Daylight Saving Time

This is a story about hubris and intervention in complex systems.

1 Introduction

And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness. And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.

– Genesis 1:3-5

Back in my Amazon days I worked with a no-nonsense, ex-Army guy named Ron. One day Ron asked me for a bulk export of some truck schedules, so I wrote a SQL query and emailed him the results as a .csv. A few minutes later, he showed up at my desk to ask about the weird number in the "departure_time" column.

"Ah, right - that's epoch time," I explained.

"Epic time."

"E-poch. It's uh… like, how computers represent time, I guess. That number is how many seconds have passed since midnight of January 1, 1970."

Ron's blank stare afforded me a few seconds to reflect on how stupid this idea sounds to anyone who's not a software engineer.

"Oh," he finally said, "of course. 1970: when the world began."

2 Act I: Hudson

Time is merely an artificial standard, which might be further adjusted if by so doing it could be made more subservient to our requirements.

– George Vernon Hudson

The choice to divide solar days into 24 equal periods is just that: a choice. If that sounds strange, consider that your MacBook is currently operating under the assumption that time dawned during the Nixon administration. Time is an artificial construct, and there's nothing stopping us from changing it.

George Vernon Hudson recognized this. Hudson was a man of simple pleasures - namely, astronomy and insects. As a father and the family's breadwinner, he pursued his hobbies responsibly: he snuck in an hour of star-gazing before bed and saved his bug-hunting expeditions for Saturday mornings while the kids were at soccer practice.

Pscyhe! That's not how you amass "the finest and most perfect collection of New Zealand insects ever formed by any one person." 1 What he actually did was mount a one-man campaign to change the way society keeps time.

Hudson's scheme began from a simple observation: by the time he got out of bed in the summer, the sun was already up; by the time he clocked out of his job at the post-office, the sun was already setting. If everyone were to start their day earlier then they'd have more daylight in the evenings, which would help them to spot way more cool bugs. 2

In 1895 he presented his paper "On Seasonal Time-adjustment in Countries South of Lat. 30°" before his scientifically-minded peers in the Wellington Philosophical Society. It didn't get the reception he was hoping for. In fact, it was so roundly scorned that the Society didn't even bother to publish it in their proceedings. They did, however, publish some of the responses to his proposal, a few of which are too good not to share 3:

  • Mr. Hustwick "was of opinion that the reform spoken of would have to wait a little longer." Translation: "Fantastic idea, George, old sport! I'll be 100% supportive just as soon as I'm dead enough not to be inconvenienced. Let's pencil this one in for right after we give rights to the Negroes and Aboriginals people."
  • Mr. Harding thought it was "wholly unscientific and impracticable."
  • Mr. Travers said it "was out of the question to think of altering a system that had been in use for thousands of years, and was found by experience to be the best."
  • Mr. Richardson thought it "would be a good thing if the plan could be applied to the young people." (Huh?)
  • Mr. Travers worried that Whippersnapper Time might be confusing, but he had a solution: just give every clock two sets of hands.
  • Mr. Hawthorne "did not see any difficulty in carrying out the views advocated so ably by Mr. Hudson" (Ahh sweet, naïve, Mr. Hawthorne - a real, glass-half-full, kinda guy)

Hudson's proposal might have amounted to nothing more than a footnote on the Wikipedia page of the guy with the biggest bug collection in New Zealand. But somehow his paper found its way into the hands of an anonymous True Believer in Christchurch, who found it so inspiring that they re-printed it and distributed thousands of copies around town.

Emboldened by the grassroots support, Hudson returned to the Wellington Philosophical Society in 1898 to refute the most common objections to seasonal time 1:

  • No, his proposal wouldn't deprive people of long winter evenings, because the clocks would only be altered during the summer. (Did you even read the paper?)
  • Yes, we could all just agree to wake up at 6:00 instead of 7:00 and show up for the noon train at 11:00, but that's never going to happen.
  • Yes, the milkman would have to start his route before dawn in the early summer. Sorry, milkman.
  • Yes, the kerosene company stood to lose some money, but they'd have more time for exercise. Can't put a price tag on your health!

