Actually we can't, the coordination problem is so massive as to basically be impossible.
For various reasons, it's actually far, far, far easier to change clocks.
And to put your question back at you -- why should the sun be highest at noon? Because that's actually a very arbitrary thing (number 12 = highest) and it's not even perfectly true except for one special longitude in a time zone.
The purpose of time zones is really just so we can have a common vocabulary for when the daily rhythms of events happen. If anything, aligning 12:00 pm with lunchtime is probably the biggest cultural anchor. Not the sun.
12 is totally arbitrary. We could use a decimal clock. That's all historical. But because noon is when the sun is highest, most people can look at the light quality outside and know immediately what time of day it is.
Many cultures eat lunch at different times than noon. Some modern cultures even like to completely skip lunch.
And I agree. The coordination problem is impossibly large and annoying. So just skip it. Don't shift clocks around to try to coordinate. Give businesses and schools more ability to set and change their hours.
Why on earth and sun should we use this arbitrary artifact of a failed attempt to drive social coordination (daylight savings) as the new normal?
Most people really can't. Not only do most people simply not pay enough attention, but it varies dramatically by month the further you get from the equator. The light at 3 pm in August is totally different from 3 pm light in November.
> Give businesses and schools more ability to set and change their hours.
You're missing the fact that they effectively can't. Business hours are set around school hours, because employees have children. School hours are set around business hours, because of parents' jobs. Not to mention train schedules, airlines schedules, and everything. The only way we can change it is all at once, and the only way to ensure everyone follows is to change the clock itself. Not to mention changing every clock is so much easier than changing every single calendar event everywhere, because we already have systems for the former, but not for the latter.
Timekeeping is just a tool designed to benefit humans, it's not divine. We can use it as a tool to implement coordination changes that result in a net societal benefit around when we experience daylight. Why wouldn't we use it for that?
The fact that solar noon is then at 12:37 pm instead of 11:37 am for somebody somewhere is nearly irrelevant compared to that.
Most things work in lock-step with other things, so even though business already have limitless ability to set their own hours, they tend to set very, very similar hours because there's no point in being closed when people expect you to be open, and not much point in being open when people expect you to be closed.
"But because noon is when the sun is highest, most people can look at the light quality outside and know immediately what time of day it is."
Where, exactly, is noon when the sun is highest? Chicago, Illinois, and Regina, Saskatchewan, are in the same time zone. When the clock ticks noon, is that the apex for both of them? Or to avoid crossing international borders, is the sun at the highest for both Indianapolis, Indiana, and Bangor, Maine?
Bangor today had a sunrise at 05:55, and expects sunset at at 17:35. Indianapolis, on the other hand, had sunrise at 07:02, and expects sunset at 18:47. They are in the same time zone, and yet solar events are more than an hour different. Today, "solar noon" is 11:45 in Bangor, but 12:54 in Indianapolis. Adjusting Indianapolis back an hour to bring noon closer to solar noon would put it at 10:45 in Bangor!
"The sun is highest in the sky in the middle of the day" is approximately true, but can be off by more than the one-hour adjustment for Daylight Saving Time, so it is clearly not precisely true, whether we shift by an hour or not.
The continental USA is 2800 miles wide, and even splitting it into four time zones doesn't make things make good sense for every location. But hey, it could be worse: China is more than 3100 miles wide, and uses a single time zone!
* This isn't aimed at you, but I always check this when comparing two cities, because it's fun: Indianapolis gets between 9:21 and 14:59 hours of daylight, December to June, while Bangor gets from 8:48 to 15:35 hours of daylight.
Conversely, why should it? Clocks are artificial devices that serve human needs, there's no physical law that says you can't have the top of the clock be sunrise every day, or any other system you could imagine.
Wait a second...that's only because you are using noon as a reference.
The intervals from noons to consecutive noons decrease for half the year and increase for half the year, averaging 24 hours, with the swing being about a minute.
Similar for the intervals from sunrises to consecutive sunrises, except the swing can reach around 4 or 5 minutes.
Either of those is stable enough to use its average as a reference.
