Dates and times in space
What ideas around dates and times are universal?
On distance
Planety intervals?
You see a lot of sci fi shows invent words for 'day' and 'year' to give you a sense of otherwordliness, yet keeping our intuitive sense of time, not having to convert anything in your head.
For example, Farscape has cycle (approximately one year), solar day (day), arn (~hour), and micron (~minute).
This always made me wonder how much sense this makes.
With people from different worlds, which concepts would translate much at all?
What parts of timekeeping seem physical, which seem more arbitrary?
Our days are physical - rotations around the planet's own axis.
This presumably would exist on any planet, but may vary wildly (TODO: investigate how wildly).
Our hours and minutes are not physical in any way.
These are about planning on the long and short term within a day. Such divisions are likely in people with things to do, but our method of dividing would is fairly arbitrary.
The first recorded subdivision we know of were Egyptians, and they divided into 12, which we know because they were sundials.
As far as a little googling will tell me, our timekeeping has
- a factor 24 in because of Egyptians duodecimal habits
- a factor 60 in it because of the Sumerians's and Babylonian's sexagesimal habits (for math and astronomy, it seems they used base 10 for other things (verify))
And there is a complex history of why those became used, and how they made it down to still be used thousands of later - often with some indirect steps.
Our guess is that these numbers come from how many knuckles we have on one hand (but it may be related to lunar cycles(verify)), so it seems unlikely that dividing a day into 24 hours, or hours into 60 minutes, would be done anywhere else.
Our years are physical - the planet's orbits around our star.
Even when we thought the sky worked differently, we had years.
It's not the circle around the sun that we notice, though.
It's our seasons, which are a thing because of the position around the sun combined with our earth's axis (which we also didn't need to know for them to, you know, happen).
It is moderately likely that a year would roughly in the same ballpark between similar-looking species from planets around similar suns, but it would also never be the same between planets, in ways that would make 'year' impractical for interplanetary timekeeping.
I also wonder how much we would lack the idea of a year without that tilt.
Our months are sort of physical - we named them after lunar cycles.
The moon and the light it gives or doesn't give is a very direct thing, and fairly practical for timekeeping as well as stories.
There happen to be 12 of them in a trip around the sun. Which probably made Babylonian astronomers happy via a sense of round numbers.
More on that
Timezones
We do timezones out of a kind of pragmatism.
Not too long ago we didn't have to care: a day worked as a day because of where we were.
It works well in most places to get up with the sun, and to bed at night (people around the poles are funny people[1][2]).
At some point it became useful to communicate time, in an at-all way.
Consider a train timetable, and shipping.
It's useful to have stations and ports to be able to say roughly when things come and go, and a little more precisely than 'at dawn' or 'in the evening'.
Eventually you may want it in more detail than a sundial would give. But also, a sundial just tells time of day where it is.
Even if you have a good chronometer and standard, then e.g. train timetables settled far away would be in that place's time.
There are multiple solutions. You could make it self-consistent converting to a sundial there, or to a clock at the station which shows a "train time" that is the same everywhere (but has a less direct relation to daylight), or adjust each timetable to local time.
Each will make it a lot easier to answer the question "but when do I need to be at the station?"
Timezones came soon after the chronometer,
because they're necessary to even have meaningful local time that is also meaningful elsewhere.
It's also a bit confusing, to this day.
There are simplifications, e.g. the military often uses UTC, to take out timezone ambiguity.
Internet time is similar, and takes out the 60-60-24 logic, by just saying a day is made of 1000 beats(works out as 1 beat being 1 minute, 26.4 seconds).
This is often understood as a local time, so that 500 is midday and 0 is midnight.
Swatch introduced Swatch Internet Time, based on BMT (Biel, Switzerland), which is essentially just CET, UTC+1, without daylight savings.
Stardate
I've repeatedly wondered how Star trek's stardate works, whether it's consistent at all, and what it actually shows.
Stardate takes out months, hours, and minutes -- at least in broad references.
This in itself makes it look meaningful, and somewhat futuristic, and functional in that it suggests being an interplanetary standard.
Again, part of it is to have meaningful date and times, just make it feel like future and sci fi, but avoid anchoring it in the now, and avoid having to have a specific theory about how timekeeping would have changed in two hundred years.
Stardate was probably more a writer thing, though.
There were instructions to writers included things like 1 stardate is roughly 1 earth day.
- which means a span of 40000 is ~110 years, which is the timespan of a good deal of Star Trek
- and fractions are within a day (so .5 is noon and .0 is midnight)
- which seems taken directly from Julian date[3], an astronomical reference that astronomers use for ease of bookkeeping/calculation, but with an epoch in the 22nd or 23rd century rather than 4713 BC
In-universe, we didn't invent this, we just adopted it mid-23rd century, though it seems to be fairly soon after its creation
- but it's fuzzy - it doesn't help that there are different alternate realities - with different stardate habits
Apparently the guide to writing scripts says something like "get stardate right within your script, the rest is details"
It also says "Stardates are a mathematical formula which varies depending on location in the galaxy, velocity of travel, and other factors, can vary widely from episode to episode", so they are clearly aware there is real world pragmatism to this.
...including potential handwaves like that quadrants or empires might have their own time reference (even if there were a reference spacetime stardate), and there are even hints at serious thought, but the show never truly addresses it - and scriptwise this is smart.
It was also an easy handwave towards pedantic people noticing little inconsistencies, such as episodes being aired in a different order from being filmed, Tasha dying a little before we last see her alive (probably just a mistake, but fun to conspire about), and such.
Actually, Star Trek seems to have avoided tying stardate to our dates so much that it seems intentional.
Probably partly to not just feel like it renamed the words for year and day.
But also it makes sense in-universe.
Between series
Series sort of had their own conventions.
Mostly becoming more consistent with newer series, though not always.
One convention was CSPPP (century, season, progression),
...where in some cases the progression was from 000 to 999 throughout the season. This made it intuitively decipherable to us.
For a decent part, most five-digit stardates have ~1000 stardates within an earth year.
And if a season took about a year of in-universe time, this actually works out decently within it.
Still, that's a factor off, being ~0.37 Earth days per Stardate days rather than the previously mentioned 1, also meaning the day-fraction stuff is broken, but if we keep thinking in earth years and don't make an explicit point of defining it, something's gotta give.
On spacetime
Okay, so, we have a more serious problem.
We are used to thinking of time to be a continuous thing, equal everywhere.
That's because the earthbound don't have to deal with the crazy speeds or distances that make that interesting.
However, since warp is not only relativistic but effectively faster than light, we now absolutely deal with spacetime.
The writers were aware that we're talking spacetime, and that warp, being effective-FTL travel,
violates the validity of single-reference time measurement.
It's sort of similar to pre-timezone timekeeping on earth, where any local time was perfectly practical because you just stick within what you live in.
In a sci fi setting, the fact that planets are relatively stationary makes this just as easy on a planet scale.
But in both cases, it starts being a confusing mess when you want to communicate it.
Fixing it to a galactic standard time doesn't help much, the range would be much larger, and wouldn't be meaningful for us.
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