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You're listening to Wait, why do we do that?
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The strange stories behind completely normal things.
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This time, why do we change the clocks?
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Now to explain the origin of it all, here's your host, Steve.
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Once a year of an hour disappears, nobody reports it missing.
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The police aren't called.
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There's no investigation.
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We just wake up on Sunday morning and collectively agree.
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Yes, apparently it's eight o'clock now.
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Even though every cell in your body knows perfectly well, it's seven o'clock.
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Then several months later, we give the hour back, which sounds generous.
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Except by then you've forgotten they took it from you in the first place.
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This is daylight saving time.
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And twice a year, millions of us perform one of the strangest rituals in modern society.
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We change time, your phone does it automatically, your computer does it automatically, your television does it automatically, your car maybe.
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The microwave definitely doesn't.
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The microwave will remain defiantly wrong for approximately six months, then suddenly it's correct again, and you feel strangely vindicated for never changing it.
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But think about what we're actually doing.
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We aren't changing daylight, we can't.
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The sun remains completely uninterested in federal legislation.
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We're changing the numbers on our clocks so that human schedules line up differently with sunlight, and we've been arguing about whether this is a good idea for more than a century.
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So wait, why do we do that?
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Benjamin Franklin, inventor, diplomat, founding father, kite enthusiast, and according to countless articles, inventor of daylight saving time.
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Except not really.
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In 1784 Franklin was living in Paris.
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One morning he was apparently awakened unusually early and noticed something astonishing.
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The sun was already up.
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Now, this was presumably less surprising to the sun, but Franklin calculated that Parisians could save enormous amounts of money on candles if they simply woke earlier and made better use of morning daylight.
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He wrote about the idea in a letter published in the Journal de Paris.
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But this wasn't a serious proposal for changing clocks.
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It was satire.
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Franklin jokingly suggested things like taxing window shutters, rationing candles, and firing cannons at sunrise to wake people up, which would certainly solve the oversleeping problem.
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Possibly several others.
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Imagine your morning routine.
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Alarm clock, coffee, shower, artillery.
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You'd be at work by seven.
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Franklin's basic observation was sensible.
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If people align their lives more closely with daylight, they use less artificial lighting, but he wasn't proposing that everyone move the clocks.
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For that, we need to meet someone else.
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More than a century later, a British builder named William Willett was out riding his horse early one summer morning.
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Willett noticed that many houses still had their blinds closed.
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Beautiful morning, sun shining, and everyone asleep?
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This bothered him.
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Apparently quite a lot.
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Most of us might think good for them.
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William Willett thought we need to redesign time.
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In 1907 he published a pamphlet called The Waste of Daylight.
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Fantastic title.
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It sounds less like a policy proposal and more like something your father says when you're still in bed at ten thirty.
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Willett argued that Britain was wasting hundreds of hours of useful daylight every year.
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His solution was wonderfully complicated.
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Rather than move the clocks forward one hour, he proposed advancing them by twenty minutes.
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On four consecutive Sundays in April.
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And then reversing the process in September, twenty minutes, four times.
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Imagine trying to explain that today.
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Don't forget to change the clocks tonight.
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How much?
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Twenty minutes.
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Didn't we do that last week?
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Yes.
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And next week?
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Again.
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At which point the microwave would simply give up.
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Willett campaigned passionately for the idea.
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A young Winston Churchill even supported daylight saving, but Parliament didn't adopt Willett's proposal during his lifetime.
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William Willett died in 1915, and then war changed everything.
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World War I created an enormous demand for energy.
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Coal mattered, fuel mattered.
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Anything that could reduce energy consumption was suddenly interesting.
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In 1916, Germany introduced daylight saving time.
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The goal was straightforward, shift people's schedules toward daylight, and reduce the need for artificial lighting and therefore conserve fuel.
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Britain followed shortly afterward.
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Other European countries did too.
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And in 1918, the United States adopted Daylight Saving Time as part of the Standard Time Act.
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So no, it wasn't invented for farmers.
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It was adopted during wartime largely as an energy saving measure.
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And farmers, many of them hated it.
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Because here's something cows are remarkably stubborn about, that they don't own watches.
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If you've been milking a cow at a particular point in its biological day, the government moving the clock forward doesn't automatically update the cow.
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There is no settings menu.
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No software patch, no.
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Would you like Daisy to automatically adjust for daylight saving time?
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Farm work is governed by sunlight, weather, and animals, not necessarily by what a clock says.
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So the idea that daylight saving time exists to help farmers is almost exactly backwards.
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Farmers became some of its most persistent opponents.
