time and take into consideration the whole interval of time between sunset and the early morning prayer (fajr) on the following day.

In practice, since each point on the terrestrial globe (except the north and south poles which are singularities) describes a circle of 360° in 24 hours around the axis of rotation of the earth, it is very easy to convert the interval of time between sunset in Makkah and the prayer of next day fajrinto an interval of longitude to the west of Makkah. We have called this limiting longitude of observation of the crescent the limiting horizon. We postulate that any sighting of the crescent up to the limiting horizon will be considered as sighting in Makkah itself, since it occurs before fajr in this town. All the more reason if the sighting takes place before the limiting horizon, at some intermediate horizon.

For each new moon, if no sighting is possible in Makkah itself, we predict the sighting to the west of this locality on the basis of calculated and plotted visibility curves. These curves have been established by Syed Khalid Shaukat. The reader will find examples of these curves on Mr. Shaukat’s site www.moonsighting.com or on our site Makkah Islamic Calendar. On the basis of the predicted visibility of the crescent we have commissioned photographs from reliable observatories or individual astronomers in the USA, Canada, Argentina and so on. A remarkable series of young crescent photographs exists in the photo gallery of our site. These photographs are a clear proof of the accuracy of our visibility curves.

The reader will find an extensive development of what is said above in the introduction to our site as well as in its FAQ section. The more technically minded reader will find in the Announcements section of our site the reference to an Islamic Calendar Article recently published in a well known international scientific journal called Selenology Today.

II. The official calendar used by the Saudi Arabian Authorities [The Umm al-Qura calendar]

Known as the Umm al-Qura calendar the Saudi Arabian Authorities uses the following criteria for determining the beginning of the Islamic month. These criteria apply since the Islamic year 1423 :
If on the 29th day of the lunar month the following two conditions are satisfied, then the next day is the first day of the new lunar month:
1. The geocentric conjunction occurs before sunset
2. The moon sets after the sun
Otherwise, the current month will last 30 days.
It is obvious that the actual sighting of the young crescent is not taken into account. Many discrepancies have been reported about the beginning of the lunar month under these circumstances. Even if the conjunction is shortly before sunset, with no possibility of viewing the crescent on that particular evening, the month will be declared as over, contrary to Islamic law.

III. The Hajj pilgrimage and the feast days as fixed by the Saudi Arabian authorities

Intrigued and worried about the accuracy of the major Islamic dates fixed by the Saudi Arabian authorities, we asked Syed Khalid Shaukat to carry out an expertise. Acting upon our request, he was kind enough to prepare three tables covering the span of 32 Hegirian years from 1400 to 1431. These tables concern:
   1. The beginning of Dhu’l Hijja (the 9^th of this month is the date of Wukuf Arafat and the 10^th is the date of Hajj)
   2. The beginning of Ramadan
   3. Eid Al Fitr (1^st of Shawwal)
Each table provides the following information:
   1. First column: the Hegirian year
   2. Second column: the Gregorian date fixed by Saudi Arabia
   3. Third column: Date of birth of the new moon in Makkah
   4. Fourth column: Time of birth of the new moon in local Makkah time
   5. Fifth and sixth columns: the status of the visibility of the moon according to calculated visibility curves (green or blue visibility zones only) on       the day before the official date fixed by Saudi Arabia. The fifth column gives the status of visibility in Makkah itself, whereas the sixth column       gives the status of visibility to the west of Makkah either at the limiting horizon or before it at an intermediate horizon. Following are the tables prepared by Syed Khalid Shaukat.

1^st Of Dhul-Hijjah

Hegirian
Year

Greogorian date fixed
by Saudi Arabia
dd/mm/yyyy (DDD)

Date of Birth
Of
New Moon [Makkah]

New Moon
Birth
Time [Makkah]

Status of Moon visibility according to the
Visibility Curves for day before this date

Green or Blue in Makkah

Green or Blue West of Makkah

1400

10-Oct-1980 (Fri)

9-Oct-1980 (Thu)