MAN: The next time you find yourself carrying out the twice yearly ritual of trying to get every clock in your house to just show the same number for once, rest assured, you are but the latest in a long line of people who have attempted, and ultimately failed, to make time perfectly obey human rules. Looking at you here, leap years. Every year, hundreds of millions of people voluntarily turn their lives upside down by setting their clocks forward one hour in the spring and back one hour in the autumn on a particular date mandated by the government, wherever they happen to live, unless that government is in one of these states, territories, or countries that doesn't play along. Because the only thing more confusing than jumbling up every clock in the world is jumbling up some of them. Daylight saving time-- yes, it's singular, not plural-- is a perfect example of how a few people with the best of intentions can end up annoying millions of the rest of us for the better part of a century. And it's time we take an honest look at how we got to this place where half the world comes unstuck in time twice a year and ask if the supposed advantages for springing forward and falling back still hold up.

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(Describer) Title: It's Okay to Be Smart

Hey, smart people. Joe here. Let's start with some history. The first person to dream up daylight saving time was none other than Benjamin Franklin, who, while living in Paris, forgot to close his shutters after a late night out and was rudely awakened by the sun at 6:00 AM instead of his usual hour of noon. He was astonished to realize that, in fact, the sun makes light as soon as it rises. And everyone was wasting beaucoup money spending part of their waking hours in candlelight instead of taking advantage of the big bright thing in the sky.

(Describer) The sun burns.

He calculated, between April and September, the people of Paris alone could save 200 million of today's dollars by getting their lazy bones out of bed to carpe more of the diem. But his solution didn't involve shifting the clocks because, in 1784, standardized time wasn't even a thing. So instead, he called for canons and church bells at sunrise. Much like the turkey as America's national bird, this Franklin idea did not catch on. But his goal was the same as every daylight-saving-time crusader who came after him-- change the hours of human activity to make the best use of daylight. Before the mid 1800s, having a bunch of different local times wasn't a huge problem because it took days to go visit anyone anyway. But once railroads started chugging, suddenly, everyone needed to agree what time it was, or no one would get anywhere.

MARTY MCFLY: Doc!

EMMETT BROWN: Marty!

JOE: By 1872, railroads had declared over 70 different official times in the U.S. alone. So in 1884, President Chester A. Arthur hosted a convention where dozens of countries agreed Greenwich, England, gets to be 0 degrees longitude. And everyone established official time zones based on that, except for France and Ireland, who hated the British and used their own official time 9 and 25 minutes different from Greenwich, respectively, until the 19-teens. In 1905, a New Zealand post office clerk named George Hudson originated the modern idea of moving the clocks twice a year because he secretly wanted more time to collect bugs after work. But the idea really took off a few years later on a different set of islands when William Willett, an English architect, went out for a morning horse ride and got sad because his sleepy-head countrymen were wasting a bunch of fine British daylight. Willett also secretly wanted more time to play golf after work. And he published a pamphlet calling for a summer clock shift promising more time to exercise, work, and enjoy the daylight; cleaner skies from burning less coal; boosts in health and happiness from breathing less of said coal smoke; and allegedly, better eyesight. He calculated that an hour clock shift would add three years more daylight to your life by age 72. According to Willett, people already wound their watches hundreds of times per year, so changing what time it was should be no big deal. But people were like, "Uh, we just "got everyone in the same time a few years ago and now, you want to go mess it up?" So Willett died in 1915 without daylight saving time becoming law. Today, he's buried under a sundial set to daylight saving time with a Latin inscription that says, "I only count the sunny hours," because Willett's daylight saving movement did finally start to catch on... in Germany during World War I. See, the Germans along with allies on their side of the trenches spraying the summer clocks forward to save energy for the war effort. And Britain and the rest of Europe weren't going to let the Germans have that advantage, so they all enacted Willett's time, only to immediately get rid of it when the war ended in 1918. All this time, scientists knew that moving numbers around on a clock doesn't actually save time. So they just followed Greenwich. But meanwhile, over in the U.S., daylight clubs had started springing up. And the lobbying from manufacturing tycoons, labor unions, and even baseball teams convinced President Woodrow Wilson to make daylight saving time federal law. As a child, you might have heard, like I did, that daylight saving time is for farmers. That's a lie. Farmers hated the idea from the beginning because the rooster still crows at sunrise and cows need milking no matter what time the clock says. American farmers hated it so much that rural Congress people got daylight saving time overturned pretty much immediately. The next few decades were a huge mess. Some cities and states followed their own time-changing laws, and some didn't, with only one in four Americans observing daylight saving time in the 1930s. And over in Europe, Germany had gotten rid of it after the Great War, while the U.K. kept it. And France, being France, did both. Confused yet? You're on the right track.

(Describer) Title: World War Two.

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World War II brought daylight saving back again, but only temporarily. In the U.S., the "every town for itself" policy continued until, in 1964, daylight saving time began on these dates and ended on these dates depending on where you lived. Trains, planes, automobile drivers, and broadcasters had had enough. Finally, in 1966, President Lyndon Johnson signed a daylight saving time into law for the whole country. Importantly, states are allowed to exempt themselves and stay on standard time, like Arizona and Hawaii do. But more on this law later. Over in Europe, the 1970s energy crisis brought daylight saving back--

ARNOLD SCHWARZENEGGER: I'm back!

