Changing clocks to Daylight Saving Time (DST) causes acute harms; remaining on DST causes chronic harms. Permanent Standard Time provides the most benefit to health, safety, schoolchildren, economy, environment, and liberty.

Public Health

Both the change of clocks to DST and the continual observation of DST pose lethal threats to human health. Changing clocks causes acute harms that persist for several days or even several weeks.BerkGiuntella & MazzonnaJenningsRoenneberg 2019-08Smith Continually observing DST causes chronic harms that last for months (in the case of seasonal observance) or years without end (in the case of year-round observance). We “never adjust”CurtisHollidayKalidindiKantermannLivingston 2016Watson to DST—instead we sleep less long and less well than we need.

The abrupt move forward in springtime by one hour is well-known for its shock to body and mind—causing traffic deaths, workplace accidents, lost productivity, and hospitalizations. Incidence of stroke spikes by 9%Watson after changing clocks to DST in spring. Incidence of heart attack increases by a range of 24%BrueckMichiganSandhu up to 50%Peralta the Monday after changing to DST, and this increase continues at a range of 5%Livingston 2016 up to 15%Livingston 2020Reddy in the week that follows. Even more notably, heart attack rates decrease by a range of 10%Livingston to 21%BrueckMichiganSandhu after returning clocks to Standard Time in autumn.

Additionally, the observance itself of DST causes subtler but stronger harms. Healthful sleep is necessary for prosperity and longevity, and it’s biologically regulated by melatonin and cortisol. The body’s natural release of these sleeping and waking hormones is tuned to the setting and rising of the sun. DST postpones both sunset and sunrise on our social clock, which disrupts the body’s hormone balance, and leads people both to stay awake late and to feel a need to sleep late.CBCCrickCytowicGiuntella & MazzonnaGuIngrahamLindsay 2019-12-05Livingston 2020O’CallaghanReddy However, social schedules demand we wake on time regardless of how we feel, and permanent DST would demand most citizens to start school or work before sunrise for a third of the year (whereas most do not now).Block & MeijerCBCHerf & LongcoreJudaLabbeLindsay 2019-12-05Meijer & FosterSladek

DST’s combination of late daylight and pre-sunrise waking robs us of 19 minutes of sleep every night on average.CermakianCSCCurtisGiuntella & MazzonnaRoenneberg 2019-08 Cortisol rhythms advance only two minutes despite clocks being advanced 60 minutes under DST.Roenneberg 2019-08 This creates a “social jet lag”, which is far worse for health than ordinary jet lag, and which never is relieved under permanent DST.BorisenkovClayEBRSFletcherGiuntella & MazzonnaGuHerfJudaMcMillanRoenneberg 2019-08SRBR The body attempts to compensate by sleeping late on non–work days, but the benefits of sleep can’t be stored.BorisenkovGuRoenneberg 2019-08

Researchers warn DST’s chronic lack of sleep “significantly”CermakianCurtisGiuntella & MazzonnaGuLewyRoenneberg 2019-08VoPham increases risks of heart disease, stroke, diabetes, cancer, high blood pressure, obesity, metabolic disorders, personality disorders, unintentional midday sleep, caffeine abuse, alcohol abuse, depression, and suicidality. It harms cognition, productivity, reaction time, stress management, immunity, and life expectancy, in both children and adults.BBCBlock & MeijerBorisenkovCBCCermakianClayCOFCOCrawford & BoyntonCrickCSCCurtisDaily HiveEBRSGibson & SchraderGiuntella & MazzonnaGuHerfHerf & LongcoreHerringIngrahamJin & ZiebarthKalidindiKaramaliLindsay 2019-12-05McCoyMeijer & FosterMerlineO’CallaghanOglioreRIVMRoenneberg 2012Roenneberg 2019-08SRBRWatsonWhiteZantinge Delaying sunset and sunrise by one hour increases rates of breast cancer by 5%Ingraham to 12%,Herf & Longcore heart disease by 11%,Crick prostate cancer by 12%,HerfHerf & Longcore colorectal cancer by 13.5%,Herf lung cancer by 13.8%,Herf heart attack by 19%,Ingraham obesity by 21%Giuntella & Mazzonna to 30%,Roenneberg 2012 liver cancer by 21%Herf & Longcore to 33%,Herf stomach cancer by 27%,Herf uterine cancer by 30%,HerfHerf & Longcore leukemia by 36%Herf & Longcore to 39%,Herf and esophageal cancer by 48%.Herf Seasonal depression is more prevalent at northerly latitudes (10% of Seattle, 25% of AlaskaHerf), where winter days are unavoidably shorter. This suffering is most effectively relieved by adding light to mornings—not evenings.GillmoreMcCoyRoenneberg 2019-08 Desire for DST’s artificially brighter evenings has been compared by scientists to desire for the pleasure of smoking, in that it ignores the volume of data that proves the harm each practice inflicts on individuals and society.Junge & Cunnington