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The United States tried daylight saving time during World War I.
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Then, after the war, Congress repealed the national requirement, and things became messy.
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Some cities kept daylight saving time, others didn't.
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Some states used it, others didn't, which is manageable if nobody travels anywhere.
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Unfortunately, Americans occasionally do.
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Imagine operating a railroad, or an airline, or a broadcasting network, when different cities are making independent decisions about what time it is.
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You leave one city at two o'clock, travel for two hours, arrive somewhere at three o'clock, or four o'clock, possibly five o'clock.
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Nobody knows.
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Welcome to transportation.
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During World War II, the United States introduced year-round daylight saving time again.
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It was nicknamed Wartime.
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After the war, federal control ended again, and once more, local governments made their own choices.
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By the 1960s, the result was chaotic.
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Different areas could begin and end daylight, saving on different dates.
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Bus companies, railroads, airlines, and broadcasters had to keep track of a patchwork of local time rules.
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Eventually, the federal government decided that perhaps and I'm paraphrasing here, everyone should agree what time it is.
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In 1966, Congress passed the Uniform Time Act.
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This established a more consistent national system for daylight saving time.
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If a state observed it, the dates would be standardized.
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States could choose not to participate, and some still don't.
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Most of Arizona doesn't observe daylight saving time.
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Neither does Hawaii, nor do several US territories, which means twice a year.
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The time difference between Arizona and other states changes.
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Arizona doesn't change, and everyone else does.
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Arizona simply sits there watching the rest of us rearrange our clocks and presumably thinking, you people seem tired.
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The US Department of Transportation now oversees the nation's time zones and uniform observance of daylight saving time.
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And yes, the Department of Transportation, not the Department of Time.
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Apparently we don't have one of those.
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Although given how government works, I'm slightly surprised.
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Now here's where things get particularly interesting.
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People have been saying, can we please stop changing the clocks?
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For decades.
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And America actually tried something close to that.
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In 1973, the country was facing an energy crisis.
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Oil prices were rising.
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Fuel shortages were a major concern.
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So Congress approved year-round daylight saving time, President Nixon signed it.
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And in January 1974, America stopped falling back.
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At first people liked the idea, then winter arrived.
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And people discovered the obvious problem with moving an hour of daylight into the evening.
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You remove it from the morning.
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In some places, children were going to school in darkness, workers were commuting in darkness.
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Sunrise came remarkably late.
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Public enthusiasm fell.
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Congress changed course.
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The experiment was shortened, and by late 1974, seasonal clock changes returned.
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Which is useful historical context whenever someone says, Why don't we just keep daylight saving time permanently?
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We tried something very similar.
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People discovered that 8 30 in the morning is considerably less cheerful when the sun hasn't turned up yet.
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Remember the original selling point?
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Energy.
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More evening daylight means less artificial lighting.
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Makes sense.
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Especially in 1916, when lighting represented a much bigger share of household electricity use.
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But modern life is different, we have efficient lighting, air conditioning, computers, televisions, appliances, data centers, and approximately 14 chargers plugged into every house.
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So researchers have repeatedly asked, does daylight saving time still save meaningful energy?
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The answer is not much.
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A US Department of Energy analysis of the extended daylight saving schedule introduced in 2007 estimated electricity savings of roughly half a percent per day during the extension period.
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Half a percent not zero, but also not exactly quick, somebody redesigned time.
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Other research has produced mixed results.
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In some climates, later daylight can actually increase air conditioning use.
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So the energy argument today is much less straightforward than it was when people were trying to save candles and coal.
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Which leaves us with another supposed benefit.
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More daylight in the evening, and businesses love that.
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If it's light outside after work, people do things.
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They shop, play golf, go to restaurants, attend sports, take children to activities, visit parks, drive places, spend money.
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Various industries have historically supported longer daylight saving periods.
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Retail, recreation, golf, barbecue, yes, barbecue.
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One of the stranger chapters in daylight saving history involves lobbying around the extension of daylight saving time.
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The basic economic argument is simple.
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If the sun is still shining, people are more likely to leave the house.
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Apparently darkness is one of the economy's greatest competitors.
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There was even political debate about whether extending daylight saving time through the late October would affect Halloween.
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More evening daylight, safer trick-or-treating, more candy sales.
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Which means somewhere in the history of American time policy, candy became relevant.
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Benjamin Franklin wanted to save candles.
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A century later, we were thinking about Snickers.
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Progress.
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There's another problem.
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Your body has its own clock.
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Circadian rhythms help regulate sleep, alertness, hormones, body temperature, and other biological processes.
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And your internal clock pays considerable attention to light, especially morning light.
