The History of Standard Time

In the past, people set their clocks by the sun. The moment the sun reached its highest point in the sky was marked as noon. This method worked in any village, as all you had to do was stand a stick in the ground and watch for when its shadow was at its shortest.

However, the time the sun reaches its peak varies from place to place. A town to the east meets noon first, while a town to the west reaches it a little later. Even a slight change in longitude shifts the time. Furthermore, because the speed of Earth's rotation fluctuates slightly across the seasons, relying strictly on the exact moment of solar noon makes the length of a day uneven. That is why people began averaging it out across a year to create a uniform day, which is known as that region's local mean time.

The key is that this was not inconvenient in the slightest. In a world where traveling to the next city took an entire day, a difference of a few minutes went completely unnoticed. When you arrived and checked that city's clock, that was simply the time there. Towns keeping different times was not a defect, but a sign that everything was working correctly. The very concept of a wrong clock didn't exist.

Every town also had its own way of setting its clocks. You could look at the large clock in the public square, listen for the toll of the bells, or watch the time ball drop at the harbor. Watchmakers and opticians would also display the local time outside their shopfronts. Time was a local affair, managed independently by each community.

This peace was shattered the moment something began moving faster than people. Trains made differences of just a few minutes glaringly obvious. When a train departing in the morning passed through several cities before lunchtime, the fact that those cities kept different times immediately became a problem. Without deciding which city's time governed the departure, it was impossible to use a timetable.

In 1841, a notice was printed in the timetable of Britain's Great Western Railway. It stated that all stations on the line would operate on London time, and that London time was about 4 minutes ahead of Reading, 11 minutes ahead of Bath and Bristol, and 14 minutes ahead of Bridgwater. As passengers read the timetable, they learned for the first time that their town's clock did not match the train's.

In November 1840, the Great Western Railway decided to use a single time—London time—across all its stations. It is an early record of aligning different local mean times into one. The reason was simple: to make a train timetable, the departure station and arrival station had to look at the same clock.

Other companies soon followed. In 1847, the Railway Clearing House, an industry body that handled settlements among various rail companies, recommended using Greenwich time at every station, and by the end of that year, British railways across the board had switched over to it. The name given to it then was railway time. It was not a standard handed down by the government, but one the industry decided among themselves.

Yet the railways were not the ones who created that time. It was the Royal Observatory, Greenwich. In 1852, a Shepherd motor clock was installed at the observatory, and the clock mounted by its gate became the first to display Greenwich time directly to the public. That time traveled along telegraph wires to cities like London, Edinburgh, and Glasgow. Stationmasters set their station clocks by the telegraph signals sent from Greenwich. While the railways chose the time, it was the observatory and the telegraph that created and carried it.

By around 1855, nearly all public clocks in Britain were set to Greenwich time, right down to the clocks on town halls and churches. So at this point, Britain was effectively a country running on a single time. But the law was different. The time written in legal documents was still interpreted as each locality's mean time.

What sorted out this mismatch was a law enacted on August 2, 1880. Its title was the Statutes (Definition of Time) Act, and it contained just two sections. The preamble begins like this: whereas it is expedient to remove doubts as to whether expressions of time in statutes and deeds refer to Greenwich time or the mean astronomical time of each locality. What the state did was not create a new time, but write down into the language of the law what everyone was already using.

In the story of standard time, the word “first” is where things get tangled most often. That is because completely different milestones end up lumped together under the exact same label. Once you separate the axes, a different protagonist steps forward for each one.

If you count the first time a single railway company used one standard time across its entire route, that was Britain's Great Western Railway in 1840. If you count railways across a whole nation agreeing to switch to a shared time, that was Britain's Railway Clearing House in 1847. Up to this point, these were agreements strictly between private companies.

If you define it as a government enforcing a single standard time across an entire nation, the answer changes. That was New Zealand on November 2, 1868. The New Zealand government encyclopedia notes this as the world’s very first instance of a government implementing standard time nationwide. However, the time New Zealand chose was 11 hours and 30 minutes ahead of Greenwich—not an integer multiple of one hour.

