Analysis - Moon Sighting UK

Details: Last Updated: 25 May 2025

(Adapted from a Istiftaa to major Darul Ulooms by Eng. Qamar Uddin, ICOUK; dated 9 June 2024) [download pdf] [YouTube]

1. Introduction

We have been asked about the use of Optical Aids for UK Moon Sightings for the past 1 year (since 2023) by some of our UK moon sighters. And there are two opinions: one group says we should only use naked-eye sightings, which is the Sunnah position. And the other group says, that because of our geographical location, where the UK being a high latitude country (and an Island between two oceans), subject to a lot of cloudy weather throughout the year, we should allow the use of Optical Aids for moon sightings, especially as we have a lot of past fatawa allowing it [ftn_1].

However, there is a change of technology since the old Fatawa were issued some 50 years ago or more. So, we were advised to refer the matter back to senior scholars, explaining the modern technology used for the UK moon sightings, such as computerized telescopes with digital cameras. Therefore, the following technologies or practices used in the UK needed to be explained so the answers to the question (“Is optical aids allowed for moon sighting?”) obtained precisely in the correct contexts, since the technologies used in the old fatawa (from the 1930s to 2000), were not as advanced as currently in use.

2. How the Human Eyes Work

Before explaining how modern optical aids behind the human eye work, we need to explain how the human eye works, so the answers are in the correct context. So, let's look at how the human eye works from the anatomy of the human eye. As you can see from Figure 1, the light from an object comes to the lens of the human eye, and it bends and focuses on the retina (on the back of the eyeball). Note that this concept of light from the object to the eye was first developed by early Muslims, as early as the 10th century, by Hasan Ibn Al-Haytham (c.965 – c.1040) [ftn_2], who developed the camera obscura that we use in modern cameras these days. As you can see from Figure 1 (Normal Vision), the light coming from the object (candle) enters the eye lens then bends and focuses on the retina. The optic nerves then take these light signals (photons) to the brain, which constructs the image in the visual cortex part of the brain. So, in this case, a normal eyesight perfectly sees the image, very clearly. That's what we call normal vision.

Now, if we look at a situation when a person is shortsighted or nearsighted (as in Figure 2), so they see the object blurry, and the reason is that the eyeball is wider, and therefore the focal point, where it focuses, is somewhere in between the eyeball and not perfectly on the retina. Therefore, they get a blurry vision. So, how can we make a correction so we can put this focal point back onto the retina for the vision to become clearer?

We can do this correction by putting a lens in front of the eye to help the weak muscles of the internal lens of the human eye to move the focal point from somewhere in the middle of the eyeball, back onto the retina, to work as a corrected vision of good eyesight (as in Figure 3; for near distances). And so, now the optic nerve takes that corrected photons of the image to the brain and helps the person see it clearly. So, that's how the human eye works. Note the light from the object is always passing through the lens and reaching the human eye and therefore we consider that as a true vision has taken place or in the jargon of jurisprudence, “Ruyah” (i.e., seeing by the human eye) has taken place, because the light of the object (or the moonlight) has entered the human eye.

3. How Telescopes Work

Now, let's consider how a telescope works. Realise that the original telescope was a refracting telescope, or a Galilean telescope, which was simply a tube with two lenses (see Figure 4). One lens at the front is the objective, which is larger, and other one is the eyepiece, which is smaller at the other end. And there is mathematics to prove that the magnification takes place, based on the distance of the objective to the focal point and the distance of the eyepiece to the focal point. So, if we divide the focal distance of the objective by the focal distance of the eyepiece, then we get the magnification [ftn_3].

$04-RefractorTelescope-conv$ So, if the focal distance of the objective is 400 mm long, and the focal distance of the eyepiece is 20 mm long, then 400 divided by 20, we get 20 times magnification. Remember, we are looking for the whole of the moon’s shape to see the crescent (Hilal) and therefore we cannot have a huge magnification, such as for looking at a small part of the moon, like the crater, or a very, very faint object. Note that the same light of the object is entering the eye through the lenses. So, in the case of optical aids, such as a telescope, where the moonlight is still entering the eye (and it is not being created by the telescope), but it is still showing the real image of the moon.

4. How Binoculars Work

$05-RefractorTelescope-conv2x$ Now, let's look at how binoculars work, which are made of two small refracting telescopes, side-by-side (see Figure 5). They take the light of the object and bring it to the eye, so we get more clearer (3D) image. But there is a little difference from seeing the object directly with the eye. The object with the telescope gets inverted, because the top rays of light from the objective come to the bottom rays of the eyepiece, and the bottom rays go to the top, causing an inversion. This inversion is not a problem for looking at the stars, as it doesn't matter if it's upside down, even if you're looking at the moon, it doesn't matter if the whole moon is upside down, but the crescent would be flipped. However, it’s confusing to look at any terrestrial objects, in landscape, such as for watching birds or sports players at a distance, upside down.

5. How Binoculars Reinvert the Images

Since binoculars are made of two small refracting telescopes that also invert the images, how can we get them reinverted for normal eye vision? That's where we use some lens blocks called porro-prisms. The porro-prism lens blocks bend the light ray multiple times to reinvert the image back to normal way up. As with the telescopes, it also magnifies it based on the ratio of the focal lengths of the objective and the eyepiece. The function of using porro-prism as corner-blocks also makes the tube shorter for easily carrying in a handbag (see Figure 6). There is a separate video given on the YouTube version of this article that shows the animation of how binoculars reinvert the images for normal eyesight [ftn_4].

