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The impact of daylight saving time on sleep and related behaviours
Abstract
Daylight saving time is currently adopted in over 70 countries and imposes a twice yearly 1 h change in local clock time. Relative ease in adjustment of sleep patterns is assumed by the general population but this review suggests that the scientific data challenge a popular understanding of the clock change periods. The start of daylight saving time in the spring is thought to lead to the relatively inconsequential loss of 1 h of sleep on the night of the transition, but data suggests that increased sleep fragmentation and sleep latency present a cumulative effect of sleep loss, at least across the following week, perhaps longer. The autumn transition is often popularised as a gain of 1 h of sleep but there is little evidence of extra sleep on that night. The cumulative effect of five consecutive days of earlier rise times following the autumn change again suggests a net loss of sleep across the week. Indirect evidence of an increase in traffic accident rates, and change in health and regulatory behaviours which may be related to sleep disruption suggest that adjustment to daylight saving time is neither immediate nor without consequence.
... Our study makes important contributions to the literature. First, we contribute to research on the effects of DST adjustments on human behavior (Monk and Folkard 1976;Coren 1996aCoren , 1996b; Barnes and Wagner 2009;Harrison 2013a;Roenneberg et al. 2019). Although prior research in diverse fields including psychology and biology demonstrates impacts of DST adjustments on individual cognitive function, prior DST research in economics generally focuses on whether a DST anomaly exists in global equity returns. ...
... Consistent with these concerns, prior research provides an abundance of evidence regarding the adverse consequences of DST phasing. Scientists have found that spring DST advances (which result in the loss of an hour of calendar time) lead to circadian arrhythmia and a fragmentation of sleep patterns that can last for up to a full week following the transition (Monk and Folkard 1976;Kantermann et al. 2007;Harrison 2013a). Building on these findings and those of prior sleep science research on the adverse cognitive effects of sleep disruption (e.g., Harrison and Horne 2000;McCoy and Strecker 2011;Medic, Wille, and Hemels 2017), other studies find that sleep disruption associated with DST advances reduces cognitive function and inhibits individuals' decision-making processes. ...
... As such, if earnings news disclosed following DST advances is unfavorable, we might observe an amplified response to such disclosures. Moreover, it may be that a one-hour adjustment in calendar time may be insufficient to materially affect investor information processing (Harrison 2013a) or that certain investors (e.g., sophisticated investors or institutions) have processes in place to safeguard against disruptions caused by external factors, such as DST adjustments. As such, whether DST advances impact investors' processing of earnings news is an open empirical question. ...
Although daylight saving time (DST) is thought to provide economic benefits, extant research documents various adverse effects of DST adjustments. However, prior research provides little conclusive evidence about the effects of DST adjustments on capital market participants. We examine the effects of “spring forward” DST advances, which disrupt the human sleep cycle and economic activities, on investors’ processing of earnings news. We find a delayed price response to earnings news released during the first week following a DST advance. We also find that this effect is stronger among firms with investors who are more likely to be trading on earnings news and among firms with less sophisticated investors. Our findings contribute to research on the unintended consequences of DST adjustments and to the growing literature on intra-investor variation in disclosure processing costs. Our study may be of interest to legislators currently debating proposed legislation that would eliminate DST phasing.
Data Availability: Data are available from the sources cited in the text.
JEL Classifications: D83; G14; M41; M48.
... Epidemiological studies of shift workers demonstrate disproportionately high levels of menstrual irregularities, spontaneous abortion, and infertility providing the first indication of the importance of circadian rhythms for fertility [2][3][4][5]. Like chronic circadian disruption attributed to shift work and social jet lag, the daylight savings time transition represents a systemic perturbation in circadian rhythm with measurable increases in sleep fragmentation and sleep latency and decreases in sleep duration and efficiency, with accumulation of sleep debt persisting for at least a week [6,7]. Data regarding any of the subjects in the study has not been previously published unless specified. ...
... This continuing practice provides a naturalistic experiment to observe changing patterns of health or illness occurring before and after subtle, but large scale, disruption of circadian rhythm. Circadian rhythm disruption resulting from daylight savings time transition is associated with higher rates of diverse adverse health outcomes, including an increase in traffic accidents, suicide attempts, acute myocardial infarctions, and alterations in the diurnal variation of acute stroke [6,[8][9][10]. ...
... This study examined the impact of undergoing an embryo transfer during the daylight savings time transition on subsequent live birth outcomes. Acute disruption of circadian rhythm as a consequence of the shifting time has been implicated in the observed higher rates of work, and traffic accidents [9], myocardial infarctions [8,10], and cerebrovascular accidents [6] during DST transition weeks and circadian rhythms appear to serve an important role in fertility and fecundity [2][3][4][5]16]. This study demonstrated lower pregnancy and live birth rates when ART, specifically embryo transfer, occurred during the transition week of daylight savings time. ...
PurposeTo study the impact of undergoing an embryo transfer during the week of daylight savings time transition on live birth rates.Methods
We performed a retrospective observational cohort study of patients undergoing embryo transfer at an academic infertility practice during the week of spring or fall daylight savings time transition (cases), or the 2 weeks preceding and following the daylight savings transition (controls) between 2015 and 2021. The primary exposure was completion of an embryo transfer during the week of daylight savings time transition. The primary outcome was a comparison of live birth rate per embryo transfer among individuals undergoing an embryo transfer during the week of daylight savings time (DST) transition and those who did not.ResultsA total of 309 embryo transfers occurred during the week of daylight savings transition and 1242 embryo transfers occurred in the control group outside of the daylight savings transition week. The live birth rate after embryo transfer during DST transition weeks was 39.2% (121/309) compared to 40.8% (507/1242) (p = 0.59). When restricting the analysis to individuals (age > 37 years), the live birth rate after embryo transfer during DST transition week was 23.5% (24/102) compared to 34.8% (149/429) (p = 0.03). This difference persisted in the mixed-effects regression model demonstrating that after adjusting for relevant covariates, embryo transfer during DST transition weeks resulted in a 45% decrease in the odds of achieving a live birth.Conclusion
Daylight savings time transition may be associated with less favorable outcomes after embryo transfer among an older infertile patient population. Future work is needed to prospectively examine the influence of circadian rhythm disruption on reproductive outcomes.
