When does the month of Ramadan begin? Science and Wisdom


 يَا أُولِي الْأَلْبَابِ لَعَلَّكُمْ تَتَّقُونَ

 O those full of insight, perhaps you would attain God consciousness. (Qur’an 2:179)

 وَمَن يُؤْتَ الْحِكْمَةَ فَقَدْ أُوتِيَ خَيْرًا كَثِيرًا وَمَا يَذَّكَّرُ إِلَّا أُولُو الْأَلْبَابِ

He gives wisdom to whom He wills, and whoever has been given wisdom has certainly been given much good. And none will remember except those of understanding. (Qur’an 2:269) 


The years come and go and the pattern seems unchanging. With the approach of the fasting month conflicts flare, tensions grow and divisions deepen. Sometimes it is individual countries; sometimes it is judicial bodies; sometimes it is the scholars who contradict each other on the interpretation of certain texts, on methods of calculation, on the use of science; or sometimes it is even relations between state . Bemused, the world’s Muslims observe the spectacle. Who should they follow? How are they to determine the exact first day of Ramadan? By following one’s sheikh, one’s local mosque, a group of religious scholars, the country in which one resides or one’s country of origin, or even Saudi Arabia, where the spiritual center of the community of believers is situated? But the scholars are divided among themselves, and the community of believers frequently does not know which way to turn so total is the confusion. The picture is a troubling, even dismaying one, especially in the light of the hesitations and errors surrounding recent decisions that have attempted to determine the first day of fasting.


For all that, the texts that determine the beginning of the fasting month, both in the Qur’an and in the Sunna, are clear and leave very little room for complex, partial or ambiguous interpretation.

  • The cycles are clearly determined

The Qur’an clearly establishes the reality of pre-determined cycles:

    هُوَ الَّذِي جَعَلَ الشَّمْسَ ضِيَاءً وَالْقَمَرَ نُورًا وَقَدَّرَهُ مَنَازِلَ لِتَعْلَمُوا عَدَدَ السِّنِينَ وَالْحِسَابَ

“It is He who made the sun a shining and the moon as a light and measured out stages that you might know the number of years and reckoning.” (Qur’an 10:5)

  • The number of months is twelve

The reference to the number of months in the revealed text leaves no doubt: 

إِنَّ عِدَّةَ الشُّهُورِ عِندَ اللَّهِ اثْنَا عَشَرَ شَهْرًا فِي كِتَابِ اللَّهِ يَوْمَ خَلَقَ السَّمَاوَاتِ وَالْأَرْضَ مِنْهَا أَرْبَعَةٌ حُرُمٌ ذَٰلِكَ الدِّينُ الْقَيِّمُ

“Surely the number of months with Allah is twelve months in Allah’s ordinance since the day when He created the heavens and the earth, of these four being sacred; that is the right reckoning.” (Qur’an 9:36)

  • The days are enumerated

Here the Qur’an refers to the fasting days, indicating that these days are pre-determined, and that they occur within a lunar month of 29 or 30 days:

يَا أَيُّهَا الَّذِينَ آمَنُوا كُتِبَ عَلَيْكُمُ الصِّيَامُ كَمَا كُتِبَ عَلَى الَّذِينَ مِن قَبْلِكُمْ لَعَلَّكُمْ تَتَّقُونَ

أَيَّامًا مَّعْدُودَاتٍ فَمَن كَانَ مِنكُم مَّرِيضًا أَوْ عَلَىٰ سَفَرٍ فَعِدَّةٌ مِّنْ أَيَّامٍ أُخَرَ وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ فَمَن تَطَوَّعَ خَيْرًا فَهُوَ خَيْرٌ لَّهُ وَأَن تَصُومُوا خَيْرٌ لَّكُمْ إِن كُنتُمْ تَعْلَمُونَ

“O you who believe! Fasting is prescribed to you as it was prescribed to those before you, that you many learn piety and righteousness” (Qur’an 2:184)

“The prescribed fasting is for a fixed number of days, but whoso among you is sick or is on a journey shall fast the same number of other days; and for those who are able to fast only with great difficulty is an expiation — the feeding of a poor man. And whoso performs a good work with willing obedience, it is better for him. And fasting is good for you, if you only knew. (2:185)

