Is the Islamic calendar actually a solar calendar? (No, it isn't).

TL/DR: No, it's a lunar calendar.

There currently is a movement / trend online which claims that we have all misunderstood the nature of the Islamic calendar. 

Their central claim is that the Islamic calendar is actually a solar calendar, or a luni-solar calendar - meaning 12 lunar months with occasional leap years with 13 months.  This is how the Jewish calendar currently works. 

They base the claim on the fact that some of the month names appear to have seasonal names, like 'Rabi al Awwal' means 'First Spring;, or that Ramadan means 'hot' which means is should always be in the summer, or just after the summer in the autumn.

Their claims appear to totally go against the Quranic narrative, which affirms 12 month (and not 13) and indeed bans the practice of adding leap years, or manipulating the calendar, called Nasi. 

Recently, astronomer Muhammad Shauket Odeh has totally refuted these claims in this video:

Dr Odeh's video is in Arabic -  here is a summary / translation of the video, provided by Chat GPT.

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TRANSLATION / SUMMARY OF VIDEO: 

In the name of Allah, the Most Merciful, the Most Compassionate. Peace and blessings be upon our master Muhammad, the best of prayers and the most complete of salutations.

Recently, an episode has spread containing many false claims. Its main topic is nasīʾ (intercalation), and it argues that the Ramadan we know in our present time is incorrectly dated and does not correspond to the true time of Ramadan, that the Hijri months are disordered, that the Arabs continued practicing nasīʾ until a late period, even into the time of our master ʿUmar ibn al-Khaṭṭāb, and other doubts raised about the Hijri calendar.

These doubts are mainly:

1. That the current time of Ramadan is wrong because of nasīʾ
2. That nasīʾ continued to be used until the time of ʿUmar ibn al-Khaṭṭāb
3. That the calendar as we know it now was put in place by ʿUmar when he supposedly established its foundations

In truth, there is not a single episode or one single treatment that addresses all of these doubts together. There are some clips that mention them all briefly, but there is one clip in particular that has spread very widely recently, and several people sent it to me asking for a response. So I felt it necessary to make this video in order to answer it in a methodical and detailed way: what exactly is the doubt, and how do we respond to it?

Everything raised in that video, especially the long one — there is a long clip, perhaps more than an hour long, discussing it in detail — so our subject now, briefly, is to respond to these doubts.

The truth is that I have been interested in this topic for a very long time. I started writing research on the topic of nasīʾ around 15 years ago, and indeed it kept growing and growing, and I have still not published it until now. I reviewed it several times. I do not mean that I have been continuously researching this topic for 15 years without pause; rather, it has been intermittent. The topic is actually very complex, and like many of our historical questions, there are no issues in it that can be stated with absolute certainty as the full truth of what was actually practiced. This is one of those topics.

We find differing sources, contradictory reports, and this has confused some people — indeed everyone. There are some matters, as I will explain shortly, that simply cannot be settled with absolute certainty.

Now, what is the reasoning of those who raise these doubts? What proofs did they present in support of their view? From the three doubts I mentioned, they mainly said:

First, what is the wisdom behind the sacred months? They claimed that the wisdom behind the sacred months was to prevent hunting animals so that they could reproduce. Since reproduction occurs in a fixed season, they say, then it would not make sense for the Hijri months to rotate through the seasons and keep changing, otherwise the sacred months would lose their meaning, because this, according to them, is the wisdom of the sacred months.

This, of course, is not correct, as I will explain later.

Second, they said that the names of the months necessarily imply that the Hijri months had to be fixed to known seasons. Their evidence was the names themselves: Ramadan from intense heat, Rabīʿ from spring, Jumādā from cold weather.

Incidentally, I myself was surprised some time ago. As I mentioned, every now and then I return to research this issue. About a year and a half or two years ago, I came across some excellent studies on this topic, and I benefited from them greatly. Unfortunately, these studies were not written by Arabs or Muslims — they were written by Orientalists. Most of these important studies, by the way, were written more than 150 years ago.