And, as before, light from the object (or the moonlight) still comes through multiple lenses and reaches the human eye so technically “Ruyah” has taken place. So, in summary, binoculars are like small telescopes, but they have two tubes and two porro-prisms, to both magnify the object (to make it easier to see) and to reinvert the image the right way up. And this is important for looking at landscape objects, like birds, trees, and other objects from a distance. Now from our past 10 years or so data in the UK, we have found that we can see an object with the naked eye within HM Nautical Almanac Office (HMNAO) Code A and B; and in the borderline case of Code B and C, after using binoculars to find the moon. But the Code C sightings were very few over the past 10 years; probably about 3 or 4 cases when the sky was very clear, but most of the time it was Code A and B.

6. How Digital Cameras Work

Let's look at how digital cameras work. Digital cameras use lenses to focus the image of the object onto a sensor. Unlike in the previous case when the human eye was behind the lenses, there is no human eye behind the camera lens (see Figure 7). It is the microprocessor sensors that the image focuses on and then the microprocessor takes that image (and sometimes applies filtering to remove bright sunlight from the image) to capture the light photons coming from an object like the moon. So, image processing takes place to generate or reconstruct the image and then it stores it in its internal memory card and displays it on the LCD screen for the human eye to see.

So, what the human eye sees is not the direct image of the object, because there is no direct light of the object (or the moonlight) entering the human eye. It is entering the processor sensor, which converts the image pixels into electrical signals. These signals are further processed to create the final image. There is a short YouTube video that explains the technical details of a camera sensor which is worth watching [ftn_5]. So, there is a significant difference between optical aids and digital cameras. Optical aids still pass the moonlight through to the human eye, whereas a digital camera or an Astro-camera (using CCD or CMOS sensors) that does filtering of sunlight, does not pass the light to the human eye. It is a reconstruction of the light signals that the camera sensor pixels have detected!

7. How to use HMNAO Visibility Maps

Let us now look at the HMNAO visibility map codes, and how we can predict the visibility of the moon at any location on Earth. Consider the visibility maps from 5th August 2024 (Safar 1446) Hilal in Figure 8, where most of the equatorial countries and Southern Hemisphere were Code A, so they were easily able to sight the moon because it was rising from the opposite Hemisphere. But the UK being a high-latitude country, it was in Code C, so it was only possible to see it if it was found with optical aids first, before seeing it with the naked eye.

The HMNAO visibility maps have been tested worldwide for its accuracy, and we have done so for naked eye visibility in the UK over the past 10+ years (since 2008). So, Code A is easily visible by the naked eye (or unaided eye). The Code B is visible if the weather is perfect (and then you will see it by the naked eye). And in Code C, you may need optical aids like binoculars to find the moon, and then you may (or may not) see by the naked eye, depending on the weather condition. And, as you can see from the map, on Monday 5th August 2024, for the Safar 1446 moon, in the UK was in Mid-Code C and we had three people who travelled for clear skies to Margate (Kent), and they were able to see the moon with binoculars only. And their report is on the ICOUK website for Safar 1446 page (bit.ly/Results1446-02) with their declarations. The Code D areas will need optical aids for people to see the moon. And for Code E, it's not possible to see with conventional telescopes. The CCD imaging capability is not included/built into the HMNAO visibility maps, like some other maps because the author, Dr Bernard Yallop, was of the view that this is not in the visible-light wavelength range. It is in the infrared wavelength range. Therefore, he did not feel the need to include CCD imaging detection of the moon on these maps. And Code F is totally invisible because there isn't enough angular separation between the sun and the moon. That is, there is not enough elongation (or it is too low on the horizon) so it's not possible to see by any means. And obviously, if the moon sets before the sun, then it is impossible to see because the moon is not in the sky! So, in summary, from our past 10+ years or so data, we found that the naked eye can see the moon within Code A and B, and with binoculars could possibly see Code C, and in one case it was also possible to see Code D, if the weather was exceptionally clear above the moon’s position (see bit.ly/Results1446-09). So, one of the questions we had is, can we allow the use of optical aids in the naked eye range only, and not in the optical aids range (Code C-D)? That was one of the questions to the senior scholars of Darul Ulooms (see Istiftaa below).

8. Summary of Optical Aids Technology

In summary of the optical aid technology explained above, the human eye uses the lens to focus the light onto the retina, and optical aids help the light to focus on the eyepiece, and then it brings it to the retina in the normal way. The telescope and binoculars magnify the distant object. However, telescopes invert the image, whereas binoculars reinvert it back to the normal way up. In the case of all optical aids, the light of the object enters the human eye through the lenses. In the case of a digital cameras, the light of the object does not enter the human eye directly.

The HMNAO Visibility Maps can help us predict the crescent moon sightings at a given location, and if we use optical aids then it will help us sight the moon within the naked eye range, and possibly in the telescope range, too. So, that's the explanation of the current technology. Note also, the modern telescopes use computerized mounts, which can precisely locate the moon more accurately than manual telescope mounts. Furthermore, the optics have improved over the last 10 years or so, whereby they can show the objects more clearly than it was possible in the previous decades.

9. Istiftaa on the Use of Optical Aids

Past Fatawa Allowing the Use of Optical Aids (c.1930 – c.2000)
1. Imdad al-Fatawi - by Maulana Ashraf Ali Thanvi (RH), vol.2, p.140,
2. Fatawi Haqqani - by Maulana Abdul Haq Haqqani (RH), vol.4, p.125,
3. Fatawi Dar Uloom Zakaria - by Mufti Razaul Haq (HA), vol.3, p.252,
4. Kitab al-Masail - by Mufti Salman Mansoorpuri (HA), Vol.2, p.124,
5. Fatawi Qasmiyyah - by Mufti Shabir Qasmi (HA), vol.11, p.443,
6. Fatawa Ramadhan - by Sheikh Saleh Al-Othaimeen (RH), vol.1, p.62,

The need to consider the use of optical aids arose due to the Major Lunar Standstills around of year 2025 (after 1987, 2006).

