12 Surprising Effects of Daylight Saving Time

bee32/iStock via Getty Images
bee32/iStock via Getty Images

Every March, clocks "spring forward" across much of the United States, robbing people of one precious hour of sleep. In November, those same clocks "fall back," giving them 60 extra minutes of shut-eye. While hearing people complain about missed alarm clocks is one not-so-surprising effect of Daylight Saving Time, the possibility of a longer prison sentence for those going before a judge on "sleepy Monday" is less expected. Here are 12 surprising effects of Daylight Saving Time—the good, the bad, and the scientifically ambiguous.

1. Increased Spending

Woman whips out her credit card while hanging out on a hammock
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In 2016, JP Morgan Chase decided to look into the economic consequences of Daylight Saving Time (DST) by examining Los Angeles and Phoenix, two cities that are large, relatively close to each other, and have stable weather. Critically, Phoenix doesn't observe DST while Los Angeles does [PDF].

Among their findings, DST was "associated with a 0.9 percent increase in daily card spending per capita in Los Angeles at the beginning of DST." Perhaps more surprising, the end of DST was associated with a per capita daily spending reduction of 3.9 percent.

2. A Higher Risk of Heart Attacks

An image of a man grabbing his chest.
iStock.com/PeopleImages

Many studies have shown that DST is associated with an increase in heart attacks, with one study showing a 24 percent increase in the number of heart attacks on the Monday after DST at a group of Michigan hospitals. According to the University of Michigan, Mondays are bad for heart attacks in general (researchers believes the stress of beginning a new workweek and changes to the sleep-wake cycle are the reason why), but DST makes everything worse. Interestingly, the Tuesday following the end of DST was associated with a 21 percent drop in patients.

3. Missed Appointments

Young man runs to catch a missed train
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Somewhat relatedly, a 2017 study found that the percentage of missed medical appointments increased significantly following DST. But as with heart attack risk, the missed appointments decreased in the fall—at least temporarily.

4. More Car Accidents … Maybe (at Least for a Few Days)

An image of a car with a broken headline after being in an accident.
iStock.com/CHRISsadowski

Another field where studies aren't as consistent as one might expect is traffic accidents. In 2001, an American study found that there was a significant increase in accidents on the Monday after the shift to DST. A 2018 New Zealand study echoed the sentiment, finding that on the first day of DST road accidents increased 16 percent. In contrast, a Swedish study found that DST didn't have any important effect in that country.

Of course, there's more to DST than just those first couple days. After DST has gotten started, there's more light on the road later in the day. Several studies have found this light reduces accidents substantially, so much so that one study concluded that a year-round DST would reduce motor vehicle occupant fatalities by 195 per year.

It's so complicated that a 2010 analysis in Minnesota listed 10 studies that found positive effects of DST on road safety, and six studies that showed negative effects in both the spring and fall changes.

5. Longer Prison Sentences

A photo of a judge handing out a sentence with a clock sitting next to her
ISTOCK.COM/TZAHIV

Researchers frequently use DST to study sleep deprivation in populations, as it's a period of time when we all wake up an hour before we’re used to. One of these studies focused specifically on judicial punishment in U.S. federal courts. The researchers looked at "sleepy Monday" (the Monday after the time change) and compared the sentence lengths to other Mondays. They found that on "sleepy Monday," judges handed out 5 percent longer sentences. But don't think you can get a lighter sentence during the fall switch; the researchers found no effect on sentencing at that time. But the researchers point out that this probably isn't limited to judges—even managers may find themselves in the mood for doling out harsher punishments.

6. More Mining Injuries

An image of mining helmets on a shelf.
iStock.com/dannyfroese

According to one study of mining injuries from 1983 to 2006, the Monday directly after the switch to DST was associated with 5.7 percent more workplace injuries and 68 percent more workdays lost because of injuries, indicating that there are more injuries that are more severe after the switch [PDF]. There isn't, however, a corresponding decrease in the fall.