No one seems to have been particularly enthused by his second speech, but at least this time the Society deemed it worthy of publication.

Sir James Hector worried that it would be hard to wake up his boys up in the morning. "There would also," he fancied, "be some trouble in getting their domestic helpers to appreciate the change" (That was thoughtful of Sir James, thinking of the servants like that).

"Mr. Hudson briefly replied," according to the official meeting minutes, and then they moved on to discussing Sir James' lizard collection. 4

And that was pretty much the end of the first campaign for seasonal time.

3 Act II: Willett

"Nevertheless, she persisted."

– Senate Majority Leader, Mitch McConnell

The cause languished for the next 9 years until one fateful summer morning in 1907. William Willett was out for a horseback ride in suburban London when he noticed that his neighbors' blinds were still drawn against the sun. This waste of daylight inspired Willett to write a pamphlet titled, "The Waste of Daylight."

Like Hudson, Willett called for the clocks to be adjusted during the summer months. Unlike Hudson, who called for a 2-hour spring forward and a 2-hour fallback, Willett proposed a series of 20 minute adjustments: 4 in the spring and 4 in the fall. 5

Willett's pamphlet echoed many of Hudson's talking points. But though the content was familiar, their rhetorical styles make for a study in contrast.

Hudson, the gentleman scientist, deployed a measured appeal to logic with some cheerful pathos thrown in for good measure: wouldn't it be nice if we had more daylight for nature walks?

Willett, on the other hand, rallied his readers for an assault on… disease, or something 6… Here's a representative excerpt:

Light is one of the great gifts of the Creator. While daylight surrounds us, cheerfulness reigns, anxieties press less heavily, and courage is bred for the struggle of life. Against our ever-besieging enemy, disease, light and fresh air act as guards in our defence, and when the conflict is close, supply us with most effective weapons with which to overcome the invader.

With fear sufficiently mongered, Willett closed his pamphlet with a call to action, urging "every man and woman, and every youth in particular" to write to their representatives in Parliament in support of a 6-month trial of seasonal time. 5

He paid out of pocket to have his pamphlet published and began distributing copies everywhere he went. Despite his zeal (or maybe because of it), the proposal didn't immediately gain traction. The Spectator, an influential London weekly, summed up its public reception: they were "not sanguine of its success."

Let us return to our study in contrast.

When Hudson received "constructive feedback" 7 at his local science club, he said that "he was sorry to see the paper treated rather with ridicule. He intended it to be practical," 3 and then went back to studying butterflies.

When The Spectator was under-enthused by his proposal, Willett responded with a scathing letter to the editor berating him for his lack of faith. If he had any hope of being taken seriously, the editor crushed it; Willet's irate reply appeared in the next issue alongside a letter from another reader who, for reasons that are unclear, felt compelled to share his feelings about squirrels. (If you're wondering, he was really high on the squirrel: "a species of handmaiden" and a "happy-go-lucky" creature "intending little ill, and if he does offend at times, his company and capers on the lawn or on the gean-tree or pear-tree make up for his mischiefs.") 8

But getting lumped in with squirrel-guy didn't phase Willett. He spent the next year writing letters, printing pamphlets, and schmoozing with business leaders and lawmakers. He eventually convinced a member of the House of Commons to introduce the First Daylight Saving Bill, which went to a committee tasked with studying its effects. The ensuing hearings provided Willett with a captive audience - an opportunity which he thoroughly abused.

The transcript of his testimony is alternately tedious and hilarious. Willett starts by asking permission to read a list with the names of all of his supporters. Mercifully, the Chairman interjects and after some argument Willett agrees to read only "the principal" names. "Principal" to Willett evidently meant "at least 84", because that's how many names he made it through (with frequent stops for parenthetical asides) before he finally got cut off. 9

I'll spare you all of the objections to his proposal. Suffice it to say that there were many, and they make for tedious reading. To give you a sense of the opposition:

  • The Liverpool Cotton Association didn't want to shorten their trading window with American markets
  • The Director of the Meteorological Office worried that the timestamps on meteorological observations would be ambiguous
  • The railway manager warned that Willett's proposed 8(!) time changes each year would cause mass confusion and delays

Several alternate proposals emerged, too:

  • Q: Why not just permanently switch timezones and adopt GMT +1:00?
  • A: Because the winter sunrise in London would be after 9:00am.
  • Q: Why not just ask everyone to wake up an hour earlier instead of changing the clocks?
  • A: Because millions of people aren't going to just simultaneously and voluntarily change their routines.
  • Q: Why do we need 8 clock adjustments per year instead of 2?
  • A: Because… well, that's a good question, actually.