One of the appeals we made to several top Darul Ulooms is that the old fatwa from the 1930s needs to be reviewed because the technology of optical aids has changed, and the old fatwas of the time were only helping what was visible by the naked eye. But nowadays the technology seems to bring objects which is perhaps slightly outside the human eye visibility range, because of the accuracy of computerised mounts and improvement in the optics (lenses).
And there is a Hanafi ruling that if the skies are clear then the witness of one or two people will not be accepted. It must be a large group (Jamme Gafir). Currently, optical aids are not carried by large groups of people. Most people are looking for the moon with the naked eyes only and maybe one or two people will have a pair of binoculars or a telescope. So, we will not get a large group sighting with optical aids. This means that if we're allowing optical aids unconditionally, then it appears to contradict the requirement of large group sightings!
Therefore, we’re appealing to the senior Ulama of Darul Ulooms to review the old Fatawa and limit the use of optical aids to naked eye range only (e.g., HMNAO Code A - B), so we can continue to get the possibility of large group sightings, if we want to ensure large group sightings in clear skies.
However, we should still take benefit of optical aids to find the moon, because in mainland Muslim countries like Morocco or Asian countries, cloudiness is an exception, and a normal clear sky is the norm. But it's the opposite in the UK where it is mostly cloudy, and in rare cases, it is very clear. So, can we still use optical aids to find the moon, and then see it with the naked eye or within the naked eye range (Code A - B)?
It is agreed by people of knowledge that CCD camera images cannot be used for testimony purposes because the testimony comes from a person and not from a computer-generated image which is like looking at a photograph. But what about using that CCD based Astro-cameras to search for the moon, so we know when we have found it and continue tracking it until after sunset, and then look at the moon with the naked eye or the optical aids?

10. Fatwa on the Use of Optical Aids

The above questions were sent in June 2024 to some of the top Darul Ulooms, including Mufti Taqi Usmani (HA) at Karachi Darul Uloom. Some of the Karachi Darul Uloom Ifta Department scholars researched the technology and investigated this issue in detail. They held multiple meetings/consultations (shura/شُورَى) and the result came about eight months later, in February 2025 (Shaban 1446). The first paragraph of the response stated: “According to our research so far, a telescope that increases the power/ability of the eye and with the help of lenses, etc., gathers the light of a celestial body on the horizon and increases its size, thus facilitating its viewing, seems to us to be correct according to Islamic law to consider the sighting of the moon seen through it as the actual sighting of the real moon.” That is, optical aids are permissible but not CCD camera images. So, they were saying that the “Ruyah” (sighting) still takes place because the moonlight is still entering the human eye, fulfilling the conditions of the Hadith: “صُومُوا لِرُؤْيَتِهِ”, meaning “begin fasting when you sight the moon” (Muslim) [ftn_6]. The meaning of “Ruyah” is seeing by the human eye, and when moonlight enters the human eye via optical aids, then it is permissible. The fatwa did not put any restrictions on the use of optical aids (as requested), because they said, this is due to individual experiences based on many other external factors, such as the practical experience of the observers, weather conditions, etc. So, if the “Ruyah” takes place (and all the other conditions are met, such as adult Muslim, reliable/not mistaken, etc.), which a testimony panel would need to establish, then optical aids are allowed. But certainly not Astro-cameras or digital cameras. You can read that fatwa on the ICOUK website fatawa page and/or on the Ramadan 1446 page with another detailed fatwa [ftn_7a] [ftn_7b].

One question asked for clarification was, how does optical aids allow large group sightings (Jamme Gafir) condition to be met? And the response came back was that it is possible to have multiple groups with one device being shared. For example, in the UK if multiple groups are looking for the moon, and each group had one pair of astronomy binoculars and multiple people see through it in clear sky, then that would meet the condition of group sightings. Otherwise, a minimum of two witnesses are required for cloudy weather (except for the start of Ramadan needing only one witness or news) [ftn_8]. The Karachi Darul Uloom Fatawa is on our website under the Publications > Fatwa section.

11. Towards a United Moon Sighting Criteria (UK)

However, not every group agrees using optical aids in the UK. Some groups think that we should only use the naked eye, like Morocco (who follows Maliki Fiqh), and that was the ICOUK previous criteria (UK - Morocco region) for naked eye range only before 2021. But since ICOUK have changed to local moon sightings (UK-only) and adopted Hanafi Fiqh with many fatawa from top Darul Ulooms [ftn_9], allowing the use of optical aids, the other groups may not agree with it (as they followed different foreign countries). So, can we find some common grounds to be united?

Let us consider the Safar 1446 (5 August 2024) moon sighting report (see Figure 9) and look at the problem. We have multiple groups in the UK, so some groups are borrowing moon sightings from the Southern Hemisphere, like South Africa, or a nearby country like Morocco (“Aqrab Al-Bilad”). On that date (5th August 2024), the UK was in Mid-Code C where the moon was sighted from Margate (Kent) with binoculars by three brothers. Their report is on the ICOUK Safar 1446 page, and the ICOUK Testimony Panel took their testimonies, and agreed to accept them. In fact, the panel was informed that other UK Ulama groups (who followed foreign countries) have already accepted optical aids for UK. The ICOUK Ulama Panel, in the light of the previous fatawa (see the Major Lunar Standstill fatwa [ftn_1]) also agreed to accept it, as all the testimony conditions were met.