JOE: --except for the U.K., who had never changed. And the E.U. made it the official rule in 1996, nearly a century after it was first devised. This incredibly messy history was apparently all necessary because daylight saving time supposedly comes with a ton of advantages-- supposedly. From World War I onwards, saving energy by using daylight instead of artificial light

(Describer) The sun.

(Describer) A street lamp.

for more of our waking hours has been one of the main justifications. While that may be true in some places, summer energy use actually goes up in others. Modern bulbs just don't suck as much electricity anymore. And while people have turned off some lights, they've turned on lots of air conditioners, computers, and TVs. Even in places where it does save energy, the effect is only a few dollars per household. So if it's not really about energy, what is it about? Maybe money. Fast-food restaurants and many retail businesses originally got behind daylight saving time because they realized it meant more sales of burgers and ice cream and everything else. And since increased sales at McDonald's, for example, leads to a greater demand for Kansas beef and Idaho potatoes, retail owners became a powerful national political movement supporting not just the existence of, but even expanding, daylight saving time. These days in the U.S., it covers 2/3 of the calendar year with the extra month of evening light bringing in half a billion dollars for the golf industry alone. But changing the hours of human activity to make the best use of daylight does have some real non-capitalism- related advantages. People do spend more time outside, which, for those of you who never try it, I can assure you is pretty nice. More evening light also leads to fewer fatal car accidents. And while more artificial light in dark places often doesn't reduce crime, adding more daylight to the evening actually does reduce crime. It's the time changing that causes problems. It's like voluntary jet lag. Literally, no one likes jet lag. Why would we do it to ourselves by choice? Shifting the clock, whether it's forward or back, messes with our circadian rhythms, the natural chemical and cellular cycles that control when we're awake, which messes with the duration and quality of our sleep. And being sleepy screws us up in a bunch of different ways. Sleep deprivation and sleep disruption in the days after time changes leads to more traffic accidents, more workplace injuries. People spend more time than usual on the internet at work. It messes up how we make decisions and can even lower stock market returns. Judges give harsher punishments. People feel more depressed when they fall back in the autumn. And the end of daylight saving time even leads to more people hitting wildlife with their cars. Think of the animals, people. Major disasters, including the Chernobyl nuclear accident, the Exxon Valdez oil spill, and the Challenger space shuttle disaster have been at least partly linked to insufficient sleep and disrupted circadian rhythms. All this changing back and forth messing with our brains and our sanity is a problem. The solution? So glad you asked because I have a pamphlet of my own.

(Describer) He bends down to pick something up.

(Describer) He holds it out.

Take it. Permanent daylight saving time could be the best solution. Set the clocks forward in the spring. Get the extra daylight when Earth is tilting that way. And just leave it. Except here in the U.S. at least, we can't because of how the federal law about daylight saving time was written. States can only opt out of daylight saving time. They can't opt out of standard time to have daylight saving time year round, not without a change to federal law. In 2019, around half the states had considered bills like this. But as of today in the U.S., it's literally illegal to make daylight saving time permanent. If you think I'm kidding, I'm not. But many scientists who study our natural biological rhythms think we should do the opposite and stay on permanent standard time. Our bodies' biological clock is set by the sun. But our social clock is set by the rules that we make, going to school, to work, et cetera. Getting up when it's dark to keep up with social time is tough. And it's hard to go to bed earlier if the sun's still out. You can end up with what's called a social jet lag, which has been linked to physical and mental health problems. According to these researchers, during daylight saving time, this social jet lag is worse. They say permanent standard time would put our sun clock more in sync with the clock that we all follow to be functional members of society. But whatever solution you prefer, this biannual clock switching needs to go.

MAN IN SUNGLASSES: It's time to stop. It's time to stop, OK? No more.

JOE: E.U. countries seem to get it and have voted to get rid of the time switching starting in 2021. But European countries will get to decide whether to stay on their standard wintertime or summertime. And thanks to Brexit, the U.K.'s clocks will just be doing their own thing. We're sort of right back where we were 100 years ago with nice orderly time zones just full of countries changing the clocks whenever they feel like it. Now, maybe that won't be too big of a problem. Most of our timekeeping devices are automatically updated these days. But they rely on other computers to tell them what time it is. And it's only a matter of time with a jumbled system like this until something goes wrong in some computer somewhere. I just hope it's an Xbox and not a nuclear power plant. This whole thing got started because most of the world's most powerful countries 100 years ago just happened to be at latitudes with long summer days and darker winters. But in a lot of the world, this just makes no sense, especially near the equator, where daylight doesn't really change from day to day. Perhaps for the good of the vast majority of people on Earth who already realize this clock-switching is a silly idea, we should truly seize the day and get ourselves to permanent DST, ASAP. If you've seen my video about the invention of the metric system, you know that the best intentions, executed poorly, can mess up history and science in some significant and unexpected ways. And this is another good reminder that the universe is a messy place that doesn't follow human rules or always fit into our nice, neat organizational bins. Trust me-- bending time to your will just doesn't work. We'll be much better off changing ourselves to make the most of our time. Stay curious.

(Describer) Title: Quote: And the best of all ways to lengthen the days is to steal a few hours from the night, my dear. Thomas Moore, "The Young May Moon".