Among the things I found there — and I found many things new to me — and by the way, this is what always forced me to postpone publication. Whenever I thought I had finished the research, I would say to myself: no, I have not yet reached final conviction, nor the stage where this is really ready for publication. So I would review it again, and with new sources new questions and new disagreements would open up for me, and so I would delay publishing it. Until now, it has still not been published. I ask Allah that it be published soon, God willing.

One of these discoveries was that Jumādā is not even related to the word jamād in the sense people usually assume — that of freezing. Rather, it is closer to another meaning entirely, and many references mention that it refers instead to barren land devoid of vegetation. That is one of the Arabic meanings of jumādā. In any case, that is not our main subject; it is just a side note.

So those raising these doubts said that the names of the Hijri months necessarily require that they be fixed to the seasons, and therefore the Arabs must have practiced nasīʾ.

Now, what is the story here? What is the basis of the whole issue?

The foundation is as follows:

The lunar year consists of 12 months, and the lunar year is 11 days shorter than the solar year. Because of that, the Hijri months rotate through the seasons — they are not fixed. Ramadan does not always come in summer, nor winter, nor spring. The reason the whole Hijri year shifts is the difference in the length of the two years. The lunar year is shorter than the solar year by 11 days. Thus every three years there is approximately a difference of one month.

So if Ramadan is on the first of March, then after three years it will approximately be on the first of February, and after another three years on the first of January, and so on. In this way it moves backwards by roughly one month every three years. Therefore, the Hijri months are not fixed to the seasons.

This is the first point.

So what problem arose from this?

The problem was that the Arabs in pre-Islamic times already had ḥajj, even before Islam. Ḥajj is something ancient. It was not suitable for the people of the Arabian Peninsula and the people of Mecca for the pilgrimage to come in the summer season, because their trade — and their very lives in that time — were built around it. Trade was very important. So it did not suit them for pilgrimage to fall during summer seasons. Therefore, they needed a solution.

How could this problem be solved? By fixing the Hijri months to the solar cycle. But how could that be done? Through something called nasīʾ. Nasīʾ, in one of its meanings, means that every few years — every two, three, or four years — one adds a month to the lunar year. Instead of the lunar year being 12 months, it becomes 13 months. This is nasīʾ in one of its meanings.

Now, there was another problem: there were sacred months, and four months were sacred, three of them consecutive: Dhū al-Qaʿdah, Dhū al-Ḥijjah, and Muḥarram. In pre-Islamic times it was difficult for some Arab tribes to stop fighting for three consecutive months, because fighting was part of their livelihood. So they found it difficult to stop war for that long.

What was the solution? To alter the sacred months. How? Through nasīʾ.

So we are in front of two main problems that arose among the Arabs of pre-Islamic Arabia, and the solution to both was said to be nasīʾ:

• solving the issue of the consecutive sacred months
• solving the problem of the pilgrimage moving into summer

Now, how do we respond to these doubts?

First, one of those clips built its argument mainly on the claim that the wisdom of the sacred months was animal reproduction, and since reproduction happens in a fixed solar season, the sacred months cannot be variable, otherwise they lose their meaning.

The real problem in that clip — the one that spread like wildfire — is that at first glance it sounds convincing, and that is the trap. Sometimes when someone presents a dialectical argument or a hypothesis, and drags the listener into it, especially if the listener has no knowledge of the matter, he forgets to ask the speaker: wait a minute — where are you taking me? You have just stated a premise and said that the reason for the sacred months is reproduction, and, “people, reproduction is fixed, so how can the sacred months vary? Therefore they lost their meaning.” And then we start responding, “well yes, that is true, how…?”

No. We should not even allow the people of doubts to drag us into their mistaken premises. Who said that the wisdom behind the sacred months is animal reproduction? This is your own opinion, your own idea. We do not find this mentioned anywhere. When we read the books of tafsīr that discuss the sacred months, we do not find this claim at all. It is not there in the معتبر works, nor even in the غير معتبر ones. It is simply an idea in your own head, and you want me to follow you into it and believe you. So your starting point is invalid, and no conclusion can be built on it.