That opens up yet another axis. If you count the first to adopt an offset of a whole number of hours from Greenwich as its national standard, that was Sweden on January 1, 1879. The entire country agreed to use the time of 15 degrees East longitude, which established the shape of the one-hour zones we use today. If you look for the first to formally enshrine it into law, that was Britain in 1880.

The United States leads on a completely different axis: dividing an entire continent into multiple zones and turning them all on at the exact same moment. That date was November 18, 1883. Prior to that, every case had been “one country, one time.” The U.S. was the first to tie multiple zones into a single cohesive system, and that is where the vertical stripes on today’s world map came from.

The final axis is international agreement. That brings us to the conference held in Washington in 1884. What this conference actually resolved, however, is quite different from the popular story. We will examine the original documents a bit later.

Once you separate the axes like this, the competing claims from different countries each settle neatly into place. That is why a “first” without qualifiers is almost always an incorrect statement in this story. Only by specifying what kind of “first” it was does a single definitive answer emerge.

The story of standard time usually begins with railroads. But in the first country where the government officially set a nationwide time, the trigger was different.

Around that time, New Zealand was stringing telegraph lines across its islands. By January 1868, about 74% of the 220,000 non-Māori population had access to the telegraph. However, Invercargill at the southern tip and Napier on the North Island differed in local time by 34 minutes. Because each telegraph office opened and closed according to its own local time, urgent telegrams sometimes didn't arrive until the next day.

Postmaster General John Hall stepped in. He couldn't order around the provincial councils, which enjoyed local autonomy. But telegraph and post offices were under his jurisdiction. In January 1868, he instructed all telegraph offices to open and close by Wellington Mean Time. Since many post offices shared the same buildings, they naturally followed suit. Knowing that these clocks were accurate, people began setting their own watches to match them.

Pushback came from Otago, then the wealthiest and most populous province. Local newspapers called Wellington's decision a whim of the rulers. There was also a mistake that made matters worse: residents of Dunedin were told to adjust their clocks by 20 minutes, when the correct offset was actually 17 minutes. Otago's objection wasn't just about regional autonomy. Since Wellington wasn't in the center of the country, using its time as the baseline would throw other cities off even more. The pushback from the losing side had its own calculations, too.

The matter was settled in the House of Representatives on September 2, 1868. A member from Dunedin proposed adopting Christchurch time, and Hall introduced an amendment changing "Christchurch" to "New Zealand." Government scientist James Hector had recommended 172 degrees 30 minutes East longitude, a line passing just west of Christchurch. In effect, Otago's argument was largely accepted. The decision was gazetted on October 31, and at noon on November 2, the clocks in Wellington and across the entire country struck 12 simultaneously. New Zealand later shifted this standard to 180 degrees East longitude on January 1, 1946.

The situation was different in the United States. The country was much larger, and it had far more railroads.

Before standard time, North America had more than 144 local times. Railroad companies each ran their trains according to the time in the city where their headquarters were located, and even by the early 1880s, there were about 80 different railroad times. In station waiting rooms, several clocks hung on the wall, each showing a different company's time. A passenger's pocket watch rarely matched any of them.

Several people proposed solutions. In 1870, Charles Dowd published a pamphlet proposing to divide the nation into four zones, and in 1876, Sandford Fleming, chief engineer of the Canadian railway, proposed a worldwide standard time based on a 24-hour system. In 1879, a standard time committee was formed at the suggestion of Cleveland Abbe, and the reason was surprisingly weather forecasting. You cannot assemble a forecast if observation times differ from place to place.

Here lies a point that is often overlooked. According to accounts from the Law Library of Congress, as pressure mounted for a unified time, railroad companies worried that the government might step in and cut into their profits, so they created a plan themselves. In other words, the railroads did not simply move ahead of the state; they acted preemptively to keep the state from getting involved.

On October 11, 1883, at a hotel in Chicago, the General Time Convention—a gathering of railroad companies—voted to adopt William Allen's proposal. They agreed to use times based on 75, 90, 105, and 120 degrees west longitude, spaced one hour apart. The date of implementation was noon on November 18. On that day, noon came twice in many cities: first the noon determined by the sun, and then, after clocks were turned back, the noon decreed by the railroads.

