against the calendar thread

a twitter thread recently made the rounds:


i thought it was pretty funny, until i thought about it a bit. i have three main gripes:

i'm going to focus mainly on the second bullet here. most of this is written off the cuff so if i have anything wrong, let me know and i'll rectify it. i've tried to be somewhat fair to this fictional human. TODO cite up

"yeah we divide our year into a number of sub units called 'months' made up a number of days, and they're not all the same length"
"I guess that's unavoidable, if your rotations-count per orbit is a prime number"
"yeah, our's isn't prime"

the name "month" really gives the game away here. it's pretty clear that it shares a root with "moon", and the months are approximately the length of a moon cycle.

"but surely you have most of these 'months' the same length and just make the last one shorter or longer?"
"No... They're different lengths following no logical pattern"

i'd say it's quite logical. every other month has thirty-one days. the others have thirty days. there are a couple of quirks here, which i'll come onto.

"and we further subdivide the months into 'weeks', which is 7 days."
"ahh, so each month is an integer multiple of weeks?"
"that would make sense, but no. Only one is, sometimes"

i'll cover this in a bit.

"yeah our orbit around the sun isn't an integer number of days, so we have to change the number of days to in a year from time to time"
"oh yes, a similar thing happens on Epsilon Indi 7, where they have to add an extra day every 39 years to keep holidays on track"
"yeah that's how ours work! Although the ratio doesn't work out cleanly, so we just do every 4 years, except every 100 years, except except every 400 years"

i can't work out if the person considers this an issue or not. i don't because it's documented enough and makes things work.

"oh, you number your years? What's the epoch?"
"uh, it's supposed to be the birth of a religious leader, but they got the math wrong so it's off by 4 years, if he existed at all."
"if? You based your calendar off the birth date of someone you're not sure exists?"
"yeah. He's written about in a famous book but historical records are spotty."

first of all, the new testament is as much a historical record as most other greek writings from that period written for the purposes of documentation. just because it's considered sacred now doesn't change that.

second, in scholarly circles there's basically no question that jesus existed. his divinity, lalala, obviously, but we can assume that he existed for all intents and purposes.

also, all historical records are spotty. history was written by the winners and all.

"interesting. I didn't realize your planet was one of the ones with a single universal religion, that usually only happens in partial or complete hive minds."
"uhh, we're not."
"You're not?!"
"yeah we have multiple religions."
"oh but they all have a common ancestor, which agrees on the existence of that leader, right?"
"uh, no. Two of the big ones do, but most of the others don't believe in him"

i'd say that judaism probably counts as one of the big ones. it's generally accepted in judaism that jesus existed, either as a jewish teacher or a false messiah. messianic jews believe in the divinity of jesus.


that's not a surprise. jesus became an important historical figure in a civilization with a large empire, which then gave birth to other civilizations with large empires. replacing indigenous systems with those of the invading culture is how colonialism works.

"well, on his birth. And yeah, we got it wrong by a couple years."

this isn't surprising either. "historical records are spotty".

"OK, fine. So, you have somewhat complicated rules about when you change the length of your years, and I'm scared to ask this, but... You definitely just add or subtract that extra day at the end, right?"
".... Nope."
"At the start of the year? "
"nah. The end of the second month"
"I'm not sure, really."

at least you say you're not sure. it's because march used to be the first month, which made february the last. a nice logical time to add that extra day.

"huh. So at this point I'm dreading asking this, but how do you measure time within each day?"
"oh that's much simpler. Each day is divided into hours, each hour has minutes, and each minute has seconds."
"ok. And 10 of each?"
"10 hours? No. There's 24 hours, 60 minutes, 60 seconds"
".... I thought you said you used a base-10 counting system"

"we do! Mostly. But our time system came from some long gone civilization that liked base-60 like 5000 years ago"
"and you haven't changed it since?"
"huh. Okay, so why 24? That's not a divisor of 60"
"oh because it's actually 12!"

i'm going to come back to my usual "pragmatic unit size" thing here. an hour is a decent length of time. we're only awake for around half the day. two halves is better than splitting into uneven sizes, so...