Let us now consider the UK winter months, when the moon visibility was/is starting from the Southern Hemisphere. The UK winter (Nov - Dec 2024) was going through a Major Lunar Standstills months, when the moon was very low altitude on the UK horizon and very high altitude in the spring (Mar - Apr 2025). It happens around every 18.6 years and so on 2nd November 2024, it was moonset-before-sunset in the UK (as it was the 28th date), and so the moon was not visible in the UK and hence there was no sighting at all. But we had other groups jump from the UK to Morocco, where it was also not seen, and then they went 8,000 miles to South Africa and followed their moon sighting! So, they started the month on 3rd November 2024, even though the moon was totally invisible in the UK (even by optical aids)!

So, how can we unite on any one criterion by following different foreign countries, having different 29th dates? Note that it is possible for the UK to be 1 day before or after other countries in some of the months, and the same as other countries in other months, according to the different orbits of the moon (as shown by visibility maps [ftn_10]). Realise that, if the UK moon visibility meets the rule of 29 or 30 days/month (over a lunar year), then it is a “normal location” for moon sighting purposes, even though the UK has adverse weather, which could be overcome by having lots of groups throughout the UK looking for the moon on the 29th. The 29-30 days/month rule has been proven to be satisfactory.

In the case of Ramadan Hilal on 28th February 2025, the moon was sighted by a highly experienced observer with binoculars (same as on 5th August 2024), but it was not sighted in Morocco or South Africa, because the moon visibility was starting from the Northern Hemisphere, the opposite side of the Major Lunar Standstill, and very high. So now the other groups who follow (or have been following) foreign countries, started disputing that we should not accept binocular sightings at all. But on 5th August 2024, the same groups were happy to accept binocular sightings and refused to accept them on 28th February 2025, which seems to contradict the rules from one month to the next! We should have consistent rules, so if we all can unite on a moon sighting boundary, then we can agree on the details (e.g., number of witnesses or use of optical aids or not, etc). The ICOUK proposal is that we can achieve unity if we can (a) collaborate in all 12 months of the year and (b) agree on a common moon sighting boundary, because there is no problem with sighting the moon in the UK throughout the year (even though it may be sometimes a day later or a day earlier than other countries). Note that in the UK winter months, we have overcome the low-altitude moons by completing 30 days, even though it may not be visible on the 30th, based on the Shariah rule, “if it is cloudy then complete the month as 30 days” (Muslim) [ftn_11].

There is one question that we have coming up for Dhul Hijjah 1446 Hilal (on 27th May 2025), where the moon might be seen by the naked eye or by optical aids in clear skies. Should we accept optical aids or not? Those who do not accept it, will complete 30 days, but those who do accept it, then it would be a united start of the month. But jumping to other countries would not lead to unity because different countries will have different 29th dates. So, all UK groups really need to agree on the UK-only boundary, and then we can discuss the details (e.g. number of witnesses or the use of optical aids or not). However, even if they do not agree with the ICOUK testimony panel declarations, they should still send their UK moon sighting report to the ICOUK website (www.moonsighting.org.uk) as it is a National Database for all the UK Muslims, regardless of the criteria they follow. Note also that there is a widespread belief that UK Eid-ul Adha should be on the same date as in Saudi Arabia. This is a misconception that was specifically clarified many years ago on the ICOUK website, which proved that Eid-ul Adha is not connected with Hajj, but with local moon sightings. Note the Hajj (in Islam) came 7 years after Eid-ul Adha was started by the Prophet (ﷺ) at the same time as Ramadan in 2 AH (Ref: https://bit.ly/EidAndHajj).

Checked by: Maulana Abdullah Ahmed (5/2025)

If you have any comments regarding the above article, please email us via our on-line Contact Us form.

Details: Last Updated: 07 August 2024

It is an Islamic tradition (Sunnah) for Muslims to look for the crescent moon (Hilal) on the 29^th of the lunar month, and if it is not sighted, then it must be seen on the 30^th (in a clear sky).

This is usually the case in all equatorial countries (i.e., in the vast majority of the Muslim countries) and it was also true in the UK for the past 15 years (since 2008) we have been doing moon sightings.

ecliptic-tilt However, there is a special phenomenon known as the Major Lunar Standstills which causes the moon in high latitude countries like the UK to be at a very low altitude on the 29^th and 30^th, such that it may not be seen in those years, e.g., 2025 (2023-2027), even in clear skies.

This low altitude happens for a few months during the winter (Sep-Dec), and then it becomes high altitude in the spring (Feb-May), which balances out the total number of 29 and 30-day months.

The above Major Lunar Standstills happen once every 18.6 years for a few years, and since it is the first time in (the history of) our UK moon sighting experience, it is necessary to look for the moon over 3 days a month for data collection.

The question arises, is it permissible to look for the moon on multiple days? This question is better answered by considering the following verse of the Quran: وَالْقَمَرَ قَدَّرْنَاهُ مَنَازِلَ حَتَّىٰ عَادَ كَالْعُرْجُونِ الْقَدِيمِ

“And [for] the moon, We have measured for it mansions (to traverse) till it returns like the old dried curved date stalk”, Quran (36:39)

It is clear from the Tafsir Jalalayn of the above verse that the moon goes through visible phases until it disappears and enters the invisible phase (Mahaq). According to Tafsir Ibn Kathir: The Arabs have a name for each set of three nights in a month, according to the phases of the moon (as stated in the table below).