Even Willett's supporters didn't agree with him on this last point. Sir Arthur Conan Doyle (yep, that Sir Arthur Conan Doyle 10), testified that "it struck me on simply reading it that a single alteration of an hour would be a round number, and cause less confusion and attain almost the same result."

But Willett was insistent: the body could absort a 20 minute loss of sleep, but a full hour would be a shock to the system. And in the inevitable mixups following a clock adjustment, being 20 minutes early or late to an appointment would be less catastrophic than a full hour.

His objections were noted but overruled. The committee's final report to the House of Commons recommended that Britain adopt two 1-hour alteration of the clocks: one in April and one in September.

A promising, young politician named Winston Churchill, then the President of the Board of Trade, "read the report of this committee with much interest and with a lively recognition" of the Bill's advantages. 11 Unfortunately for Willett, Prime Minister Herbert Asquith took a less lively view of the bill's advantages and dismissed it before it could even be discussed. 12

Really, Herbert? Would it have killed you to say something sooner? Like, before everyone spent 8 weeks discussing the best time of day to harvest plums?

Willett being Willett, he responded by writing a letter to the editor - 400 editors, in fact, of every newspaper he could find - soliciting support for seasonal time. In 1909 he won over a member of the House of Commons who agreed to introduce a revised Daylight Saving Bill which dropped the controversial 20-minute adjustments in favor of the 1-hour adjustments recommended by the committee.

Several representatives who had been on the 1908 Committee were understandably less-than-enthused by the prospect of another visit from Willett. They hastily moved to squash the bill before it could be read, and probably would have succeeded had Winston Churchill not rescued it with the type of rousing speech for which he would soon become famous.

Churchill touted the many benefits that could be gotten in exchange for an "extra yawn some morning in April, an extra snooze some morning in September." He urged his colleagues to refer the bill to committee (again) and his motion passed. (In the cinema of my imagination, Churchill shouts an "extra snooze some morning in September!" over a triumphant crescendo of horns, followed by a raucous chorus of cheers in the House of Commons.) 13

So once again Willett found himself with a captive audience. And once again, he made everyone miserable. By way of greeting the Chairman told Willett, "I had better ask you at once to state, as shortly as you can, the fresh evidence you have to place before the Comittee in regard to this Bill?"

Of course he totally ignored the qualifier "as shortly as you can" and launched into reading from an enormous stack of letters. He made it abundantly clear that he was unhappy with the 1-hour adjustments, and would prefer to "effect his alteration in the habits of forty odd millions of people… [with] the thin of the wedge… and not the thick end first." 14

The second set of hearings were much like the first: tedious and divisive. They got hung up on all the same arguments as the first committee: why not just adopt a different time-zone? Why not just wake up earlier? Was a 1-hour adjustment better than several smaller ones? And most importantly, will the women mind waking up an hour earlier to make tea?

Side-note: this part of the transcript makes for hilarious reading: a roomful of men arguing over how womankind will react, as if they were discussing an inscrutable, alien, race with a collective mind whose inner-workings can only be guessed at. Given the time period I guess it's no surprise that no one thought to just ask some women. Or, even more unthinkable: perhaps the men could make their own tea?

The committee met 16 times over nearly 5 months. They ultimately concluded that due to the "great diversity of opinion… your Committee recommend that the Bill be not further proceeded with." 15

Willett spent the rest of his life campaigning for seasonal time. Every year from 1911 to 1914, his allies in the legislature proposed the bill, and every year Asquith refused to even hear it. 16

Willett died of the flu one year later in March 1915 at age 58.

For a guy obsessed with time-keeping, his timing really sucked.