  • The new moon (hilâl) must be sighted according to the prophetic tradition:

The words of the Prophet (pbuh) are explicit:

 صوموا لرؤيته وأفطروا لرؤيته” متفق عليه 

When you see the crescent (of the month of Ramadan), start fasting, and when you see the crescent (of the month of Shawwal), stop fasting; and if the sky is overcast (and you cannot see it) then regard the crescent (month) of Ramadan (as of 30 days).” (Cited in Bukhari and Muslim)

The general formulation of the hadith implies that the diversity of moon risings is not taken into account

 (لاعبرة باختلاف المطالع لعموم الخطاب)

as established by the Muslim Committee of Islamic Legislation  in 1986.

  • The natural order and the extreme precision of the movement of the stars: 

The Qur’anic formula, in which the stylistic figure amplifies the reference to precise calculation,provides clear information on the precision of the movements of the sun and moon:

الشَّمْسُ وَالْقَمَرُ بِحُسْبَانٍ 

“The sun and moon follow courses exactly computed.” (Qur’an 55:5)

Muslim scholars have always paid close attention to the natural order and have recognized the accuracy of scientific calculation based on the meaning of the above-cited verse, which points to the precise and meticulous order that governs the movement of the heavenly bodies. Astronomical observation has made it possible to determine the times of prayer, thus respecting as closely as possible the meaning of the verse:

 إِنَّ الصَّلَاةَ كَانَتْ عَلَى الْمُؤْمِنِينَ كِتَابًا مَّوْقُوتًا

Indeed, prayer has been decreed upon the believers a decree of specified times.” (Qur’an 4:103)

Above and beyond the Qur’anic formula that stipulates that the fast must begin when a white thread can be distinguished from a black thread

كُلُوا وَاشْرَبُوا حَتَّىٰ يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ ثُمَّ أَتِمُّوا الصِّيَامَ إِلَى اللَّيْلِ 

“And eat and drink until the white thread becomes distinct to you from the black thread of the dawn.” (Qur’an 2:187)

Scholars have accepted that astronomical calculation derived from the movement of the earth and sun determine the exact moment at which we must stop eating and at which the dawn prayer begins, just as these movements determine the other day and night prayers. Thus the reference to scientific knowledge in better applying the Qur’anic injunction to pray at the appointed hour, or to begin or to end the fast, just like the knowledge of the number of days per month (29 or 30 lunar days) is a time-honored one, which was never viewed as a problem by the scholars of long ago nor of today, irrespective of their school of jurisprudence or tradition.


Astronomy has significantly evolved, becoming a full-fledged scientific discipline that has achieved an impressive capacity for observation of the universe using instruments that make it possible to track the movements of the planets with the highest precision, to locate them in the firmament and to calculate down the minute their respective positions. Astronomers can predict with great exactitude the moment of conjunction (the alignment of the sun, earth and moon), which marks the end of the lunar month and thus the beginning of a new month. Scientists are now able to determine the day and the exact moment of conjunction for hundreds of years to come, if not more.

Scientific determination of the conjunction does not suffice from an Islamic point of view (according to a majority of scholars), given the clarity of the hadith that requires that the new moon be observed by the human eye. It is the sighting of the new moon at whatever place on earth that marks the start of the lunar month for the believers. Bearing this requirement in mind, scientists are able to inform us of the objective conditions that make moonsighting possible, either by the naked eye or by telescope. Aside from the fact that the conjunction must take place before sunset in order for the moon to be sighted, astronomers have determined the following conditions:

1. The moon must have disappeared after sunset.

2. The declination of the moon relative to the horizon must not be less than five degrees.

3. The angular separation must not be less than eight degrees.

We can then understand that astronomical calculation is not exclusively used without taking account of visibility, but functions as the scientific reference that makes it possible to determine with greatest accuracy when moonsighting is objectively possible—or impossible—at any point on the surface of the earth.


