What Is Time Are Time Zones?

I was going to write an article about the nature of time.

Then I looked at the clock and realized I didn't have enough of it. (buh dum dum, gum gum)

So let's talk about time zones instead.

That sounds considerably safer until you spend a few minutes thinking about them.

If I call someone in London or Okinawa, we are speaking at the same moment. Not approximately the same moment. Not the American, British, or Japanese version of my moment. The same moment. Yet my clock says one thing, hers/his says another, and both of us consider this perfectly normal.

And it is  normal. However...

For most of human history, local time made enormous sense because human life was overwhelmingly local. The Sun came up. People went about their business. It reached its highest point in the sky. Some dirty gunslingers spun and settled some odd arguments. 🤷🏻 

Eventually it went down. We didn't need a worldwide system to coordinate a farmer walking into a field.

Even noon is more interesting than the number we have attached to it. Solar noon describes a real local event: roughly speaking, the Sun crossing the local meridian and reaching its highest point in the sky that day. There is nothing in physics requiring a clock to display 12:00 when that happens. We associated noon with twelve because our clocks developed that way.

Noon doesn't need to be twelve.

I won't do this often, but would you please read that last sentence again? That's a small distinction until you realize how many assumptions are hiding inside it.

Before standardized time, communities could keep their own local solar time. Move east or west and noon moved with you. That wasn't particularly troublesome when traveling between communities took considerably longer than the difference between their clocks.

Then humans invented a machine capable of moving rapidly between them.

Enter the railroads. Oh, you railroad barons. You thought you were so clever.

To be fair, they were.

Railroads created a legitimate coordination problem. Trains needed schedules that passengers, stations, crews, and other trains could understand. Telegraphy was simultaneously allowing information to move almost instantaneously between places whose clocks disagreed.

Local solar time had met technologies that could outrun it.

So railroads helped drive the adoption of standardized regional time, governments formalized it, international standards followed, and humanity eventually divided the planet into the patchwork of civil time zones we recognize today.

It was an ingenious solution that didn't just coordinate a few choo-choo trains. The system brought understanding to when depending on where. Railroads moved faster than local solar time could comfortably coordinate, and “we'll just text you when we're close” wasn't yet an option.

Ladies and Gentlemen, it's been about 140 years.

We have satellites now (to say the least). 

And before we treat our current arrangement as somehow inherent to living on a rotating planet, it is worth looking at China. (Please, please, please just keep reading a lil' bit). China is geographically enormous. Based on longitude and the movement of the Sun, it could easily span several time zones. Historically, it did.

Today it uses one.

The entire country officially operates on UTC+8, commonly called Beijing Time, despite stretching thousands of miles east to west. People can look at identical clocks while experiencing dramatically different relationships to sunrise, sunset, and solar noon.

This creates quirks, especially in western China, and people adapt their schedules accordingly. But more than a billion human beings provide a rather substantial demonstration of something we rarely stop to consider:

Perhaps China sounds like the strange one only because I'm writing this from the United States. Most countries don't divide themselves across a collection of time zones at all. The nations using more than two are a remarkably short list, populated largely by geographic giants and countries with far-flung territories. France technically beats Russia because of its overseas holdings, while China—nearly as wide as the continental United States—uses one. Maybe the unusual thing isn't that China decided one clock was enough. Maybe it's that Americans have grown so accustomed to four across the continental country that we rarely consider the alternative.

The number on a clock does not have to describe the position of the Sun.

The sun handles that quite well on its own. No really. The sun that's been providing warmth, nourishment, and countless good days is going to be totally cool (hehehe) with anyone here on the little blue marble discussing clocks and their situationship with the sun. In fact, I'd bet it is 100% indifferent to the notion.

Once that clicked for me, another question followed.

If two people are experiencing the same moment, why shouldn't their clocks call it the same thing?

We don't even need to invent a system. We already have it. (screeching the mental brakes, what?!)

Coordinated Universal Time, or UTC, already provides a shared reference for aviation, computing, telecommunications, navigation, science, military operations, international business, and countless other systems that need people or machines in different places to agree about when something happened.

So I'm not proposing Global Earth Freedom Time. There is no new atomic clock hidden beneath a volcano. Nobody needs to create a Ministry of Temporal Harmony.

Just use UTC everywhere. Really, hear me out.

If it is 18:42 UTC, it is 18:42 in Wisconsin. It is 18:42 in London. It is 18:42 in California. It is 18:42 in Beijing.

One moment. One time. And absolutely nothing about that requires everyone to live the same schedule.

That distinction has to be almost annoyingly explicit because there is a physiological reality underneath all of this. Humans evolved on a planet with daylight and darkness. Circadian rhythms matter. Sleep matters. Seasonal changes in sunlight matter. A child in California should not be sent to school during the biological middle of the night because someone decided everyone on Earth should begin school at the same UTC hour.

That would be catastrophically stupid.

The clock can be universal.

Human life cannot be.

