From Britannica, ProCon.org (excerpt)
DST was implemented in the United States nationally on Mar. 31, 1918, as a wartime effort to save an hour’s worth of fuel (gas or oil) each day to light lamps and coal to heat homes. It was repealed nationwide in 1919 and then maintained by some individual localities (such as New York City) in what Time Magazine called “a chaos of clocks” until 1966, when the Uniform Time Act made DST consistent nationwide.
DST has been “permanently” implemented nationwide twice, once during World War II and once in the 1970s. As the war ended, only 17% wanted to keep “wartime” (DST) year-round. In the winter of 1973-1974, DST was used to conserve fuel during the energy crisis. 53% opposed keeping DST, probably because in some parts of the country (primarily western edges of time zones) wouldn’t see the sunrise until after 9 am.
Sixty-four countries used Daylight Saving Time in 2022, while 9 countries used DST in some jurisdictions and not others (like the United States), and 175 countries did not use DST in 2021. In the United States, 48 states participate in Daylight Saving Time. Arizona, Hawaii, some Amish communities, and the American Territories (American Samoa, Guam, Puerto Rico, the Virgin Islands, and the Northern Mariana Islands) do not observe DST.
55% of Americans said they were not disrupted by the time change, 28% reported a minor disruption, and 13% said the change is a major disruption. A 2020 poll found 40% of Americans would prefer to stay in Standard Time all year, and 31% would prefer to stay in Daylight Saving Time all year, eliminating the time change. 28% of Americans would keep the time change twice a year. However, a 2022 Monmouth University poll found 61% of Americans would stop changing time twice a year, of whom 44% would keep DST, and 13% would stay on standard time all year. 35% would keep the time changes.
On Mar. 15, 2022, the U.S. Senate unanimously approved a bill that would make DST permanent as of Nov. 20, 2023, if approved by the House and signed by President Biden. The delay is meant to give airlines and other transportation providers time to adjust to the change as they set schedules months ahead of time. As of Feb. 6, 2023, no action has been taken in the U.S. House of Representatives to advance the bill.
Pro 1
Daylight Saving Time’s (DST) longer daylight hours promote safety.
Longer daylight hours make driving safer, lowers car accident rates, and lowers the risk of pedestrians being hit by a car.
Economists Jennifer Doleac and Nicholas Sanders found that robberies drop about 7% overall, and 27% in the evening hours after the spring time change. They state, “Most street crime occurs in the evening around common commuting hours of 5 to 8 PM, and more ambient light during typical high-crime hours makes it easier for victims and passers-by to see potential threats and later identify wrongdoers.”
Also, daylight in the evening makes it safer for joggers, people walking dogs after work, and children playing outside, among others, because drivers are able to see people more easily and criminal activity is lowered.
Pro 2
DST is good for the economy.
Later daylight means more people shopping after work, increasing retail sales, and more people driving, increasing gas and snacks sales for eight months of the year (the time we spend in DST).
The golf industry reports that one month of DST was worth $200 to $400 million because of the extended evening hours golfers can play. The barbecue industry estimates their profits increase $150 million for one month of DST. In 2007, an estimated $59 million was saved because fewer robberies were committed thanks to the sun being up later.
Chambers of Commerce tend to support DST because of the positive effect on the economy. Consumer spending increases during DST, giving the economy a boost. Compared to Phoenix, Arizona, which does not have DST, Los Angeles, California, shoppers spent 3.5% less at local retailers after DST ended in the fall.
Pro 3
DST promotes active lifestyles.
When the day is lighter later, people tend to participate in more outdoor activities after work.
Hendrik Wolff, Associate Professor of Economics at Simon Fraser University, states, because of DST “people engaged in more outdoor recreation and less indoor-TV watching… An additional 3 percent of people engaged in outdoor behaviors who otherwise would have stayed indoors.”
Michael Downing, author of Spring Forward, states, “Baseball [was] a huge early supporter, too, because there [was] no artificial illumination of parks, so [they could] get school kids and workers to ball games with the extended daylight, they have a later start time.”
Con 1
Daylight Saving Time (DST) is bad for your health.
Changing sleep patterns, even by one hour, goes against a person’s natural circadian rhythms and has negative consequences for health. One study found that the risk of a heart attack increases 10% the Monday and Tuesday following the spring time change.
Researchers found an increase in cluster headaches (sudden and debilitating headaches) after the fall time change.
James Wyatt, Associate Professor at Rush University Medical Center, states, “We’re encountering an increase in extra auto and workplace accidents on Monday or perhaps even carrying through the first week of the Spring time shift.”
In the weeks following the spring DST time change, male suicide rates rose in Australia compared to the weeks following the return to standard time in the fall.
DST increases the risk that a car accident will be fatal by 5-6.5% and results in over 30 more deaths from car accidents annually.
Con 2
DST drops productivity.
The Monday after the spring time change is called “Sleepy Monday,” because it is one of the most sleep-deprived days of the year. The week after the spring DST time change sees an increase in “cyber-loafing” (employees wasting time on the internet) because they’re tired.
Till Roenneberg, a German chronobiologist, who studies the body’s relationship with light and dark, notes that the human circadian clock doesn’t adjust to DST and the “consequence of that is that the majority of the population has drastically decreased productivity, decreased quality of life, increasing susceptibility to illness, and is just plain tired.”
Con 3
DST is expensive.
William F. Shughart II, economist at Utah State University, states that the simple act of changing clocks costs Americans $1.7 billion in lost opportunity cost based on average hourly wages, meaning that the ten or so minutes spent moving clocks, watches, and devices forward and backward could be spent on something more productive.
The Air Transport Association estimated that DST cost the airline industry $147 million dollars in 2007 thanks to confused time schedules with countries who do not participate in the time change.
According to the Lost-Hour Economic Index, moving the clocks forward has a total cost to the US economy of $434 million nationally, factoring in health issues, decreased productivity, and workplace injuries.