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So when we suddenly move the clocks forward, your body doesn't immediately say, ah yes, federal regulation, I'll adjust.
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You lose an hour of sleep.
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Morning becomes darker, evening becomes lighter, and for several days, sometimes longer, your body has to adapt.
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Sleep researchers have associated the spring transition with disrupted sleep and increased risks in areas including traffic safety and cardiovascular health.
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The American Academy of Sleep Medicine has gone further.
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It supports eliminating seasonal clock changes and adopting permanent standard time, not permanent daylight saving time.
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Standard time.
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Because standard time more closely aligns our schedules with the natural light dark cycle, which creates an interesting situation.
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Lots of people agree, stop changing the clocks, then you ask the next question.
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Fine, which time should we keep?
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And suddenly the argument starts again.
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This is the heart of the modern debate.
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Permanent daylight saving time gives us more evening light.
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Which many people love.
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Summer evening, dinner outside, walk the dog, play golf.
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Sit in the yard, it feels like you're getting more day, you're not.
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Again, we don't manufacture daylight, we've just moved the label.
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But permanent daylight saving also means darker winter mornings.
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Permanent standard time gives us earlier morning light.
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Sleep scientists generally prefer that because it aligns more closely with human circadian biology, but then sunset comes earlier.
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Which people don't like.
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So the argument is essentially would you rather have sunlight before work or after work?
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And because different parts of the country experience sunrise and sunset differently, but there isn't one experience shared by everyone.
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Someone in Maine and someone in western Indiana can live in the same time zone and have very different relationships with daylight, which brings us to the real reason this problem refuses to die.
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There is no way to move an hour of daylight into the evening without taking it from somewhere else.
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The sun is annoyingly strict about the budget.
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And yet, twice a year?
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We continue.
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Spring forward, fall back, phones quietly change themselves overnight, smart watches update, computers update.
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Then Sunday morning becomes an archaeological expedition through your house.
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Microwave, oven, wool clock, car.
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Alarm clock in the guest bedroom nobody has touched since 2019.
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And there's always one clock you forget.
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You discover it three weeks later.
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You look at it, panic.
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Oh no, I'm late.
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Then remember, no, the clock is wrong.
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And experience the smallest possible version of time travel.
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There is also the annual tradition of someone reminding everyone.
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Don't forget to change the batteries in your smoke detectors.
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Which is sensible advice.
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Although increasingly, the smoke detector has a ten year battery, and the clock changes itself.
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Eventually, daylight saving weekend may consist entirely of us doing nothing, while our devices quietly handle a tradition nobody can explain.
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So why do we change the clocks?
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Originally to make better use of daylight.
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Then to conserve energy, especially during wartime.
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Later, to create a uniform national system out of a chaotic collection of local rules.
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And today, the arguments are much less clear.
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Energy savings appear relatively small and depend on circumstances.
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Businesses value evening daylight, many people enjoy it.
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Sleep researchers worry about the biological effects of changing the clocks and generally favour permanent standard time.
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Politicians repeatedly propose changing the system, and the public seems remarkably united around one idea.
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We don't like changing the clocks.
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We just can't agree what to replace it with.
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Which is wonderfully human.
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We have identified the problem, we have broadly agreed the problem is annoying, we have several possible solutions, and therefore we'll continue doing exactly the same thing.
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Quarty would be proud.
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So, why do we change the clocks?
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If Benjamin Franklin didn't invent daylight saving time, farmers didn't ask for it, and we aren't actually saving daylight as the modern idea grew from attempts to align human activity with summer sunlight.
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William Willet campaigned for it in Britain.
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Germany first implemented it nationally during World War I as an energy saving measure.
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The United States followed, then abandoned it, then brought it back, then abandoned national coordination again, then standardized it, then tried year-round daylight saving time, then changed its mind, and here we are.
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More than a century later, still moving an hour forward.
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Then moving it back and arguing about whether we should stop.
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Or because we're trying to solve one fundamental problem.
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The sun doesn't run on our schedule.
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So twice a year, instead of changing our schedule, we change time.
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Or at least the numbers on the microwave.
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Assuming anyone can remember how, I'm Steve.
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And apparently there's a reason for almost everything, even if it isn't a particularly good one.
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You're listening to Wait, why do we do that?
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The strange stories behind completely normal things.
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This time, why do we change the clocks?
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Now to explain the origin of it all, here's your host, Steve.
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Once a year of an hour disappears, nobody reports it missing.
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The police aren't called.
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There's no investigation.
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We just wake up on Sunday morning and collectively agree.
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Yes, apparently it's eight o'clock now.
