Sources

§71 entries

roll238 U.S. House of Representatives, Roll Call 238 — H.R. 139, Sunshine Protection Act, On Passage, 14 July 2026, 5:17 PM. Passed 308–117. https://clerk.house.gov/evs/2026/roll238.xml Some outlets reported this as 308–171. The Clerk's record says 308–117.
rules139 House Committee on Rules, bill file for H.R. 139 (119th Congress). https://rules.house.gov/bill/119/hr-139
s623 Sunshine Protection Act of 2021, S. 623 — passed the Senate by unanimous consent, 15 March 2022. No recorded vote. Died without House action. https://www.govtrack.us/congress/bills/117/s623
ncsl National Conference of State Legislatures, Daylight Saving Time State Legislation (updated 2 March 2026). 19 states have enacted permanent-DST laws contingent on Congress. https://www.ncsl.org/transportation/daylight-saving-time-state-legislation
nist NIST Time and Frequency Division, Daylight Saving Time — non-observing states and territories, including the Navajo Nation exception within Arizona. https://www.nist.gov/pml/time-and-frequency-division/popular-links/daylight-saving-time-dst
aasm2024 Rishi MA, Cheng JY, Strang AR, et al. Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2024;20(1):121–125. https://pubmed.ncbi.nlm.nih.gov/37904574/
aasm2020 Rishi MA, Ahmed O, Barrantes Perez JH, et al. Daylight saving time: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2020;16(10):1781–1784. https://pubmed.ncbi.nlm.nih.gov/32844740/
srs2022 Malow BA. It is time to abolish the clock change and adopt permanent standard time in the United States: a Sleep Research Society position statement. Sleep. 2022;45(12):zsac236. https://pubmed.ncbi.nlm.nih.gov/36156090/
srbr2019 Roenneberg T, Wirz-Justice A, Skene DJ, et al. Why Should We Abolish Daylight Saving Time? J Biol Rhythms. 2019;34(3):227–230. https://pmc.ncbi.nlm.nih.gov/articles/PMC7205184/
ama2022 AMA calls for permanent standard time. American Medical Association press release, 15 November 2022. https://www.ama-assn.org/press-center/press-releases/ama-calls-permanent-standard-time
nsf National Sleep Foundation, Position on Permanent Standard Time (22 March 2021). https://www.thensf.org/wp-content/uploads/2021/03/NSF-Position-on-Permanent-Standard-Time_3.22.2021.pdf
esrs EBRS, ESRS and SRBR joint statement to the European Commission on Daylight Saving Time (2018): permanent Central European Time is the best option for public health. https://esrs.eu/wp-content/uploads/2019/03/To_the_EU_Commission_on_DST.pdf
css Canadian Sleep Society, Position Statement on the Practice of Daylight Saving Time — recommends termination of DST in favour of permanent Standard Time. https://css-scs.ca/society-news/position-statement-of-the-canadian-sleep-society-on-the-practice-of-daylight-saving-time-dst/
cpst Coalition for Permanent Standard Time one-pager: the position is shared by more than 20 medical, scientific and civic organizations. https://sleepresearchsociety.org/wp-content/uploads/2024/10/CpST-One-Pager.pdf
giuntella Giuntella O, Mazzonna F. Sunset time and the economic effects of social jetlag: evidence from US time zone borders. J Health Econ. 2019;65:210–226. An extra hour of evening natural light reduces sleep by an average of 19 minutes. https://pubmed.ncbi.nlm.nih.gov/31030116/