Proponents of DST claim the practice increases exercise. Circadian scientists consider this claim “de­bunked”.Watson Increases in physical activity are better attributed to the natural change of season, not the artificial change of clocks.SRBR The study to back DST’s exercise claim only considered regions that observe summer DST (ignoring those on permanent Standard Time), its gains averaged just two minutes per day (not the full hour the clock gets advanced), and these small gains were seen only in Europe and Australia (with no gains in America).Livingston 2016 Another study that did compare close regions with different time observations found no increase or decrease in exercise.KalidindiZick Furthermore, evening exercise can disrupt sleep, and lack of sleep can increase sports injuries by 70%.Herf

Circadian-health experts “around the world”CermakianCSC “unanimously”JudaFletcherLindsay 2019-12-05 endorse permanent Standard Time for health, safety, and prosperity as scientific “consensus”.BuiOgliore Leading organizations include the American Academy of Sleep Medicine,AASM the National Sleep Foundation,NSF the Canadian Sleep Society,CSS the Canadian Society for Chronobiology,CermakianCSC the Society for Research on Biological Rhythms,Roenneberg 2019-06 the European Biological Rhythms Society,EBRS and the European Sleep Research Society.ESRS See Save Standard Time’s list of policy endorsements for additional organizations and individuals of note who reject permanent DST and support permanent Standard Time.

Public Safety

DST risks the lives of commuting children and adults, whether we observe it seasonally or year-round.BBCClayJennings

The springtime change to DST shocks the human circadian system with a sudden loss of 40 minutes of sleep on average.Barnes & Wagner This disruption negatively affects reaction times,Medina which causes traffic deaths in the US to spike 17% the Monday after changing to DST.Boynton The increase in road deaths persists at a rate of 5.6%Smith to 6%Fritz the remaining week after changing. A minimum average of 28 lives per year are lost due to “springing forward”.Fritz Other studies estimate as many as 195 motorists’ and 171 pedestrians’ lives each year are lost.Merline

Proponents of DST claim that DST’s artificial shift of daylight from morning to evening reduces traffic deaths. The data proves otherwise. Lack of visibility is a contributing factor in DST-related traffic deaths, but sleep deprivation is the stronger cause,FritzKarlik and permanent DST makes sleep deprivation chronically worse.CBCSRBR

Permanent DST would force most citizens to start school or work before sunrise for a third of the year (whereas most do not now).Block & MeijerCBCHerf & LongcoreJudaLabbeLindsay 2019-12-05Meijer & Foster Mornings are the worst time for dark commutes, when grogginess from lack of sleep (19 minutes average lost every night under DST)CermakianCSCCurtisGiuntella & MazzonnaRoenneberg 2019-08 is strongest for walking or busing children, inexperienced teen drivers, and driving adults alike.ClarkHerf Motor vehicle accidents are the primary cause of accidental death in the US.Smith 70% of all US pedestrian deaths occur under darkness, and 20% of all US pedestrians killed are children.Mercury In 1974, eight children’s lives were taken on dark winter mornings in just one month of permanent DST in Florida.Downing 2018JenkinsMerline

The National Education Association,Jenkins the National School Boards Association,Jenkins the National PTA,Achenbach the American Federation of Teachers,Jenkins and the German Teachers’ AssociationDeutscher Lehrerverband have all opposed permanent DST, citing children’s safety. The Association of Canadian Ergonomists has opposed permanent DST and endorsed permanent Standard Time, citing concerns for public health and safety.ACE See Save Standard Time’s list of policy endorsements for additional organizations and individuals of note who reject permanent DST and support permanent Standard Time.

Start Times for School & Work

Experts in the research of circadian health warn permanent DST “undermines”Cell Press and “negates”Skeldon & Dijk the necessary and popular benefits of starting school later, and that lawmakers who support both Start School Later and permanent DST are “confused”.NedelmanSkeldon & Dijk

Proponents of permanent DST claim civil clocks are arbitrary. Meanwhile, data and history show “every cell”CytowicReddy in our bodies is “entrained”GuKantermannRoenneberg 2019-08Thomas to solar time, and that we “never adjust”CurtisHollidayKalidindiKantermannLivingston 2016Watson to DST, even when DST is made permanent. Standard Time by design aligns civil clocks to solar time “most closely”,Daily HiveHollidayOgliore most practically, and for maximal benefit to individuals and society.