Lunar Dates	Arabic Names	Description
1-3	Ghurar / غُرَر	They call the first three nights Ghurar;
4-6	Nufal / نُفَل	the next three nights Nufal;
7-9	Tusa / تُسَع	the next three nights Tusa` (nine) -- because the last of them is the ninth.
10-12	Ushar / عُشر	The next three nights are called `Ushar (ten) -- because the first of them is the tenth.
13-15	Al-Bid / البیض	The next three nights are called Al-Bid (white) -- because of the light of the moon which shines brightly throughout these three nights.
16-18	Dura / دُرَع	The next three nights are called Dura`, the plural of Dar`a', because on the first of them the night is dark from the moon rising late. Dar`a' refers to the black sheep, i.e., the one whose head is black;
19-21	Zulam / ظُلَم	the next three nights Zulam;
22-24	Hanadis/حَنَادِس	then Hanadis,
25-27	Da'adi / دآدى	then Da'adi;
28-30	Mahaq / محاق	then Mahaq, because of the absence of moonlight at the beginning of the month.

Therefore, it is not wrong to look for any number of the visible or invisible phases of the moon, especially if it can help establish a more accurate predicted crescent visibility (Imkan Al-Ruyat) calendar, InshaAllah.

Hence, we would like to request all UK Muslims to report their moon sightings to our Moon Sighting UK (ICOUK) website on the 29^th and the next 2 days of the month (based on the UK count) during the UK winter months.

For example, look for the Rabi-ul Awwal 1446 moon on the following dates: 3^rd, 4^th and 5^th Sep 2024; and similar dates for the next two months (e.g. 3^rd, 4^th and 5^th Oct 2024; and 2^nd, 3^rd and 4^thNov 2024), InshaAllah. JazakAllahu Khaira!

Checked by: Maulana Abdullah Ahmed (9/2023)

Details: Last Updated: 27 November 2022

By Eng. Qamar Uddin, ICOUK (July 2022/Dhul Hijjah 1443) [download pdf]

Further to my previous email/article last year (April 2021) about Local and Regional Moon Sighting where I had proposed that up to then (2021/1442), we have undertaken the role of the public to do Moon Sightings and Reportings but to adopt an independent Local Moon Sighting System, we will also need to undertake Testimonies and make Declarations too (very rapidly and accurately).

Over the past year, we have conducted the above trials with the help of many UK Moon Sighting volunteers and Trial Testimony Ulama Panels. We have overcome some minor teething problems during the trial and I am pleased to report that the result of the complete Local Sighting trial is both practical and achievable, Alhamdulillah.

However, the number of people reporting to the ICOUK website this year (1443/2022) has gone down slightly from last year (1442/2021), especially during the winter months (when sunset is during the working hours) but the total number of months the moon was sighted remained the same (10 out of 12 months), which continues to fully meet the Hijri Calendar rules of the Shariah (eg. “If the sky is cloudy then complete 30-days [1]” [Muslim:1081c]).

Looking at the past 5-years UK Moon Sighting data, it is clear that if a few 29^th-day sightings are missed (due to lack of sighters or clouds), it is automatically corrected by the end of the following month without accumulating (adding up) errors to the subsequent month. If we get wider community support for Local Sighting in the future, then this monthly data can be further improved, InshaAllah. [bit.ly/Comparison-UK-MA2]

It is well-known that Local Moon Sighting is the original position of the Shariah, as established from the Sunnah of the Prophet (ﷺ) and the Khulafa Rashideen (RA). However, since UK Muslims have been following different foreign countries for historical reasons, it was necessary to seek advice from those institutions that advised us to follow foreign countries in the first place. The question (Istiftaa) asked last year provided the past 4-years actual observation data with 2-years predicted crescent visibility (Imkan Al-Ruyat) data, to show that Local Moon Sighting is indeed possible. We have now received several fatawa to follow Local Moon Sighting, provided we seek the majority agreement, InshaAllah. [bit.ly/SummaryFatawa2]

There are many social/political benefits of uniting on Local Moon Sighing in a non-Muslim country (eg. to easily organise time off from work, education etc). However, this unity cannot be achieved by a few people doing Local Moon Sighting voluntarily to revive the Sunnah but will require the full support and commitment of the majority of UK Muslims (including the Imams, Scholars and Mosque Committees).

We have also received messages of support from senior UK ulama [2] to lead the change to Local Moon Sighting criteria and hence we have started an online consultation survey, seeking wider community support to change. Please complete the short survey as soon as possible (or by the end of Dhul Hijjah 1443/July 2022). [bit.ly/UKcriteriaSurvey2]

Note that for historical reasons the current ICOUK Moon Sighting criteria is the UK to Morocco Region. Any change of criteria will require a few months' notice for publicity (and update of IT systems/Apps), as informed by the survey.

[1] During Major Lunar Standstills (once every 18.6 years), there may be a few months of consecutive 30-days, due to low altitude
[2] including from (a) Wifaqul Ulama (UK): “آپ کو چاہیے کہ مقامی رویت ہلال پر عمل کرنا شروع کر دیں [You (ICOUK) should start following Local Moon Sighting]”. (WhatsApp, 8/5/2022) [MP3] / (b) Jamiat-e-Ulama Britain (CMSC): “آپ مراکش کو چھوڑ سو فیصد مقامی رؤیت پر عمل کرنا شروع کریں [You should leave Morocco and start following only Local Moon Sighting]” (WhatsApp, 23/6/2022)

Details: Last Updated: 06 May 2025

(Adapted from a Testimony Panel presentation by Eng. Qamar Uddin; dated 7 September 2021) [download pdf] [YouTube]

Introduction

There is a lot of confusion about the local (or regional) moon sighting boundary (Matla) amongst the Muslims. Some people consider that to be within their own country (eg. UK) and include neighbouring countries in the same region (eg. Morocco). Yet, some others consider the countries in the opposite Hemisphere is also included in the boundary (eg. South Africa or South America)! So, let’s explore these definitions from a technical and scientific perspective to see if we can define the local sighting boundary in the light of the Quran and Sunnah (using the Day and Night Maps).