4 Act III: Total War

You never want a serious crisis go to waste. And what I mean by that, it's an opportunity to do things you think you could not do before.

– Rahm Emanuel, former White House Chief of Staff

Ironically, the "invaders" that Willett warned about in his pamphlet were the first to adopt his proposal. Germany instituted seasonal time just 14 months after Willett's death, and the British House of Commons passed Willett's Daylight Saving Bill a week later.

Votes in favor? 120. Votes against? 2.


If you were paying attention in your history class, you'll recall that there was a war going on by the time the bill passed in 1916. At the beginning of WWI, the Liberal British government's policy was "Business As Usual." As you were, citizenry! Just a bit of war, nothing to fret about!

But it's hard to stay nonchalant with a giant zeppelin dropping bombs in your backyard, which is what London was dealing with by the spring of 1915 17. The flood of innovation and mechanization that carried over from the Industrial Revolution resulted in a sort of Cambrian explosion of killing machines: in addition to zeppelins, the Great War also marked the battlefield-debut of chlorine gas, "aeroplanes", barbed wire, tanks, submarines, and machine guns.

Once human ingenuity turned towards the problem of how to kill as efficiently as possible, we traded bayonets for machine guns and heavy artillery. The results were devastating. The British lost more men on the first day of the Battle of the Somme than they did during the entirety of the Second Boer War, which had ended a mere 14 years earlier.

57,000 men in one day. 18 , 19 To put that in modern context, the United States spent 9 years fighting in Iraq and suffered <37,000 casualties 20.

All this to say, "Business as Usual" didn't last long. It was followed by the policy of "Total War," which overhauled every aspect of society and reoriented the economy around wartime manufacturing. Running a bomb factory requires energy, and by May of 1916 the British empire needed all the energy it could get. Voting against a wartime energy-saving measure wouldn't have been a good look, politically, and opposition to seasonal time quickly evaporated.

So for all of Willett's pamphlet-publishing and haranguing newspaper editors and wining-and-dining of politicians, all it took in the end was the outbreak of the bloodiest war in human history.

5 Interlude: On Hubris and Conviction

Who could anticipate or provide for such a succession of hopes and
schemes? Only an unimaginative man would think he could; only an
arrogant man would want to.

-- Jane Jacobs

Here's part of what fascinates me about this story.

When I start speaking, I have an internal timer that begins counting down from ~10 seconds - a little more if I'm with friends, a little less if I'm in front of a big or unfamiliar group. Once that timer expires, all I hear is a blaring alarm warning me to STOP TALKING IMMEDIATELY FOR THE LOVE OF GOD so that everyone in the room will look anywhere besides at me.

Willett clearly had no such timer.

Or sometimes at work I'll be asked to weigh in on some unsettled question. And every once in a while, a weird and scary thing happens: people actually listen to my argument and change their minds. As soon as I recognize that I'm being persuasive, I have to quell a sense self-defeating panic: are they really listening critically, or are they just acquiesing because of our relative positions in a largely arbitrary corporate hierarchy? Maybe I don't have enough information to have an informed opinion. What if I'm missing some crucial bit of context? How should I qualify my opinion to reflect my level of uncertainty? How culpable am I now for the outcome of this decision???

I can't imagine Willett having this internal monologue. I'm fully aware that I'm an outlier on the introspective/introverted tail of the personality spectrum, probably to an unhealthy degree, but I'm still amazed that people like Willett exist.

Where did he get the conviction? Opponents of seasonal time emerged from every sector of society. This should have been a strong signal that tampering with something so fundamental to society would have ripple-effects that he couldn't anticipate. Did he ever have doubts? Or was his outward bluster a reflection of perfect inner-tranquility?

In my experience, this type of irrational and totally unfounded level of self-assurance is disproportionately common in two groups of people: lunatics and rich white guys. Willett was a card-carrying member of both.