"yeah each day is 24 hours but they are divided into two sets of 12."
"and that's 5 12s, right, I see the logic here, almost. So like, after hour 12, it becomes the second half, which is 1?"
"No, after 11."
"oh, you zero-index them! So it's hours 0-11 in the first half, then 12-23 in the second half?"
"No. 12 to 11 in the first half, and again in the second half"

i don't know the reasoning behind this (but i'm sure that there is something super interesting!), i'd guess it's to do with the fact we have round clocks though. it's a zero indexed twenty four hour system, represented on a twelve hour clock. because we're awake during the day and mostly asleep at midnight, it makes more sense to have the second half of the day represented on the clock face.

"that is not how numbers work. And how do you tell first 12 apart from second 12?"
"oh we don't use numbers for that!"
"you don't number the two halves of your day?"

a lot of places just use twenty-four hour time. in speech often it's not necessary to clarify. luckily we have a way...

"nah, we call them AM and PM"

at this point i think am and pm can be considered words in their own right. and as interesting as etymology is, you don't actually need to know it to successfully use the words. maybe ayem and piem are words for one and two in a language? then the alien would be happy.

"I think it's ante-meridian and post-meridian? But I'm not sure, I dont know much Latin"
"yeah it's an ancient language from an old empire which controlled a lot of the world and we still use some of their terms"

glad you acknowledge the old empire which controlled a lot of the world and forced their customs on the rest of the empire now.

"oh, and that was the civilization that liked base-60 and set up your time system?"
"that would make sense, but... No, completely different one."

this doesn't not make sense though. i'm uncertain of how the system for measuring time spread through the near east, but something so fundamental is difficult to change significantly once people are used to it. caesar's calendar reform was incremental, so it worked. napoleon's metric week didn't catch on because it was too different (and he made weekends shorter), so it didn't catch on.

"okay, and what do you do to if you want to measure very short times, shorter than a second?"
"oh we use milliseconds and microseconds"
"ahh, those are a 60th of a second and then 60th of the other?"
"No. Thousandths."
"so you switch to base-10 at last, but only for subdivisions of the second?"
"but at thousands, ie, ten tens tens"
"yeah. Technically we have deciseconds and centiseconds, which are 1/10 of a second, and 1/100 of a second, but no one really uses them. We just use milli."

"that seems more like a base-1000 system than a base-10 system."

i agree that switching to base ten here is confusing. obviously it happened because the metric system was widespread by the time we had the ability to accurately measure second subdivions. but you've admitted it's still a base ten system with deciseconds and centiseconds. the thing is, anyone who cares about measuring time with a resolution of less than a second probably wants as much accuracy as possible, so why bother with deciseconds when milliseconds are right there?

"it kinda is? We do a similar thing with measures of volume and distance and mass."
"but you still call it base-10?"

yeah, maybe we should have made a different weight the standard. i personally think metric is a very okay system at best, so i'm not going to defend it too hard. the reason we prefer kilograms is the reason i think imperial measures are better: it's a weight that is more in alignment with the things we weigh regularly.

"so let me see if I get this right:
Your years are divided in 10 months, each of which is some variable number of days, the SECOND of which varies based on a complex formula...
and each day is divided into two halves of 12 hours, of 60 minutes, 60 seconds, 1000 milliseconds?"
"12 months, actually."
"right, because of the ancient civilization that liked base-60, and 12 is a divisor of 60."
"No, actually, that came from the civilization that used latin. Previously there were 10."

i think "previously" is quite an unhelpful phrase here, because that long ago there wasn't a standard calendar system used everywhere. the original roman calendar had ten months, starting around the march equinox. it was a lunar calendar (as we established earlier). after the tenth month, it was winter, which was not part of any month. i'll cover the twelve months in a moment.

the babylonian calendar had twelve months. those months were aligned to the moon phases. they added leap months occasionally to bring themselves back in alignment to the seasons. we didn't get our twelve month calendar from there, but they did have one.

the julian calendar was heavily inspired by the egyptian calendar (remember how caesar spent a lot of time with cleopatra? something rubbed off), which calculated a year as being three-hundred-and-sixty-five-and-a-quarter days, which is impressively accurate, and still what we mostly use. the egyptians also had a twelve month lunar calendar. seems that twelve months is pretty standard for calendars, which makes sense because as i said above, the easiest way to track time is with the phases of the moon.