Allah says: {وَالْقَمَرِ إِذَا تَلَاهَا ‎; وَالشَّمْسِ وَضُحَاهَا},

“And by the sun and its brightness; And by the moon, as it follows it (the sun)” [Quran 91:1-2]

In the commentary of the Quran (Tafsir Ibn Kathir), one of the eminent companions of the Prophet (ﷺ), Qatada (RA) said that this verse means, In the night of the crescent moon (Hilal), the moon must follow the sun. That is, the sun sets first and then the moon becomes visible (until the moon sets). So, this verse is telling us the sighting of the moon is between sunset to moonset. It is also well-known that sunset and moonset are related to a given location on earth and they (sunset and moonset) do not happen at the same time in all places of the earth.

Similarly, a number of authentic Ahadith mentioned that “If the sky is cloudy for you, then complete 30-days” (Muslim, Book 13/Hadith 6). It is well-known amongst the weather/meteorology experts that cloudiness is a local phenomenon and the entire country or the whole world is never cloudy at the same time. Hence, the Ahadith indicate Local Moon Sighting, as was the practice of the Prophet (ﷺ) and his Rightly Guided Khulafa Rashideen (Ref: Advice of Umar (RA) to the residents of the mountains to follow their own moon sighting – see ref [1])!

Definition of Local Boundary

We shall explain and define the boundary using the Day and Night maps based on the globe as given on various astronomy websites such as TimeAndDate.com or SkyViewCafe.com etc.

The Day and Night maps indicate the sunset and sunrise times for every location on earth at regular intervals. They are then plotted on a world map so the curves can be seen through different dates (see Fig.1). If we consider the UK boundary and take the easternmost city (eg. Great Yarmouth) for the seasons, then we find that the difference between Sunset and Moonset is about 1 - 1.5 hours (using HMNAO Websurf Moon_Viz program).

For example, on 11 June 2021, the Moonset Lag time for Great Yarmouth (UK) is 81 mins (HMNAO/Code B), which varies slightly from month to month down to 60 mins (approx.). The difference between the sunset and the moonset for a given location is called the Moonset Lag time, which defines the limit of the Hilal visibility window. Note that the moon may not become visible until sometimes after the sunset due to solar glare. So, for all practical purposes, if we can share similar sunset and moonset times through all the areas of our locations (or cities) in a country, then we can say this is the Local Sighting boundary because of the same possibility of sighting the moon anywhere within that area. This definition of the Local Moon Sighting boundary (or Sharing of Night) is consistent with the Quran and Sunnah.

To define the Moon Sighting zone (Matla), let us consider the Day and Night Maps cover around the UK. Rather than going through all the 365 days of the year’s Day and Night Maps, we shall just choose four key dates as follows:

Spring - when the Days and Nights are equal lengths (March),
Summer - when the earth is tilting towards the Sun ie. longer Days and shorter Nights (June) and
Autumn - when the Days and Nights are back to equal length (September),
Winter - when the earth is tilting away from the Sun ie. shorter Days and longer Nights (December)

Hilal Visibility Window for Spring

Consider the Day and Night Map for 21 March 2021 (Sunset at 18:10 GMT) in the East of the UK (Great Yarmouth). If we move West of the sunset point by 1 hour and 10 mins later, then we see that Sunset covers the whole of the UK from the East to the West.

Recall that the Moonset Lag time is about 80 mins (ie. 1 hour and 20 mins) for Great Yarmouth. So, using that Lag Time from the sunset on the Eastern point to the sunset on the Western point will be the width of the Hilal Visibility Window for the Spring season (see Fig.2).

Hilal Visibility Window for Summer

Now, let us move to 21 June 2021, which is the longest day of the year in the Northern Hemisphere (as the Earth is tilted 23.5° towards the sun) and it will be the shortest day of the year in the Southern Hemisphere.

Looking at the Sunset curve at the Eastern point of the UK (Sunset at 21:20 BST), which is tilting from the top-right (East) towards the bottom-left (West), shows the neighbouring Regions (i.e. Europe and West Africa) have already past their Sunset and probably past their Moonset too.

If we now move 1 hour and 10 mins or so towards the West, that would be the Moonset point. As before, the width of the curve between the sunset and the moonset points is the Hilal Visibility Window for the Summer season, which is at that angle like a forward-slash / (see Fig.3).

Hilal Visibility Window for Autumn

Let us now move to 21 September 2021 (Autumn), which is similar to the Spring type of days and nights, where the length of days and nights are almost equal (ie. 12 hrs each), and the Hilal Visibility Window is also similar to in the Spring season. The Sunset is 18:55 BST in the East of the UK (Great Yarmouth). If we move West of the sunset point by 1 hour and 10 mins later, then we see that Sunset covers the whole of the UK from the East to the West. And again, using that Lag Time from the sunset on the Eastern point to the sunset on the Western point will be the width of the Hilal Visibility Window for the Autumn season (see Fig.4).