... This directional effect was also evident in Study 3, wherein the transition to DST impaired donation amount, though the effects following the return to ST did not reach statistical significance. A plausible reason for the stronger effect of DST relative to ST (which has been a common feature in numerous studies assessing functions different to helping [41,43,59,60]) is that the option to sleep an extra hour following the transition to ST is not always taken, in contrast to the imposed loss of sleep opportunity caused by the transition to DST. Alternatively, it is known that individuals suffer less sleep disruption following a phase delay (which would be more similar to the phase shift associated with the switch to ST), relative to a phase advance (more akin to the DST transition challenge) [61,62]. ...
... Perhaps most critical, this effect on realworld consequential behavior was not through the extreme and less common experience of total sleep deprivation, but instead, the societally pervasive loss of just 1 h of sleep, and for 1 night. Indeed, the shift to DST has consistently been demonstrated to involve a 40 to 60 min reduction in total sleep amount, coupled with a 10% reduction in sleep efficiency due to increased sleep fragmentation [59,60,63,64]. ...
... For each donation, the following information was calculated and used in the statistical analyses: the day of the week/month/year of the donation and the time of day the donation was made. In accordance with prior reports [41,43,63,120,121], analysis focused on the weekdays following the transition, as both the ST and DST transitions result in sleep consequences lasting up to 5 days before sleep onset and offset times revert, and habitual sleep patterns return [59,122]. Analyses therefore focused on a robust window that spanned multiple days of assessment (see Note D in S1 Text for a secondary analysis focusing on posttransition Monday alone). ...
Humans help each other. This fundamental feature of homo sapiens has been one of the most powerful forces sculpting the advent of modern civilizations. But what determines whether humans choose to help one another? Across 3 replicating studies, here, we demonstrate that sleep loss represents one previously unrecognized factor dictating whether humans choose to help each other, observed at 3 different scales (within individuals, across individuals, and across societies). First, at an individual level, 1 night of sleep loss triggers the withdrawal of help from one individual to another. Moreover, fMRI findings revealed that the withdrawal of human helping is associated with deactivation of key nodes within the social cognition brain network that facilitates prosociality. Second, at a group level, ecological night-to-night reductions in sleep across several nights predict corresponding next-day reductions in the choice to help others during day-to-day interactions. Third, at a large-scale national level, we demonstrate that 1 h of lost sleep opportunity, inflicted by the transition to Daylight Saving Time, reduces real-world altruistic helping through the act of donation giving, established through the analysis of over 3 million charitable donations. Therefore, inadequate sleep represents a significant influential force determining whether humans choose to help one another, observable across micro- and macroscopic levels of civilized interaction. The implications of this effect may be non-trivial when considering the essentiality of human helping in the maintenance of cooperative, civil society, combined with the reported decline in sufficient sleep in many first-world nations.
... For most individuals, the alignment to the new time takes up to seven days [29,34], although a few studies suggested some degree of individual variation [29], essentially due to chronotype [30] and latitude [35]. Whether there is a difference across ages on the ability to cope with the circadian disruption induced by DST has been less widely assessed [20], but it has been hypothesized that the changes in sleep architecture due to aging (increased sleep fragmentation and latency [34]) may cause a prolongation of the time required to adjust the circadian misalignment [36]. ...
... For most individuals, the alignment to the new time takes up to seven days [29,34], although a few studies suggested some degree of individual variation [29], essentially due to chronotype [30] and latitude [35]. Whether there is a difference across ages on the ability to cope with the circadian disruption induced by DST has been less widely assessed [20], but it has been hypothesized that the changes in sleep architecture due to aging (increased sleep fragmentation and latency [34]) may cause a prolongation of the time required to adjust the circadian misalignment [36]. Although we did find a borderline significant 7% increase in AMI risk among the elderly, our findings did not support entirely such hypothesis, which requires confirmation. ...
... Despite the fact that about 1.6 billion people experience DST worldwide [30], with a mounting debate on its economic benefits [37], the available evidence on the health effect of the shifts in and out of DST is limited [11]: a few studies reported no effects of DST on the risk of stroke [36], manic episodes [38], suicide attempts [39] and spontaneous deliveries [40]. On the contrary, other publications reported an association between DTS shifts and several conditions including fatigue, headache, loss of attention and alertness, reduced motivation [34], traffic and workplace injures [33,41], missed medical appointments [42] and general mortality [11]. To the best of our knowledge, however, this is the first meta-analysis quantifying the potential effects of DST transitions on a severe, life-threatening condition such as AMI and the present estimates are the only currently available to quantify the overall cardiovascular burden following the shifts. ...
Background:
The available evidence on the effects of daylight saving time (DST) transitions on major cardiovascular diseases is limited and conflicting. We carried out the first meta-analysis aimed at evaluating the risk of acute myocardial infarction (AMI) following DST transitions.
Methods:
We searched cohort or case-control studies evaluating the incidence of AMI, among adults (≥18 y), during the weeks following spring and/or autumn DST shifts, versus control periods. The search was made in MedLine and Scopus, up to 31 December 2018, with no language restriction. A summary odds ratio of AMI was computed after: (1) spring, (2) autumn or (3) both transitions considered together. Meta-analyses were also stratified by gender and age. Data were combined using a generic inverse-variance approach.
Results:
Seven studies (>115,000 subjects) were included in the analyses. A significantly higher risk of AMI (Odds Ratio: 1.03; 95% CI: 1.01⁻1.06) was observed during the two weeks following spring or autumn DST transitions. However, although AMI risk increased significantly after the spring shift (OR: 1.05; 1.02⁻1.07), the incidence of AMI during the week after winter DST transition was comparable with control periods (OR 1.01; 0.98⁻1.04). No substantial differences were observed when the analyses were stratified by age or gender.
Conclusion:
The risk of AMI increases modestly but significantly after DST transitions, supporting the proposal of DST shifts discontinuation. Additional studies that fully adjust for potential confounders are required to confirm the present findings.