vopham VoPham T, Weaver MD, Vetter C, et al. Circadian misalignment and hepatocellular carcinoma incidence in the United States. Cancer Epidemiol Biomarkers Prev. 2018;27(7):719–727. A 5° eastward-to-westward increase in longitude within a time zone: IRR 1.07 (95% CI 1.01–1.14). https://pubmed.ncbi.nlm.nih.gov/29636342/
kantermann Kantermann T, Juda M, Merrow M, Roenneberg T. The human circadian clock's seasonal adjustment is disrupted by daylight saving time. Curr Biol. 2007;17(22):1996–2000. https://pubmed.ncbi.nlm.nih.gov/17964164/
heissel Heissel JA, Norris S. Rise and Shine: The Effect of School Start Times on Academic Performance from Childhood through Puberty. J Human Resources. 2018;53(4):957–992. https://jhr.uwpress.org/content/53/4/957
khalsa Khalsa SBS, Jewett ME, Cajochen C, Czeisler CA. A phase response curve to single bright light pulses in human subjects. J Physiol. 2003;549(3):945–952. Peak-to-trough amplitude 5.02 h; maximal delay −3.60 h, maximal advance +2.01 h. https://pmc.ncbi.nlm.nih.gov/articles/PMC2342968/
fritz Fritz J, VoPham T, Wright KP Jr, Vetter C. A Chronobiological Evaluation of the Acute Effects of Daylight Saving Time on Traffic Accident Risk. Curr Biol. 2020;30(4):729–735.e2. 732,835 fatal crashes, 1996–2017; +6% after the spring transition, larger in the morning and further west within a time zone; no fall effect. https://pubmed.ncbi.nlm.nih.gov/32008905/
hurst Hurst A, Morfeld P, Lewis P, Erren TC. Daylight Saving Time Transitions and Risk of Heart Attack. Dtsch Arztebl Int. 2024. Pooled RR 1.04 (95% CI 1.02–1.07) after spring; autumn not significant. https://pubmed.ncbi.nlm.nih.gov/38888468/
manfredini Manfredini R, Fabbian F, Cappadona R, et al. Daylight Saving Time and Acute Myocardial Infarction: A Meta-Analysis. J Clin Med. 2019;8(3):404. Spring OR 1.05 (1.02–1.07); autumn not significant. https://pubmed.ncbi.nlm.nih.gov/30909587/
smith2016 Smith AC. Spring Forward at Your Own Risk: Daylight Saving Time and Fatal Vehicle Crashes. American Economic Journal: Applied Economics. 2016;8(2):65–91. >30 deaths annually, $275M social cost. https://www.aeaweb.org/articles?id=10.1257/app.20140100
barnes Barnes CM, Wagner DT. Changing to daylight saving time cuts into sleep and increases workplace injuries. J Appl Psychol. 2009;94(5):1305–1317. Workers sleep 40 minutes less on the Monday following; no fall effect. https://pubmed.ncbi.nlm.nih.gov/19702372/
osborne Osborne-Christenson EJ. Saving light, losing lives: How daylight saving time impacts deaths from suicide and substance abuse. Health Econ. 2022;31(Suppl 2):40–68. Spring transition +6.25% suicide rate; no fall effect. https://pubmed.ncbi.nlm.nih.gov/36000150/
sipila Sipilä JOT, Ruuskanen JO, Rautava P, Kytö V. Changes in ischemic stroke occurrence following daylight saving time transitions. Sleep Med. 2016;27–28:20–24. RR 1.08 (1.01–1.15) for the first two days; the whole-week effect is not significant. https://pubmed.ncbi.nlm.nih.gov/27938913/
sandhu Sandhu A, Seth M, Gurm HS. Daylight savings time and myocardial infarction. Open Heart. 2014;1(1):e000019. +24% Monday after spring, −21% Tuesday after fall, and NO difference in the total weekly count — a shift in timing, not incidence. https://pmc.ncbi.nlm.nih.gov/articles/PMC4189320/
havranek Havránek T, Herman D, Iršová Z. Does Daylight Saving Save Electricity? A Meta-Analysis. The Energy Journal. 2018;39(2):35–61. 162 estimates from 44 studies; mean 0.34% savings; no publication bias; savings concentrate far from the equator and reverse in subtropical regions. https://meta-analysis.cz/dst/