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Even though every cell in your body knows perfectly well, it's seven o'clock.
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Then several months later, we give the hour back, which sounds generous.
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Except by then you've forgotten they took it from you in the first place.
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This is daylight saving time.
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And twice a year, millions of us perform one of the strangest rituals in modern society.
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We change time, your phone does it automatically, your computer does it automatically, your television does it automatically, your car maybe.
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The microwave definitely doesn't.
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The microwave will remain defiantly wrong for approximately six months, then suddenly it's correct again, and you feel strangely vindicated for never changing it.
00:01:21.200 --> 00:01:22.879
But think about what we're actually doing.
00:01:23.040 --> 00:01:24.959
We aren't changing daylight, we can't.
00:01:25.120 --> 00:01:28.480
The sun remains completely uninterested in federal legislation.
00:01:28.719 --> 00:01:37.599
We're changing the numbers on our clocks so that human schedules line up differently with sunlight, and we've been arguing about whether this is a good idea for more than a century.
00:01:37.760 --> 00:01:39.599
So wait, why do we do that?
00:01:39.840 --> 00:01:50.640
Benjamin Franklin, inventor, diplomat, founding father, kite enthusiast, and according to countless articles, inventor of daylight saving time.
00:01:51.120 --> 00:01:52.640
Except not really.
00:01:52.879 --> 00:01:55.840
In 1784 Franklin was living in Paris.
00:01:56.079 --> 00:02:01.359
One morning he was apparently awakened unusually early and noticed something astonishing.
00:02:01.599 --> 00:02:03.120
The sun was already up.
00:02:03.359 --> 00:02:15.840
Now, this was presumably less surprising to the sun, but Franklin calculated that Parisians could save enormous amounts of money on candles if they simply woke earlier and made better use of morning daylight.
00:02:16.159 --> 00:02:20.000
He wrote about the idea in a letter published in the Journal de Paris.
00:02:20.639 --> 00:02:23.599
But this wasn't a serious proposal for changing clocks.
00:02:23.840 --> 00:02:24.960
It was satire.
00:02:25.120 --> 00:02:36.159
Franklin jokingly suggested things like taxing window shutters, rationing candles, and firing cannons at sunrise to wake people up, which would certainly solve the oversleeping problem.
00:02:36.400 --> 00:02:37.759
Possibly several others.
00:02:38.000 --> 00:02:39.439
Imagine your morning routine.
00:02:39.680 --> 00:02:42.719
Alarm clock, coffee, shower, artillery.
00:02:42.879 --> 00:02:44.240
You'd be at work by seven.
00:02:44.400 --> 00:02:46.960
Franklin's basic observation was sensible.
00:02:47.199 --> 00:02:56.159
If people align their lives more closely with daylight, they use less artificial lighting, but he wasn't proposing that everyone move the clocks.
00:02:56.479 --> 00:02:58.560
For that, we need to meet someone else.
00:02:58.879 --> 00:03:05.199
More than a century later, a British builder named William Willett was out riding his horse early one summer morning.
00:03:05.439 --> 00:03:08.639
Willett noticed that many houses still had their blinds closed.
00:03:08.960 --> 00:03:13.520
Beautiful morning, sun shining, and everyone asleep?
00:03:13.840 --> 00:03:14.800
This bothered him.
00:03:14.960 --> 00:03:16.159
Apparently quite a lot.
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Most of us might think good for them.
00:03:19.360 --> 00:03:22.319
William Willett thought we need to redesign time.
00:03:22.800 --> 00:03:27.599
In 1907 he published a pamphlet called The Waste of Daylight.
00:03:27.919 --> 00:03:29.039
Fantastic title.
00:03:29.199 --> 00:03:35.439
It sounds less like a policy proposal and more like something your father says when you're still in bed at ten thirty.
00:03:35.759 --> 00:03:40.800
Willett argued that Britain was wasting hundreds of hours of useful daylight every year.
00:03:41.039 --> 00:03:43.360
His solution was wonderfully complicated.
00:03:43.520 --> 00:03:48.800
Rather than move the clocks forward one hour, he proposed advancing them by twenty minutes.
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On four consecutive Sundays in April.
00:03:51.520 --> 00:03:55.759
And then reversing the process in September, twenty minutes, four times.
00:03:56.080 --> 00:03:58.560
Imagine trying to explain that today.
00:03:59.120 --> 00:04:01.360
Don't forget to change the clocks tonight.
00:04:01.599 --> 00:04:02.159
How much?
00:04:02.400 --> 00:04:03.199
Twenty minutes.