... The spring transition -when clocks are shifted forward-charges with the burden of the proof because the advance in the phase of human social rhythms is accompanied by a sleep deprivation which, eventually, may give rise to the increase in the incidence of acute diseases and accidents. (Harrison, 2013;Meira e Cruz et al., 2019) DST transitions set a natural experiment in which every individual participates. Yet when it comes to a research study that assesses the correlation between transition dates and societal issues, things are further limited: it is only one health or one societal issue that is analyzed in a limited region -a country, some region, or some hospital-and during a limited period of time -one year, a few years, one or two decades. ...
... We analyze a set of thirteen well-known research studies that associated the incidence of acute myocardial infarction, ischemic strokes or traffic accidents with DST transition dates. Many of them were retrieved from review reports (Harrison, 2013;Manfredini et al., 2018). They are frequently cited in review literature to support the discontinuity of DST practice (Roenneberg et al., 2019;Watson, 2019). ...
The assessment of the acute impact of daylight saving time (DST) transitions is a question of great interest for an understanding of the benefits and inconveniences of a practice that is now under public scrutiny in Europe and America. Here, we report a thorough analysis of a record of 13 well-known research studies that reported increased risks associated with DST transitions in health issues - acute myocardial infarction, ischemic strokes and trauma admissions - and in societal issues - accidents, traffic accidents and fatal motor vehicle accidents. We found that five increase of the risks suffices to understand the reported increased risks associated with the spring transition. Reported values above this threshold are impacted by the sample size of the study. In the case of the autumn transition, no increase in the risks is found.
... Using electronic monitors to precisely measure hours of sleep for 40 high school students, Medina et al. (2015) find that teens lose approximately 32 min of sleep a night. The effect of this loss can be felt between two and 14 days (Barnes & Wagner, 2009;Harrison, 2013;Medina et al., 2015). Therefore, the Spring transition causes observers to enjoy more exposure to sun but discretely lose between 32 and 40 min of sleep and cumulatively lose up to two hours and 42 min of sleep in the weeks following the transition. ...
... In the Fall, clocks move backward an hour at 2:00a.m., which increases the total number of hours in the day to 25. While it's possible the extra hour would cause people to sleep more, there is little evidence that they do (Barnes & Wagner, 2009;Harrison, 2013). Therefore, the cumulative impact of the Fall transition is solely a loss in sun exposure. ...
This paper estimates the impact of Daylight Saving Time (DST) on deaths from suicide and substance abuse in the United States. Using Multiple Cause‐of‐Death Mortality Data from the National Vital Statistics System of the National Center for Health Statistics from 1979 to 1988, the effect is identified in two ways: a regression discontinuity design that exploits discrete time changes in the Spring and Fall; and a fixed effects model that uses a policy change and a switching mechanism that introduces random variation to DST's start and end dates. This is one of the first attempts to estimate the impact of DST on deaths due to suicide and substance abuse and the first to use either identification strategy. The results from both methods suggest that the sleep disruptions during the Spring transition cause the suicide rate to rise by 6.25 percent and the death rate from suicide and substance abuse combined to increase by 6.59 percent directly after the time change. There is no evidence for any change in these outcomes during the Fall transition. The contrasting results from Spring to Fall suggest the entire effect can be attributed to disruptions in sleep patterns rather than changes in ambient light exposure.
... The spring transition -when clocks are shifted forward-charges with the burden of the proof because the advance in the phase of human social rhythms is accompanied by a sleep deprivation which, eventually, may give rise to the increase in the incidence of acute diseases and accidents. [2,3] DST transitions set a natural experiment in which every individual participates. Yet when it comes to a research study that assesses the correlation between transition dates and societal issues, things are further limited: it is only one health or one societal issue that is analyzed in a limited region -a country, some region, or some hospital-and during a limited period of time -one year, a few years, one or two decades. ...
... We analyze a set of thirteen well-known research studies that associated the incidence of acute myocardial infarction, ischemic strokes or traffic accidents with DST transition dates. Many of them were retrieved from review reports [2,5]. They are frequently cited in review literature to support the discontinuity of DST practice [6,7]. ...
The assessment of the acute impact of Daylight Saving Time (DST) transitions is a question of great interest for an understanding of the benefits and inconveniences of a practice that is now under public scrutiny in Europe and America.
Here we report a thorough analysis of a record of twelve well-known research studies that reported increased risks associated with DST transitions in health issues —acute myocardial infarction, ischemic strokes— and in societal issues —accidents, traffic accidents and fatal motor vehicle accidents—.
We found that a 5 % increase of the risks suffices to understand the reported increased risks associated with the spring transition. Reported values above this threshold are impacted by the sample size of the study.
In the case of the autumn transition, no increase of the risks is found.
... The 1-h clock-shift relative to diel circadian rhythm sleeping patterns can disrupt sleep and have transient health effects, lasting up to five days (Lahti et al., 2010;Varughese and Allen, 2001). One consequence of sleep disruption is fatigue; people report feeling sleepy after a clock-shift (Harrison, 2013). Disruption to the sleeping cycle can reduce motivation, attention, and alertness, which may lead to an increase in automobile accident rates (Harrison, 2013;Hicks et al., 1983;Lahti et al., 2010;Robb and Barnes, 2018). ...
... One consequence of sleep disruption is fatigue; people report feeling sleepy after a clock-shift (Harrison, 2013). Disruption to the sleeping cycle can reduce motivation, attention, and alertness, which may lead to an increase in automobile accident rates (Harrison, 2013;Hicks et al., 1983;Lahti et al., 2010;Robb and Barnes, 2018). DST associated increases in vehicle accidents have been documented in a number of countries (Carey and Sarma, 2017;Fritz et al., 2020;Prats-Uribe et al., 2018). ...