kotchen Kotchen MJ, Grant LE. Does Daylight Saving Time Save Energy? Evidence from a Natural Experiment in Indiana. Rev Econ Stat. 2011;93(4):1172–1185 (NBER w14429, 2008). DST increased residential demand ~1%, costing Indiana households $9M/year. https://www.nber.org/papers/w14429
doe2008 U.S. Department of Energy, Impact of Extended Daylight Saving Time on National Energy Consumption, October 2008. 1.3 TWh saved — 0.5% per day of extended DST, 0.03% of annual national electricity consumption. https://www.osti.gov/biblio/1216568
kellogg Kellogg R, Wolff H. Daylight time and energy: Evidence from an Australian experiment. J Environ Econ Manage. 2008;56(3):207–220. The Sydney Olympics DST extension produced no reduction: +0.11% (SE 0.39). https://ftp.iza.org/dp2704.pdf
eia U.S. Energy Information Administration, Use of energy in homes. Lighting is roughly 6% of US residential electricity; air conditioning 19% and space heating 12%. https://www.eia.gov/energyexplained/use-of-energy/electricity-use-in-homes.php
coate Coate D, Markowitz S. The effects of daylight and daylight saving time on US pedestrian fatalities and motor vehicle occupant fatalities. Accid Anal Prev. 2004;36(3):351–357. Full-year DST would reduce pedestrian fatalities by 171/year (13%) and occupant fatalities by 195/year (3%). https://pubmed.ncbi.nlm.nih.gov/15003579/
ferguson Ferguson SA, Preusser DF, Lund AK, Zador PL, Ulmer RG. Daylight saving time and motor vehicle crashes: the reduction in pedestrian and vehicle occupant fatalities. Am J Public Health. 1995;85(1):92–96. An estimated 901 fewer fatal crashes over 1987–1991 — roughly 180/year, not 901/year. https://pmc.ncbi.nlm.nih.gov/articles/PMC1615292/
doleac Doleac JL, Sanders NJ. Under the Cover of Darkness: How Ambient Light Influences Criminal Activity. Rev Econ Stat. 2015;97(5):1093–1103. Robbery falls ~7% daily and ~27% in the shifted sunset hour; $59M/year avoided robbery costs from the three-week extension. https://njsanders.human.cornell.edu/DST_Crime_RESTAT.pdf
goodman Goodman A, Page AS, Cooper AR. Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries. Int J Behav Nutr Phys Act. 2014;11:84. https://pmc.ncbi.nlm.nih.gov/articles/PMC4364628/
jpmc JPMorgan Chase Institute, Shedding Light on Daylight Saving Time. Card spending in Los Angeles rises 0.9% in the 30 days after DST begins and falls 3.5% in the 30 days after it ends, relative to Phoenix. https://www.jpmorganchase.com/institute/research/household-income-spending/institute-shedding-light-on-daylight-saving-time
hansen Hansen BT, Sønderskov KM, Hageman I, Dinesen PT, Østergaard SD. Daylight Savings Time Transitions and the Incidence Rate of Unipolar Depressive Episodes. Epidemiology. 2017;28(3):346–353. The FALL transition is associated with an 11% increase (CI 7–15%), dissipating over ~10 weeks; the spring transition showed no such effect. https://pubmed.ncbi.nlm.nih.gov/27775953/
martinolalla2025 Martín-Olalla JM, Mira J. Assessing the best hour to start the day: an appraisal of seasonal daylight saving time. R Soc Open Sci. 2025;12(3):240727. Argues seasonal clock change solves a real problem — that sunrise time varies enormously by season while work schedules are fixed. https://doi.org/10.1098/rsos.240727 This publisher returns 403 to automated requests. The link resolves normally in a browser.