7. Fewer Koala Collisions

A street sign warns of koala bears
iStock.com/hidesy

One study decided to look at how DST affected human-wildlife interaction, specifically koala-vehicle collisions [PDF]. Because koalas are largely nocturnal, they often cross the road in the evening or at night. By shifting traffic patterns to times when it wasn't dark, the researchers found that DST could "decrease collisions with koalas by 8 percent on weekdays and 11 percent at weekends" (although the difference between weekend and weekdays wasn't significant, the researchers proposed that a slight increase in morning collisions lessened the benefit during the weekday). The researchers hope that further study can be done on human-animal interactions and DST.

Koalas aren't the only ones crossing a road that benefit from DST; pedestrians might be safer as well. One study found "no significant detrimental effect on automobile crashes in the short run" and in the long run was associated with "a 8 to 11 percent fall in crashes involving pedestrians … in the weeks after the spring shift to DST." Meanwhile, another study found that a year-long DST would mean 171 fewer pedestrian fatalities a year.

8. Decreased Satisfaction With Life in General (and Increased Use of the Word Tired)

A woman sitting in front of a computer looking tired.
istock.com/PeopleImages

In both the UK and Germany, studies have shown that life satisfaction deteriorates in the first week after the switch to DST in the spring. One study even quantified the deterioration in Germany with money. For the entire sample, the cost was calculated to be €213 (about $262), but for people in full employment—with relatively inflexible schedules—that increases to €332 ($408). And for the men in the sample, the cost of transition was €396 ($487).

Meanwhile, a Facebook analysis looked at the "feelings" people were sharing on the platform. On the Monday after the start of DST, the use of the word tired increased by 25 percent, with similar increases for "sleepy" and "exhausted" (as well as "wonderful" and "great"). In just the period from 5 a.m. to 12 p.m. on Monday, "feeling tired" usage increased an average of 86 percent, from a 12 percent increase in the non-DST Arizona up to a 231 percent increase in Delaware. By Thursday, "tired" is back to normal.

9. Sleepier Kids (Maybe)

A little girl sleeping with her mouth open.
iStock.com/quintanilla

The studies surrounding DST and school children are surprisingly inconclusive. On the one side, a 2009 article in Sleep Medicine looked at 469 Germans from 10 to 20 years old and divided them up into 'larks' (those who go to bed early and wake up early) and 'owls' (those who go to bed late and wake up late). They found that after the DST transition the group was sleepier for three weeks after the transition, with owls showing higher daytime sleepiness, and proposed that tests shouldn't take place in the week following the switch over to DST.

A 2017 article in Economics of Education Review, however, looked at 22,000 Europeans students and found that, at least for low-stakes tests, the effect wasn't statistically significant.

10. More Cyberloafing on the Job

A woman gets caught cyberloafing at work
iStock.com/Manuel-F-O

Another study looked at people's Google search trends for the Mondays before the switch to DST, immediately after the switch, and a week after, with a specific focus on sites like Facebook, YouTube, and ESPN (i.e. entertainment sites that people probably aren't Googling for their jobs). They found that on the Monday after the switch, people searched for 3.1 percent more entertainment websites than the Monday before DST, and 6.4 percent more than the subsequent Monday. While the researchers caution they can't be sure this was all "cyberloafing," the fact that there was nothing else special about these Mondays meant it very likely was.

11. Mistimed Insulin Shots

A woman injecting herself with an insulin pen.
iStock.com/6okean

It might seem that in this age of smartphones and connected devices that figure it all out, the twice-yearly ritual of finding all the clocks to change is a thing of the past. But that's not necessarily true. In a 2014 article in the Journal of Diabetes Science and Technology, the authors pointed out an easy clock to miss: insulin pumps. Because most commercial pumps aren't GPS-enabled and lack internal time change mechanisms, they have to be manually set up. The study authors discuss an international college student with an insulin pump that came from a country that didn't observe DST, meaning the clock was an hour off. They say that no significant harm resulted, but it just serves as a reminder to make sure you check all your clocks.

12. Higher Energy Bills

Man reviews an energy bill on a tablet app
iStock.com/baloon111

One of the main rallying cries for DST is that it saves energy, but studies have been mixed. In 1975 the Department of Transportation issued a report about whether a short-lived, year-long DST experiment had been worthwhile [PDF]. They declared "modest overall benefits might be realized by a shift from the historic six-month DST system," but cautioned that these benefits were difficult to isolate. Optimistically, though, they said DST might help reduce 1 percent of electricity use.