To devise effective measures for reducing hazardous wildlife-vehicle collisions, it is necessary to know when during the year accidents occur most frequently, and what factors cause the seasonal patterns. Daylight Saving Time (DST) 1-h clock-shifts around the spring and fall equinoxes at temperate zone latitudes are associated with increased vehicle accidents, attributed to driver error caused by disrupted sleep patterns and changes in visibility during peak driving times. Collision with deer is a significant cause of motor vehicle accidents in North America; in New York State alone, 65,000 vehicle accidents annually are caused by collision with white-tailed deer (Odocoileus virginianus). We asked whether white-tailed deer-vehicle collisions (DVC) increased in frequency after DST clock shifts in New York State, by analyzing 35,167 New York State DVC reports from 2005 to 2007. For the spring, when the clock is shifted an hour forward relative to sunrise (i.e. later sunrise and sunset), there was either no change or possibly a small decrease in workweek evening DVC after the clock shift. For fall, when the clock is shifted an hour back relative to sunrise (i.e. earlier sunrise and sunset), the DVC rate was far higher than spring. The DVC rate was higher after the clock shift than before, caused in part by an ongoing seasonal trend for increasing DVC associated with deer behavior around the time of rut, peaking about two weeks after the clock shift. However, there was also a reduction in workweek morning DVC after clock-shift, but an even greater increase in DVC in the evening. DVC rates are highest around dusk and during the fall, and the fall DST clock-shift caused more workweek commuter traffic to coincide with the annual hourly period of peak risk of DVC. We conclude that in New York State, DST clock-shift results in an increase in the number of DVC, and therefore injuries and property damage associated with such accidents. The justification for DST clock-shifts is controversial; when evaluating the benefits and costs, one should include the consequences for risk of wildlife-vehicle collisions, especially in regions where ungulate-vehicle accidents are frequent, and clock-shifts coincide with the rut or other periods of peak accident risk.
... The switching of clocks due to seasonal time changes (daylight savings/standard time) could potentially have affected our results. However, we excluded data for the week following daylightsaving time adjustments [102][103][104][105] . We also note that work schedules would also have adjusted with the time changes. ...
... We excluded data entries from days where participants were detected to be away from home (see travel calculations above). We also excluded the five weekdays after each daylight savings time (DST) change in our data period (March 11, 2018, November 4, 2018, and March 10, 2019), as DST changes have been shown to generally affect sleep patterns up to a week after the change [102][103][104][105] . To account for missing actigraphy data (e.g., dead battery, device not worn) and to ensure adequate data for each participant in each season, we excluded participants who had data for <50% of weekdays during any of the four seasons (i.e., at least 33 weekdays per season). ...
Previous studies of seasonal effects on sleep have yielded unclear results, likely due to methodological differences and limitations in data size and/or quality. We measured the sleep habits of 216 individuals across the U.S. over four seasons for slightly over a year using objective, continuous, and unobtrusive measures of sleep and local weather. In addition, we controlled for demographics and trait-like constructs previously identified to correlate with sleep behavior. We investigated seasonal and weather effects of sleep duration, bedtime, and wake time. We found several small but statistically significant effects of seasonal and weather effects on sleep patterns. We observe the strongest seasonal effects for wake time and sleep duration, especially during the spring season: wake times are earlier, and sleep duration decreases (compared to the reference season winter). Sleep duration also modestly decreases when day lengths get longer (between the winter and summer solstice). Bedtimes and wake times tend to be slightly later as outdoor temperature increases.
... Figure 1 visualizes this effect by showing how DST impacts the amount of evening light on the Sunday that DST begins (ends) in the spring (fall) compared the same Sunday one week before and after. 10 Studies of DST have often focused on public safety, measured primarily through fatal vehicle accidents (Ferguson et al. 1995;Varughese and Allen 2001;Sullivan and Flannagan 2002;Coate and Markowitz 2004;Stevens Jr and Lord 2006;Sood and Ghosh 2007;Huang and Levinson 2010;Harrison 2013;Smith 2016). Other studies have examined daylight saving time's effect on the stock market (Kamstra, Kramer, and Levi 2000;Berument, Dogan, and Onar 2010;Gregory-Allen, Jacobsen, and Marquering 2010), SAT scores (Gaski and Sagarin 2011), elementary school test scores (Herber, Quis, and Heineck 2017), life satisfaction (Kountouris and Remoundou 2014), mental health disorders (Heboyan, Stevens, and McCall 2018), workplace accidents (Holland and Hinze 2000;Robb and Barnes 2018), and heart attacks (Manfredini et al. 2018). ...
... 15 As DST adds an hour to the day during spring and removes it during fall, it is hypothesized to reduce sleep by an hour in spring and increase sleep by an hour in fall. Studies that examine this empirically find that the shift to DST during spring reduces sleep by approximately 30-40 minutes with sleep patterns returning to normal by the sixth day after the change (Monk and Folkard 1976;Kantermann et al. 2007; Barnes and Wagner 2009;Harrison 2013;Sexton and Beatty 2014). The effect of the end of DST in fall is unclear with studies finding either a small effect size or no effect on sleep. ...
Changing the physical design of an area has been long understood to be an effective way to change people's behavior. Within the field of criminology, Crime Prevention Through Environmental Design (CPTED) is an approach that alters the physical environment to decrease opportunities for crime. This dissertation examines two common tools used to reduce opportunities for crime: door locks and outdoor lighting. Though these tools are ubiquitously used, there are limitations in the current research on what effect these tools have on crime. This dissertation uses three papers to extend the CPTED literature by filling in some of these gaps in knowledge. The first paper assesses the effect of installing smart locks on the exterior doors of campus buildings on a major urban university campus. Results show that there is no significant change in the number of crimes per month on buildings that install these locks relative to a comparison group. The second paper measures how the number of outdoor, nighttime crimes change as the amount of moonlight - a relatively dim source of light - changes. Results show that nights with more moonlight have more crime, a finding in contrast to much of the literature on lighting. This suggests that the effects of lighting are non-linear - that a small increase of lighting may increase crime while significant increases in lighting decrease crime. The final paper evaluates one possible mechanism for the bulk of the lighting literature's finding that lighting decreases crime: that more light increases the risk of detection. This study uses the change in evening lighting when the United States transitions to (from) daylight saving time in spring (fall) which causes the evening the gain (lose) an hour of daylight. Results show that when evenings are brighter, the odds of an arrest for violent crimes - and for robbery in particular - significantly increase. Together, these studies advance the field of criminology by providing evidence on the effectiveness of two widely utilized crime control tools - door locks and outdoor lighting - to affect criminal behavior. This contribution can assist both researchers in the CPTED field as well as policy makers who must decide whether - and in which situations - to use door locks or outdoor lighting as crime control measures.