Start School Later and Save Standard Time share the goal of assuring adequate sleep for optimal health and scholastic potential. DST’s artificially delayed sunsets and sunrises disrupt human hormones, they make sleep during unnaturally bright evenings harder, they make waking during unnaturally dark mornings harder, and they reduce exposure to morning light (which is when physical and mental health needs sunlight most).CrickCytowicGiuntella & MazzonnaIngrahamLindsay 2019-12-05Livingston 2020O’CallaghanReddy

By solidifying civil clocks’ connection to solar time, permanent Standard Time provides an essential foundation to protect Start School Later policy.Alexia 2020 Additionally, permanent Standard Time extends the benefits of Start School Later to adults, who also need adequate sleep for health, safety, and success.CrickFletcherSRBR

The average American school day begins at 8:03am, and the median American workday begins at 7:55am—though many begin 30 or even 60 minutes earlier.CDCSilver Postponing start times helps, but simultaneously advancing clocks “contravenes”Alexia 2020 or “cancels out”Nedelman such help. The result can be an arms race against start times, wherein we push clocks forward for more daylight after school and work, then we push start times later for more daylight before school and work. We gain no daylight, we lose more sleep, we obscure the objective meaning of time’s hours, and we muddle decades of scientific records.HerfRoenneberg 2019-08 Permanent DST also opens the way for double DST, when we advance clocks two hoursCohenKorchYorkshire and double the harms to public health.ClayHammillHerfHerf & Longcore

When Russia tried permanent DST from 2011 to 2014, mental and physical health continually suffered over three years.Borisenkov Spain observes an advanced time zone, and their population loses nearly an hour of sleep each night.Kelley When the US last tried permanent DST in 1974, eight children’s lives were needlessly taken by groggy motorists on unnaturally dark winter morning roads.Downing 2018JenkinsMerline Lack of roadway visibility is a factor in DST-related fatalities, but sleep deprivation is the stronger cause.FritzKarlik

Permanent DST would artificially delay sunrise as late as 8:37am in Florida, 8:44am in California, 8:48am in New York, 9:04am in Texas, and 9:48am in the contiguous US.Time & Date Sunrise rarely occurs after 8am in most North American cities, but permanent DST would artificially delay sunrise past 8am as many as 106 days (3.5 months) in California, 109 days (3.6 months) in New York, 118 days (3.9 months) in Florida, 152 days (5.0 months) in Texas, and 169 days (5.6 months) in the contiguous US.Time & Date See how your community fares under Standard Time versus DST with Save Standard Time’s Sunrise Chart.

Economy & Wages

Both changing to DST and remaining on DST have high economic costs, which manifest as stock-market disruption, lost productivity, workplace injuries, healthcare expenses, and overall lower earnings.CBCDaily HiveJin & ZiebarthKalidindiWatson

Workplace injuries in US laborers increase 5.7% in the days after moving clocks forward to DST in spring, due to the sudden loss of an average of 40 minutes of sleep. Injuries increase in severity too, resulting in 67.6% more days lost after moving clocks forward.Barnes & Wagner US office productivity drops 20% upon the springtime clock change to DST, for a loss of $434M annually nationwide.WagnerWagner & Barnes Stocks drop 200 to 500% more than usual the Monday after moving clocks forward to DST, at a cost of $31B in the US.Roenneberg 2019-08 These injuries, missed days, lost productivity, and stock losses don’t reoccur in the autumn return to Standard Time, nor are they ever recouped.Barnes & WagnerRoenneberg 2019-08Wagner & Barnes

Economic losses continue under DST beyond the springtime clock change, as seen in data from western and eastern edges of time zones, where sunsets and sunrises naturally differ by an hour. One added hour of sunlight in evenings and its corresponding lost hour in mornings reduce sleep duration by an average of 19 minutes nightly.CermakianCSCCurtisRoenneberg 2019-08 This continual loss of sleep every night manifests as health problems (at a cost of $2.35B annually in the US), as lost productivity (totaling 4.4M lost work days, at a cost of $613M annually nationwide), and even as lower earnings (3.0 to 4.9% less than in neighboring counties with a one-hour earlier sunset and sunrise). An increase in average nightly sleep by a full hour can increase earnings by the same amount as half a year of added education would, and it can increase productivity more than an entire year of added education.Gibson & SchraderGiuntella & MazzonnaIngraham