Hilal Visibility Window for Winter

Now, let us move to 21 December 2021 (Sunset at 15:55 GMT), which is tilting from the top-left (West) towards the bottom-right (East). It is the shortest day of the year in the Northern Hemisphere (as the Earth is tilted 23.5° away from the sun) and it will be the longest day of the year in the Southern Hemisphere. If we now move 1 hour and 10 mins or so towards the West, that would be the Moonset point. As before, the width of the curve between the sunset and the moonset points is the Hilal Visibility Window for the Winter season, which is at that angle like a backward-slash \ (see Fig.5). Note that the neighbouring Regions (i.e. Europe and West Africa) are still in the day-time (early afternoon), well before their Sunsets.

Since the UK sunset is a few hours before the neighbouring Regions, it is possible to see the Hilal and start the month before them as was the case many years ago (eg. 2009), when the elliptical orbit of the moon was over the Northern Hemisphere, before the Southern Hemisphere (and in future during Major Lunar Standstills, eg. in 2025, 2043 etc)!

Hilal Visibility Window for all seasons

If we now replace all the previous Day and Night curves over the UK with the bandings for all four seasons (Spring, Summer, Autumn and Winter), then we will find they all form a diamond-shaped area that is shared through all seasons.

This method is similar to the Venn Diagram used in Mathematics, where we can say that the common area for all seasons of the Hilal Visibility Window is the area inside the diamond-shaped/triangle area. So that means, the moon would be visible within that area throughout all the seasons, but not outside that area because we are not sharing the Sunset to Moonset times of that area with other places on the globe (see Fig.6).

If we were to go through all the seasons daily, the diamond-shape will form into a circle because the world is a sphere (round) and not a flat plane. Note that the area under the circle is approximate in order to explain the concept of how to define the Local Areas or Local Boundary scientifically. But we can confidently say that this is the Local Sighting boundary because the probability of anyone sighting the moon within the circle is almost equal.

Regional Boundary (Exceptional Case)

Let us now consider the scenario if the moon was not seen for a few consecutive months due to Major Lunar Standstills, as was the case many decades ago (eg 1987, 2006 etc). In such a situation, we may have to resort to finding other solutions for such a Haraj (hardship) to sight the moon for Ramadan and Eid. In that case, we have to either complete consecutive 30-days or expand our local area to the Local Region (i.e. Nearest Latitude/Aqrab Al-Balad) towards the Equator, as an Exceptional Case.

The question arises, what is the outer-limit of the Nearest Latitude or how far distance can we expand? We can use the area under the outer triangle as markers for the limit of expanding the Local Region because most of the time in the year (i.e. 3 out of 4 seasons or 8 out of 12 months), our Hilal Visibility Window will be the same in that region and for the other few months, it will be slightly before or slightly after the UK sunset times (see Fig.7). So, this is for the Exceptional Case (استثنائی حالات).

Note that this principle of the Nearest Latitude also agrees with the Fiqh ruling described in Allamah Dr Khalid Mahmood’s book, “Why Two Eids?”. It says in his book, “similarity of rising [visibility] time”. He also said that it is not correct that “Unity of Horizon” (Ittihad e Matale) or Global Sighting is the Hanafi position! That is not true. He says that the Hanafi scholars only use that for nearby locations and they rejected it for far distance countries. The concept of nearby countries also agrees with our current understanding of the world with global communications, which may not have been the case in the 15th century, but certainly, it is the case in the 21st century. That is, Unity of Horizons is only valid for locations within a reasonable distance because Time Zone differences make some parts of the world as night and other parts as day, hence the whole world can never have Unity of Horizon for moon sighting purposes!

Local Sighting Boundary of Kuraib Hadith

A question may arise, how does the above principle (using Day and Night maps) compare with historical facts? So, let us now fast backward in time to the 7th century and apply the same principle to the Kuraib Hadith as recorded in many books of Ahadith (e.g. Sahih Muslim) which highlights the Moon Sighting boundary (Matale). The Hadith mentions that a traveller from Madinah (Saudi Arabia) went to visit Damascus (Syria) where the crescent moon of Ramadan was sighted on Friday and when he returned to Madinah (before the end of Ramadan) he discovered that it was sighted on Saturday. However, Ibn Abbas (RA) did not back-date the start of Ramadan to the previous day based on the moon sighting by Mu'awiya (RA) in Damascus (a far distant city) and insisted on following the Local Moon Sighting of Madinah or completing 30-days, as commanded by the Prophet (ﷺ). Note that these two places mentioned in the Hadith (ie. Madinah and Damascus) are two capital cities in two far distant countries of the world mentioned in historical texts (and not like the neighbouring cities in the modern world within short distances).

If we apply the same principle of the Hilal Visibility Window (using Day and Night maps) as explained above, we will find that the Local Moon Sighting of Damascus is different from that of Madinah. That is, they both have a separate area of Local Moon Sighting zones through all seasons and do not overlap with each other (see Fig.8). So, now we can use this explanation to support the Kuraib Hadith that both cities of the world had separate Sighting Zones. It was not as some people misunderstood that Damascus was in the West of Madinah and hence, they didn't follow it (or vice versa).

Now, let us fast forward from the Kuraib Hadith in the 7th century to the 14th century. That is the lifetime of Shaykh ul-Islam Ibn Taymiyyah (RA) who used to live in Damascus. He was a Hanbali scholar, but accepted by all Maslak, as a leading scholar of his time and he said in Majmua Fatawa (vol.13/p.62) that if there is a sighting in the East, then it must be sighted in the West but not the other way around (ولا ينعكس). What is not clear is that the distance between the East and West was the maximum travelling distance of their time through which the news can be conveyed. Realise that in the 14th century, news could not be conveyed from Australia to America (East to West) in one evening, especially when they are Day and Night apart. So, we can reasonably conclude that the ruling by Ibn Taymiyyah (RA) applies to the East-West of the Local Sighting zone, which also agrees with the Kuraib Hadith.

