DST
The notifications in one of our systems is aligned with UTC because it needs to be for a whole bunch of background services to function. Periodically (every couple of years) someone raises a ticket to complain that the time of their notifications is an hour out, and the 2nd line support worker will think “well that’s easy, I’ll just change the server time to BST”. This then brings this whole suite of applications to a crashing halt as everything fails.
OMG, I’m dealing with a developer right now that is dealing with patient collected samples in several timezones, allowing the patients to either enter the time they collected, or use current time, and storing it in UTC time.
We do not receive any timezone data, patient collection data is showing different days than the patient could write on their samples depending on the time of day, and the developer said ‘just subtract X hours’ (our timezone)… for which not all patients would live in.
I suppose I could, if they’d provide the patient’s timezone, but they don’t even collect that. Can you just admit your solution is bad? It’s fine to store a timestamp in UTC, but not user provided data… don’t expect average users to calculate their time (and date) in UTC please.
Depends on what’s collecting the information. If it’s a website, then the client-side code could most certainly normalize everything to UTC based on the browsers time zone before submitting. That’s what I would probably do, if the user’s time zone isn’t needed or wanted…
This is actually the best approach.
Obviously they are getting timezone information otherwise the app could only display whatever time the user entered in.
If you want to sort things by the actual time, it’s simple and performant if all of the times are in the same timezone, and UTC would be the standard one to use. Pushing the timezone calculations to the client makes sense because the UTC time is correct, it’s just a matter of displaying it in a user friendly way, ie. show the time in the user’s timezone.
IMO, the biggest problem with timezones is that the people who initially created them were fairly short sighted.
That and there have been way too many changes to who lives in what timezone. The one that boggles my mind is that apparently there’s a country in two timezones, not like, split down the middle or anything, but two active timezones across the entire country depending on which culture you’re a part of, or something. It’s wild.
I still don’t know if there’s any difference between GMT and UTC. I couldn’t find one. They both have the same time, same offset (+0), and represent the same time zone area.
I use UTC because I’m in tech, and I can’t stand time formats, so I exclusively use ISO 8601, with a 24 hour clock. Usually in my local time zone, via UTC. We have DST here which I’m not a fan of, but I have to abide by because everyone else does.
My biggest issues with time and timezones is that everyone uses different standards. It drives me nuts when software doesn’t let me set the standard for how the time and date is displayed, and doesn’t follow the system settings. It’s more common in web apps, but it happens a lot. I put in a lot of effort to try to get everything displaying in a standard format then some crudely written website is just mm/dd/yy with 12h clock and no timezone info, and there’s nothing you can do about it.
UTC exists as a historical compromise because the British felt that GMT was the bees knees and the French felt differently. The letter order is most definitely a compromise between French and English word order. You can call it Universal Time Coordinaire.
Historically, GMT became the international time reference point because the Greenwich observatory used to be the leader in the field of accurately measuring time. It probably helped that the British navy had been dominant earlier and lots of countries around the world and across time zones had been colonised by the British.
UTC is an international standard for measuring time, based on both satellite data about the position and orientation of the earth and atomic clocks, whereas GMT is a time zone. Nowadays, GMT is based on UTC not independent telescopic observation.
What’s the difference? You can think of a time zone as an offset from UTC, in the same sense that a 24h clock time is an offset from midnight. GMT = UTC+0.
Technically, UTC isn’t a valid time zone any more than “midnight” is a valid 24h clock time. UTC+0 is a time zone and UTC isn’t in a similar sense that 00:00 is a time in 24hr clock and “midnight” isn’t.
Of course, and perfectly naturally, I can use midnight and 00:00 interchangeably and everyone will understand, and I can use UTC and UTC+0 interchangeably and few people care, but GMT = UTC+0 feels like the +0 is doing nothing to most eyes.
Fun fact: satellite data is very accurate and can track the UTC meridian independently from the tectonic plate on which the Greenwich observatory stands. The UTC meridian will drift slowly across England as the plates shift. Also, the place in the stars that Greenwich was measuring was of by a bit, because they couldn’t have accounted for the effect of the terrain on the gravitational field, so the UTC meridian was placed several tens of metres (over 200’) away from the Greenwich prime meridian. I suspect that there was a lot more international politics than measurement in that decision, and also in making the technical distinction between UTC and GMT, but I’m British, so you should take that with a pinch of salt.