Ok, fine, "lunatic" may be overstating it, but not by much. Remember when he chastised the editor of The Spectator for being "less than sanguine" of Willett's success? The editor who printed Willett's letter alongside Squirrel Guy? Here's a representative excerpt of his letter:

Are these words quite worthy of the Spectator? … [I]t is clear that we have passed the Slough of Despond. We are now climbing the Hill Difficulty. The Palace Beautiful awaits us at the top. Mistrust and Timorous will never reach it! Surely the "Great Heart" of the Spectator should encourage pilgrims to climb the Hill, and should use every weapon he can against any Grims that may bar the way or any lions that may appear to forbid the happy arrival of the Bill before his Majesty the King. What is there to fear? 8

Contrast that response to critism with Hudson's closing remarks at the Wellington Philosophical Society, in which he basically said, "Well, shucks, I thought it was a good idea. Sorry for wasting your time," then fled home to his telescope and a carton of Ben and Jerry's.

That's Timorous for you! Throwing down his weapons and abandoning the pilgrimage to the Palace Beautiful at the first sign of a few lions and Grims!

Hudson is the kind of person who, when he has to send an email with more than 3 recipients, rereads it at least 10 times and has to google the rules regarding semicolon usage before clicking send; Willett is the guy who hits reply-all to 300 people and dashes off the first thing that pops into his head, ignoring all those red and green squiggles because he's pretty sure the word 'lose' has two 'o's - thanks anyway, spell-check!

The depressing thing is that Willett's (over)confidence was effective and maybe even rational. Hudson's healthy sense of humility got him nowhere; Willett's total lack of humility took him pretty far. Without an irrational level of self-belief, he would have abandoned his campaign after his 100th un-answered letter to the editor.

Imagine if Willett had been intellectually honest and said, "Gosh, you raise a good point, Farmer Ben - I hadn't taken the shelf-life of gooseberries into account. I concede that altering our society's timekeeping practices will affect our lives and our children's lives in ways that no one in this room can possibly anticipate. Some effects may be harmful, but given the limited information that's available to us, I think it's more likely than not that seasonal time will be a net positive. So whaddya say, gang? Who's with me?"

No one obviously - he would have been bullied out of the room by some farmer or railroad operator who was just as irrationally opposed to DST as Willett was in favor of it.

In fact, there's some evidence that he began with a healthy skepticism and was forced to abandon it along the way: his original pamphlet called for a 6-month trial of DST. But when asked if he believed the Bill could be passed on a trial basis, the contradiction in his response was telling. "Yes," he said, "but then you immediately impart an element of doubt, and you cannot expect the House of Commons, I should think, to justify a Bill at all with an element of doubt in it."

Even more depressing is that Willett's overconfidence was probably necessary, yet insufficient: his bill didn't actually pass until the opposition was leveled by the most horrifying and pointless war in modern history.

Humans generally hate radical change. Historically this aversion to boat-rocking has served us well: we've never eaten that potentially poisonous berry before, so why start now? Remember the great harvest we had after we planted corn and did the rain dance last year? Let's plant some corn and get to dancing.

When things are good, we have a lot of inertia; when things are bad, we're willing to experiment. The Patriot Act would have been inconceivable on September 10th, 2001; a national speed limit of 55 mph would never have passed without the oil crisis of 1973; it took Pearl Harbor to get the United States into WWII; the idea of women working in factories was unthinkable before WWI, but somebody had to build the bombs that the men were busy dropping.

If you've been taking notes on how to effect change, the formula so far is:

  1. Delude yourself and others to build influence.
  2. Wait for tragedy to strike, and then…
  3. Exploit the ensuing chaos to secure your objective before anyone can object.

Sorry, kid. The world is an icky place.

6 Act IV: Today

Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.

– The Second Coming, W.B. Yeats

The United States followed Britain in adopting seasonal time for the duration of WWI, reinstituted it year-round in the aftermath of Pearl Harbor, and then dropped it again in 1945. Absent a federal standard, a patchwork of DST adoption emerged across the country. By 1966 everyone was thoroughly confused, so the Uniform Time Act mandated DST as the standard (the law does allow states to opt-out, but as of 2020 only Arizona and Hawaii have done so 21).

Between 2002 and 2005, the average price of a regular unleaded gallon of gas in the US nearly tripled, soaring to almost $3.00 22. Average Joe was unhappy, so Congress put on its collective concerned face and passed the Energy Policy Act of 2005.