That is point number one. The wisdom behind the sacred months has nothing to do with animal reproduction. So the whole argument you spent fifteen minutes developing in that video is invalid from its very starting point.

Second, that clip specifically — and many others — exaggerated the claim that ʿUmar ibn al-Khaṭṭāb established the Hijri calendar, and that nasīʾ continued to be used among the Arabs until the Prophet’s time, the Companions’ time, and even after that, and that the Arabs — the Muslims in particular — kept using a calendar with nasīʾ until ʿUmar abolished it.

This is, in truth, an extremely ugly statement, and there is no evidence or reference for it.

There is something we must pay great attention to, and unfortunately many ordinary people lack it in religious and scientific matters — and I am especially focusing on scientific method here in my response: it is not valid for someone to present a claim and then start elaborating on it before giving the source. No. Wait. If you give me something, give me your reference, your chain, your evidence, tell me who said this. Do not invent a suspicion and then demand I follow you into it.

This الكلام is not correct. ʿUmar did not establish the Hijri calendar in the sense being claimed. Nor were the months thirteen, nor was the year thirteen months until ʿUmar stopped it.

The year being 12 months is something very ancient. If we go back to Sūrat al-Tawbah, verse 36, Allah says:

“Indeed, the number of months with Allah is twelve months in the Book of Allah, from the day He created the heavens and the earth. Of these, four are sacred.”

So the fact that the year is 12 months is known. This was not invented by ʿUmar, nor even by the Muslims. In fact, this is something known by human beings naturally from ancient times, not just in Arab and Islamic societies. The peoples of the earth all followed this.

And this verse confirms it:

“The number of months with Allah is twelve months… from the day He created the heavens and the earth.”

This is not a new legislation, otherwise this verse would not have been revealed years before ʿUmar. So this whole claim is incorrect.

So what did ʿUmar actually do? I am not saying that ʿUmar did nothing, but he did not found the calendar in the way being claimed. The twelve months were known منذ زمن بعيد among Arabs and non-Arabs, Muslims and non-Muslims. Even their names and order were known since long ago.

We read in the books of history that the leaders of the Arab tribes gathered in Mecca in the year 412 CE, which corresponds to about 220 years before the Hijrah, and at that time they agreed to unify the calendar and they assigned the names of the months then. For those who ask when Muḥarram, Ṣafar, Rabīʿ al-Awwal, Rabīʿ al-Thānī, Jumādā, Ramadan, Shawwāl, Dhū… these names were assigned — approximately then.

I am not trying to specify the exact year because we know this is one of the disputed issues. 412 is one opinion. There are other opinions a little before or after that. But the point is that we are within a range of roughly 200 years before the Hijrah.

So the fact that the year was 12 months, and that these names were known, is something from long ago, followed by the Arabs in the Jāhiliyyah and later in Islam.

As for what ʿUmar did, I will come to that shortly.

Now, what is nasīʾ?

Let me separate completely the meaning of nasīʾ.

Linguistically, nasīʾ has two meanings:

• postponement
• addition

And that is what the Arabs did — or at least these are the two possible forms attributed to them. We will later discuss whether they did both or only one.

So first: nasīʾ of postponement. This solves the first problem we mentioned, namely the sacred months coming one after another: Dhū al-Qaʿdah, Dhū al-Ḥijjah, Muḥarram. The Arabs are said to have begun using nasīʾ, according to nearly all studies, around 200 years before the Hijrah.

What did they do? They said: when the pilgrimage ended, the Arabs would gather in Mecca, and a man called al-Qalammus — which was a title, not a personal name, and a number of known men held this office in succession — if there was need in that year, he would announce: “People, this year Muḥarram is not the sacred month. The sacredness of Muḥarram is transferred to Ṣafar.”

So instead of Muḥarram being sacred, Ṣafar became sacred that year, thus creating room for fighting after the ḥajj. This is the “postponement” type of nasīʾ.