Not everyone welcomed the change. An Indianapolis newspaper wrote that people would now have to marry by railroad time and die by railroad time. It added that the sun, moon, and stars might try to defy the railroad convention's orders, but in the end, they would surrender. It was an exaggeration, but what the paper pointed out was undeniably real: the entity now marking the hours of the day was a corporation.

There is a widespread story: that the 1884 International Meridian Conference in Washington divided the world into 24 time zones. It is even written that way on the website of the company managing Britain's railway infrastructure. But open the original conference proceedings, and a different story emerges.

The conference opened on October 1, 1884, at the U.S. Department of State, with 25 nations participating in the voting. Seven resolutions were adopted: establish a single initial meridian; fix it at the meridian of the Greenwich Observatory; count longitude from there up to 180 degrees east and west; adopt a "universal day"; start the universal day at mean midnight of the initial meridian and count from 0 to 24 hours; express the hope that astronomical and nautical days would also begin at midnight; and resume studies on the decimal division of angles and time. Not one of the seven mentions time zones.

In fact, it was quite the opposite. The fourth resolution included a proviso: that the universal day would be used for such purposes as may be convenient, and would not interfere with the use of local or other standard time where desirable. The Ottoman delegate voted in favor only after having this proviso confirmed, explaining that in his country, reckoning the start of the day from sunset was woven into agriculture and prayer times, and could not be abandoned.

There was a proposal that came closest to time zones. In the final session, British delegate Strachey submitted a draft resolution to mark meridians around the globe at intervals of 10 minutes or integral multiples thereof to reckon time. But he never called for a vote. Because it was extraordinarily difficult to find wording that suited everyone's views, and because setting local time had to be left to each locality anyway, he withdrew it himself. The Russian delegate also mentioned the idea of 24 meridians spaced 15 degrees apart, but noted that since the various governments had not yet examined it, it was hard to express an opinion.

Then why was Greenwich chosen? The basis was a table submitted to the conference. At the time, 72% of the world's shipping tonnage already reckoned longitude from Greenwich, while the remaining 28% was scattered across ten other meridians. Gathering around the most widely used choice incurred the lowest switching cost. The French delegate pointed out this very fact: Greenwich's sole advantage was the cluster of interests surrounding it, not scientific merit. France abstained from the vote on the initial meridian.

Standard time is a strange thing. It requires almost no material resources to change. Altering the standard dimensions of shipping containers requires manufacturing brand-new boxes, but with time, all you have to do is turn the hands on a clock. Yet it still took decades to establish. The reason is that the cost lay not in physical materials, but in consensus.

This exact dynamic is recorded in the document Allen submitted to the 1884 Washington Conference. Railroad managers did not want to run their lines on a time that the public did not use, because passengers would not understand it. Conversely, the public refused to adopt a time that drastically upended their daily habits. Allen noted that while one might argue this attitude was unreasonable, it was nonetheless an undeniable fact that could not be ignored. Both sides were waiting for the other to make the first move.

Standards behave this way because their value grows as more people use them. If you alone use a different time, you are out of sync with your neighbors and suffer a loss, but if everyone adopts it together, everyone benefits. That means someone has to bear the initial cost of adopting a time nobody else uses. In the United States, the railroads paid that price. After drafting the plan, railroad officials visited municipal governments one by one to persuade them, and newspapers printed guides on how to adjust clocks alongside maps of the new zones.

Once a standard takes root, an opposing force sets in. On October 9, 1884, eleven months after implementation, American and Canadian railroad managers gathered in Philadelphia and unanimously adopted a resolution to send to the Washington Conference. Its core message was an appeal not to move the prime meridian anywhere other than Greenwich. If it were moved, their standard meridians would no longer align with whole degrees, and their rationale was that changing to another standard would require an amount of legislation very difficult to obtain. It had taken less than a single year for the standard to freeze firmly in place.

The very same force acted on the side that was pushed aside. After abstaining in 1884, France did not change its law until March 9, 1911. The wording of that statute is quite amusing. It defined France's legal time as Paris Mean Time retarded by 9 minutes and 21 seconds. If you calculate it, it equals Greenwich Time, yet the word Greenwich appears nowhere in the text. It was not until a 1978 decree that French law directly referenced Coordinated Universal Time as its baseline. The United States was equally slow. The system created by the railroads did not become federal law until March 19, 1918, at which point the authority to define time zone boundaries was handed over to the Interstate Commerce Commission.