The texts must be considered with seriousness and devotion. Moonsighting, wherever it may occur on earth, is essential; scientific knowledge, based on precise calculation, enables us to determine when and where moonsighting can take place. In this way scriptural knowledge and scientific knowledge fold into one another, allowing us to be strictly and deeply faithful to the divine injunction.

The benefit of this approach, above and beyond the basic principle of the union of the requirements of revelation and scientific knowledge, is that it allows us to arrive at a higher certainty in determining the beginning of the lunar months—which today’s astronomical science makes possible, as a photograph of the precise moment of conjunction may now be taken—as well as uniting Muslims around the world.

Concretely, it should allow Muslims to organize their social and professional lives, both individual and collective, well in advance, in a unified, confident and self-assured manner, while avoiding legalistic disputation or power struggles among scholars, schools of jurisprudence, or States. Scientific astronomical knowledge today makes it possible to unite the Muslims on the basis of faith informed by knowledge in the strict requirements of Revelation. The reconciliation of religious and scientific knowledge, the unity of the world’s Muslims and the organizational predictability of Muslim affairs stand forth as its three essential benefits.

We know to what extent the Pilgrimage is a moment that unites Muslims from all around the world. The same principle applied to astronomical calculation and, ultimately, a coherent approach for every month, including Ramadan, would clarify matters and unite us on clear and accepted bases.


Criticism and controversy has not been lacking; over the years, schools of thought, scholars and even States have differed sharply on the methods used to determine the beginning of Ramadan. The arguments put forward by those who criticize the use of scientific knowledge cannot be substantiated in debate or against the principles of Islam. The most frequently encountered arguments are:

1. Hadith (prophetic tradition) is clear and speaks of moonsighting with regard to the human eye alone:there should be no reference to scientific calculation.But this interpretation of the hadith is faulty and reductive, given that the Prophet (pbuh) refers to the means available to man of his time to determine the new moon. The Qur’an, however, is clear  الشَّمْسُ وَالْقَمَرُ بِحُسْبَانٍ   The sun and moon follow courses exactly computedand if through science we gain greater knowledge of the movement of the planets and the exact beginning of each month, it is our duty—and a matter of collective intelligence—to use all that it has placed at our disposal. The same method is used in determining prayer times.

2. Some have put forward the idea that the Muslims make up a faith community that must rely on simple and natural means and knowledge, for as the Prophet (pbuh) says in an authentic hadîth:

 (إنا أمة أمية لا نكتب لا نحسب،الشهرهكذاوهكذا  البخاري)  “We are an illiterate nation, we do not write, neither do we make calculations.” It then follows that no reference can be made to astronomical calculations, which would contradict the meaning of the hadith. That would be a reductive reading of a hadith that describes the condition of the early Muslims and as such would appear to contradict the fundamental teaching of Islam, which calls for reading, for knowledge, and for understanding the world. The history of Islamic civilization demonstrates precisely the opposite of an appeal to ignorance as manifested by the scientific spirit that developed in all fields of knowledge, from medicine to astronomy by way of architecture and the arts. Yet again Muslims refer unquestioningly to astronomical calculation to determine prayer times without this particular hadith ever being invoked.

3. It has been argued that the “day of doubt” is an integral part of the preparation for the Ramadan fast, by placing the believer in a peculiar psychological state. Aside from the fact that no revealed text or Prophetic tradition can be cited to confirm the notion that that doubt forms an integral part of pre-fast preparation, it can be easily understood that the “day of doubt” is nothing more than the consequence of doubt arising from moonsighting by the naked eye and possesses no spiritual merit. On a deeper level, the state of Muslim societies and communities around the world proves that the current situation carries with it a danger of real and potential disturbances, divisions and tensions that interfere with proper preparation for the fast far more than they allow for meditation and calm.