monmouth Monmouth University Polling Institute, 15 March 2022 (n=809). 61% want to end switching; among options, 44% prefer year-round DST vs 13% year-round standard time. https://www.monmouth.edu/polling-institute/reports/monmouthpoll_us_031522/
apnorc AP-NORC Center, October 2025 (n=1,289). Only 12% favor keeping the twice-yearly change; 56% prefer year-round daylight saving vs 42% year-round standard. https://apnorc.org/projects/few-people-support-the-daylight-saving-time-system-and-more-want-year-round-light-in-the-evenings/
gallup Gallup, January 2025 (n=1,001). 48% prefer permanent standard time vs 24% permanent DST, with 19% preferring to keep switching — the reverse of Monmouth and AP-NORC. https://news.gallup.com/poll/657584/half-daylight-saving-time-sunsetted.aspx
eje2026 A systematic review of epidemiological studies into daylight-saving time & health identifying beneficial & adverse effects. Eur J Epidemiol. 2026. 157 studies, 36 countries. Concludes the messaging of transitions and summer DST being uniformly detrimental 'is not supported' and calls for a balanced approach. https://pubmed.ncbi.nlm.nih.gov/41721993/
bmj2025 de Lange MA, Birnie K, Richmond RC, et al. Acute effects of daylight saving time clock changes on mental and physical health in England: population based retrospective cohort study. BMJ. 2025. 683,809 people, 2008–2019: little evidence of change after the spring clock change; the autumn change was associated with fewer events. https://pubmed.ncbi.nlm.nih.gov/41412603/
pnas2025 Circadian-informed modeling predicts regional variation in obesity and stroke outcomes under different permanent US time policies. PNAS. 2025;122(38):e2508293122. The source of the widely-quoted 300,000-stroke figure. Subject to a published correction and three critical letters. https://pubmed.ncbi.nlm.nih.gov/40953265/
pnasrefut The sum of absolute circadian shifts: Questioning the metric linking daylight saving time policy to stroke and obesity. PNAS. 2026;123(17):e2532075123. Argues the summed-absolute-shift metric cannot distinguish a stable circadian phase from one that drifts monotonically. https://pubmed.ncbi.nlm.nih.gov/41996167/
arxivbug The full methodological critique, and the document that actually identifies the code-level defect: the longitudinal offset was divided by Ω = −15°/hour instead of +15°/hour, which 'effectively inverted the US East-West axis within the model,' cross-correlating each county's health data against a geographically flipped counterpart. https://arxiv.org/html/2606.19541
erren2026 Challenges of county-level circadian modeling for time-policy debates. PNAS. 2026;123(17):e2527389123. The second of the two critical letters, raising ecological-inference objections. https://pubmed.ncbi.nlm.nih.gov/41996169/
pnascorr Correction for Weed & Zeitzer. PNAS. 2026;123(18):e2612351123. https://pubmed.ncbi.nlm.nih.gov/42044348/
jama2025 Rymer JA, Li S, Chiswell K, Kansal A, Nanna MG. Daylight Savings Time and Acute Myocardial Infarction. JAMA Netw Open. 2025;8(9):e2530442. 168,870 patients across 1,124 hospitals, 2013–2022: no significant difference in AMI incidence in the DST week, spring or fall. https://pubmed.ncbi.nlm.nih.gov/40924425/
monica Are daylight saving time transitions associated with changes in myocardial infarction incidence? BMC Public Health. 2015;15:778. German MONICA/KORA registry, n=25,499: no significant overall change after either transition. https://pmc.ncbi.nlm.nih.gov/articles/PMC4535383/
samplebias Sample size bias in the empirical assessment of the acute risks associated with daylight saving time transitions. Chronobiol Int. 2023;40(2). Across 13 well-known studies the largest effect sizes come from the smallest samples; a ~5% spring increase suffices to explain all of them. https://pubmed.ncbi.nlm.nih.gov/36594375/
spamann Are Sleepy Punishers Really Harsh Punishers? Comment on Cho, Barnes, and Guanara (2017). Psychol Sci. 2018;29(6):1006–1009. Reanalysis finds no significant 'sleepy Monday' sentencing effect. https://pubmed.ncbi.nlm.nih.gov/29683778/
gooley2025 The adolescent circadian clock entrains to social time rather than sun time. Curr Biol. 2025;35(9):2100–2111.e5. n=112 adolescents with measured melatonin onset — a direct challenge to the strong sun-time entrainment claim. https://pubmed.ncbi.nlm.nih.gov/40245866/