00:04:03.360 --> 00:04:04.800
Didn't we do that last week?
00:04:05.039 --> 00:04:05.599
Yes.
00:04:05.840 --> 00:04:06.960
And next week?
00:04:07.280 --> 00:04:07.919
Again.
00:04:08.560 --> 00:04:11.039
At which point the microwave would simply give up.
00:04:11.280 --> 00:04:13.840
Willett campaigned passionately for the idea.
00:04:14.080 --> 00:04:20.959
A young Winston Churchill even supported daylight saving, but Parliament didn't adopt Willett's proposal during his lifetime.
00:04:21.199 --> 00:04:26.480
William Willett died in 1915, and then war changed everything.
00:04:26.720 --> 00:04:29.759
World War I created an enormous demand for energy.
00:04:30.079 --> 00:04:32.079
Coal mattered, fuel mattered.
00:04:32.319 --> 00:04:35.920
Anything that could reduce energy consumption was suddenly interesting.
00:04:36.160 --> 00:04:40.399
In 1916, Germany introduced daylight saving time.
00:04:40.720 --> 00:04:48.879
The goal was straightforward, shift people's schedules toward daylight, and reduce the need for artificial lighting and therefore conserve fuel.
00:04:49.120 --> 00:04:51.120
Britain followed shortly afterward.
00:04:51.360 --> 00:04:53.519
Other European countries did too.
00:04:53.759 --> 00:05:00.079
And in 1918, the United States adopted Daylight Saving Time as part of the Standard Time Act.
00:05:00.399 --> 00:05:03.360
So no, it wasn't invented for farmers.
00:05:03.600 --> 00:05:07.279
It was adopted during wartime largely as an energy saving measure.
00:05:07.519 --> 00:05:10.000
And farmers, many of them hated it.
00:05:10.160 --> 00:05:14.480
Because here's something cows are remarkably stubborn about, that they don't own watches.
00:05:14.639 --> 00:05:22.480
If you've been milking a cow at a particular point in its biological day, the government moving the clock forward doesn't automatically update the cow.
00:05:22.800 --> 00:05:24.079
There is no settings menu.
00:05:24.240 --> 00:05:25.839
No software patch, no.
00:05:26.720 --> 00:05:30.480
Would you like Daisy to automatically adjust for daylight saving time?
00:05:31.360 --> 00:05:37.279
Farm work is governed by sunlight, weather, and animals, not necessarily by what a clock says.
00:05:37.519 --> 00:05:43.199
So the idea that daylight saving time exists to help farmers is almost exactly backwards.
00:05:43.519 --> 00:05:46.399
Farmers became some of its most persistent opponents.
00:05:46.639 --> 00:05:50.079
The United States tried daylight saving time during World War I.
00:05:50.480 --> 00:05:56.720
Then, after the war, Congress repealed the national requirement, and things became messy.
00:05:57.199 --> 00:06:00.480
Some cities kept daylight saving time, others didn't.
00:06:00.639 --> 00:06:05.519
Some states used it, others didn't, which is manageable if nobody travels anywhere.
00:06:05.680 --> 00:06:08.879
Unfortunately, Americans occasionally do.
00:06:09.199 --> 00:06:17.839
Imagine operating a railroad, or an airline, or a broadcasting network, when different cities are making independent decisions about what time it is.
00:06:18.079 --> 00:06:25.600
You leave one city at two o'clock, travel for two hours, arrive somewhere at three o'clock, or four o'clock, possibly five o'clock.
00:06:25.759 --> 00:06:26.800
Nobody knows.
00:06:27.040 --> 00:06:28.639
Welcome to transportation.
00:06:28.879 --> 00:06:33.839
During World War II, the United States introduced year-round daylight saving time again.
00:06:34.079 --> 00:06:37.439
It was nicknamed Wartime.
00:06:37.839 --> 00:06:44.879
After the war, federal control ended again, and once more, local governments made their own choices.
00:06:45.120 --> 00:06:47.839
By the 1960s, the result was chaotic.
00:06:48.079 --> 00:06:52.000
Different areas could begin and end daylight, saving on different dates.
00:06:52.240 --> 00:06:58.959
Bus companies, railroads, airlines, and broadcasters had to keep track of a patchwork of local time rules.
00:06:59.199 --> 00:07:06.480
Eventually, the federal government decided that perhaps and I'm paraphrasing here, everyone should agree what time it is.
00:07:06.720 --> 00:07:10.560
In 1966, Congress passed the Uniform Time Act.
00:07:10.800 --> 00:07:15.040
This established a more consistent national system for daylight saving time.