"yeah the Latin guys added two months part of the way through their rule, adding two more months. That's why some are named after the wrong numbers"

there were a few calendar reforms in rome, including the republican calendar which made it more of a solar calendar, with months alternating between being thirty-one and twenty-nine days long. two months were added in winter here, january and february, which had twenty-eight days. however these lengths weren't enough for a full solar year, so a leap month was added every few years. the year still started around the equinox at this point, so the numbered months were still in the right place. and while they did technically add two more months, it's not like they squeezed them in, they just had a big gap.

julius caesar initiated a calendar reform---the julian calendar---i believe when he was in power. made months thirty or thirty-one days, to bring the calendar to almost the same length as the tropical calendar, and instituted a regular leap year where a day was added to february. i don't know why, but he chose to have two february twenty-thirds, rather than the extra day we have today.

"you just said two things I am having trouble understanding.
1. Your months are named, not numbered?

this is a cultural thing. go to china, and your months are 一月,二月,三月,四月,all the way up to 十二月. also, admittedly it's a little inconsistent, but half the months are numbered? the other half all had important cultural meaning to the romans.

janus is the god of beginnings, i believe around the time of the julian reform, the year was made to start on the winter solstice, so the month at that time the year began was named after... you get it. the was a festival in february called februa. march comes from the god of war, mars, and was when the romans began their military campaigns each year. i'm not sure about april. may comes from maia, the goddess of growth. june comes from juno, queen of the gods and goddess of fertility, make of that what you will. july was called quintilis at this time. august was called sextilis at this point. and the rest are obvious.

"yep! Our 9th month is named after the number 7, and so on for 10, 11, and 12."
"your 12th month is named... 10?"

yeah shifting the start of the year was dumb.

"what are the other ones named after?!"
"various things. Mainly Gods or rulers"

see above. qunitilis was renamed july after julius died. octavian augustus renamed sextilis during his reign because he wanted to be great like caesar.

i'd be interested to know at what point the non-numbered months became non numbered. it would make sense that they all started out numbered, right?

"oh, from that same religion that your epoch is from?"
"uh... No. Different one."
"so you have an epoch based on one religion, but name your months based on a different one?"

though note that it was the same empire that enforced both.

"yeah! Just wait until you hear about days of the week."
"so yeah we group days into 7-day periods-"
"which aren't an even divisor of your months lengths or year lengths?"

seven days being approximately a quarter of the lunar cycle. we've been over this enough times now.

"but we name the days of the week, rather than numbering them. Funny story with that, actually: there's disagreement about which day starts the week."

once again, cultural. chinese days are 星期一,星期二,etc. even some romantic languages, like portugese, number the days: segunda-feira, terça-feira, quarta-feira...

"you have a period that repeats every 7 days and you don't agree when it starts?"
"yeah, it's Monday or Sunday."

the international standard is that it's monday. pretty much everyone thinks so, the main exception being the us.

"and those names come from..."
"celestial bodies and gods! The sun and moon are Sunday and Monday, for example"
"but... I looked at your planet's orbit parameters. Doesn't the sun come up every day?"

while i'm not a hundred percent on this, i believe that the germanic civilizations worshipped a particular thing each day. sunday was the day they worshipped the sun, just as thursday was the day the worshipped thor.

"oh, do you have one of those odd orbits where your natural satellite is closer or eclipsed every 7 days, like Quagnar 4?"
"no, the sun and moon are the same then as every other day, we just had to name them something."

we didn't just "name them something". we named them after a significant part of culture.