Energy & Environment

DST observation (not the changing of clocks) wastes energy and increases pollution. Artificially moving an hour of daylight from mornings to evenings might reduce evening lighting costs as originally promised, but any savings is canceled by increased morning lighting. Furthermore, modern lighting is not a considerable energy expense when compared to the far-less efficient expenses of heating and air conditioning.BambrickHandwerkKotchen & Grant 2008-10Kotchen & Grant 2008-12Porter

DST increases demand both for morning heat and evening air conditioning.Albeck-RipkaBambrickKotchen & Grant 2008-10Kotchen & Grant 2008-12Porter DST also encourages more evening driving, which led the petroleum industry to become a major lobby for DST.BambrickBlockCohenHandwerkPorter These increases to heating, air conditioning, and driving all increase energy costs, pollution, and climate change.BambrickHandwerkKotchen & Grant 2008-10Kotchen & Grant 2008-12Porter

When Indiana changed from permanent Standard Time to summertime DST in 2007, annual consumer electricity demand rose 1 to 4%. This jump cost residents an extra $9M per year in utilities, and up to $5.5M annually in added pollution expenses.BambrickKorchKotchen & Grant 2008-10Kotchen & Grant 2008-12 The same effect was seen in Sydney, Australia, when DST was extended for the 2000 Summer Olympics.Handwerk Energy waste could be even worse in regions with greater populations or more extreme weather.Kotchen & Grant 2008-10

Religious Freedom

Standard Time has been known as “God’s time”KorchMauerHammill to many farmers and religious populations, for its proximity to natural (solar) time. DST’s arbitrarily added hour disrupts time-based prayers, creates scheduling conflicts for worshipers each morning and night, and places undue burden on their surrounding communities and businesses.

Judaism, for example, calls for daily prayers that are timed to sunrise, but permanent DST’s artificially delayed sunrises would force morning prayers to overlap with work hours in winter. Other observations are timed to sunset, and permanent DST’s artificial delay of sunset reduces the number of business that remain open into twilight.CohenEllerJTAKeller

Agudath Israel of America,JTA Agudath Israel of Florida,Eller and Agudath Israel of ChicagoKeller have all opposed permanent DST, citing civil liberties and religious freedom. See Save Standard Time’s list of policy endorsements for additional organizations and individuals of note who reject permanent DST and support permanent Standard Time.

Special-Interest Lobbies

Observation of DST harms health, safety, education, productivity, wages, and environment. But it also leads us to drive, shop, and golf more—which benefits the special interests of select billion-dollar industries, mainly retail, golf, tourism, oil, and candy.

The petroleum industry noticed a connection between DST and consumer spending as early as 1930, and they’ve lobbied ever since to resurrect DST when it was abolished after World Wars I and II, and to extend its duration beyond just the summer months.BlockPorterSchlanger The US Chamber of Commerce has also been a longtime promoter of DST, acting on behalf of convenience stores and retailers of outdoor products.CohenSchlangerVictor

The 1980s saw the formation of the National Daylight Saving Time Coalition, comprised of wealthy corporations from the industries of golf, candy, fast food, convenience stores, barbecue equipment, and amusement parks. The Coalition worked closely with legislators to extend DST’s duration; the Department of Transportation reported candy pumpkins on senators’ seats were one visible sign of inducement. The Coalition’s effort proved a success in 1986, when DST’s start date moved from the last Sunday of April to the first Sunday of April, which extended the length of DST from six months to seven. They won another extension in 2005, when DST’s start date was moved to the second Sunday in March, and its end date from the last Sunday in October to the first Sunday in November, making DST observation now eight months long in North America.Avid GolferBuiGray & JenkinsHoustonIsraelMorgan Today’s chambers of commerce and lobbyists for golf and tourism continue to support seasonal and permanent DST.Avid GolferHaugheyJohnsonKieselMGCA

Farmers have mistakenly been blamed for DST, when in fact they were among the first and strongest to work to end DST after wartime and to resist its return and extensions.HammillKorchVictor Farmers start work with the sun, and their most productive time of day is morning. But when they sell their goods, they must abide the civil clock, and DST’s advancement of civil time and artificial reduction of morning hours gives farmers less time to get their goods to market.Gray & JenkinsHoustonIsraelLivingston 2016MorganSchlanger

DST proponents argue that what benefits special interests must benefit the economy. But they ignore or deny the evidence that DST observation chronically harms health and safety (which increases healthcare costs),Giuntella & MazzonnaPearceStevens and it chronically reduces productivity and wages (which lowers individual prosperity and the overall economy).Gibson & ShraderIngrahamJin & ZiebarthRoenneberg Profits for a few special interests shouldn’t come at the expense of the general populace. Permanent Standard is the best and fairest clock for society.