4. Some scholars have claimed that moonsighting must be confirmed in each country or region; others assert that it should be confirmed in Saudi Arabia, the nominal center of the community of believers, while still others put forward the idea that Muslims must follow the first to sight the moon wherever in the world it might occur. Beneath these differing legal opinions lurk power struggles, informal rivalry among States determined to defend their authority to set the beginning of Ramadan. We are no longer involved in a debate over the wisest and most thorough-going interpretation of the texts, but in unhealthy conflicts that are in total contradiction with the call to unity that lies at the heart of Islam:

 وَاعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًاوَلَاتَفَرَّقُو   

And hold firmly to the rope of Allah all together and do not become divided.” (Qur’an 3:103)

The Prophetic tradition (hadith) dealing with the sighting of the new moon is of a general nature, which scholars have agreed upon: whoever has first sighted the new moon, wherever it may be, should be followed. This measure makes it possible to unite the world’s Muslims who will come naturally to agree upon the date of the Pilgrimage, which must be the same for all. Coherence and unity would be the happy result.

These criticisms lack consistency and suffer from crucial weakness in the light of analysis of the revealed texts, the Prophetic traditions (ahâdîth) and the heritage of Muslim thought (turâth). In the name of superficial analyses, partial or incomplete interpretations, power struggles and absence of representation, we see around us divisions and fractures within the community, serious divisions and fractures that are counter-productive and that undermine the unity of the world-wide spiritual community of Muslims. For a faith community that claims to celebrate unity and knowledge, it is sad to see quite the opposite occurring every year: endless division because leaders and scholars refuse to make timely use of the scientific knowledge of the contemporary era that would enable Muslims to unite, and to concentrate on what is essential: the spiritual experience of the fast.


The Muslims must be called to knowledge and wisdom. Our religion demands that we use our intelligence for the good, and that we rely upon our knowledge to advance. The great centuries of Muslim civilization were founded on the fusion of deep faith, intellectual and scientific curiosity, and ethical inquiry into the ultimate goals of knowledge and the use to which it might be put. It is high time to reconcile ourselves with the spiritual and intellectual energy of the early days. Science used with conscience is a celebration of the soul. If scholars dare not, if States are opposed because of base political considerations, if institutions fear their own shadow, it remains to the faithful themselves, to women and men, to set forth upon this path, to venture out onto the highroad of fidelity to the text while relying upon scientific data, and urge scholars and states to reconsider their positions.

We must begin our journey by ceasing to complain about the incompetence of this or that individual, institution or state while we ourselves have chosen to follow blindly his or her country, this or that scholar or the majority without considering the objective arguments and available information. The history of Islamic thought and law has in the past witnessed scholars and States reconsidering their official positions under pressure from the believers. The time has come to make an informed choice by relying upon the knowledge and the wisdom that will eventually, insha’Allah, unify the Muslims.

Last year, some Muslim authorities acknowledged that they had erred on setting the beginning of Ramadan. Catastrophe was narrowly averted: though the lunar month lasted 30 days, it was possible to reduce it to the admissible figure of 29 days. That was 1434/2013. But we are still caught up in the same debate, which has begun again only a few days from the beginning of Ramadan 1435/2014. What a sorry spectacle!

Astronomical calculation, based on all the elements and conditions discussed above, informs us that sighting of the new moon will be possible on Friday, June 27, in several countries of South America, and in French Polynesia. The first day of Ramadan will thus fall on June 28 2014. Based on the same calculations and date, Eïd al Fitr will take place Monday July 28 2014.

We need wisdom in order to unite, to make more informed use of science and knowledge, the better—it goes without saying—to respond to the call of the Most High.

For God is Most Knowing, Most High and Most Wise.

Prof. Tariq Ramadan


14 Commentaires

  1. Many thanks for this Professor Ramadan; being a new Muslim, this year will be my first year of Ramadan, and it is confusing to say the least to hear all of these different viewpoints and to have no idea at all on what day Ramadan even starts.

    I really appreciate you taking the time to research and write this for others; I’m looking forward greatly to your video series.

    Jazak Allah khayr.

    As salamu alaikum.

  2. Very well explanation mr. Ramadan. I also got confused about the beginning of the Ramadan but you made it clear. Thanks. Ramadan kareem.

  3. Dear brother in Islam,

    I am glad I came across your article. It further, confirms my view that we have to unify in fasting as we unify during the Hajj pilgrim. I do not understand Arabic at the moment, hence, have to rely on interpretations done by scholars and pray to Allah to give me the knowledge to see the truth through those interpretations.

