The Method

Allah is He, who created the sun, the moon, and the stars (all) governed by laws under His command.   Qur'an 7:54

There has been a gradual, but relentless, migration from a regional view of the application of the Islamic calendar to a global view. This comes as no surprise since it is impossible to coordinate activities among Muslims who are located all over the world without using a shared timekeeping system.

Today the dominant timekeeping system used worldwide is the solar calendar known as the Gregorian calendar. Most Muslims have adopted its use globally for conducting their "civil" affairs, and have adopted the Islamic calendar on a regional basis for conducting their "religious" affairs. But this is changing. The use of a solar calendar that pays tribute to false gods or some portion of Allah's creation has always been a contradiction among the only people on earth who profess not to associate partners with Allah in any way.

Now there are other forces at work. What frequently has been described as a call for uniting Muslims throughout the world to celebrate major events such as 'Eid-ul fitr and 'Eid-ul Adha on the same day, is becoming an insistence on applying globally a common Islamic calendar to end the confusion over what day is today for the different regions of the world. And what has been widespread divergent views on the use of the sighting of the crescent in one region to apply to a different region, is now giving way to the increasing convergent view that a sighting in one part of the world applies to the whole world.

Over the years, a number of dedicated Muslim brothers and sisters have engaged in a disciplined effort to understand better Allah's laws that govern the visibility of the new crescent moon. As of 1432 AH, the combined results of these efforts have led to the method used in this site for determining the calendar dates of the Islamic timekeeping system. Here is an explanation of how it works.

First, let's make sure we recognize the difference between the new moon and the new crescent. The Figure below shows the phases of the moon as it moves around the earth. The phase labelled "New" is invisible to everyone on the earth. It occurs when the moon passes between the earth and the sun closest to the sun-earth line. The phase labelled "Waxing Crescent" represents the new crescent which is the first visible phase of the moon.

It is a well established fact that the time of the occurrence of the new moon phase is known accurately and this knowledge has been widely available for many years. To determine when the new crescent is formed following the new moon phase, a point of reference must be used. The International Date Line is the best place to be used as a reference point because it does not cross large land masses and it is already known to the world as a dividing line that changes the date as a person travels across it.

It is also a fact that the new crescent is never visible across the entire globe at the same time, as shown in the visibility curve below where the color-coded areas indicate visibility. The red area describes the region where a naked eye sighting is possible.

This means that committed Muslims who want to use a global Islamic calendar must accept the fact that depending on the region of the globe in which we live, we may or may not see the new crescent at the beginning of every month. We must recognize that other committed Muslims who make up the same global community will see it, and their sighting is valid for us.

In the method used for the Time & Strategy site, only the portion of the calculated visibility curve that indicates naked eye sighting of the new crescent in the major land mass regions of the globe, as shown in the following illustration, are considered as valid for identifying the beginning of each month.