Summary of Moon Sighting Boundary

The Moon Sighting Zone (Matla) is defined as the Hilal Visibility Window that is shared through all seasons (using Day and Night maps) and it is under the same legal jurisdiction. However, if there is an exceptional case due to some hardships (Haraj) when the moon cannot be seen for many consecutive months on the 29^th lunar date, then the Moon Sighting Boundary may be expanded to the Regional Sighting Zone where the visibility must be shared for most of the seasons. The Regional Sighting Zone could be interpreted as the old equivalent of Ittihad Matla (Unity of Horizons), which was commonly interpreted as “Global Sighting” in the past, but it should be interpreted as Regional Sighting in the 21^st century. The expansion of the Local Sighting to Regional Sighting boundary should be only used for the duration of any hardships and not beyond that (e.g. while developing Sighting Locations in critical areas).

The above definition of the Local Moon Sighting Boundary is fully consistent with the Quran (2:189/ 9:36/ 91:1-2), Sunnah/Kuraib Hadith (Bukhari/Muslim), Fiqh (Ikhtilaf Al Matale) and Islamic History, as explained by Shaykh ul-Islam Ibn Taymiyyah (RA) in the 14^th century Damascus (Syria). It is also consistent with the advice of Khulafa Rashideen, such as Umar (RA) to the residents of the mountains to follow their own moon sighting, even if it differs from other regions![1] Note also, the Prophet (ﷺ) said: {فَعَلَيْكُمْ بِسُنَّتِي وَسُنَّةِ الْخُلَفَاءِ الرَّاشِدِينَ الْمَهْدِيينَ}, “Follow my Sunnah and the Sunnah of the Khulafa ar-Rashideen” (AbuDawud, Book 42/Hadith 12) (Tirmidhi, Book 41/Hadith 32).

Therefore, it can be safely concluded that following Local Moon Sighting by the British Muslims from within the British Isles is fully consistent with the Quran and Sunnah. We hope and pray that the UK Muslims will support their Imams and Scholars to unite on Local Moon Sighting, sooner than later, InshaAllah. [Qamar Uddin / June 2022]

Reference: UK Moon Sighting Fatawa 1443/2022 (English/Urdu PDF, 70 pages, 40 MB) / [YouTube: Kuraib Hadith on Local Moon Sighting]

[1] Ghareeb al-Hadith, Imam Abu Suleiman al-Khattabi, Vol. 2/P.103, Umm al-Qura University, Makkah, Saudi Arabia.

UPDATE: The above article from 2021 proposed that if the crescent moon was not sighted in the UK for many consecutive months on the 29th lunar date (due to the low altitudes), then the local boundary could be expanded to the regional boundary (i.e., UK to Morocco) during those exceptional circumstances. However, having gone through the low-altitude moons of the Major Lunar Standstills during the winters of the past two years (2023 - 2024), it appears that the UK-only local calendar has upheld the rule of 29-30 days/month successfully, Alhamdulliah. Therefore, it is not necessary to expand the local boundary to the regional boundary anymore, InshaAllah. [QU/5/2025]

Details: Last Updated: 21 June 2022

Many people who use Weather Forecast to decide if they can put out their washing for drying (or stargazing from directly above their head/zenith), also use the same logic to decide if they should go out for moon sighting or not (when it’s predicted to be visible)?

The above comparison is not correct since the distance to the horizon is usually much further away from the observation location than the horizon (where the weather forecast could be clear skies)!

The reason the actual weather may be much better at the horizon is because, cloudiness is a local phenomenon i.e. the whole region is never (or very rarely) cloudy at the same time, such that two locations, 10 – 20 miles apart may have totally different weather conditions (clear and cloudy).

The question arises, how far distance is your horizon (l) so you can estimate the weather forecast more accurately? The answer to that depends on both the height of your observation location (which is variable, h) and the radius of the earth (which is a constant, R = 3959 miles), as given in the formula below:

Distance to the horizon (l) = 1.22495 √h where h is in feet and l is in miles OR
Distance to the horizon (l) = 3.56972 √h where h is in meters and l is in kilometres (km)

Examples:
1. What is the distance to the horizon for someone at 10m height of location and 1.5m tall? Distance = 1.22495 x √(32.8 + 5) = 7.53 miles OR = 3.56972 √(10 + 1.5) = 12.12 km
2. What is the distance to the horizon for someone at 1000 ft height of location and 6ft tall? Distance = 1.22495 x √(1000 + 6) = 38.84 miles OR = 3.56972 √(305 + 1.8) = 62.51 km

The above example calculations are for York (height, 10 m) and Thirsk (height, 1000 ft) in North Yorkshire.

It is clear from the above calculations that the higher the location, the further away the horizon will be and hence the weather at that distance may not be as cloudy as the location of the observer.

Furthermore, when it’s partly cloudy, it has been found that the location near sunset may have a clear gap, allowing the moon to be easily seen, even though other parts of the skies are totally cloudy.

Therefore, never give up looking for the moon (until moon set times), even if the forecast is cloudy, since there may be a clear gap to see the moon through a break in the clouds (at the horizon)!

Note that it is advisable to use the first part of your postcode (eg. YO10) for the UK regional weather forecasts (which may include locations near your distant horizons).

Ref: How far away is the horizon? (PDF) | See also: How to Calculate the Distance to the Horizon