    Your bold statement does create a question. In your opinion what is the responsibility of the individual to respond to the knowledge when our residing country do not follow?
    “The first day of Ramadan will thus fall on June 28 2014. Based on the same calculations and date, Eïd al Fitr will take place Monday July 28 2014.”

    Allah is most knowing and most wise.

    Salaam, Amei

    • Maybe the individual could start a reliable website that publishes the necessary astronomical calculations and predictions from this viewpoint. I’m sure all those who reflect will eventually see reason. For the first time ever, my next door neighbour and I celebrated Eid on different days last year. Since then I’ve been trying to get my head around how pathetic that was. So glad to read this paper, so glad. We need to spread the word until this voice of reason is heard and understood. Demystification around this topic is necessary. So if you now understand it, break it down for others. If I could afford to do it I would certainly take part in such an awareness campaign. Hey, maybe we can work together on it. What do you think?

  4. Excellent article, as usual. I finally understand why there are divisions with regard to sighting of the moon in Nigeria. Thank you Sir.I have shared with dozens.

  5. Salam Professor Ramadan,

    Thank you for your excellent article, I would like to ask whether the first day should be 28 June for all countries, or those for which the sun set after the first sighting in South America and polenesia? Should we be relying on the “world date line” rather than the time of the setting of the sun to determine the start and end of our days?

    Jazak Allah khair
    Bro Akram

  6. Thanks, Dr. Ramadan for this timely article. It gives us a starting point to move towards building a consensus decision in future.

  7. Your opinion, M. Ramadan, may be right or may be wrong. If you say that the hadith you cited saying that it is general, I am sorry even the companions of the Prophet didn’t agree with. I am sure that you are aware of the hadith of Ibn Abbas!
    Also, my concern is why starting Ramadan through different days is a problem? We are not praying Fajr, Maghrib ant the other prayers the same time in the day all around the world. So why do we have to start Ramadan the same day?
    Also, an opinion to be valid in Islam must be true whatever the place and the time in history. I mean, for example, go 200 years before, there were no Internet, phones, planes etc. and let’s say we saw the moon in USA, how could you warn the Africans and the Europeans the same night by riding a horse?
    If tomorrow, Internet and all the electronic technology vanish, starting Ramadan the same day would just be unrealizable, every area would have to sight for itself.
    To summarize, there is no problem to start Ramadan on different days according to the region we are as we have different Salat times depending on our position in the earth.

    • Please clarify things for me if I’ve misunderstood – When you’re praying Fajr on let’s say the 7th day of Rajab, it’s logical to think Muslims in a different time zone have already done so or will be doing so within the same day. It’s illogical for them to be praying Fajr of the 6th or 8th of Rajab within the same day regardless of time zone. To be honest, I think daily prayer is only relevant in this topic from the standpoint of how the calculations are made and the fact that this is accepted by most Muslim officials. This same methodology is used for calculating new moon sightings; so to start Ramadan on different dates around the world is not only a contradiction but also a huge problem when you live in an age of instantaneous worldwide communication, because it leads to chaos on a local level. To my mind, in the hadith you’re referring to, as they had already started Shawwal in Syria at the time the conversation took place in Medina, the only relevant issue was Medina’s observation of their perceived 29 or 30 days of Ramadan. If the Muslims in Syria had a way of communicating with the Muslims in Medina in real-time, they might have reported the moon sighting immediately, but this imagining as well as a future technological dystopia even for argument’s sake is counterproductive. In our current reality, Muslim consensus is to rely on officials to declare sightings. As all officials accept Saudi Arabia’s sighting for Dhu al-Hijjah, it would be cool if all officials could accept Saudi Arabia’s entire lunar calendar including Ramadan and Shawwal. It would however be even cooler if Saudi Arabia could in turn seek to unite all Muslims by implementing a consistent method of calculation that supports the first sighting on our planet. If the knowledge of our time makes it possible to calculate where and when the first sighting is likely to occur and a photograph can be taken, there’s no reason to still debate this topic. I guess it’s just another sad example of how we Muslims are failing Islam – Unless I’ve misunderstood.