Schools should open when it makes sense locally. Businesses should serve customers when customers are awake. Families should eat when they're hungry. People should sleep when their bodies and environments tell them to sleep. Religious observances, work schedules, community routines, and cultural traditions remain exactly what they are: local human decisions.

Standardize the clock. Localize the schedule.

Which brings us, inevitably, to Bob. Oh, I love Bob.

Bob has eaten lunch at noon for 63 years, and Bob would like a word.

“You're telling me I'm supposed to eat lunch at 18:00?”

No, Bob. I'm telling you to eat lunch at lunchtime.

This sounds flippant until we recognize that Bob has identified one of the strongest intuitive arguments against the entire idea. We have spent our lives attaching meaning to clock numbers. Seven means morning. Twelve means lunch. Dolly taught us all five means the workday is ending. Eleven at night means whoever is calling had better have a good reason. Those associations feel natural because they are deeply learned, but morning actually is natural. So are daylight, darkness, sunrise, sunset, hunger, fatigue, and the biological rhythms influenced by them. The number seven isn't.

So let's make this slightly less ridiculous and try the idea on one country instead of the entire planet. What if the United States simply stopped using American time zones and adopted UTC as its civil clock?

The first few months would be glorious.

One side of our hypothetical national debate would announce that Washington was now trying to control time itself. (Umm, hi. I'm Earth. Have we met? you just spent the first few minutes learning how governments already determine civil time zones. Silly.) Meanwhile, the opposing master debaters would be equally unbearable, presumably pointing outside and asking whether the Sun was up before triumphantly declaring, “Congratulations. It's morning.”

Which, irritatingly, has a point.

Someone in California accustomed to eating breakfast around 7:00 AM might now eat it around 14:00 UTC. Someone in Wisconsin might eat around 12:00 UTC, while someone in New York might eat around 11:00 UTC, depending on season and routine. (Don't focus on the math you nerds) Nobody moved breakfast, California, or the Sun. We changed the number displayed on the clock. People's actual days would continue unfolding beneath the same daylight they did yesterday.

There would, however, be real transition costs, and pretending otherwise would make the whole thought experiment dishonest. Laws and contracts reference times. Schools, courts, airlines, hospitals, transit systems, restaurants, television networks, factories, financial markets, calendars, parking signs, appointment systems, alarms, and countless pieces of software would need to adapt. Human habits might be harder still. We have spent generations learning what certain numbers on a clock are supposed to feel like, and familiarity itself has value.

Old systems often survive because they are useful, familiar, or both. That deserves more respect than simply declaring everything universal inherently superior. Meters are wonderful. So are kilograms. But I will offer a small defense of cups, teaspoons, ounces, and the other survivors of the imperial measuring system before someone confiscates my kitchen privileges. Cooking and especially baking depend on critical proportions, familiar quantities, and recipes handed between humans who aren't calibrating laboratory equipment. Sometimes a convention remains useful simply because people know how to use it. (Yeah, I know that deviates from the topic at hand. Get over it...please.)

The question isn't whether old conventions are stupid. Time zones certainly aren't. The better question is whether a convention continues doing enough useful work to justify the complications it creates. That's where time zones become considerably more interesting in the twenty-first century.

Imagine our American experiment five years after adoption. A football game starts at 21:25. That's when it starts in Wisconsin, California, and New York. A company with employees in Seattle, Chicago, and Boston schedules an all-hands meeting for 17:00, and nobody needs to ask which 17:00. A national emergency occurs at 03:42, and every American recognizes the same 03:42. A friend says, “Call me at 20:00,” and you know exactly when to call.

What you may not know is what part of that friend's day 20:00 represents, and that isn't a trivial objection. Local time zones currently perform two jobs at once. They identify a moment while also providing a rough clue about our position within the local solar day. If someone tells me it is 8:00 AM where they are, I know more than a timestamp. I know they are probably somewhere near the beginning of their waking day.

Universal UTC appears to throw that information away. Except this is where those clever railroad barons encounter technology they couldn't possibly have anticipated.

My phone knows when the Sun is going to set. It knows when it rose. It knows where I am and can calculate daylight, twilight, and local solar conditions with far greater precision than the hour hand on a clock ever could. So perhaps my phone displays 18:42 UTC — Sunset in 5 hours. Someone else might prefer 18:42 UTC — Afternoon, while an outdoor worker chooses 18:42 UTC — Daylight, dusk at 00:37. Someone routinely working across continents might see Wisconsin: Afternoon · London: Evening · Tokyo: Night beneath the universal time.

Bob's phone can say 18:42 UTC — Lunchtime. (smoke 'em if you got 'em)

But wait! There's a bit more.

We've spent centuries asking the clock to communicate both the moment and our local condition because, for most of that history, it was an elegant way to accomplish both. Today's technology can separate those functions. UTC becomes the standard while the context becomes personal, and those contextual displays could be as permanent or temporary as the individual wants.

During a transition, someone might prefer “morning,” “afternoon,” and “evening” displayed prominently. Someone else may care more about hours until sunrise or sunset. An outdoor worker may want daylight remaining, while international coworkers could pin the local daylight conditions of the people they contact most often. Children could have visual cues. People accustomed to the old system could even display legacy local time underneath UTC for a while.