But as modern researchers have noted, electricity usage has shifted since then. Chief among the changes: Only 46 percent of the new single family households completed in 1975 had air conditioning, compared to 93 percent in 2016 [PDF].

Indiana provided a good place to test this change, because in 2006 they decided to observe DST as an entire state (individual counties had observed DST before). A study ultimately concluded that while DST does save electricity in lighting, this is more than offset by increased demands for heating and cooling, resulting in Indiana households being hit by $9 million per year in higher electricity bills [PDF]. However, the study only looked at residential electricity consumption, not commercial or industrial.

Around the same time, the Department of Energy also looked into DST and found that during a four-week extension, electricity use decreased about half a percentage point per day. Ultimately, Stanton Hadley at the Oak Ridge National Laboratory told Live Science, "I could see the answer being either way."

This story originally ran in 2018.

13 Father's Day Gifts for Geeky Dads

Amazon/Otterbox/Toynk
Amazon/Otterbox/Toynk

When in doubt, you play the hits. Watches, flasks, and ties are all tried-and-true Father’s Day gifts—useful items bought en masse every June as the paternal holiday draws near. Here’s a list of goodies that put a geeky spin on those can’t-fail gifts. We’re talking Zelda flasks, wizard-shaped party mugs, and a timepiece inspired by BBC’s greatest sci-fi series, Doctor Who. Light the “dad” signal ‘cause it’s about to get nerdy!

1. Lord of the Rings Geeki Tikis (Set of Three); $76

'Lord of The Rings' themed tiki cups.
Toynk

If your dad’s equally crazy about outdoor shindigs and Tolkien’s Middle-earth, help him throw his own Lothlórien luau with these Tiki-style ceramic mugs shaped like icons from the Lord of the Rings saga. Gollum and Frodo’s drinkware doppelgängers each hold 14 ounces of liquid, while Gandalf the Grey’s holds 18—but a wizard never brags, right? Star Wars editions are also available.

Buy it: Toynk

2. Space Invaders Cufflinks; $9

'Space Invaders' cufflinks on Amazon
Fifty 50/Amazon

Arcade games come and arcade games go, but Space Invaders has withstood the test of time. Now Pops can bring those pixelated aliens to the boardroom—and look darn stylish doing it.

Buy it: Amazon

3. Legend of Zelda Flask; $18

A 'Legend of Zelda' flask
Toynk

Saving princesses is thirsty work. Shaped like an NES cartridge, this Zelda-themed flask boasts an 8-ounce holding capacity and comes with a reusable straw. Plus, it makes a fun little display item for gamer dads with man caves.

Buy it: Toynk

4. AT-AT Family Vacation Bag Tag; $12

An At-At baggage tag
ShopDisney

Widely considered one of the greatest movie sequels ever made, The Empire Strikes Back throws a powerful new threat at Luke Skywalker and the Rebellion: the AT-AT a.k.a. Imperial Walkers. Now your dad can mark his luggage with a personalized tag bearing the war machine’s likeness.

Buy it: ShopDisney

5. Flash Skinny Tie; $17

A skinny Flash-themed tie
Uyoung/Amazon

We’ll let you know if the Justice League starts selling new memberships, but here’s the next best thing. Available in a rainbow of super-heroic colors, this skinny necktie bears the Flash’s lightning bolt logo. Race on over to Amazon and pick one up today.

Buy it: Amazon

6. Captain America Shield Apron; $20

A Captain America themed apron
Toynk

Why let DC fans have all the fun? Daddy-o can channel his inner Steve Rogers when he flips burgers at your family’s Fourth of July BBQ. Measuring 31.5 inches long by 27.5 inches wide, this apron’s guaranteed to keep the cookout Hydra-free.

Buy it: Toynk

7. Doctor Who Vortex Manipulator LCD Leather Wristwatch; $35

A Doctor Who-themed watch
Toynk

At once classy and geeky, this digital timepiece lovingly recreates one of Doctor Who’s signature props. Unlike some of the gadgets worn on the long-running sci-fi series, it won’t require any fancy chronoplasm fuel.

