Moon sighting in UK; problems and prospects


They ask you concerning the crescent moons, say they are measurements of time for people and for the pilgrimage” (2:189).

There is underlying wisdom in the Shariah’s use of the lunar calendar. By observing the moon even the simple nomads living in the desert can easily know the date. Also the use of the lunar calendar leads to the month of Ramaḍan rotating around the seasons of the year. Thus people can experience various lengths of fasting, as well as having the chance to perform the Hajj in a particular season.

Yet the peculiarities of the lunar calendar can lead to controversy, particularly in a country such as Britain where there is no consensus as to how exactly it is to be implemented. Particularly at the beginning and end of Ramaḍan. What is particularly interesting is that the divergent perspectives that have divided the ʿulama and common believers alike are all based on the above ayah of the Qur’an and the ḥadith narrated by Abu Hurayrah (may Allah be pleased with him), he reports that the Prophet (peace and blessings be upon him), said: “Fast after sighting the moon and end the month after sighting it, if it is cloudy then complete thirty days of Shaban” (Saḥiḥ al-Bukhari).

Before looking at the different interpretations that have been made of this evidence from the Qur’an and Sunnah let us look at some astronomical facts.

The role of the moon as Allah’s timepiece for humanity

The crescent moon is the sign for Muslims to begin their months, the meaning here is that they are Allah’s sign that the month has started, the earliest formation of the crescent corresponding to the beginning point of the month. We are also told that the moon, as one of Allah’s timepieces for humanity, fulfils its function precisely. Allah says: “The sun and the moon follow precise courses” (55:5).

It is He Who made the sun to be a shining glory and the moon to be a light, and measured out stages for it: that you might know the number of years and the count of time” (10:5).

The moon, We have measured for it stages (to traverse) till it returns like the old dried curved date stalk” (36:39).

During its monthly orbits, when the moon first becomes visible that is the crescent that follows after its conjunction. The following diagrams illustrate how this happens:

Diagram of Conjunction

The moon is invisible until it moves out of this line, as shown in the next diagram

Diagram of First Visible Crescent

A sliver line of the moon becomes visible as a crescent as it moves into the waxing phase.

The conjunction can be predicted very accurately. But when the moon becomes visible after conjunction there is a crucial question. The moon can only be visible if the light reflected by it can be seen by an observer on the earth. This will happen if the moon is in a certain geometrical position relative to the sun and the earth.

The following factors determine the possibility of sighting the crescent:

1. Sun-Moon elongation angle greater than 8° degrees ie, Moon 8° degrees.

2. The minimum age of moon after conjunction must be 17 hours high on horizon.

3. Weather conditions, clear or cloudy sky.

4. Use of telescope (this advances sighting by about one day compared to the naked eye).

5. The moon set must be 40 – 50 min after the sunset.

Interpretation of the Evidence

Practically speaking and without yet delving into the Fiqḥ arguments of each position, the evidence from the Qur’an and Sunnah in regard to starting Ramaḍan have been interpreted in Britain in the following six ways:

1. Global sighting – The proponents of this method hold that the crescent moon must be seen by witnesses, somewhere in the world. Once news of this is reliably transmitted, individuals in other countries may act upon it. Thirty days of the month are only to be completed if no reliable report of a sighting is to be found.

2. Regional sighting – This method proposes a certain region within which sightings should be carried out. In the case of Britain this could be the country itself, or perhaps could include Continental Europe as well. Again, an actual sighting must be reliably witnessed, but if it comes from an area outside of the region it will not be counted.

3. Local sighting – This is the same as the previous two but the acceptable range of sightings is limited to one’s locality, such as the city or town of one’s residence.

4. Sighting with calculation to exclude impossible claims – This method is still fundamentally based on sightings and on the principles of any of  the methods 1-3. The difference is that astronomical calculations are applied to make sure that no sighting is claimed that according to the location in which it is made. The crescent moon is not sufficiently old to be seen by the naked eye/binoculars/telescope. However, according to this method, if the sky is completely cloudy, and no sightings have been reported, it is necessary to count 30 days in the month even if from calculations it is thought that the crescent would have been seen.

5. Calculation when sighting is not possible – This method accepts the validity of traditional sightings in locations that tend to have good visibility, but argues that in more cloudy climates, such as that of Britain, a different approach can be beneficial. This is that astronomical calculations can give an accurate indication of what would be seen if cloud cover was not present and therefore, can be used to decide if 30 days should be counted. Like method 4, this perspective is able to include a number of variants, based on what type of sighting – global, regional or local – it utilises and whether it envisages calculation for a region as a whole, or just a locality.

6. Pure calculation – This method determines the lunar calendar solely based on astronomical calculation, with sighting reports, if used at all, playing purely a corroborative role. Again this can take a variety of forms, depending on whether it seeks to develop a global, regional, or local calendar and what parameters are set in place, for instance, in the minimum acceptable time from the birth of the new moon until a new month can be established.

It is interesting that different interpretations can be made from the same evidence of the Qur’an and ḥadith.

Moon sighting in the UK

Where the new crescent can be easily and regularly seen, as in the Arabian Peninsula and the Subcontinent, there is no reason to depart from the traditional practice of moon sighting by the naked eye, although it is useful to deploy calculations to exclude ‘impossible’ claims and as a guide for when to look. However, in the UK, it is fine to attempt this Sunnah practice, which can certainly be a spiritual experience but atmospheric conditions often leave the observer disappointed, as it is impossible to see even if it is known that in clear sky the same age crescent would have been possible to spot.

A way forward or continued chaos?

There is no doubt that the varying ijtihads made by scholars with regards to this issue are sincere attempts to follow the shariah. However, without consensus or a recognised authority to enforce a particular approach, it is not surprising that there is confusion. It is our contention that the most appropriate moon sighting method for British Muslims to follow is a regionally-based variant of the formula ‘calculation when sighting is not possible’ (method 5 above). The way in which this would work is that the days on which the crescent moon is visible over any point in the UK would be calculated on a month by month basis. Several websites provide such information and also sighting reports. The most prominent of these is There is also and many others. If sightings can be carried out in the available weather conditions, then the Islamic lunar month can be established in this way.

If it is impossible to carry out a sighting, then reference can be made to astronomical calculations showing that the crescent would have been visible, which includes a minimum age of at least 17 hours. If this is not the case, then 30 days are counted. Note, that if calculations state it should be visible with the naked eye and despite good conditions it is still not seen anywhere in the UK, then 30 days are also counted. We know that the moon’s visibility curves do not exactly correspond to national boundaries, but the UK is a small country and there would be no significant problems with using a single physical/calculated crescent sighting for all of it. The new month would be confirmed by a national council of ʿulama’ representative of the entire British Muslim community and followed throughout the country. This method would make UK moon sighting independent of influences from abroad, which sadly lead to disagreements , a remedy for overcoming the disunity in Muslim diaspora in UK.