Public Opinion

Many politicians assume the public prefers DST, but data and history indicate otherwise. Preference between the two times is rarely asked, and polls depend heavily on how and when they’re conducted. Most people don’t know which time is which (granted, it can be confusing). Many who think they prefer DST usually just prefer summer’s naturally longer days, without realizing how dark winter mornings would be under permanent DST.AchenbachHerfMeijer & FosterRasmussen

Those who favor one time or the other are generally split (40% Standard vs 31% DST in a 2019 October scientific poll of 1,075 Americans;AP-NORCDavies 35% DST vs 28% Standard in a 2019 March scientific poll of 1,288 AmericansBallard).

The majority clearly wish to stop changing clocks as soon as possible (93% in a 2019 governmental poll of 223,273 British Columbians;Crawford & Boynton 84% in a 2018 governmental poll of 4.6M Europeans;CohenCommissionSchreuerWatson 67% in a 2018 scientific poll of 600 Pacific Northwesterners;PEMCO 60% in California’s 2018 Prop 7 ballot measure;HerfSheeler 54% in a 2019 scientific poll of 1,288 AmericansBallard).

History has shown when public opinion favors permanent DST before enactment, support quickly reverses to opposition after DST’s long, dark winter mornings are experienced. This happened most clearly in the US in 1974, when support for permanent DST dropped from 79% to 42% in a matter of months. Similar outcomes occurred in the UK in 1971, and in Russia in 2014.BBCHerfHerf & LongcoreLindsay 2019-12-05MerlineRipleyYorkshire

Public opinion demands we stop changing clocks now. The quickest, easiest, safest way is to restore permanent Standard Time. Moreover, public health demands we both stop changing clocks now and choose permanent Standard Time. Public health must take precedence over shifting public opinion of the two times.HerfHerf & LongcoreRoenneberg 2019-08

Learn from History

The US tried permanent DST in 1974. While initially supported by an estimated 79% of the population, its popularity quickly plummeted to 42% after its first winter. Several children died on their way to school, the public bemoaned the unnaturally late, dark mornings, and the two-year experiment was ended a year and a half early.ClarkDowning 2005Downing 2018HerfJenkinsMerlineRipleyRoenneberg 2019-08

Permanent DST was similarly tried in the UK from 1968 to 1971, and in Russia from 2011 to 2014. Each time, the program was greeted with initial optimism, followed by public outcry and reversal.BBCHerfHerf & LongcoreLindsay 2019-12-05MerlineRoenneberg 2019-08Yorkshire Why waste time, money, and lives repeating bad history?

Quickest & Simplest Solution

The quickest way to end clock changes in North America is to restore permanent Standard Time. Congress already permits states to restore permanent Standard Time, while permanent DST is federally prohibited. Arizona, Hawaii, and all US territories restored permanent Standard Time decades ago, without difficulty or drawback.CravenJenningsKorchMauerMercurySkelton 2018Watson

Permanent DST would require sweeping change to federal law by Congress—which could take several years, which might never occur, or which might be changed then reverted (as happened in 1974).Alexia 2020CravenCrickHerfLindsay 2019-12-18MerlineSkelton 2018Skelton 2019Ripley Permanent DST defies the people’s will for an immediate end to clock changes; it’s a waste of legislative time and taxpayer money.

A return instead to permanent Standard Time would cost nothing and could be enacted in mere months. It would benefit public health, public safety, the environment, energy usage, productivity, and wages. It would prove more popular both for its quickness and its lasting approval. It would be an easy win for lawmakers.Herf & LongcoreRoenneberg 2019-08

No bill can make winter’s daylight as long as summer’s daylight. DST is mistakenly associated with summer’s naturally longer days, but summer days will still be just as long under permanent Standard Time as they were under DST.Meijer & FosterRoenneberg 2019-08US Naval

DST is akin to vanity sizing, wherein clothiers arbitrarily assign different numbers to the same sizes to make consumers feel thinner. DST’s arbitrarily added hour falsely makes some people feel they have more daylight. We could add six hours to the clock to postpone daylight until a false midnight, but it would then be dark until a false noon.Herf

Standard Time is the most practical model for timekeeping that is based in objective reality. It’s an approximation of solar time, which is itself a geometric measurement of nature. Twelve noon corresponds to the sun’s highest point in the sky; twelve midnight corresponds to the darkest point of night. Twelve was chosen for its even fractions (half, third, quarter).US Naval

Standard Time facilitates many simple estimations: time of day from the sun’s position, time of night from the moon or stars, time of sunrise or sunset, time zone differences, latitude on earth, sunburn hours… This knowledge—this connection to nature—is needlessly obscured under DST.ChristensenHirsberg & WintherKher