A politician would probably call this bill "comprehensive". A normal person who bothered to read its 11 page table of contents would probably call it a schizophrenic, kitchen-sink of a bill. Among other things, it proposed to:

  • Invest $200 million into coal (the energy of the future!)
  • Authorize tax credits for wind energy producers (just in case the coal doesn't work out, for some reason)
  • Arm security personnel at nuclear plants with machine guns
  • Fund a scholarship on behalf of the Nuclear Regulatory Commission
  • Exempt fracking companies from the protections in the Safe Drinking Water Act (Totally reasonable. Nothing to see here!)
  • Cut royalties that oil companies are obligated to pay the federal government to incentivize deepwater drilling in the Gulf of Mexico
  • Commission a study on the benefits of telecommuting for federal employees

And, oh yeah, it would also extend Daylight Savings Time by 1 month 23.

Unsurprisingly, a lot of people hated the idea, including the Conference of Catholic Bishops and the United Synagogue of Conservative Judaism, who opposed the extension on the grounds that no one wants to go to church before the sun is up in the spring. The head of the National Parent Teacher Association warned that children walking to school were at increased risk of being mowed down by cars and kidnapped in the morning darkness.24

Stop me if you've heard this one: a priest, a rabbi, and a school teacher walk into the door of their congressman's office.

That's it - that was the joke.

They walk into a closed door, because the lobbyist from the sporting goods industry is already inside with a bottle of scotch and a check made out to the re-election campaign and oh-by-the-way just so happens to think seasonal time is great for both America and sales of baseball gloves.

Forget it, it was funny in my head.

To the chagrine of clergymen and the delight of Dick's Sporting Goods shareholders, George Dubya signed the bill on August 8th, 2005. But the bill included an uncharacteristically sensible provision: it required the Department of Energy to report back on the effect of extending Daylight Saving Time.

The DoE put a few Ph.D's on it and 3 years later they came back with their findings. An extra month of Daylight Savings Time does save energy - 17 Trillion Btu of it.

"Hooo-wee, that's a whole-buncha Btus!" you're probably thinking.

But it's not; the US consumed 101,000 trillion Btu in 2007. In other words, Extended Daylight Saving Time resulted in total energy savings of 0.02%. 25 Which admittedly isn't great, but it gets worse.

A 2008 study examined the effects of DST in Indiana, which until 2006 was unique in that only certain counties in the state practiced DST. The presence of a naturally occurring treatment and control group made the Hoosier state the perfect place to study the effect of seasonal time on energy consumption.

Incidentally, "Indiana, the perfect place to study the effect of seasonal time on energy consumption," would be a better state motto than "The Crossroads of America." Or how about, "Indiana: We apologize for Mike Pence." You can have those for free, Indiana Department of Tourism.

Anyways, the authors of the study concluded that not only did DST not save energy - it actually increased energy consumption by 1%! What happened?

Air-conditioning, mostly. In Willett's day, residential energy consumption in the summer was driven by the demand for electric lighting. Now it's driven by air-conditioning, and people returning home from work an hour earlier means an extra hour of running the AC at full blast. 26

And if the most serious problem with DST were air-conditioner usage in Indiana, The Atlantic wouldn't be running articles with titles like, "Daylight Saving Time Is America's Greatest Shame."

Huh. Greatest shame… really? Genocide against the indigenous population, slavery, Japanese internment camps - fine, not our proudest moments. But according to the Atlantic, our barbaric timekeeping practices are what send America ducking behind the cereal display whenever it spots Sweden in the supermarket.

Looking past the ridiculous headline, the article does reflect a growing resentment for seasonal time. This petition to abolish DST currently has over 380,000 signatures from concerned citizens like "steve k.", who urges lawmakers to "stop daylight time right now do it right now its too much for florida get it out of florida."


Someone from Cascade, IA warns "Please end daylight savings time.. it's always even more later than you think!" Yikes. What does Someone from Cascade, IA know that we don't?

"Please listen to all the voices," says Someone from Alpharetta, Georgia, "and end this chaos in the name of saving energy! We are not magically creating an hour of daylight by changing our clocks by an hour! We're creating chaos that we don't need in the world."