It might seem like standard time is settled once and for all, but that is not the case. The Korean Peninsula's reference meridian has shifted four times. According to records compiled by the National Archives of Korea, it was set at 127 degrees 30 minutes east on April 1, 1908, shifted to 135 degrees east on January 1, 1912, returned to 127 degrees 30 minutes on March 17, 1954, and went back to 135 degrees on August 7, 1961. Each time it changed, a separate legal decree was enacted. Standard time was a matter of technology, but it was also a matter of who got to decide.

Some places do not even follow official standard time. Tea plantations in Assam, India, set their clocks one hour ahead of the official time. It is a custom carried over from the British colonial era. India uses a single standard time for the entire nation, even though sunrise between its eastern and western tips differs by about 2 hours. In 2018, researchers at the National Physical Laboratory of India published a proposal in an academic journal to split the country into two standard time zones. What is fascinating is how they chose the dividing line. They selected the border between West Bengal and Assam because it was a stretch with few train stations where railway schedules could be managed manually. The bond between time zone borders and railways is still not over today.

Other countries have moved in the opposite direction. On March 1, 2024, Kazakhstan merged its two time zones into one, standardizing on a time 5 hours ahead of Coordinated Universal Time. One of the reasons cited by the government was that the old clock time fell out of step with actual solar time, disrupting people's circadian rhythms. But in the eastern parts of the country, winter sunsets arrived far too early. In Oskemen, sunset around the winter solstice fell at around 3:30 p.m. In a December 2024 poll by the research organization Demoscope, 53% opposed the consolidation while 22% supported it, and that same month, a court in Astana dismissed a lawsuit brought by eastern residents.

The toll of clocks falling out of sync with the sun has even been measured in real terms. A study published in 2019 took advantage of time zone borders in the United States. Communities on either side of a border share very similar lifestyles, yet their clocks differ by one hour. The study estimated that an extra hour of natural evening light cuts average sleep by 19 minutes. Which box you fall into genuinely touches a person's everyday life.

In the European Union, a different kind of gridlock emerged. On September 12, 2018, the European Commission submitted a proposal to end seasonal time changes. A public consultation gathered about 4.6 million responses, with 84% favoring abolition. However, because member states could not agree on which time to adopt permanently, the proposal stalled. There was agreement on making a change, but no agreement on what to change it to.

You don't need to predict the future. Instead, based on the rules this story has taught us, let's simply map out what to watch so you can spot the clocks shifting before anyone else.

First, watch who pays the bill. To change a standard, someone has to be the first to adopt a time that nobody else uses. In the United States, it was the railroads; in New Zealand, it was the Post and Telegraph Department. If talks about time zones arise in any country today, you should look first at whether an organization exists that is willing and able to foot that cost.

Second, look at the cost of turning back. Standards take a long time to set, but once fixed, undoing them takes just as long. Just as American railroads remarked less than a year into implementation that changing it would require legislation all over again. When a proposal comes up, if you want to know whether it will actually happen, it is far more accurate to count how many laws and systems have to be touched again than to judge how good the proposal sounds.

Third, see how much misalignment with nature can be tolerated. From the start, standard time was a pact to fall out of step with the sun. In its early days of implementation, Sweden accepted a discrepancy of over 30 minutes within the country. The question is how wide that gap can stretch. Early sunsets in eastern Kazakhstan and early sunrises in northeastern India are unfolding right along that boundary line.

Fourth, look at the shape of consensus. As the case of the European Union shows, even if a majority agrees on changing things, nothing happens if they split over where to shift. Standards are not a matter of majority rule, but of converging onto a single point. If a country touches its time zones in the future, just watch whether it has narrowed its target to one.

Finally, just one more thing. In this story, neither the side that changed the time nor the side that defended it acted on silly reasons. Otago felt its region was being slighted, the Ottoman representative had to protect prayer times, and France viewed yielding its meridian not as an issue of science, but of power. Moving the hands of a clock costs almost nothing in physical goods. Yet that is precisely why people fought over it for so long.