okay but let me explain something about medieval timekeeping https://twitter.com/sbuss/status/1371323426296668162

that was meant to be a one liner tweet but okay okay let me get coffee and I will explain because yes this is basically how medieval time worked

Right, so, I know I said medieval but this is actually a LOT older than that. You know sundials, yeah? The story starts there, and a hell of a lot closer to the equator than modern Britain.

The oldest record of a sundial is, I think, circa 700BCE (in the Torah), but archaeologists have found ones in ancient Egypt dating back to at least 1500 BCE. ancient Egypt, worth noting, spreads from roughly 12 degrees N to 26 degrees N of the equator.

The equator, besides being the circumference of Earth, is also perpendicular to the earth's axis of rotation around the sun, meaning that the sun shines directly above it, meaning that on the equator, day and night are the same length by any measure.

I will point out quickly that i do not know a single equatorial country that has daylight savings time. correct me if i'm wrong.

now by extension, it would follow that the poles, being extreme opposites of the equator, were respectively completely dark and completely sunlit, but the earth is tilted, so instead, the further you get from the equator, the weirder your seasons get. THIS IS RELEVANT I PROMISE

So we have sundials, invented in an region where day and night are roughly the same length, constantly. We don't have many (any?) written records of how they were used, but hey, they're recognisably sundials.

ENTER THE ROMANS.

somewhere around 250 BCE, the Roman empire officially adopts (read: colonises) sundials and, with them, a system of dividing the day into 12 equal parts from sunrise to sundown. Midnight was the midpoint between sundown and sunrise.

Now, Rome is 41 deg. north of the Equator, so by modern counting, their hours ranged from like 45 mins in the winter and 75 mins in the summer. Important to point out that only the day had hours because sundials don't work at night. The night had watches but that's another thread

The romans knew this- they knew lat and long and the the earth is tilted on its axis, so as the Roman empire spread north, we see evidence that sundials are being calibrated to match local latitude. which is cool! Largely, though- this whole thing was a civic set up.

By which I mean- the government used time and hours and what have you, but most people just continued functioning on agricultural calendars, which revolved much more around what the weather was doing than whether it was before or after midnight or at a given hour.

This worked fine for everyone and was widely regarded as a Good Idea for several centuries.

ENTER THE CHURCH.

Now, from this point on I'm gonna focus on medieval England because that is what I know, feel free to add European Tidbits in the replies.
Anyways, when the roman empire changed gears into the holy roman empire (i am paraphrasing), they kept some bits. Including the timekeeping.

But they added in Regular Prayers Throughout The Day.

They also added bells to signal, both to clergy and lay people, Time For Prayers.

Bells rang at Prayer Times, which were, you guessed it, spaced equally from dawn to dusk.

I think Ian Mortimer did a whole mapping out of this, but roughly you had eight prayer times, ranging from just before dawn to after sunset, and spaced accordingly. So, in London, at midsummer, you've got Matins at 2:30 am. at midwinter... 6:40 am. Noon? same, year round.

Something I find really interesting with this is that noon is the standard here! Midnight moves, but noon is always the sun at its zenith. Compare that to modern day DST, when high noon may not actually be high noon.

Anyways, a fun fact about england is that it's extremely cloudy and grey here. so, sundials were like...

well, anyways, the water clock (which didn't need the sun) had been invented by this point, and became popular. I have no idea how it works. Moving on,,,

A number of people recognised the need for something to keep track of the hours that didn't rely on weather being stable or predictable, so we start seeing different types of mechanical clocks emerge. And, although there's no 'Eureka' moment, people clearly realised...

with a mechanical clock, there was no need to rely on the sun at all. This issue of hours being shorter in the winter and longer in the summer *could* be sorted out.

It wasn't, but it COULD be.

enter the colonisers.

As the Europeans started sending ships across the Atlantic, and everywhere else, they needed to keep track of longitude. Simplification; this required accurate and precise time tracking. At some indeterminate time, a 24 hour day, complete with minutes and seconds, emerged.

(and because of all the colonising, got pretty universally implemented. anyways.) most sailors measured longitudes using a meridian 0 that passed through their country of origin. In England, it specifically was Greenwich, for assorted reasons.

Because of England being England, at some point the Greenwich Meridian became Longitude Zero for like, the world. Now, people knew that long. affected time, but nobody was exactly travelling quick enough for it to make a difference. But noon in England was not noon in Florida.

So, time zones. Kind of. Different places started calculating time based on their longitudinal difference from Greenwich. 15 degrees was an hour different. This is loosely how modern time zones work.

But since every place was doing it individually, what you really had was random cities being like "Well, we're 1.25 degrees West of Greenwich, so that's five minutes, so noon in Greenwich is 11:55 here". and then, you know, time setting accordingly.

C H A O S.

But, again, nobody was travelling quick enough for it to matter, really, so you just reset your watch when you got where you were going oh wait what was that

CHOO CHOO TRAIN TIME

trains were fast enough for it to matter. And, at least in theory, trains ran on a schedule, so people needed to know if that train was leaving at 12 noon London time or 12 noon Oxford time.

And so, modern time zones.

(for everyone except Oxford because lol they are stubborn prats and at least six of the city's bells still ring 5 minutes off schedule.)

Okay so why daylight savings? long story short, no it's nothing to do with farming that's a myth

The thing about the standardised 24 hour day based off Greenwich is that it's not efficient use of daylight in non-equatorial regions. Since sunset moves around, but modern work hours (beginning with factory work) does not, that meant using more artificial light.

And during WWI, and the USA rationing energy supplies, that was an issue, so they implemented mass DST to have workers scheduled during the daylight, requiring less artificial lighting. They did it again during WWII, and the capitalist overlords liked it so much they kept it.

Incidentally, the farming myth was started to make the measure more popular by appealing to people's empathy, since DST has uh, pretty much always been universally hated.

And here we are today. I have zero pithy end to this thread except to say that time is fake, time has pretty much always been fake, and time will continue to be fake. all that changes is how we measure the fakeness! but that is still pretty cool.

thanks for coming along on this ride and if you are in the UK, please do us all a favour and write/tweet/email your MP and ask them to vote against the policing bill that's up before Parliament today. How are we gonna protest DST if they ban protesting?