... Changes in clock time driven by energy policy influence behavior by upsetting patterns of time distribution. Entering DST in Spring costs on average between 40 min and 60 min of sleep and leads to medium term disruption of sleep patterns that can last for up to 2 weeks 1 [4,21,51]. DST-induced disruptions in sleep patterns affect circadian rhythms [21,34], increase accidents [4,52] and impact health [57]. Exploring whether a link exists between residential fire occurrence, DST and sleep can assist in designing fire safety policies and information campaigns especially as sleep deprivation is becoming increasing prevalent in contemporary societies [7,59]. ...
... Entering DST in Spring costs on average between 40 min and 60 min of sleep and leads to medium term disruption of sleep patterns that can last for up to 2 weeks 1 [4,21,51]. DST-induced disruptions in sleep patterns affect circadian rhythms [21,34], increase accidents [4,52] and impact health [57]. Exploring whether a link exists between residential fire occurrence, DST and sleep can assist in designing fire safety policies and information campaigns especially as sleep deprivation is becoming increasing prevalent in contemporary societies [7,59]. ...
Residential fires pose threats to living environments, generating costs to health and property. Understanding the roles of human behavior and social organization in determining fire occurrence is important for developing strategies to manage fire risk. This paper tests the impact of daylight saving time (DST) transitions on dwelling fire occurrence. DST transitions affect sleep patterns, impairing human cognitive and motor performance, potentially influencing the incidence of dwelling fires. Employing a regression discontinuity design with time as the running variable and using data from over 260,000 primary dwelling fires that took place in the U.K. over 8 years we do not find evidence suggesting that DST transitions impact on dwelling fire occurrence. For both the start of DST and end of DST transitions, estimated effects is quantitatively small and statistically insignificant. Results suggest that disruptions in sleep patterns induced by DST are not a driver of dwelling fires in the U.K.
... The resulting desynchrony is increased by one hour for part of the year, when we transition to Daylight Saving Time (DST). The use of DST is currently under debate in Europe and has been associated with negative health effects, including sleep curtailment/disturbance [5], and also an increase in cardiovascular events [6]. Further, the DST period has been associated with an increase in attendances to the emergency room [7] and in the likelihood of occurrence of road traffic accidents, observed both in studies based on recorded accidents [8] and experiments with driving simulators [9]. ...
The human circadian timing system depends on the light/dark cycle as its main cue to synchronize with the environment, and thus with solar time. However, human activities depend also on social time, i.e. the set of time conventions and restrictions dictated by society, including Daylight Saving Time (DST), which adds an hour to any degree of desynchrony between social and solar time. Here, we used Google Trends as a data source to analyze diurnal variation, if any, and the daily peak in the relative search volume of 26 Google search queries in relation to the transitions to/from DST in Italy from 2015 to 2020. Our search queries of interest fell into three categories: sleep/health-related, medication and random non sleep/health-related. After initial rhythm and phase analysis, 11 words were selected to compare the average phase of the 15 days before and after the transition to/from DST. We observed an average phase advance after the transition to DST, and a phase delay after the transition to civil time, ranging from 25 to 60 minutes. Advances or delays shorter than 60 minutes, which were primarily observed in the sleep/health-related category, may suggest that search timing for these queries is at least partially driven by the endogenous circadian rhythm. Finally, a significant trend in phase anticipation over the years was observed for virtually all words. This is most likely related to an increase in age, and thus in earlier chronotypes, amongst Google users.
... In an analysis by Harrison et al., the results of studies were summarized, indicating that time changes affect the quality and duration of sleep, and these disturbances persist for about a week. Initially, the impact of these changes on the body was underestimated, but with an increasing number of analyses, behavioral disturbances, increased stress, and reduced concentration levels were observed, leading to a higher incidence of road accidents [22]. ...
Introduction:
Many factors related to the switch to summer/winter time interfere with biological rhythms.
Objectives:
This study aimed to analyze the impact of time change on clinical outcomes of patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI).
Patients and methods:
Electronic data of 874,031 patients with ACS who underwent invasive procedures were collected from the Polish National Register of Interventional Cardiology Procedures (ORPKI) between 2014 and 2021. We determined the number of patients undergoing PCI and periprocedural mortality during the day of spring or autumn time change and within the first 3 and 7 days after the time change.
Results:
We demonstrated the impact of time changes on the periprocedural mortality of ACS patients within 1 day and the period of 3 and 7 days from the time change. We observed that the occurrence of all ACS and NSTEMI on the first day was lower for both time changes and higher in the case of UA and spring time change. The autumn time change significantly reduced the occurrence of all types of ACS. A significant decrease in the number of invasive procedures was found after autumn transition in the period from the first day to 7 days for ACS, NSTEMI, and UA.
Conclusions:
The occurrence of ACS and the number of invasive procedures were lower for both changes over time. Autumn time change is associated with increased periprocedural mortality in ACS and a less frequent occurrence of UA and NSTEMI within 7 days.
... da manhã e 20 hrs da noite, sugerem que o efeito do sono para acidentes é zero durante o dia em função da incidência de luminosidade. Há indícios na literatura de que o efeito do sono na transição do horário de verão poderia durar até duas semanas (Valdez et al, 1997;Harrison, 2013). A fim de detectar estas evidências, foram estimadas as regressões para os dois primeiros dias, 6 primeiros dias e 10 primeiros dias do horário de verão (Tabela 13). ...
O horário de verão é uma política de redução do consumo de energia instituída no Brasil todos os anos a partir da segunda semana de outubro. O presente trabalho tem por objetivo avaliar os possíveis efeitos da política do horário de verão sobre os acidentes nas rodovias federais brasileiras. Os dados de ocorrência de acidentes da polícia rodoviária federal utilizados compreendem o período de 2007 a 2013, agregados por dia e hora para cada Estado brasileiro. Primeiramente foram apreciados os efeitos a curto prazo sobre o número de acidentes na transição de entrada do horário de verão nos estados que sofreram a intervenção, por meio do modelo de Regressão Descontinua. A transição para o horário de verão, aproximadamente os primeiros vinte e quatro dias, reduzem o risco de acidentes nas rodovias federais através da realocação de uma hora de luminosidade da manhã para a tarde. Logo após foi mensurada a duração do efeito da mesma política a longo prazoem todos os estados, por meio do modelo de Diferenças em Diferenças. Ambos os modelos revelaram que a aplicação da política do horário de verão apresentou evidências na redução sobre o número de acidentes nas rodovias federais brasileiras. A fim de complementar a análise, foram realizados testes de robustez que determinaram os efeitos de tendências anteriores, Estados com maior risco de acidentes, decomposição em horas de luminosidade e período final do horário de verão. Os resultados apontaram que os Estados em que a política do horário de verão foi utilizada os acidentes sofreram redução de 10% (dez por cento).