pl93182 Emergency Daylight Saving Time Energy Conservation Act of 1973, 87 Stat. 707, signed 15 December 1973. Authorized year-round DST for a two-year trial beginning 6 January 1974. Congress found that 'year-round daylight saving time would produce an energy saving in electrical power consumption.' https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
pl93434 88 Stat. 1209, signed 5 October 1974 — amended the Act to restore standard time from 27 October 1974 to 23 February 1975, ending the winter portion of the experiment in under ten months. https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
crs Congressional Research Service, Daylight Saving Time (R45208). Quotes the DOT's finding that effects 'were so small that they could not in general be reliably separated from effects of other changes occurring at the time,' and the National Bureau of Standards' finding of no significant energy savings or difference in motor vehicle fatalities. https://www.everycrsreport.com/reports/R45208.html
nbs National Bureau of Standards, Review and Technical Evaluation of the DOT Daylight Saving Time Study (1976): the increase in morning school-age fatalities 'cannot be simply interpreted as a DST effect, in view of the many other factors that influence traffic fatalities.' https://www.congress.gov/crs_external_products/R/PDF/R45208/R45208.3.pdf
history1974 The U.S. tried permanent daylight saving time in the 1970s. Public support fell from roughly 79% in December 1973 to 42% by February 1974 in surveys run by NORC at the University of Chicago. https://www.history.com/articles/permanent-daylight-saving-time-1970s The original survey report is not publicly available; treat the exact figures as widely reported rather than primary.
russia Russia adopted permanent summer time in March 2011 and, after three winters of very late sunrises, moved to permanent standard time on 26 October 2014, where it has remained. The reversal passed the Duma near-unanimously; we could not reach a primary record of the exact tally, so we do not state one. https://www.bbc.com/news/world-europe-29773559
bst1968 The United Kingdom held clocks at GMT+1 year-round from 27 October 1968. After a free vote in the Commons on 2 December 1970, Britain returned to GMT on 31 October 1971. https://www.legislation.gov.uk/ukpga/1968/45/contents/enacted
hansard1970 House of Commons debate on British Standard Time; the House rejected continuation on a free vote. https://api.parliament.uk/historic-hansard/commons/1970/dec/02/british-standard-time
portugal Portugal moved to Central European Time in 1992 and reversed to Western European Time in 1996 after protests over dark winter mornings and unrealized energy savings. https://www.upi.com/Archives/1996/02/16/Portugal-turns-back-the-clock/1455824446800/
mexico Mexico's Senate approved abolition of daylight saving time on 26 October 2022, effective 30 October 2022, citing health costs and minimal energy savings. US border municipalities are exempted. https://apnews.com/article/mexico-bbb06a9e3f83717f72202589cb8e2626
willett William Willett's self-published pamphlet proposing that clocks advance 80 minutes in four 20-minute steps across April, reversed in September. He died in 1915, before adoption. https://www.webexhibits.org/daylightsaving/willett.html
franklin Franklin's letter to the Journal de Paris is satire. He proposed waking Parisians with church bells and cannon fire, taxing shuttered windows and rationing candles — and no clock change of any kind. https://en.wikisource.org/wiki/Works_of_the_late_Doctor_Benjamin_Franklin/An_economical_Project
wilsonveto Congress repealed the DST provision of the Standard Time Act over President Wilson's veto in August 1919 — House override 223–101 on 19 August, Senate 57–19 on 20 August. Farm interests led the repeal. https://www.senate.gov/legislative/vetoes/presidents/WilsonW.pdf
standardtimeact Ch. 24, 40 Stat. 450, 19 March 1918 — created US statutory time zones and first established daylight saving time nationally. https://www.govinfo.gov/content/pkg/STATUTE-40/pdf/STATUTE-40-Pg450.pdf
uta1966 P.L. 89-387, 80 Stat. 107, 13 April 1966. A state may exempt itself into permanent standard time; adopting permanent daylight saving time requires an act of Congress. https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
usno USNO Astronomical Applications, rise/set/transit times API — used to verify every sunrise figure computed on this site. https://aa.usno.navy.mil/data/RS_OneYear
noaa NOAA Global Monitoring Laboratory solar position algorithm — the basis of this site's sunrise computations. https://gml.noaa.gov/grad/solcalc/