Why some countries should start Ramadan 2012 on 20th July 2012 and why others on 21st July 2012 - Explanation

[Note: Please click here to see the country list arranged by the date of starting the Ramadan 2012.]

We recall to the visitor our methodology for calculating the beginning of the month for determining the calendar for Makkah.
After the new moon is born, we first look for the earliest crescent in the evening sky of Makkah. If it is visible, then the new month starts the next day. If not, we look further and further west until the time of fajr in Makkah. If the crescent is visible anywhere to the west before fajr in Makkah, then the new month starts on the next day, exactly as if the crescent had been visible in the evening in Makkah itself. We call this concept that of extended visibility.

The methodology for calculating the beginning of the month in Makkah can be applied to any place on earth. The month will begin next day if: (1) the new moon is born (2) if the young crescent is visible in the evening sky of the place considered, or (3) if it is visible at somewhere to the west of the place before fajr there. Otherwise the month will last a day longer.
We follow this methodology in order to determine the beginning of important Islamic dates for the various countries of the world. For several strategically chosen countries on different continents we choose a town towards the eastern limit of the country. We choose the eastern limit because fajr in the east is earlier than fajr in the west. If visibility is acquired for the east, then it will also be acquired for the west where fajr is even later. We avoid situations where there is visibility for the west but not for the east, because in such cases, the country will be divided into two for celebrating the feast day. For most countries, such a situation will not be acceptable.

The visibility curves

We now invite the reader to consult the visibility curves for the beginning of Ramadan 1433 (Ramadan 2012). Two visibility curves are pertinent: that of 19th July 2012 and that of 20th July 2012. The new moon is born on 19th July 2012 at 04 hours 23 minutes Universal Time. The blue and green zones represent the areas of the world where the crescent can be seen with the naked eye, blue under good atmospheric conditions, green representing easy visibility.
The visibility curve for 19th July 2012 shows most of the earth in a non visibility zone. Thus there will be no direct sighting on the various continents. However, a blue and green zone covers a large part of the Pacific Ocean. Thus it becomes essential to calculate whether fajr in some countries – with no direct visibility on the evening of 19th July 2012 – is not after the visibility of the crescent on some Pacific island, thus insuring visibility to the west of the country under consideration, before fajr in the country. These countries can thus start the fasting of Ramadan 2012 on 20th July 2012.
For the other countries the visibility curve for 20th July 2012 will apply. Here most of the world is in a green zone. Thus all countries which cannot start Ramadan 2012 on 20th July 2012 will start fasting on 21st July 2012.

The choice of the island

For calculating the visibility limit for countries in the first category, i.e. those that will start fasting on 20th July 2012, the choice of the island in the Pacific Ocean becomes essential. Many of the islands are small and the population insignificant. In the Sharia, testimony to the sighting of the young crescent is capital. In our days of modern science, this testimony can best be furnished in the form of photographs of the new crescent taken by reliable persons, groups of astronomers, for instance. Until now, the accuracy of our Makkah calendar is confirmed by the large collection of photographs in our photo gallery. Thus we gave special importance towards choosing the island in function of the photograph we may be able to obtain there – weather conditions permitting – on the evening of 19th July 2012.
These considerations led us to the choice of French Polynesia as the key island for checking visibility of the new moon in the Pacific Ocean on 19th July 2012. The population of French Polynesia is estimated at almost 300 000 in 2011. Representative of French Polynesia is the city of Papeete, situated at 17.5 ° S and 149.5 °W. The archipelago is situated in the green zone in the visibility curve. Thus the sighting of the young crescent with the naked eye is easy. As mentioned above, we are very hopeful of obtaining a photograph of the crescent in French Polynesia around sunset on 19th July 2012.

The best time of visibility for the new crescent : the situation in Papeete

In his paper “A Method for predicting the first sighting of the New Crescent Moon”, the British astronomer B. D. Yallop gives the following formula for determining the best time for sighting the new moon after sunset in a given place (HM Nautical Almanac Office NAO, NAO Technical Note, Updated April 1998) :
Best time of visibility of the new moon = Sunset time + 4/9 * (Difference between sunset and moonset time)
Let us now examine the situation after birth of the new moon (conjunction) on 19th July 2012 at 04H23M Universal Time (UTC):

- Conjunction in local time at Papeete is 18th July 2012, 18H23M (UTC – 10 hours)
- In the countries of reference which we have chosen, we want to examine the situation at fajr on 20th July.
- We will compare the time of fajr in these countries with the time of visibility of the new moon in Papeete on 19th July evening, about 24 hours after conjunction.
- On 19th July 2012, in local time the sun sets in Papeete at 17H41M and the moon sets at 18H31M. The time difference between the two is 50 minutes, and applying the above formula, we find that the best time for observing the young crescent in Papeete is at 18H03M, or 22 minutes after sunset.
- For comparing this time of visibility of the crescent with fajr time in the chosen countries, it is more convenient to work in Universal Time (UTC). We have to add ten hours to local time in Papeete in order to obtain the time in UTC. The above times for sunset, moonset and visibility time in UTC become sunset 03H41M moonset 04H31M and visibility of the new crescent 04H03M. Since midnight is crossed in adding ten hours these times are on 20th July 2012 in UTC.
- More than 24 hours after conjunction and with a large time difference between sunset and moonset in Papeete, it will be easy to observe the new moon. It should be remembered that Papeete is in the green zone in the visibility curve concerned.

In universal time UTC, we will take 4H03M on 20th July 2012 (please remember that local time is 19th July 2012 18H03M) as a time of reference for sighting the crescent in Papeete. If in the cities we consider, fajr in universal time is after 4H03M, then Ramadan will start on 20th July 2012, otherwise, it will start next day.

The results

Once the place and time of visibility were determined, we chose 23 strategically situated cities in Africa and Europe and 8 in the Americas. Makkah and Jerusalem are also given for reference.
The results of the calculation are reproduced in the following table. The sources used for determining the fajr times are indicated at the head of the table.

[Please click here to see the above table plotted on Google Maps.]

We invite the reader to carefully study this table. The columns are self-explanatory. The sixth column gives the fajr times in the cities under consideration, in universal time. If these fajr times are after 4H03M, the time of visibility of the new moon in Papeete, then Ramadan will start on 20th July 2012. Otherwise it will start next day. The last two columns explain this.
We may mention the particular cases of South Africa and of Equatorial Guinea, highlighted in blue in the table. In both these countries, fajr in the east – in Durban and in Ebebiyin – are before visibility in Papeete whereas fajr in the west – in Cape Town and in Evinayong – are after visibility in Papeete. But to avoid the division of these countries into two, we estimate that Ramadan should start on 21st July 2012.

List of cities and map

We have used these results to establish a list of countries according to the date of the beginning of Ramadan 2012. The reader can consult this table by clicking here.
For the facility of the reader, we have also provided a map with markers of different colours for countries which start Ramadan 2012 on 20th July 2012 and those that do so next day.


The concept of extended visibility to the west of a place before fajr in the place, together with careful choice of the place of visibility has allowed us to publish the dates of the beginning of Ramadan 2012 for various countries. In future we intend to develop this concept of extended visibility to each and every point of the globe, thus leading to an accurate calendar for all places in the world.