No international commission needs to decide which interface is correct. Program it however you want. The underlying moment remains the same.

Then something much more interesting happens if we fast-forward not five years, but a generation. A child raised entirely on UTC would never learn that 18:00 inherently means dinner. It would just mean 18:00. That child might know Grandma usually eats lunch around 18:00, a friend in London eats around 12:00, and someone elsewhere generally goes to sleep around 04:00. Those aren't conversions performed every time they communicate. They're simply facts about people and places.

We already develop this kind of intuition geographically. We know California is west of Wisconsin without calculating longitude. We know January in Australia is summer without mentally rotating the planet every time someone mentions Sydney. A generation raised with one clock might develop temporal geography in much the same way. They may inherently know approximately when another part of the world eats lunch, sees sunset, or begins its morning because those relationships never move around behind different clock labels.

Technology could make even that knowledge optional. A call from Sarah might simply appear as Sarah · 18:42 UTC · Evening. The time tells me the moment we're sharing; the final word reminds me what Sarah is experiencing locally.

There is something surprisingly human about that distinction. Today our clocks emphasize that Sarah and I are in different times. Her clock says one thing and mine says another, even though we are speaking to each other right now. A universal clock paired with local context says something more precise: we're both here at 18:42, but it's afternoon for me and evening for her.

Would that make humanity more understanding? Maybe, although people have demonstrated an impressive ability to misunderstand one another under every timekeeping system we've invented. Still, it would make our simultaneity explicit. Instead of mentally translating someone into my time, I would know we're already sharing one. The difference between us isn't the moment. It's the condition we're each experiencing within it.

And then, of course, politics enters the room.

One clock for everyone is exactly the sort of phrase capable of producing some spectacular master debating. “Global control!” meets “New World Order!” while someone somewhere inevitably announces that they've come for your clock. There is, beneath all that shouting, a legitimate concern. Timekeeping is partly political. Governments establish civil time, choose offsets, create boundaries, adopt or reject daylight saving, and occasionally change those decisions.

That creates a wonderfully awkward response to the accusation that universal UTC would suddenly give governments control over what time it is: they already have it. A move to UTC could actually remove much of their ability to manipulate the civil clock, although phrasing it that way is precisely where the political speed bump becomes large enough to damage the suspension.

So perhaps don't frame it that way.

No global authority needs to order anyone to adopt UTC. Nations could independently choose it as their civil standard. Businesses could increasingly display it. International events could emphasize it. Technology could make it easier to use, and adoption could spread simply because common standards tend to become more useful as more people use them.

We already accept shared measurements without assuming they require shared government. A meter doesn't tell you where to walk, a kilogram doesn't tell you what to weigh, and GPS coordinates don't tell you where to live. UTC doesn't tell you when to have lunch either. Standards describe common reference points; people remain perfectly capable of deciding what to do with them.

And before anyone interprets that as an argument that every existing system of measurement should immediately be thrown into the ocean, please remember my kitchen. Human beings are perfectly capable of keeping conventions that remain useful while standardizing the things that benefit from interoperability. The existence of a superior international standard doesn't automatically render every familiar local convention worthless.

That may be the more interesting question anyway. Time zones weren't a mistake. They were a brilliant response to a world being transformed by railroads and instantaneous communication. But our world transformed again, and then it did it again.

Telephones connected distant voices. Airplanes compressed continents. Satellites linked the planet. Computers began communicating across borders constantly, and the internet made interactions once considered “international” feel completely ordinary. A small business can have customers on another continent. A child can play a game with someone thousands of miles away. Families can live across oceans and still see one another's faces every day. Companies can remain operational around the clock by handing work from one part of the planet to another as people wake and sleep beneath the moving Sun.

The organization can operate continuously even though the humans inside it cannot. UTC already coordinates much of the machinery underneath that world. We just keep translating it for ourselves.

Maybe that's still the right choice. Local time is intuitive, deeply embedded, and remarkably efficient at giving us a rough sense of the local day. Replacing it would impose enormous transition costs for benefits that are difficult to quantify, and familiarity itself has value. But familiarity is not the same thing as inevitability.

Noon doesn't have to mean 12:00, morning doesn't have to mean 7:00, and dinner doesn't have to mean 18:00. Those numbers acquired their meanings because our clocks developed alongside local life. The Sun was always doing something else.

Perhaps the technology that once made time zones necessary now gives us the ability to move beyond them without sacrificing the local information they provided. The railroad barons really were clever. The question isn't whether they were right. It's whether we still are.

The Sun can tell us what part of our day we're living, our devices can tell us how that day is unfolding, and the clock can simply tell us which moment we're sharing.

Maybe someday someone halfway around the world will say, “It's getting late here,” while we're still looking out the window at daylight. We'll understand what they mean without needing their clock to be different from ours.

“Talk again tomorrow at 16:00?”

“Perfect.”

Different lives beneath the same Sun, sharing the same moment and, perhaps eventually, calling it the same time.

Hope to see you at noon. ;)