This is what is meant in the verse:

“that they may keep count of what Allah has made sacred”

Meaning: they keep the number of sacred months at four, but they shift which month is sacred.

This form of nasīʾ is not disputed. No one seriously disputes that the Arabs practiced this kind of postponement. Al-Ṭabarī mentioned it in his Tafsīr, Ibn Abī Ḥātim, al-Naḥḥās, Ibn ʿAṭiyyah, al-Bayhaqī, al-Suhaylī, Ibn al-Jawzī, al-Qurṭubī, Ibn Kathīr, al-Nīsābūrī, al-ʿAynī, al-Biqāʿī, al-Suyūṭī, Abū al-Suʿūd, Ibn ʿAjībah, al-Shawkānī, Ḥaydarābādī, Sayyid Quṭb, Ibn ʿĀshūr — and many others.

These are not the only ones, but they are among those whose words I personally found and read in their manuscripts or published books.

So, nasīʾ of postponement is abundantly attested.

Now we come to the second form: nasīʾ of addition.

Nasīʾ of postponement does not solve the issue of fixing ḥajj to a season. To do that, one would need something else: nasīʾ in the sense of adding a thirteenth month every so often.

So: did the Arabs do this?

This is a large and complicated discussion.

What is certain is that the Jews practiced intercalation. They inserted seven months over a cycle of nineteen years. Because Jews lived among Arabs and Muslims in Medina, some argue that the Arabs learned this from them in pre-Islamic times and adopted it as a way to fix ḥajj to a stable season.

But after more than 15 years of research, I say decisively: there is no definitive proof that the Arabs practiced this form of nasīʾ of addition. There are explicit texts from commentators, historians, and astronomers saying that they did, and some even explain how they supposedly did it. Some said they used a cycle like the Jews. Others said they added a month every two years. Great astronomers such as Abū Maʿshar al-Balkhī, al-Bīrūnī, and al-Nīsābūrī said this.

But there are other views too. Al-Maqrīzī said they intercalated nine months every 24 years. Al-Masʿūdī said every three years. So the matter is not settled.

And in fact, there are strong arguments that they did not practice nasīʾ of addition at all.

One of the Orientalist researchers I read argued this cleverly through non-Muslim historical records. He took an ancient event recorded outside the Muslim sources, tied it to the pilgrimage and to a known historical date in the Roman calendar, and showed that when you convert the Hijri date using our present non-intercalated system, it matches perfectly. If intercalation had been in effect, the dates would not line up.

So some researchers used such external evidence to argue strongly that the Arabs did not practice nasīʾ of addition at all.

But let us assume, just for the sake of argument, that they did use both forms: postponement and addition.

Then a very important point comes:

Nasīʾ was prohibited by a clear Qur’anic verse.

Allah says in Sūrat al-Tawbah, verse 37:

“Indeed, nasīʾ is only an increase in disbelief, by which those who disbelieve are led astray. They make it lawful one year and unlawful another year, so as to correspond to the number made sacred by Allah, and thus make lawful what Allah has forbidden. The evil of their deeds has been made pleasing to them, and Allah does not guide the disbelieving people.”

This verse, according to the strongest opinion, was revealed in the 9th year after Hijrah.

If we read the verse carefully, it actually points more strongly to nasīʾ of postponement rather than addition, because it says: “they make it lawful one year and unlawful another year, so as to correspond to the number Allah has made sacred.” This fits shifting the sacredness from Muḥarram to Ṣafar.

Still, whether it refers to postponement alone or both, the key point is this: nasīʾ was forbidden in the 9th year.

Now think: does it make any sense that after a verse says:

“nasīʾ is an increase in disbelief”
and
“Allah does not guide the disbelieving people”

that the Muslims and the Companions — from Abū Bakr onward, and then ʿUmar — would continue practicing nasīʾ after that?

Of course not.

This verse decisively ends the question. There could not have been nasīʾ after this verse.

Even if the last occurrence of nasīʾ was before that — in the 8th year, or 7th year — once the verse was revealed in the 9th year, the practice was over. Finished.

