“Will they not then ponder on the Qur’an? If it had been from other than Allah they would have found therein much incongruity.” (4:82)
One of the problems with the Islamic calendar is its based on the moon, which doesn’t line up well with a solar year. According to the Quran, its forbidden to add months to the Islamic calendar, because Allah has fixed time in 632 AD so we shouldn’t mess with it. As usual, Muhammad was a product of his limited situation and didn’t perceive the flaws in this method of observing time.
Why do we have leap years
Precisely calculating time to match a year is difficult because the Earth’s rotation slightly changes due to earthquakes and other reasons. It’s also quite difficult to divide it into exactly 12 months and measure it using the moon or using the position of the sun in the horizon. The reason they wanted the calendar is to know when they planted their crops and things. So because of this people in ancient times used to mess with the calendar in order to keep the seasons fixed to keep the calendar useful to them.
That’s why they added a leap month, or a leap week or a leap day (like we do every 4 years)
With Muhammad, all he was doing is explaining the existing calendar that was already in existence with the pre-Islamic sacred months staying intact and actually forbade them to add a month to make it match. We see Muhammad meddling with the natural scientific progress in the following narration as well:
“What is this noise?” They said: “Palm trees that are being pollinated.” He said: “If they did not do that it would be better.” So they did not pollinate them that year, and the dates did not mature properly. they mentioned that to the Prophet (ﷺ) and he said: “If it is one of the matters of your religion, then refer to me.” (Ibn Majah)
How to measure time according to the Quran
They ask you, [O Muhammad], about the new moons. Say, “They are measurements of time for the people and for Hajj.” And it is not righteousness to enter houses from the back, but righteousness is [in] one who fears Allah. And enter houses from their doors. And fear Allah that you may succeed. (2:189)
So Allah agreed with the ancient practice of measuring time by lunar months, coincidentally that was the same method pre-Islamic Arabs used in that culture. Surely Muhammad is a product of his time and the Quran is a product of its time.
Emphasis on a strict 12 month lunar calendar
The Quran strangely emphasizes this concept, as if the current pre-Islamic Arab practices are set in stone.
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 […] (9:36)
Postponing (of the sacred month) is only an addition in unbelief, wherewith those who disbelieve are led astray, violating it one year and keeping it sacred another, that they may agree in the number (of months) that Allah has made sacred, and thus violate what Allah has made sacred; the evil of their doings is made fairseeming to them; and Allah does not guide the unbelieving people. (9:37)
And apparently this was so important (unlike abolishing slavery) that he mentioned it in his final sermon. Prophet Muhammad said:
Time has completed a cycle and assumed the form of the day when Allah created the heavens and the earth. The year contains twelve months of which four are sacred, three of them consecutive, viz. Dhul-Qa’dah, Dhul-Hijjah and Muharram and also Rajab of Mudar which comes between Jumadah and Sha’ban.
The solar calendar is off by about 10 days, causing the seasons to go out of whack. In order to fix this, the ancient Arabs used to practice “Nasi”, which means they used to add 1 or 2 months to the calendar,
“in order to harmonize the lunar with the solar year so that the Haj should always fall in the same season and they should be saved from the bother and inconvenience that are experienced by its observance according to the lunar year.”[ref]see Tafsir for Sayyid Abul Ala Maududi – Tafhim al-Qur’an[/ref]
Many cultures use a solar calendar because of the flaws inherent with the lunar one. Bengalis as well have their own calendar. According to one theory, the new calendar was adopted in order to make it easier to collect taxes for the harvest.
During the Mughal rule, land taxes were collected from Bengali people according to the Islamic Hijri calendar. This calendar was a lunar calendar, and its new year did not coincide with the solar agricultural cycles. According to some sources, the current Bengali calendar owes its origin in Bengal to the rule of Mughal Emperor Akbar who adopted it to time the tax year to the harvest. (Bengali Calendars on Wikipedia)
Is the Quran truly the word of God? Or a product of it’s time? What do you think?