00:07:15.279 --> 00:07:18.480
If a state observed it, the dates would be standardized.
00:07:18.720 --> 00:07:21.759
States could choose not to participate, and some still don't.
00:07:22.000 --> 00:07:25.040
Most of Arizona doesn't observe daylight saving time.
00:07:25.199 --> 00:07:30.639
Neither does Hawaii, nor do several US territories, which means twice a year.
00:07:30.879 --> 00:07:34.160
The time difference between Arizona and other states changes.
00:07:34.399 --> 00:07:37.040
Arizona doesn't change, and everyone else does.
00:07:37.360 --> 00:07:44.480
Arizona simply sits there watching the rest of us rearrange our clocks and presumably thinking, you people seem tired.
00:07:44.720 --> 00:07:51.120
The US Department of Transportation now oversees the nation's time zones and uniform observance of daylight saving time.
00:07:51.439 --> 00:07:56.000
And yes, the Department of Transportation, not the Department of Time.
00:07:56.160 --> 00:07:58.240
Apparently we don't have one of those.
00:07:58.480 --> 00:08:02.639
Although given how government works, I'm slightly surprised.
00:08:02.879 --> 00:08:05.759
Now here's where things get particularly interesting.
00:08:06.000 --> 00:08:09.600
People have been saying, can we please stop changing the clocks?
00:08:09.920 --> 00:08:10.879
For decades.
00:08:11.360 --> 00:08:14.240
And America actually tried something close to that.
00:08:14.480 --> 00:08:18.319
In 1973, the country was facing an energy crisis.
00:08:18.560 --> 00:08:20.319
Oil prices were rising.
00:08:20.639 --> 00:08:23.040
Fuel shortages were a major concern.
00:08:23.199 --> 00:08:27.920
So Congress approved year-round daylight saving time, President Nixon signed it.
00:08:28.160 --> 00:08:32.480
And in January 1974, America stopped falling back.
00:08:32.720 --> 00:08:36.240
At first people liked the idea, then winter arrived.
00:08:36.480 --> 00:08:41.440
And people discovered the obvious problem with moving an hour of daylight into the evening.
00:08:41.679 --> 00:08:43.279
You remove it from the morning.
00:08:43.440 --> 00:08:49.120
In some places, children were going to school in darkness, workers were commuting in darkness.
00:08:49.440 --> 00:08:51.759
Sunrise came remarkably late.
00:08:52.080 --> 00:08:53.679
Public enthusiasm fell.
00:08:53.919 --> 00:08:55.519
Congress changed course.
00:08:55.759 --> 00:09:01.919
The experiment was shortened, and by late 1974, seasonal clock changes returned.
00:09:02.159 --> 00:09:08.879
Which is useful historical context whenever someone says, Why don't we just keep daylight saving time permanently?
00:09:09.120 --> 00:09:10.879
We tried something very similar.
00:09:11.120 --> 00:09:16.960
People discovered that 8 30 in the morning is considerably less cheerful when the sun hasn't turned up yet.
00:09:17.200 --> 00:09:18.960
Remember the original selling point?
00:09:19.120 --> 00:09:19.679
Energy.
00:09:19.919 --> 00:09:22.879
More evening daylight means less artificial lighting.
00:09:23.200 --> 00:09:24.240
Makes sense.
00:09:24.480 --> 00:09:30.879
Especially in 1916, when lighting represented a much bigger share of household electricity use.
00:09:31.039 --> 00:09:43.120
But modern life is different, we have efficient lighting, air conditioning, computers, televisions, appliances, data centers, and approximately 14 chargers plugged into every house.
00:09:43.440 --> 00:09:49.039
So researchers have repeatedly asked, does daylight saving time still save meaningful energy?
00:09:49.279 --> 00:09:51.679
The answer is not much.
00:09:52.080 --> 00:10:04.480
A US Department of Energy analysis of the extended daylight saving schedule introduced in 2007 estimated electricity savings of roughly half a percent per day during the extension period.
00:10:04.720 --> 00:10:10.480
Half a percent not zero, but also not exactly quick, somebody redesigned time.
00:10:10.879 --> 00:10:13.440
Other research has produced mixed results.
00:10:13.679 --> 00:10:18.240
In some climates, later daylight can actually increase air conditioning use.
00:10:18.480 --> 00:10:24.159
So the energy argument today is much less straightforward than it was when people were trying to save candles and coal.
00:10:24.399 --> 00:10:26.720
Which leaves us with another supposed benefit.
00:10:26.960 --> 00:10:30.960
More daylight in the evening, and businesses love that.