But there is something else that confirms this even more powerfully.

We have the famous hadith of the Prophet ﷺ in the Farewell Pilgrimage, narrated in Bukhārī and Muslim, where he said:

“Time has returned to its original form as it was on the day Allah created the heavens and the earth. The year is twelve months, of which four are sacred…”

This hadith is authentic beyond dispute.

And it is astonishing to me that anyone still speaks after this hadith as if there is still confusion. Whether the Arabs practiced nasīʾ of postponement or addition, or both, this hadith settles the matter: time had returned to its proper order by the Farewell Pilgrimage.

If, for argument’s sake, they had used intercalation for around 200 years, then eventually the cycle would come full circle. And the Prophet ﷺ explicitly said that at that point, time had returned to how Allah originally made it. So the matter is closed.

Nasīʾ was prohibited. Its effects ended. The file was closed. Finished.

I honestly wonder what the purpose of these people is. I am not even relying on a weak hadith. This is a hadith agreed upon by Bukhārī and Muslim, a hadith that no one questions.

So what did ʿUmar do then?

Very simply: ʿUmar did one thing — and I do not diminish it, but we should not exaggerate it in a way that makes people think the Muslims lived for sixteen or seventeen years on a confused calendar.

No. Their calendar was already clear and orderly after the prohibition of nasīʾ.

What happened was that a letter came to Abū Mūsā al-Ashʿarī dated simply “Shaʿbān” without any year. So he wrote to ʿUmar saying: “Commander of the Faithful, letters come to us dated in Shaʿbān, but we do not know which Shaʿbān this is — this year, last year, or another year?”

That was the issue.

The Arabs before Islam, and even the Muslims early on, used months, but they did not number the years systematically. Events were often dated by major happenings, like “the Year of the Elephant,” “the Year of Sorrow,” and so on.

So ʿUmar gathered the Companions and they discussed the issue. They realized they needed to assign numbers to the years. They debated: from what point should we start? The birth of the Prophet? His death? The Hijrah? They settled on the Hijrah, because it was one of the greatest events in Islamic history.

The Hijrah itself did not occur on 1 Muḥarram — it occurred in Rabīʿ al-Awwal — but they decided to make the year in which the Hijrah occurred Year One, beginning from Muḥarram of that year.

That is all ʿUmar did:

• he numbered the years
• he did not invent the months
• he did not establish the fact that the year had twelve months
• he did not fix the order of the months
• he did not create the calendar from nothing

All of that already existed long before Islam.

Now to conclude:

Some may say: you have given many religious proofs. Fine. Let me add that there are also scientific and historical proofs.

We have many historical events — from the Hijrah onward, the death of Ibrāhīm the son of the Prophet ﷺ, and many later events — recorded in Hijri dates and also in other calendars: Roman, Hebrew, and so on, in non-Muslim sources. When scholars convert those Hijri dates into other calendars using our current non-intercalated system, the dates match. If there had been nasīʾ operating among Muslims after the 9th year, those dates would not line up.

So in addition to Qur’an and Sunnah, there is also historical evidence from external sources that there was no nasīʾ practiced by Muslims after, at the latest, the 9th year of Hijrah.

Therefore, the Hijri months are orderly and sound.

Finally, someone may ask: if the months move through the seasons, then why are they called Ramadan, Rabīʿ, and so on?

The answer is simple, and the books usually mention two possibilities:

First, when the Arabs named the months around 200 years before Hijrah, they named them according to the climatic conditions prevailing at that time.

Second — and this is the explanation I personally lean toward, though I do not claim a definitive proof — when they named them, they may also already have been practicing nasīʾ and keeping them fixed at those seasons at that time. Later, when nasīʾ was abolished, the names remained.

Either way, this is not a difficult problem. The naming of the months has a simple explanation and does not require all this exaggerated debate.

This is what I felt obliged to clarify.

Thank you for listening.

And peace be upon you, and the mercy of Allah, and His blessings.