As a general rule, when someone urges me to do something at the behest of "the voices," I do not do that thing. However, in this case, Someone from Alpharetta, Georgia, has a point: DST does create chaos. Twice a year, every year, we reset our clocks and brace for:

  • Thousands of traffic fatalities 27
  • A 3-5% increased risk of heart attack every March 28
  • Countless lifetimes of prison sentences issued by grumpy, sleep-deprived judges 29
  • A 5.7% increase in workplace injuries each March 30
  • Nearly half of a billion dollars in lost productivity annually in the United States alone 31

Ironically, the one person who foresaw all of this was DST's biggest supporter: Willett. Remember that business about "the thin end of the wedge" and the need for 20-minute adjustments? He warned everyone repeatedly that a 1-hour time change would be too great a shock for fragile meat-sacks like us to cope with, and he was right.

Every March during the week following the time change, sleep deprivation makes us do dumb things like wrap our cars around telephone poles and eat enough Hardee's french fries to power an NFL stadium for 34 hours. (Gross but true, see Appendix).

DST's modern-day defenders argue that, sure, sleep-deprived motorists crash more often during one week in March, but on aggregate DST makes our highways safer by reducing the number of cars on the road after dark. But that argument has been pretty convincingly refuted; sleepy drivers are much more likely to crash than a well-rested person driving after dark, and even the small effect of ambient light merely shifts crashes from the brighter evenings to the darker mornings. 26

It's increasingly clear that DST's days are numbered. The EU has already voted to permanently adopt summer time starting in 2021. The situation in the United States is a bit tricky: while each state does have the right to opt-out of seasonal time, they do not have the right to choose a different time zone, which is exactly what most states want to do by adopting "year-round" Daylight Saving Time.

Year-round DST has its merits, but comments like the one from Someone from Alpharetta, GA ("We are not magically creating an hour of daylight by changing our clocks by an hour!") cause me to worry that some people don't really understand what they're asking for. So before we consign seasonal time to the scrap-heap of history, let's look at how it actually works…

7 Act V: Tomorrow

Chairman: I rather gather from what you have said that your ideal
   method of making the change would be - if by a miracle
   every clock and every watch could be made to gain a minute
   a day?
Willett: Half a minute almost would do it.
Chairman: Gain a minute a day beginning in the beginning of April, and
   get half an hour fast by July, and then lose a minute each
   day afterwards, and get right on the 1st of October?
Willett: Yes.
Chairman: That would be your idea of perfection?
Willett: Yes.
Chairman: But, of course, that is impossible?
Willett: Of course, that is impossible.

Let's get one thing out of the way: the people who argue, "If Daylight Saving Time is so great, why don't we have it the whole year?" are fundamentally missing the value proposition of seasonal time.

The Earth has a tilted axis and orbits the Sun in an ellipse; this is why we have seasons, and it's also why the days are longer in the summer. The chart below shows when the sun rises and sets in local, solar time 32 at varying latitude throughout the year.

Notice that the length of the day depends on just two variables: the day of the year and the latitude. Time zones, which are demarcated by longitude, determine the hour of sunrise and sunset but have no effect on the length of the day. So go ahead, join the time zone to your east - have fun with your pre-dawn commute to work.

Let's choose a fixed location on that chart above - say, Seattle, Washington. Here's how the length of the day changes throughout the year:

Let's arbitrarily pick 6:30 am as the ideal hour for sunrise. In the graph above, the entire dark-yellow region below the horizontal line at y=6:30 is "wasted" daylight.

Now let's add DST:

We've reclaimed most of that "wasted" daylight, but the curve has these ugly discontinuities in March and November. These are the Sleep-Deprivation Death Zones in which the lucky people get sleepy and grouchy for a week or so and the unlucky people get dead, forever.

So changing the clock kills people in car crashes, but not changing the clock wastes daylight and makes us less happy and healthy. Can we have it both ways? Technically, yeah - we could.