00:10:31.200 --> 00:10:33.919
If it's light outside after work, people do things.
00:10:34.080 --> 00:10:42.240
They shop, play golf, go to restaurants, attend sports, take children to activities, visit parks, drive places, spend money.
00:10:42.559 --> 00:10:46.559
Various industries have historically supported longer daylight saving periods.
00:10:46.879 --> 00:10:51.360
Retail, recreation, golf, barbecue, yes, barbecue.
00:10:51.600 --> 00:10:58.080
One of the stranger chapters in daylight saving history involves lobbying around the extension of daylight saving time.
00:10:58.320 --> 00:11:01.039
The basic economic argument is simple.
00:11:01.279 --> 00:11:05.440
If the sun is still shining, people are more likely to leave the house.
00:11:05.679 --> 00:11:09.279
Apparently darkness is one of the economy's greatest competitors.
00:11:09.600 --> 00:11:15.840
There was even political debate about whether extending daylight saving time through the late October would affect Halloween.
00:11:16.080 --> 00:11:20.240
More evening daylight, safer trick-or-treating, more candy sales.
00:11:20.399 --> 00:11:25.919
Which means somewhere in the history of American time policy, candy became relevant.
00:11:26.159 --> 00:11:28.799
Benjamin Franklin wanted to save candles.
00:11:29.039 --> 00:11:32.240
A century later, we were thinking about Snickers.
00:11:32.559 --> 00:11:33.279
Progress.
00:11:33.600 --> 00:11:34.799
There's another problem.
00:11:35.039 --> 00:11:36.720
Your body has its own clock.
00:11:36.960 --> 00:11:45.679
Circadian rhythms help regulate sleep, alertness, hormones, body temperature, and other biological processes.
00:11:45.919 --> 00:11:50.639
And your internal clock pays considerable attention to light, especially morning light.
00:11:50.879 --> 00:11:58.559
So when we suddenly move the clocks forward, your body doesn't immediately say, ah yes, federal regulation, I'll adjust.
00:11:58.879 --> 00:12:00.480
You lose an hour of sleep.
00:12:00.720 --> 00:12:08.720
Morning becomes darker, evening becomes lighter, and for several days, sometimes longer, your body has to adapt.
00:12:08.960 --> 00:12:17.840
Sleep researchers have associated the spring transition with disrupted sleep and increased risks in areas including traffic safety and cardiovascular health.
00:12:18.159 --> 00:12:21.120
The American Academy of Sleep Medicine has gone further.
00:12:21.360 --> 00:12:29.200
It supports eliminating seasonal clock changes and adopting permanent standard time, not permanent daylight saving time.
00:12:29.519 --> 00:12:30.240
Standard time.
00:12:30.559 --> 00:12:37.360
Because standard time more closely aligns our schedules with the natural light dark cycle, which creates an interesting situation.
00:12:37.600 --> 00:12:42.240
Lots of people agree, stop changing the clocks, then you ask the next question.
00:12:42.559 --> 00:12:44.720
Fine, which time should we keep?
00:12:44.960 --> 00:12:47.360
And suddenly the argument starts again.
00:12:47.679 --> 00:12:49.759
This is the heart of the modern debate.
00:12:50.000 --> 00:12:53.759
Permanent daylight saving time gives us more evening light.
00:12:54.080 --> 00:12:55.519
Which many people love.
00:12:55.840 --> 00:13:00.080
Summer evening, dinner outside, walk the dog, play golf.
00:13:00.720 --> 00:13:04.080
Sit in the yard, it feels like you're getting more day, you're not.
00:13:04.320 --> 00:13:08.159
Again, we don't manufacture daylight, we've just moved the label.
00:13:08.320 --> 00:13:11.759
But permanent daylight saving also means darker winter mornings.
00:13:12.000 --> 00:13:14.799
Permanent standard time gives us earlier morning light.
00:13:15.039 --> 00:13:22.480
Sleep scientists generally prefer that because it aligns more closely with human circadian biology, but then sunset comes earlier.
00:13:22.799 --> 00:13:24.320
Which people don't like.
00:13:24.559 --> 00:13:31.200
So the argument is essentially would you rather have sunlight before work or after work?
00:13:31.519 --> 00:13:38.240
And because different parts of the country experience sunrise and sunset differently, but there isn't one experience shared by everyone.
00:13:38.480 --> 00:13:50.000
Someone in Maine and someone in western Indiana can live in the same time zone and have very different relationships with daylight, which brings us to the real reason this problem refuses to die.
00:13:50.320 --> 00:13:55.759
There is no way to move an hour of daylight into the evening without taking it from somewhere else.