... Time of awakening is additionally correlated with sunrise and tends to be later in the winter [22]. Establishing year-round DST could therefore result in population-level sleep disruption and fatigue, particularly during winter months [4,6,22,23]. ...
Background: Permanent Daylight Savings Time (DST) may improve road safety by providing more daylight in the evening but could merely shift risk to morning commutes or increase risk due to fatigue and circadian misalignment. Methods: To identify how potential daylight exposure and fatigue risk could differ between permanent DST versus permanent Standard Time (ST) or current time arrangements (CTA), generic work and school schedules in five United States cities were modeled in SAFTE-FAST biomathematical modeling software. Commute data were categorized by morning (0700-0900) and evening (1600-1800) rush hours. Results: Percent darkness was greater under DST compared to ST for the total waking day (t=2.59, p=0.03) and sleep periods (t=2.46, p=0.045). Waketimes occurred before sunrise 63%±41% percent of the time under DST compared to CTA (42%±37%) or ST (33%±38%; F(2, 74)=76.37; p<0.001). Percent darkness was greater during morning (16%±31%) and lower during evening rush hour (0%±0%) in DST compare to either CTA (morning:7%±23%; evening:7%±14%) or ST (morning:7%±23%; evening:7%±15%). Discussion: Morning rush hour overlapped with students’ commutes and shift worker reverse commutes, which may increase traffic congestion and risk compared to evening rush hour. Switching to permanent DST may be more disruptive than either switching to ST or keeping CTA without noticeable benefit to fatigue or potential daylight exposure.
... Various applications have been implemented since this date. From the early 1900s, worldwide applications were expanded for maximum savings from the DST [1,2]. A paper titled 'The Waste of Daylight' by William Willett, a businessperson and builder in the UK, suggested the plan in earnest in 1907 and Germany became the first country to adopt the DST transition to protect its resources such as food, medicine and ammunition during the First World War [3,4]. ...
Objectives. Turkey canceled the Daylight Saving Time (DST) transition and started the permanent clock application. Considering the effect of this new regulation on working hours, it has been examined whether there is a relationship with the increase in the number of work accidents in shifts. Methods. Data on work accidents was obtained from the Republic of Turkey Social Security Institution (SSI) filed between 2011 and 2020. We estimate accident rates with using Poisson regression and log-linear models as a function of a variety of date-based factors. Results. The results show that DST transition is effective (ineffective in terms of gender) on changes in the number of work accidents. With statistical analyzes, the hour distribution of work accidents was made and calculated, indicating at which hour the work accidents occurred the most, using the work accident frequency rate. The number of prevented work accidents was calculated 286,793 and how Turkey would be affected. Conclusion. The findings from these studies suggest that the cancellation of DST transition does not have a negative effect on the incidence of work accidents in Turkey, on the contrary, this practice also serves the purpose of preventing work accidents.
... Therefore, generally stating that 1 week or 5 days is needed for readjustments is somehow misleading. 30 This study included office workers subjected to regular work hours and work and family responsibilities. These settings have a substantial impact on sleep timing. ...
The relationship between everyday light exposure and sleep was studied for office workers. The study was conducted during the upswing of the COVID-19 pandemic, enabling a comparison between Office and Home Workdays. Fifteen full-time office employees were monitored for a period of 4–6 weeks. They wore a light-tracking device on their clothes and had a sleep tracker at home. Compared to an Office Workday, light exposure was lower in the afternoon and total sleep time was almost 5 minutes longer on a Home Workday. Sleep efficiency was the same on both workday types. A higher median illuminance level in the afternoon was significantly related to later sleep onset on an Office Workday. Higher median illuminance levels in the morning were related to earlier awakening. Counter to expectations, higher light levels in the evening were also related to earlier awakening. Everyday light exposure matters for sleep quality but may affect circadian functioning differently than the often more extreme light interventions employed in laboratory experiments. Moreover, differences in outcomes between Office and Home Workdays signal the need for further investigation to provide supportive light levels during workhours.
... Furthermore, it is assumed that the switch back to standard time in the fall (with the possible addition of one hour of sleep) would either have no effect on the risk of diseases, accidents and mortality or would be a protective factor 6,7,20,21,26,33 . After adjusting for temporal, meteorological, geographic, country-specific, and population variables, our findings point to a significant increase in mortality in the first and second week after the DST fall transition. ...
Daylight saving time (DST) consists in a one-hour advancement of legal time in spring offset by a backward transition of the same magnitude in fall. It creates a minimal circadian misalignment that could disrupt sleep and homoeostasis in susceptible individuals and lead to an increased incidence of pathologies and accidents during the weeks immediately following both transitions. How this shift affects mortality dynamics on a large population scale remains, however, unknown. This study examines the impact of DST on all-cause mortality in 16 European countries for the period 1998-2012. It shows that mortality decreases in spring and increases in fall during the first two weeks following each DST transition. Moreover, the alignment of time data around DST transition dates revealed a septadian mortality pattern (lowest on Sundays, highest on Mondays) that persists all-year round, irrespective of seasonal variations, in men and women aged above 40. How daylight saving time shift (DST) affects mortality dynamics on a large population scale remains unknown. Here, the authors examine the impact of DST on all-cause mortality in 16 European countries for the period 1998-2012.
... On the other hand, in recent decades, the detrimental effects of DST on health have been investigated [5,17]. In this sense, several studies found a relationship between DST and ST transitions and cardiovascular events, although with moderate effects [18][19][20][21]. ...