Meh. Just pick something, I guess. But this isn't an engineering problem and there's no correct solution.
It was an engineering problem, very literally an engineer problem. Standardized time zones were needed to keep trains, the big heavy things driven by engineers, from smacking into each other at speed. Coordinating all the train station clocks wasn't done for social reasons but for safety and efficiency. Imagine trying to run a modern air transport network if every airport changed its clock a few minutes every day. Total chaos.
In the bay area daylight hours will vary, going as low as 10 hours in winter and as high as 14 hours in summer.
Standard time in December has 5pm occur after sunset.
Assume a standard 8 hour workday of 9 to 5. That's 8 of the 10 daylight hours dedicated to "work" with none left over for after work leisure time.
Numbers above are rough estimates, don't come at me with exact sunset time of some arbitrary day.
I propose that a very large percentage of workers do not do a type of work that is dependent on sunlight. The vast majority of people work indoors in a building with electric lights. Leisure time on the other hand is often spent outdoors. Or would be if we were to arrange our clocks so that there was more daylight after work.
Let's go wildly overboard with this thought experiment: Create a time zone overlay called "Fun in the Sun Time". FitST has 12 noon occur around the time when the sun rises. Everyone will have woken up while it's still dark out using some electric lights at home, then gone to work (where the lights are on 100% of the work hours regardless of what timezone, real or imagined). Lunch break takes place during sunlight hours, and after work there are still at least 5 hours to go hiking/biking/sun bathing/BBQing/whatever.
This is a bit extreme, obviously, but a somewhat less extreme version of this would be to have the bay area run on Eastern Standard Time (or equivalent) year round. This 3 hour shift would synchronize businesses here with the east coast.
Or we could do the easiest, least intrusive thing, shift to PDT now in March and never switch back.
Not to mention geography also plays a huge part in this. 4pm in the Netherlands vs 4pm in Egypt could look very different outside depending on the local weather. If you live in a part of the world with constant cloud cover, it will seem darker outside than in the desert, but you both share the same clock.
The upside to the way method we use now, is that it only happens twice a year and at most, you might miss something by 1 day. If that happened once a quarter, maybe we could get everyone on board, but again it's highly dependent on where you live. Some places can add 3-5 minutes of extra sunlight per day in the Spring! Over a week or two, that's a substantial amount of extra light/darkness.
While I agree that the current situation is not ideal, there are a lot of scenarios I can imagine being much worse for very little gain.
I'm not putting forward insane counterfactuals. I'm just saying that we can set things up so that noon is very approximately local noon, with no changes at random parts of the year, and we will be fine. As in, the state of things before we started trying to "save" daylight. Why daylight savings time should be the new normal is beyond me, and it doesn't seem that anyone can explain why except that it's some kind of funny political phenomenon.
But that is exactly what we're doing when we all agree to switch our clocks. Whoever ends up in the minority that really feels strongly one way or the other can still adjust their schedules if it's convenient for them.
Your days will be longer than 24hrs from winter to summer solstice, and shorter from summer to winter.
You cannot have the same time system across an entire line if longitude.
Which sunrise do you pick? The equitorial one? 45 north? This may be more fraught than you were considering.
We could move from measuring time with a 24 hour clock to one based on solar angle.
We could also measure geographic distance in relative change of solar angle, combining our time and distance systems.
Some think it overly complex, but the increased geometry proficiency would save many lives.
I am far enough north that at some point as summer rolls around, I transition to sunset based structure, setting my morning alarm for 9 or 10 hours after sunset.
In practise, whether the sun is 15 degrees to the left or right at exactly noon doesn't have much practical effect on people in the way that it getting dark before they even can see the sky in the evenings does.
Anyway people should do this daylight saving forever experiment and contemplate these issues in the dead of winter. We can come back to this in a few decades.
All those standard start times are based on a world centered on solar noon. Maybe the semi ancients were onto something.
Eventually the noon reference became fixed upon, but it's only noon because it was easier to measure the shadow in that way. Other than a vague but unfounded sense of aesthetic need and the obsolete practically of synchronization with a sundial, solar noon isn't special.
Why don't sunset and sunrise count?