Buy it: Toynk

8. Wonder Woman 3-Piece Grill Set; $21

Wonder Woman three-piece gill set
Toynk

At one point in her decades-long comic book career, this Amazon Princess found herself working at a fast food restaurant called Taco Whiz. Now grill cooks can pay tribute to the heroine with these high-quality, stainless steel utensils. The set’s comprised of wide-tipped tongs, a BBQ fork, and a spatula, with the latter boasting Wonder Woman’s insignia.

Buy it: Toynk

9. Harry Potter Toon Tumbler; $10

Glassware that's Harry Potter themed
Entertainment Earth

You can never have too many pint glasses—and this Father’s Day, dad can knock one back for the boy who lived. This piece of Potter glassware from PopFun has whimsy to spare. Now who’s up for some butterbeer?

Buy it: EntertainmentEarth

10. House Stark Men’s Wallet; $16

A Game of Thrones themed watch
Toynk

Winter’s no longer coming, but the Stark family's propensity for bold fashion choices can never die. Manufactured with both inside and outside pockets, this direwolf-inspired wallet is the perfect place to store your cards, cash, and ID.

Buy it: Toynk

11. Mr. Incredible “Incredible Dad” Mug, $15

An Incredibles themed mug
ShopDisney

Cue the brass music. Grabbing some coffee with a Pixar superhero sounds like an awesome—or dare we say, incredible?—way for your dad to start his day. Mom can join in the fun, too: Disney also sells a Mrs. Incredible version of the mug.

Buy it: ShopDisney

12. Star Wars phone cases from Otterbox; $46-$56

Star Wars phone cases from OtterBox.
Otterbox

If your dad’s looking for a phone case to show off his love of all things Star Wars, head to Otterbox. Whether he’s into the Dark Side with Darth Vader and Kylo Ren, the droids, Chewbacca, or Boba Fett, you’ll be able to find a phone case to fit his preference. The designs are available for both Samsung and Apple products, and you can check them all out here.

Buy it: Otterbox

13. 3D Puzzles; $50

3D Harry Potter puzzle from Amazon.
Wrebbit 3D

Help dad recreate some of his favorite fictional locations with these 3D puzzles from Wrebbit 3D. The real standouts are the 850-piece model of Hogwarts's Great Hall and the 910-piece version of Winterfell from Game of Thrones. If dad's tastes are more in line with public broadcasting, you could also pick him up an 890-piece Downton Abbey puzzle to bring a little upper-crust elegance to the homestead.

Buy it: Hogwarts (Amazon), Winterfell (Amazon), Downton Abbey (Amazon)

At Mental Floss, we only write about the products we love and want to share with our readers, so all products are chosen independently by our editors. Mental Floss has affiliate relationships with certain retailers and may receive a percentage of any sale made from the links on this page. Prices and availability are accurate as of the time of publication.

8 Facts About the Stonewall Riots

Monica Schipper, Getty Images for Airbnb
Monica Schipper, Getty Images for Airbnb

A pivotal moment in civil rights took place the week of June 28, 1969. That day, police raided a gay bar called the Stonewall Inn in New York City's Greenwich Village. The move was a clear condemnation by law enforcement officials of the city's gay population. The volatile riots that followed sparked a new sense of urgency about demanding tolerance for persecuted communities.

1. The Stonewall Inn was operated by an organized crime organization.

In the 1960s, homosexuality was under fire from all directions. Because it was perceived as being amoral, individuals caught engaging in so-called "lewd behavior" were arrested and their names and home addresses were published in their local newspapers. Homosexual activity was considered illegal in most states.

As a result, being part of the LGBTQ community in New York was never without its share of harassment. Several laws were on the books that prohibited same-sex public displays of affection; a criminal statute banned people from wearing less than three “gender appropriate” articles of clothing. Commiserating at gay-friendly bars was also problematic, because officials often withheld liquor licenses from such establishments.