Several studies have investigated the relationship between daylight saving time (DST) and sleep alterations, psychiatric disorders, cardiovascular events and traffic accidents. However, very few have monitored participants while maintaining their usual lifestyle before and after DST. Considering that DST transitions modify human behavior and, therefore, people’s light exposure patterns, the aim of this study was to investigate the potential effects of DST on circadian variables, considering sleep and, for the first time, the human phase response curve to light. To accomplish this, eight healthy adults (33 ± 11 years old, mean ± SD) were recruited to monitor multivariable circadian markers and light exposure by means of a wearable ambulatory monitoring device: Kronowise®. The following night phase markers were calculated: midpoints of the five consecutive hours of maximum wrist temperature (TM5) and the five consecutive hours of minimum time in movement (TL5), sleep onset and offset, as well as sleep duration and light intensity. TM5 for wrist temperature was set as circadian time 0 h, and the balance between advances and delays considering the phase response curve to light was calculated individually before and after both DST transitions. To assess internal desynchronization, the possible shift in TM5 for wrist temperature and TL5 for time in movement were compared. Our results indicate that the transition to DST seems to force the circadian system to produce a phase advance to adapt to the new time. However, the synchronizing signals provided by natural and personal light exposure are not in line with such an advance, which results in internal desynchronization and the need for longer synchronization times. On the contrary, the transition back to ST, which implies a phase delay, is characterized by a faster adaptation and maintenance of internal synchronization, despite the fact that exposure to natural light would favor a phase advance. Considering the pilot nature of this study, further research is needed with higher sample sizes.
... Furthermore, this study did not assess the prevalence of respondents who tested positive for COVID-19 in the general population. Moreover, during the lockdown, the respondents experienced the spring daylight-saving time transition, which is followed by an increase in sleep latency and sleep fragmentation (45). Still, we believe that the clock change impact was not as long-lasting and strong as the impact of the lockdown itself. ...
Aim:
To investigate the effects of the coronavirus disease 2019 (COVID-19) lockdown on sleep habits in the Croatian general population.
Methods:
In this cross-sectional study, 1173 respondents from the general population (809 women) completed a self-report online questionnaire that gathered demographic data and data on sleep habits and mood changes before and during the COVID-19 lockdown.
Results:
During the lockdown, bedtime (from 23:11±1:07 to 23:49±1:32 h, P<0.001) and waketime were delayed (from 6:51±1:09 to 7:49±1:40 h, P<0.001). Sleep latency increased from 10 (5-20) to 15 (10-30) minutes (P<0.001). Bedtime and waketime delays were more pronounced in women and respondents younger than 30. Compared with other age groups, respondents younger than 30 more frequently reported insomnia for the first time during the lockdown and had less frequent night-time awakenings (P<0.001), less common problems falling asleep (P<0.001), less frequently felt calm (P<0.001) and rested (P<0.001), but more frequently felt sadness (P<0.001) and fear (P=0.028).
Conclusion:
The effect of the lockdown on sleep needs to be better understood. Sleep hygiene education could serve a first-line lifestyle intervention for people in lockdown experiencing sleep disruption.
... While the usefulness of ML-based techniques has been demonstrated in diverse indoor environment applications, particularly in indoor air quality [20][21][22] and energy consumption [23][24][25], their application in indoor daylight modelling has not been extensively reviewed and evaluated. Moreover, while there are numerous review studies regarding various aspects of daylighting in indoor spaces such as about daylighting strategies in various types of buildings [2,[26][27][28][29], daylighting fundamentals and design strategies [30][31][32][33][34], daylighting and visual comfort assessment tools [35][36][37][38], the impact of daylighting on humans [39][40][41][42][43][44], daylighting control strategies [45][46][47][48], the chronological development of daylighting strategies [49][50][51] etc., the application of ML methodologies to daylight design and control has not been substantially reviewed. To the best of the authors' knowledge, only a recent single study [52] provides a comprehensive review on ML approaches in daylighting studies. ...
Proper use of daylighting improves visual and thermal comfort in indoor environments and minimizes dependency on artificial lighting, saving substantial amounts of energy. Consequently, optimizing daylighting performance in the early stages of building design and during the operation stage of buildings is crucial if conducive and energy-efficient visual environments are desired. Machine learning (ML) techniques present advanced approaches for optimizing daylighting design and control. The present article comprehensively reviews the existing literature on ML methods to optimize daylighting performance both in the early design stages and during building operation. The literature analysis showed that most studies employed supervised learning methods with specific algorithms, particularly artificial neural networks (ANN). This highlighted the need for more advanced ML methods as potential alternatives to improved daylight modelling. Additionally, the generalization and scalability capabilities of the developed models were seldom discussed and are seen as the main reason for the lack of deployment of said models in actual buildings. We present potential solutions to the highlighted issues in the context of future research directions. Considering the increasing need for conducive indoor environments, the present review provides insights into the potential use of ML techniques to efficiently design and control indoor visual environments.
... Sleep may be considered a 'canary in the mine', as it is sensitive to both small and large environmental changes (Harrison, 2013;Kahn, Sheppes, & Sadeh, 2013). With the outbreak of COVID-19, experts warned of the potential negative impact this pandemic may have on sleep-particularly in childrenfor whom dramatic developmental changes impacting sleep are constantly occurring (Altena et al., 2020;Becker & Gregory, 2020). ...
Background:
With the outbreak of the COVID-19 pandemic, pediatric experts called attention to the potential adverse effects of living restrictions (e.g., lockdown) on child well-being, but at the same time- acknowledged their possible benefits. To date, only few data-driven reports have been published on child sleep during COVID-19, and all have been based on parent- or self-reports. This study used auto-videosomnography to capture the effects of COVID-19 stay-at-home orders imposed in the USA on objectively measured infant sleep.
Methods:
Auto-videosomnography metrics of infants assessed nightly between January and May 2020 were compared with metrics of an equivalent infant cohort, assessed in the corresponding 2019 period. A total of 610 infants (50.7% girls) aged 6-18 months (M = 11.8, SD = 3.6) were included, with 71,472 analyzed nights. Multilevel models were applied to assess differences between 2019 and 2020 infant sleep pre- and during-lockdown.