That’s quite the lesson you just laid down.
It’s actually made things a lot more clear for me. To put it as tersely as I can, UTC is the international time, GMT is a timezone, which also happens to be UTC+0.
So GMT is a place/zone/region of earth, and UTC is a time coordination, with no physical location (beyond the prime meridian, which is where it is tracking the time of).
Awesome.
I know people who actively fight me on ISO 8601. They don’t like the way it sorts their files/folders, reliant on whatever behavior the operating system does. Whenever data recovery happens or their files are moved, all the change times are blown out the window and the sorting they expect is blown away.
I’m not yet using a 24-hour clock. But it has me thinking. That’s not such a bad transition for 24-hour local time into UTC. Or just using both. At some point the inconvenience of the local will become vestigial and UTC is what remains.
I use 24h clocks and ISO 8601 dates almost always
Honestly, I’m better at organizing code than I am my actual life
Timezones are kind of a necessary evil though, because without them then you’d have to check regions (or zones) to see if 1PM in China is the same thing as 1PM in Australia is the same thing as 1PM in Bolivia.
Even then, 1pm in Beijing is something different than 1pm in the Tibet since all of China is technically one time zone.
Is GMT and UTC not the same? I’m happy to not have to code for timezones
At least most of us don’t need to worry about time dilation caused by relatively yet. Have fun with that, space faring developers.
We kinda do, with GPS satellites that have to correct their clocks due to the effects of gravity and speed
And communication with space probes
obligatory: https://qntm.org/abolish
Before I read this article, I also thought it would be a great idea to get rid of timezones entirely and just use UTC for everything. To quote from the link, (please forgive me for being lazy and not formatting it correctly)
Abolishing time zones brings many benefits, I hope. It also:
- causes the question “What time is it there?” to be useless/unanswerable
- necessitates significant changes to the way in which normal people talk about time
- convolutes timetables, where present
- means “days” (of the week) are no longer the same as “days”
- complicates both secular and religious law
- is a staggering inconvenience for a minimum of five billion people
- makes it near-impossible to reason about time in other parts of the world
- does not mean everybody gets up at the same time, goes to work at the same time, or goes to bed at the same time
- is not simpler.
As long as humans live in more than one part of the world, solar time is always going to be subjective. Abolishing time zones only exacerbates this problem.
Eh, I think the article blows the situation out of proportion. Overall you’re still in the same situation as before. Instead you would just be looking up a timetable of sunrises/sunsets, instead of a timezone chart. It ends up mostly reframing the question from “what time is it there?” to “what time of day is it there?”. The real version of “after abolishing time zones” is “google tells me it is before sunrise there. It’s probably best not to call right now.”
I’ve been using UTC on my own clocks without issue, and the change is not some completely reality-breaking thing - not anymore than DST. From a matter of personal perspective it just shifts what time correlates to what time of day.
using UTC also simplifies the questions “what times can I call you at?” And “when should we have our call?” since you have the same temporal standard. Even before that, I was scheduling calls with family by stating the call would be at such-and-such time UTC.
The biggest difference is with when the date changes, and I think that ultimately is the hardest pill to swallow, and that’s even compared to stomaching the sun rising at 2 AM. Having it change from June 5th to June 6th in the middle of a workweek, or even jumping to another month would bother alot of folks in a significant fashion.
Ultimately it’s just a personal practice. No nation is going to abolish time zones if everyone still uses time zones. I just prefer it for various reasons.
If you want your sunrise to be at 12am, go ahead.
If you really want to fix something. Fix months
Between the two, months is much harder. With time,.you just set your clocks to UTC. To get months fixed you need mass adoption, rewriting calendar software, etc.
Bold of you to assume people will agree to having sunrises at 9am while some other country gets the privilege of getting it at the usual 6
Yeah it’s just being angry about the fact that the Earth is rotating ball. Wanting to abolish timezones is different from Flat Earth only be degrees.
Sure the “what time is it there?” question goes away, but it’s replaced by “what are your business hours?”
Ultimately it will be daytime in one part of the world while it’s night in another part of the world. That will always cause problems.