This kind of persecution led to members of the mafia purchasing and operating gay-friendly clubs. It was not an altruistic endeavor: The mob believed that catering to an underserved clientele by bribing city officials would be profitable, and it was. The Genovese crime family owned the Stonewall Inn on Christopher Street, which became known for welcoming drag queens and giving homeless teenagers and young adults a place to gather. Often, these places got tipped off before a raid took place so they could hide any liquor. But the June 28 raid at the Stonewall Inn was different: No one was tipped off.

2. Police had to lock themselves inside the Stonewall Inn to barricade themselves from the crowd.

During the June 28 raid, police (who were alleged to have targeted Stonewall for its lack of a liquor license and the owners' possible blackmail attempts on gay attendees) confiscated alcohol and arrested 13 people in total, some for violating the statute on inappropriate gender apparel. After some patrons and local residents witnessed an officer striking a prisoner on the head, they began lashing out with anything within arm’s reach—including bottles, stones, and loose change. A number of people even pulled a parking meter from the ground and tried to use it as a battering ram.

The police, fearing for their safety, locked themselves inside the Stonewall Inn as the angry mob outside grew into the thousands. Some were attempting to set the property on fire. Reinforcements were eventually able to get the crowd under control—for one night, at least.

3. The situation got worse on the second night of the Stonewall riots.

After getting the crowd to disperse, police likely thought the worst of their problems was over. But on the second night, the Stonewall Inn reopened and another mob formed to meet the police response. Both sides were more aggressive on the second night of the Stonewall Uprising, with residents and customers forming a mob of protestors and police using violent force to try and subdue them.

“There was more anger and more fight the second night,” eyewitness and participant Danny Garvin told PBS’s American Experience. “There was no going back now, there was no going back … we had discovered a power that we weren’t even aware that we had.”

4. Protestors set their sights on The Village Voice.

Tempers flared again days later when The Village Voice published two articles using homophobic slurs to describe the scene at the Stonewall Inn. Angry about the demeaning coverage, protestors once again took to the streets, with some descending on the offices of the Voice, which were located just down the street from the Stonewall.

5. Not all of the protests were violent.

During the demonstrations—which some observers later referred to as an “uprising”—some protestors opted for a nonviolent approach in order to be heard. Eyewitnesses reported residents forming Rockettes-style kick lines that performed in front of stern-faced policemen. Others sang or participated in chants like “Liberate the bar!”

6. The Stonewall Riots led to New York’s first gay rights march.

Once the riots had subsided, protestors were filled with motivation to organize for their rights. A year after the riots, residents began marching on Christopher Street and Sixth Avenue. The date, June 28, was dubbed Christopher Street Liberation Day. Thousands of people marched the streets while thousands of other people lined up alongside them to protest the treatment of the LGBTQ community at the hands of law enforcement officials and society at large.

Some members of a New York Police Department who had confronted protestors during the Stonewall Riots one year before were now being ordered to protect those same protestors during the walk. Other marches took place in other cities, marking the country's first widespread demonstration for gay rights.

7. The Stonewall Inn is now a national monument.

Since the events of 1969, the Stonewall Inn has been considered an important and historic venue for the new era of gay rights. On June 24, 2016, President Barack Obama made that official when he designated the Stonewall Inn and the surrounding area a National Historic Landmark under the care of the National Park Service. Many credit the Stonewall Uprising with the subsequent surge in gay rights groups. One participant, Marsha P. Johnson, started Street Transvestite Action Revolutionaries (STAR) the following year, an organization devoted to helping homeless LGBTQ youth.

8. The Stonewall Inn is still standing.

Following the riots, the Stonewall’s patrons were still faced with police harassment and were growing uncomfortable with the mob affiliation. Months after the event, the Stonewall became a juice bar before subsequent owners tried operating it as a bagel shop, a Chinese restaurant, and a shoe store in the 1970s and 1980s. New owners renovated the building in 2007.

Today, the Stonewall is once again operating as a bar and club at 53 Christopher Street in Manhattan. Naturally, everyone is welcome.

Note: An earlier version of this article misidentified Marsha P. Johnson's organization as Street Transgender Action Revolutionaries. The correct name is Street Transvestite Action Revolutionaries.