AHC: Make the Hijri Calendar the Most Widely Used Calendar

[Happers]

Islam seems to be a favorite topic on here. So, allow me to give you a challenge.

Make the Hijri Calendar (Islamic Calendar) as widely used as the Gregorian Calendar today.

Try not to just say "Make Islam the Majority Religion", be creative, think about it, the Hijri Calendar was advanced compared to other calendars. Non-Muslims could have adopted it for its accuracy.

 

[Kishan]

Hijri Calendar is not a solar calendar, but a lunar one. It also doesn't make adjustments to synchronize it with solar years, as in the case of luni-solar calendars. In agricultural societies the weather changes based on the revolution of earth is very important and the agricultural activities are planned based on those calculations. If a total lunar calendar with 354 days in place of 365.25 days is adopted, there will be a constant drifting of seasons, with an advanced arrival of seasons. This will make a mess of agricultural planning. I think the Muslim countries face this difficulty with Hijri Calendar, but they stick on with that calendar due to their religious faith.

 

[Mental_Wizard]

Does it acutally have to be the Hijri Calendar, or can it be an exactly equal lunar calendar that is not that calendar?

 

[Happers]

Does it acutally have to be the Hijri Calendar, or can it be an exactly equal lunar calendar that is not that calendar?

Lunar calendar is fine. I realize that the Hijri calendar is basically impossible to make the primary calendar of the world.

 

[Happers]

Hijri Calendar is not a solar calendar, but a lunar one. It also doesn't make adjustments to synchronize it with solar years, as in the case of luni-solar calendars. In agricultural societies the weather changes based on the revolution of earth is very important and the agricultural activities are planned based on those calculations. If a total lunar calendar with 354 days in place of 365.25 days is adopted, there will be a constant drifting of seasons, with an advanced arrival of seasons. This will make a mess of agricultural planning. I think the Muslim countries face this difficulty with Hijri Calendar, but they stick on with that calendar due to their religious faith.

Yeah...after posting this I realized how inaccurate and unhelpful the Hajri calendar is.

Is there another Lunar calendar that is more accurate and could actually be helpful?

 

[Mental_Wizard]

@Happers

Babylonian, Celtic, Chinese, and Japanese. There are others- such as Vietnamese and Mongolian, but I am talking about cultures that consistently were culturally influential.

 

[Dan1988]

Hijri Calendar is not a solar calendar, but a lunar one.

Except Iran and Afghanistan, where they adapted the Hijri calendar to their existing solar calendars. That's probably the form of Hijri calendar that the OP is talking about. Which is OK as far as solar calendars go, except for the fact that it is observation-based and thus is prone to human error. At the base of the Solar Hijri calendar is actually the Jalâlî sidereal calendar, with the months corresponding to the zodiac. In which case either Zoroastrianism becomes the majority religion if we use earlier forms, or we actually have the Assyrian Church of the East become associated with this form of the Solar Hijri calendar, with the zodiac months largely swapped with the months from the Babylonian and Lunar Hijri calendars and whatever point of origin the Church of the East can come up with that corresponds with Jesus. Such modification would be akin to how the Ottoman Empire modified the Julian calendar to suit its needs, from which comes the Arabic names for the Gregorian calendar months in Iraq and the Levant. Overall, though, at its core, the Lunar Hijri calendar is only accurate if you're on the Arabian Peninsula. Outside of the Arabian Peninsula, you're going to have problems - which is why you have these modifications of the Hijri calendar to make it fit the usual solar calendar.

 

[Happers]

Except Iran and Afghanistan, where they adapted the Hijri calendar to their existing solar calendars. That's probably the form of Hijri calendar that the OP is talking about. Which is OK as far as solar calendars go, except for the fact that it is observation-based and thus is prone to human error. At the base of the Solar Hijri calendar is actually the Jalâlî sidereal calendar, with the months corresponding to the zodiac. In which case either Zoroastrianism becomes the majority religion if we use earlier forms, or we actually have the Assyrian Church of the East become associated with this form of the Solar Hijri calendar, with the zodiac months largely swapped with the months from the Babylonian and Lunar Hijri calendars and whatever point of origin the Church of the East can come up with that corresponds with Jesus. Such modification would be akin to how the Ottoman Empire modified the Julian calendar to suit its needs, from which comes the Arabic names for the Gregorian calendar months in Iraq and the Levant. Overall, though, at its core, the Lunar Hijri calendar is only accurate if you're on the Arabian Peninsula. Outside of the Arabian Peninsula, you're going to have problems - which is why you have these modifications of the Hijri calendar to make it fit the usual solar calendar.