00:13:56.000 --> 00:13:58.639
The sun is annoyingly strict about the budget.
00:13:58.799 --> 00:14:00.559
And yet, twice a year?
00:14:00.879 --> 00:14:01.840
We continue.
00:14:02.240 --> 00:14:09.440
Spring forward, fall back, phones quietly change themselves overnight, smart watches update, computers update.
00:14:09.600 --> 00:14:13.200
Then Sunday morning becomes an archaeological expedition through your house.
00:14:13.360 --> 00:14:16.799
Microwave, oven, wool clock, car.
00:14:17.360 --> 00:14:21.039
Alarm clock in the guest bedroom nobody has touched since 2019.
00:14:21.360 --> 00:14:23.279
And there's always one clock you forget.
00:14:23.440 --> 00:14:25.039
You discover it three weeks later.
00:14:25.200 --> 00:14:26.559
You look at it, panic.
00:14:26.799 --> 00:14:27.679
Oh no, I'm late.
00:14:27.840 --> 00:14:30.639
Then remember, no, the clock is wrong.
00:14:30.960 --> 00:14:34.320
And experience the smallest possible version of time travel.
00:14:34.639 --> 00:14:38.399
There is also the annual tradition of someone reminding everyone.
00:14:38.639 --> 00:14:41.919
Don't forget to change the batteries in your smoke detectors.
00:14:42.240 --> 00:14:44.159
Which is sensible advice.
00:14:44.480 --> 00:14:50.720
Although increasingly, the smoke detector has a ten year battery, and the clock changes itself.
00:14:50.960 --> 00:14:59.039
Eventually, daylight saving weekend may consist entirely of us doing nothing, while our devices quietly handle a tradition nobody can explain.
00:14:59.360 --> 00:15:01.279
So why do we change the clocks?
00:15:01.519 --> 00:15:04.559
Originally to make better use of daylight.
00:15:04.879 --> 00:15:09.120
Then to conserve energy, especially during wartime.
00:15:09.440 --> 00:15:15.440
Later, to create a uniform national system out of a chaotic collection of local rules.
00:15:15.679 --> 00:15:18.720
And today, the arguments are much less clear.
00:15:19.039 --> 00:15:23.120
Energy savings appear relatively small and depend on circumstances.
00:15:23.360 --> 00:15:26.960
Businesses value evening daylight, many people enjoy it.
00:15:27.279 --> 00:15:34.240
Sleep researchers worry about the biological effects of changing the clocks and generally favour permanent standard time.
00:15:34.559 --> 00:15:41.200
Politicians repeatedly propose changing the system, and the public seems remarkably united around one idea.
00:15:41.440 --> 00:15:43.440
We don't like changing the clocks.
00:15:43.600 --> 00:15:45.840
We just can't agree what to replace it with.
00:15:46.080 --> 00:15:47.360
Which is wonderfully human.
00:15:47.600 --> 00:15:56.799
We have identified the problem, we have broadly agreed the problem is annoying, we have several possible solutions, and therefore we'll continue doing exactly the same thing.
00:15:57.120 --> 00:15:58.879
Quarty would be proud.
00:15:59.120 --> 00:16:00.799
So, why do we change the clocks?
00:16:00.879 --> 00:16:13.440
If Benjamin Franklin didn't invent daylight saving time, farmers didn't ask for it, and we aren't actually saving daylight as the modern idea grew from attempts to align human activity with summer sunlight.
00:16:13.679 --> 00:16:16.879
William Willet campaigned for it in Britain.
00:16:17.120 --> 00:16:22.159
Germany first implemented it nationally during World War I as an energy saving measure.
00:16:22.399 --> 00:16:35.600
The United States followed, then abandoned it, then brought it back, then abandoned national coordination again, then standardized it, then tried year-round daylight saving time, then changed its mind, and here we are.
00:16:35.840 --> 00:16:39.679
More than a century later, still moving an hour forward.
00:16:39.919 --> 00:16:44.000
Then moving it back and arguing about whether we should stop.
00:16:44.320 --> 00:16:46.960
Or because we're trying to solve one fundamental problem.
00:16:47.200 --> 00:16:49.360
The sun doesn't run on our schedule.
00:16:49.519 --> 00:16:53.600
So twice a year, instead of changing our schedule, we change time.
00:16:53.759 --> 00:16:56.320
Or at least the numbers on the microwave.
00:16:56.559 --> 00:16:59.519
Assuming anyone can remember how, I'm Steve.
00:16:59.759 --> 00:17:04.720
And apparently there's a reason for almost everything, even if it isn't a particularly good one.