In Willett's day, adjusting non-networked, mechanical clocks was a hassle; today we have iPhones. If they chose to, Apple could push out an update tomorrow that "springs-forward" by a few seconds every day. The clock would still change, but it would happen so gradually that we wouldn't even notice. Here's how it would look:

See? No wasted daylight, and no perceptible clock adjustments.

In a previous draft of this post, I made a whole-hearted pitch for this idea, the irony of which was not lost on me. But whatever system we adopt next will undoubtedly kill people in both predictable and unpredictable ways, and I just don't have the appetite for it.

I'm more of a Hudson, so I'll leave the campaign for continuous seasonal time to a Willett and return to my bugs - specifically, the ones in this Github repository. It has has the source code for all of the charts and the clock at the top of this page (artwork courtesy of Gabrielle Bates), which shows the time at Willett's home in Pett's Wood under continous seasonal time ("Willett Time" has a nice ring to it, don't you think?)

My bug collection is (hopefully) smaller and (definitely) less interesting than Hudson's. He painted over 3500 insects and they are painfully beautiful. Here's one from New Zealand Moths and Butterflies which was published in 1898, the same year that he spoke before the Wellington Philosophical Society.

So here's to the reformers: to Willett, and to whoever takes up his mantle and undoes what he did. May your results be as good as your intentions.

Reading the debates which took place in Parliament on daylight saving in 1908, 1909, and 1911, one marvels that so feeble a case should have been sustained so long, and that a measure whose effect has been to enlarge the opportunities for the pursuit of health and happiness among the millions of people who live in this country should have met with so frigid a reception. Let us, then, as we put forward our clocks for another summer, drink a silent toast to the memory of William Willett, who spared neither labour nor money over a long period of his life in his advocacy of this great reform. He did not live to see success crown his unselfish efforts; he died in 1915, a year before the passing of the wartime Act. But he has the monument he would have wished in the thousands of playing-fields crowded with eager young people every fine evening throughout the summer and one of the finest epitaphs that any man could win: He gave more light to his countrymen.

– Winston Churchill, A Silent Toast to William Willett 33

8 Appendix

8.1 How long could you power an NFL stadium with the energy from the extra fries sold at Hardee's following start of DST?

avg_sales_increase_dollars = 880 #
burger_combo_price_dollars = 7.09 #
num_locations = 5812 #
med_fry_grams = 132.0 #
kcal_per_fries = 410 #
avg_russet_grams = 155.0 #
nfl_stadium_mw = 10 #

total_extra_fries_sold = (avg_sales_increase_dollars / burger_combo_price_dollars) * num_locations
total_extra_potatoes = total_extra_fries_sold * (med_fry_grams / avg_russet_grams)
total_extra_kcal = total_extra_fries_sold * kcal_per_fries
fry_mwh = total_extra_kcal / 859845.22785899
nfl_stadium_hours = fry_mwh / nfl_stadium_mw

print "Hardee's DST fries sold: {}".format(total_extra_fries_sold)
print "Potatoes required for Hardee's DST fries: {}".format(total_extra_potatoes)
print "Kilocalories from Hardee's DST fries: {}".format(total_extra_kcal)
print "Megawatt-hours from Hardee's DST fries: {}".format(fry_mwh)
print "Hours an NFL stadium could be powered by Hardee's DST fries: {}".format(nfl_stadium_hours)
Hardee's DST fries sold: 721376.586742
Potatoes required for Hardee's DST fries: 614333.609354
Kilocalories from Hardee's DST fries: 295764400.564
Megawatt-hours from Hardee's DST fries: 343.973997856
Hours an NFL stadium could be powered by Hardee's DST fries: 34.3973997856



I'm assuming. No entomologists were consulted for this post.


This may have been less deranged than it sounds, out of context. If Europe at the turn of the century was a keg party, then Germany was like that red-faced guy making everyone uneasy with progressively louder and more confrontational proclamations of his naval superiority (it's been a while since I've been to a keg party). So it's possible the martial metaphor may have been less jarring to his contemporaries - but still, a bit much.


This is corporate HR-speak for "criticism."


"Solar time" means we're ignoring the effect of time zones. In reality, the further east you go within a time zone, the earlier the hour of sunrise.