"and the other days, those are named after gods?"
"from your largest religion, I imagine?"
"nah. That one (and the second largest, actually) only has one god, and he doesn't really have a name."
"huh. So what religion are they from? The Latin one again?"
"nah, they only named one of the God-days"

two points. first, they were named after the largest religion at the time they were named. second, the abrahamic god does have a name or many.

"the third or forth biggest, I assume?"
"nah, it's one that... Kinda doesn't exist anymore? It mostly died out like 800 years ago, though there are some modern small revivals, of course"

fair. but at least acknowledge its importance that millinium ago?

"but the months and the days of the week are named after gods from different religons from the epoch religion, and indeed, each other?"
"yeah! Except Saturday. That's the same religion as the month religion"
"and the month/Saturday religion is also from the same culture who gave you the 12 months system, and the names for the two halves of the day, which are also named?"
"right! Well, kinda."
"please explain, slowly and carefully"
"yeah so cultures before then had a 12 month system, because of the moon. But they had been using a 10 month system, before switching to 12 and giving them the modern names"

finally :) other cultures !!

"the... Moon? Your celestial body?"
"yeah, it completes an orbit about every 27 days, so which is about 12 times a year, so it is only natural to divide the year into 12 periods, which eventually got called months"
"ok, that makes sense. Wait, no. Your orbital period is approximately 365.25 days, right?"
"yeah. That's why we do 365 or 366 based on the formula"
"but that doesn't work. 365 divided by 27 is ~13.5, not 12"
"yeah I'm not sure why 12 was so common then. Maybe it goes back to the base 60 people?"

the moon completes an orbit every twenty-seven-and-a-bit days, but the lunar cycle (of new moon to new moon), is twenty-nine-and-bit-days (if i recall). this is because the earth isn't static. we get moon phases based on the light from the sun reflecting off the moon, but because the earth is also moving, for the moon to get to the same position it started at and therefore be the same amount of reflected, it takes a little bit longer. this bigger number results in somewhere between twelve and thirteen lunar cycles per year, but it's twelve full ones so that's what we go with.

that doesn't explain why we went for twenty-eight days to a month. i think the reason for that is because twenty-nine is a prime (as the alien touched on above), and a shorter grouping of days is useful to have. with a twenty-eight day month, you can still only fit twelve in a year, though it's a lot closer to thirteen, which explains the need for leap months or excessive drifting in early calendars.

"And then each half [of the day] is divided into 12 hours, but you start at 12, then go to 1, and up to 11"
"all I can say is that it makes more sense on analog clocks."
"i don't know what that is and at this point I would prefer you not elaborate.

i hope that this isn't a slight against analogue clocks. analogue clocks are better than digital clocks. even douglas adams, who was a big fan of digital things, thought digital clocks were ridiculous for the way they took an interface incrementally designed to perfectly serve its function and simply chucked it out, which was why they played such a prominent part in the hitchhiker's guide.

(i discovered this in the letters of note newsletter, where he wrote a letter protesting the us graphic novel release for replacing digital watches with mobile phones. i can't find this reference on the site, and i currently can't access the substack, so if anyone could send me a link or the quote i would be grateful).

So each of those hours is divided into 60 minutes and then 60 seconds, and this comes from an ancient civilization, but not the one that gave you the month names"
"yep. Different guys. Different part of the world."

this pains me, because there are little references to understanding that different parts of the world will have different traditions, and cross-cultural travel will mix these up, but this is entirely ignored to push a "look how dumb this is" narrative.

that's all of the time related content. i know this piece is a comedy piece, but a lot of the comedy comes at the expense of humanity. it's laughing at, not laughing with. humans are impermanent, time means everything to us. and like seeing the beauty in stretch marks and laughter lines, we should strive to see the beauty in the way we pass it by, because the psyche of civilizations is embedded within it.

but if somebody was to write something like this about the metric system i'd lap that shit up. "so you're telling me you thought it was a good idea to base your temperature system on how water acts? and you piss on anyone who suggests it might make more sense to use a system based around human tolerance thresholds?"