Timezones make intuitive sense for humans
UTC / Unix timestamps make intuitive sense for computers
The issue is bridging the gap
Well, a large part of the issue are all the damn exceptions
This is a fantastic write-up, thanks for sharing!
stardate superiority
It’s only bad when used incorrectly. Just store time in UTC and convert it to timezone of your setting to present it. Most modern languages offer a library that makes it just one more line of code. Not only it’s then clear and unambiguous, it supports all timezones.
Doesn’t always work, especially if you need to work with any sort of calendar or recurring schedule.
Yeah, timestamps should always be stored in UTC, but actual planning of anything needs to be conscious of local time zones, including daylight savings. Coming up with a description of when a place is open in local time might be simple when described in local time but clunkier in UTC when accounting for daylight savings, local holidays, etc.
bingo. Timezones became easier when I learned that all apps and databases should have all times be in UTC. Let the UI do it’s thing and accept local time and convert it, and vis versa.
+1 for this. This is kinda the same issue with encoding, just UTF-8 everything and move on.
You’ve got make sure you program the time machine correctly though…
and bring enough stolen plutonium when you visit 1955
😄
It could have been worse. The romans had the day divided into 24 hours, like we do, but the hours varied in length so that from sunrise to sunset, you would always have 12 hours.
Imagine if that was the agreed upon time system, and we had to program that into computers.
It’s called temporal hour. Many cultures around the world had such a time system. Like in Japan they made clocks and watches that could tell temporal hours called wadokei.
My suggestion has always been universal sidereal time. It is singular, doesn’t change, and carries no colonial baggage since it rotates around the whole earth. Even suitable as a home time if we become spacefaring.
doesn’t change
Citation needed.
Do you use leap seconds to stay in sync with earth’s rotation? When would they be applied? How would spacefarers be notified of these updates?
Also, what meridian do you choose for this ‘universal’ time? Is it still Greenwich? Because that’s peak colonial baggage.
peak colonial baggage
I get the thought, but wouldn’t changing it just end up performative?
I think changing the date system from AD/BC to CE/BCE is peak performative, and that’s coming from me as an atheist. We still use the same years based on the mistaken belief of when the Christ was born.
Where would we change UTC to be? Best place I could think of is where the current International date line is in the middle of the Pacific but that area is already a clusterfuck of zig zagging not that current UTC 0 is much better. And then, what do we call it? Do we keep UTC because it was a compromise between English and French speakers? Should we go with Mandarin Chinese since that is the most widely spoken language natively in the world? But there is plenty of colonialism within Chinese history of the Han people versus all other Chinese ethnicities and languages. Or English because it is the most widely spoken language when adding first and additionally spoken languages (definitely colonialism there)?
I’d sincerely love to know your thoughts on this. I’ve pondered it before and couldn’t come up with a good change besides using an artificially made language like Esperanto but that comes with a whole host of other issues.
wouldn’t changing it just end up performative
Exactly. Sidereal time does get rid of time zones and leap years, but it’s still referenced to a single physical object and relies on a arbitrary choice of start point. So it doesn’t create some perfect cosmic time standard.
The international date line doesn’t help since that’s just 180° offset from Greenwich itself.
The point of standards is that they can be followed by everyone. The AD/BC epoch is fine. The Greenwich meridian is fine. UTC is fine. Changing them would cause so much disruption that it cannot be worth it.
Daylight savings can go die in a ditch though.
“Daylight savings biting curb at 4k” as the kids would say.
Timezones are fine to program around.
DST is a bit of a pickle to plan around, but can be done just fine by a computer program.Historical dates; considering leap years, skipped leap years, and times when leap years weren’t a thing or when humanity just decided we skip a bunch of years; are the bane of all that is good.
I hear timezone names can also be a slight issue at times, some Australians call the eastern time zone EST. Leap years aren’t so bad at times either though. Kind of agree with the rest of it, much of the complexity is from historical dates.
We call eastern coast time AEST
Proleptic Gregorian Calendar enjoyers
I fucking hate timezones. Whatever it is, I’d rather read the current clock as 4 a.m. even if it’s noon than have timezones.
Well you can. Just switch your clock to UTC and you’re done. You won’t even have DST to deal with.
Only freaks have AM/PM in their time system.
24hr clock supremacy