So, would making the Hijri Calender more like the Iranian and Afghan calender fix a lot of the problems with the traditional Hijri calendar?

 

[Dan1988]

So, would making the Hijri Calender more like the Iranian and Afghan calender fix a lot of the problems with the traditional Hijri calendar?

Most, but not all. There would have to be a way to devise a mathematical formula to predict which year would have leap days or not - which would be absolutely helpful for those times where astronomical phenomena cannot be seen due to things like, for example, clouds. Of course, this all goes for any calendar, not just the Hijri one (especially once you remove the point of origin determining the years away from the Hegira), but for the Hijri calendar it would be even more so it one outside of the Arabian Peninsula wanted to adopt it for civil purposes. It should be noted, at this point, that New Year's Day in those areas which adopt a Solar Hijri or variation of the Babylonian calendar would coincide with the arrival of spring and occurring at the same time as the vernal equinox, such as Nowruz; timing the beginning of the calendar with the arrival of spring is very useful if you're a farmer and want to know when to start planting crops.

 

[sloreck]

The Jewish calendar is a lunar calendar, however it inserts an extra month every so many years to keep things in line with the solar year. What this means is that there is a "wobble" of about 1 1/2 weeks +/- centered on the mean during the cycle. This why holidays (such as the New Year which is in the fall) vary some but stay within the "season" they belong in. The bottom line is any lunar calendar has to have a system dealing with the asynchrony between the lunar year and the solar year.

 

[Fabius Maximus]

Try not to just say "Make Islam the Majority Religion", be creative, think about it, the Hijri Calendar was advanced compared to other calendars. Non-Muslims could have adopted it for its accuracy.

You wouldn't necessarily have to make Islam the majority religion, but you'd probably have to make it more influential compared to OTL. Have the Islamic world remain at the forefront of scientific and technological innovation, have Islamic states rather than Christian ones become globally dominant, and you'd see other countries adopting the Islamic calendar for much the same reasons as they adopted the Gregorian calendar IOTL.

Hijri Calendar is not a solar calendar, but a lunar one. It also doesn't make adjustments to synchronize it with solar years, as in the case of luni-solar calendars. In agricultural societies the weather changes based on the revolution of earth is very important and the agricultural activities are planned based on those calculations. If a total lunar calendar with 354 days in place of 365.25 days is adopted, there will be a constant drifting of seasons, with an advanced arrival of seasons. This will make a mess of agricultural planning. I think the Muslim countries face this difficulty with Hijri Calendar, but they stick on with that calendar due to their religious faith

Maybe you could have a Caliph *Gregory come along to fix it at some point?

The Jewish calendar is a lunar calendar, however it inserts an extra month every so many years to keep things in line with the solar year.

Theoretically that was what the pre-Julian Roman calendar was like, although over time it drifted pretty badly due to laxity/corruption on the part of the pontiffs who were meant to add the extra months when appropriate. (E.g., an election is scheduled next month, you want more time to canvass, so you bribe the pontiff to add an extra month first.) By the time Caesar did his reforms the Roman calendar had drifted by something like two months.

 

[Dan1988]

The Jewish calendar is a lunar calendar, however it inserts an extra month every so many years to keep things in line with the solar year. What this means is that there is a "wobble" of about 1 1/2 weeks +/- centered on the mean during the cycle. This why holidays (such as the New Year which is in the fall) vary some but stay within the "season" they belong in. The bottom line is any lunar calendar has to have a system dealing with the asynchrony between the lunar year and the solar year.

That's because with the exception of the Anno Mundi epoch (borrowed largely from the Byzantines) much of the Jewish calendar is an adaptation of the Babylonian calendar, which operates along the same principles.

 

[Wallet]

Arabs win both the Battle of Tours and take Constanople around 730. Islam advances more into Central and Eastern Europe. Eventually Italy and Moscovia convert. The Muslims are pushed back into the Middle East after centuries (ATL crusades were Northern European states freeing Europe) but the peasants would still use the lunar calendar afterwards.

 

[Kishan]

The lunar calendar can be synchronized with the solar calendar by adding additional months in between. The difference between a lunar year and solar year is 11 days and in eight years the difference become 90 days. The lunar year become three months shorter in eight years and an addition of three months can make them almost equal. The three months may be added in an interval of two or three years ie. in third, sixth and eighth years. The usual length of a lunar year is 354 with months of 30 and 29 days alternatively. If the additional months are added the number of days in eight years will be (1)354, (2)354, (3)384, (4)354, (5)354, (6)383, (7)354, (8)384, and so on. This sequence may require changes as it progresses. In Hindu lunar calendar similar method of additional months are used to keep it in line with the solar calendar.