    • your analysis is very lame. think about the way forward,do not drag the muslim umma backward. the professor has presented a very clear analysis.

  8. I have great respect for Dr. Ramadan, but with this article attempting to “end the debate” on this issue, he is actually revealing his lack of knowledge on the subject, and exposing a lack of scrupulousness in his scholarship. I honestly feel a bit embarrassed for him.

    The only argument he provides for calculating the dates of Ramadan is that it is sad to see Muslims arguing over this issue. That is hardly a proof. But even if it were, he is not putting the argument to rest. He is merely taking sides, notably with those who claim we need not follow the Prophetic injunction for us to sight the moon.

    This is not a unifying approach at all. Does he expect the ummah to stop observing the moon and relating its sightings to eachother, for the sake of unity? We all know that won’t occur. Sometimes the moon will be seen and sometimes it will not. We must simply go and look. This is not a complicated issue.

    Dr. Ramadan is right that we know a lot about when and where it might be possible and impossible to sight the moon. The key word there is “possible.” We don’t know for sure that it will be seen. We must go look. Every month is different and there are many variables. Sometimes it should be easily seen, but isn’t. Sometimes the moon age or lag time make it so we know that is will be extremely difficult to see. We simply need to go and look.

    For the start of Ramadan he says,”sighting of the new moon will be possible on Friday, June 27, in several countries of South America, and in French Polynesia. The first day of Ramadan will thus fall on June 28 2014.” Well, was the moon sighted in South America or French Polynesia or anywhere that night. NO! There was not a single, even dubious, sighting claim from those areas. So what does his calculation determine now? Would he like to adjust it to make it a bit more conservative? If he accepts the absurd sighting report that night from Yemen as credible, then he is basically admitting that calculation is completely irrelevant, and his whole argument collapses.

    He also appears to be espousing a “global sighting” position (ie. if a Muslim sees the moon anywhere everyone follows that sighting for the start of their dates.) Hmmm…. Does he not know that is impossible to implement? Does he not know of the international date line? For instance, how does he imagine Muslims in Sydney, Australia would follow a sighting on Friday night in Los Angeles, California? The California sighting would occur on Friday 8:45 their time, which is 1:45pm Saturday (THE NEXT DAY) in Syndey time. So how could everyone both start a “unified” fast on Saturday? The Aussies will have already finished eating lunch by the time they find out that Saturday was the 1st day of Ramadan! This is obviously unworkable.

    The solution is not complicated. We need to follow the sighting of the moon in our own region, and just go out and wait to see it. No need to worry about the standard ridiculous sighting claims from Saudi Arabia and Nigeria. Just stick to your home and go out and look for yourself. And if some people fast on a different day because they are following the Saudi’s or some Fiqh Council or some miraculous sighting claim, get over it. It is not such a big deal. Wish every Ramadan Mubarak and move on with it.

    The greatest proof is when you sight the moon yourself. It is exhilarating and moving. The kids love to do it. It brings people together out in nature together. It is the sunnah or our Prophet and it just plain feels right. Go try it every month for a year like the ancients always have, and you will see what I mean.

    Upon the Astronomical New Moon of 16 June 2015 14:00 UT
    sighted with the inner vision of God-given intellect.
    Peace to all.

  10. Assalamo Alaikum. Your website reads as follows:
    Aside from the fact that the conjunction must take place before sunset in order for the moon to be sighted, astronomers have determined the following conditions:

    1. The moon must have disappeared after sunset.
    2. The declination of the moon relative to the horizon must not be less than five degrees.
    3. The angular separation must not be less than eight degrees.

    I have two comments: 1) Condition# 1 is not clear. If the moon has disappeared before sunset, we can rule out sighting. But disappearance of moon after sunset says nothing 2) It is important to identify the scientists/astronomers who vouch for conditions 2 and 3 because they run quite contrary to what (the scientists of US Navy and UK’s Her Majesty Nautical Almanac Office say.

    I will appreciate your reply as I am a humble learner.


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