Why do we have daylight saving time? 100 years of history

People in the United States will feel a
bit more refreshed on November 4 as daylight saving time
2018^[1] ends. The clocks fall
back at 2 a.m. ET on Sunday, ushering in three months of getting up
in the dark until the winter solstice welcomes back the sun on
December 22.

You’ve probably heard that Ben
Franklin kind of proposed daylight saving time^[2]
(also erroneously called daylight savings time) centuries
before it was implemented, and that the twice-yearly switch was
initially adopted to save us money on energy needs.

But if you dig deeper, you’ll find out
that the daylight-hoarding tradition—which was adopted in the
United States a hundred years ago—has an even more colorful
history. Around the world, daylight saving time has been affecting
international relations, creating nested time zones, and
potentially influencing your health.

Here are a few of the lesser-known facts about daylight saving
time.

In 1895, George Hudson, an entomologist^[3] from New Zealand, came
up with the modern concept of daylight saving time. He proposed a
two-hour time shift so he’d have more after-work hours of sunshine
to go bug hunting in the summer.

Seven years later, British builder William Willett (the great-great grandfather^[4]
of Coldplay frontman Chris Martin) independently hit on the idea
while out horseback riding. He proposed it to England’s Parliament
as a way to prevent the nation from
wasting daylight^[5]. His idea was championed
by Winston Churchill and Sir Arthur Conan Doyle—but was initially
rejected by the British government. Willett kept arguing for the
concept up until his death in 1915.

In 1916, two years into World War I, the German government
started brainstorming ways to save energy.

Soon, England and almost every other country that fought in
World War I followed suit. So did the United States: On March 9,
1918, Congress enacted its first daylight saving law—and it was a
two-fer: In addition to saving daylight, the Standard Time Act
defined time zones in the U.S.

In those days, coal power was king, so people really did save
energy (and thus contribute to the war effort) by changing their
clocks.

Today, the idea of springing forward and falling back is a bit
more controversial, in part because it no
longer really saves energy^[6]. But when you hear from
a time-change skeptic, consider the source and where they live. If
they’re from a more northerly place, they may be inclined to like
saving daylight more.

It’s a matter of geography. The further you travel from the
Equator, the more drastic the seasons will be. That’s because
Earth is tilted on its
axis^[7] with respect to the sun,
so the top and bottom portions of the globe receive more or less
sunlight at different times of the year, making the loss of
daylight hours more pronounced.

In the middle portions of the planet, the amount of sun is about
the same all year ‘round. As a result, the seasons are milder and
there’s less of a need to make adjustments to maximize daylight.
Just look at a map of the countries that
use daylight saving time^[8]
today to see which regions really find the shift worthwhile.

Daylight saving time indifference causes one U.S.
state—Hawaii—to brush off the time change entirely. Arizona, where
scorching temperatures often make night the only bearable time to
be outside, also said no to moving its clocks around, because its
residents preferred to savor the cool nighttime hours.

“In the summer, everybody loves to have an extra hour of
daylight in the evening so they can stay out another hour,” Prerau
explains. In Arizona, it’s just the opposite, he says. “They don’t
want more sunlight, they want less.”

However, the daylight saving situation within Arizona is even
more confusing. While most of the state ignores daylight saving
time, the Navajo Nation, which covers part of northeastern Arizona,
observes it. Meanwhile, the Hopi
Reservation^[9], which is surrounded
entirely by the Navajo Nation, does not. And within the Hopi
Reservation sits a small slice of the Navajo Nation that, you
guessed it, does observe daylight saving time.

Long story short: If you’re driving through northeastern
Arizona, you might want to ask for the time instead of relying on
your own watch.

And on March 5, the Florida State Senate passed the Sunshine
Protection Act^[10], which would make
daylight saving time always on in the state. Opting in year-round
will require approval from Congress, but if it’s granted,
Floridians will join the ranks of those who no longer need to worry
about the biannual time warp.

Well, kind of. The transition to and from daylight saving time
has been linked to higher heart
attack risk^[11], more
car accident fatalities^[12], and other bad
outcomes. But Prerau points out that those effects—thought to be
due to sleep deprivation and circadian rhythm changes—are just
temporary.

“It’s very important for people to understand the difference
between short-term, transitional effects and long-term benefits,”
he says. “You’re talking about an eight-month benefit versus a one-
or two-day negative.”

There’s no way to enjoy those benefits if you do die of a heart
attack or get hit by a car during the transition, but Prerau has a
point. If you’re able to tough out the sometimes bumpy time shift,
you’ll enjoy months with more light—and for many of us, that’s a
good enough reason to overlook a few rough days.