Results:
Whereas infant cohorts were equivalent in demographic and January-March/April sleep characteristics, during the 2020 lockdown infants had longer nighttime sleep durations (Mdifference = 11.0 min, p = .01), later morning rise times (Mdifference = 9.5 min, p = .008), and later out-of-crib times (Mdifference = 12.3 min, p < .0001), compared to the equivalent 2019 period. In addition, weekday-weekend differences in sleep onset and midpoint times were diminished during 2020 home-confinement compared to the equivalent 2019 period (2019: Mdifference = 5.5 min, p < .0001; Mdifference = 4.5 min, p < .0001; 2020: Mdifference = 2.3 min, p = .01; Mdifference = 3.1 min, p < .0001, respectively).
Conclusions:
Notwithstanding the negative implications of COVID-19 living restrictions in other domains, our findings indicate that there might be a silver lining-in promoting longer and more consistent infant sleep. These benefits should be considered in determining policy for the current and future pandemics.
... Although the transition to summer time seems to be more problematic than the transition to standard time, studies have also shown negative effects following the latter. For instance, studies suggest that the transition to standard time in the autumn may lead to more fragmented sleep and a net loss of sleep across the following week (Harrison 2013;Lahti et al. 2008). ...
Daylight Saving Time is highly debated and associated with several health risks. Health experts recommend terminating adjusting the clock time, and to keep permanent standard (winter) time year around. The aims of the study were to investigate preferences for keeping or terminating this biannual adjustment of clock times and for permanent standard or summer time, in the general Norwegian population. Furthermore, we aimed to investigate whether such preferences depended on individual chronotype and home address’ latitude/longitude. The online survey included 47,194 participants. Chronotype was measured with the Composite Scale of Morningness (morning types, intermediate types, evening types). Results showed that 78.2% preferred to terminate adjusting the clock time. Summer time year around was preferred by 61.5% whereas 29.1% preferred standard time year around, and 9.4% did not have any preference. Preferences for terminating adjustment of clock times and summer time year around were found in all chronotypes and regardless of living south (latitude 58–59°N), north (latitude 69–71°N), west (longitude 5–6°E) or east (longitude 19–31°E). However, a relatively larger proportion of evening chronotypes preferred to terminate adjusting the clock time compared to morning chronotypes, and relatively more people living north or east preferred termination than people living south or west, respectively. Permanent standard time was more strongly preferred by extreme morning types in comparison with the other chronotypes. In conclusion, nearly four out of five participants reported to prefer to terminate adjusting the clock time, in line with recommendations. However, in contrast to advice from health experts, permanent summer time was preferred by twice as many as permanent standard time. Both chronotype and home address’ latitude and longitude mattered in regard to such preferences, but only to a small degree.
... From this large follow-up sample, we included in the reported analyses only the 2,123 respondents (mean age ± standard deviation, 33.1 ± 11.6; range, 18-82; 401 men, see Table 1) who completed the first survey during the four days preceding the daylight-saving time (March 25-28, 2020; Survey wave 1). This allowed us to avoid interfering and confounding effects at the baseline measurement due to the summertime beginning (for a review, [43]). During the follow-up survey (Survey wave 2), participants completed the same questionnaires of Survey wave 1. ...
Study Objectives
During the coronavirus disease 2019 (COVID-19) lockdown, there was a worldwide increase in electronic devices’ daily usage. Prolonged exposure to backlit screens before sleep influences the circadian system leading to negative consequences on sleep health. We investigated the relationship between changes in evening screen exposure and the time course of sleep disturbances during the home confinement period due to COVID-19.
Methods
2,123 Italians (mean age ± standard deviation, 33.1 ± 11.6) were tested longitudinally during the third and the seventh week of lockdown. The web-based survey evaluated sleep quality and insomnia symptoms through the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. The second assessment survey inquired about intervening changes in backlit screen exposure in the two hours before falling asleep.
Results
Participants who increased electronic device usage showed decreased sleep quality, exacerbated insomnia symptoms, reduced sleep duration, prolonged sleep onset latency, and delayed bedtime and rising time. In this subgroup, the prevalence of poor sleepers and individuals reporting moderate/severe insomnia symptoms increased. Conversely, respondents reporting decreased screen exposure exhibited improved sleep quality and insomnia symptoms. In this subgroup, the prevalence of poor sleepers and moderate/severe insomniacs decreased. Respondents preserving screen time habits did not show variations of the sleep parameters.
Conclusions
Our investigation demonstrated a strong relationship between modifications of evening electronic device usage and time course of sleep disturbances during the lockdown period. Monitoring the potential impact of excessive evening exposure to backlit screens on sleep health is recommendable during the current period of restraining measures due to COVID-19.
... This ability is related to an individual circadian preference (chronotype) [11]. People with an extreme chronotype experience more profound effects of DST on sleep disruption and a potential adverse effect of this disruption on their health [12]. Studies on chronotype distribution around the globe report differences between countries, gender and age categories [13,14]. ...
Background
In multiple studies, the potential relationship between daylight saving time (DST) and the occurrence of acute myocardial infarction (MI) has been investigated, with mixed results. Using the Dutch Percutaneous Coronary Intervention (PCI) registry facilitated by the Netherlands Heart Registration, we investigated whether the transitions to and from DST interact with the incidence rate of PCI for acute MI.
Methods
We assessed changes in hospital admissions for patients with ST-elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) undergoing PCI between 1 January 2015 and 31 December 2018. We compared the incidence rate of PCI procedures during the first 3 or 7 days after the transition with that during a control period (2 weeks before transition plus second week after transition). Incidence rate ratio (IRR) was calculated using Poisson regression. Potential gender differences were also investigated.
Results
A total of 80,970 PCI procedures for STEMI or NSTEMI were performed. No difference in incidence rate a week after the transition to DST in spring was observed for STEMI (IRR 0.95, 95% confidence interval (CI) 0.87–1.03) or NSTEMI (IRR 1.04, 95% CI 0.96–1.12). After the transition from DST in autumn, the IRR was also comparable with the control period (STEMI: 1.03, 95% CI 0.95–1.12, and NSTEMI: 0.98, 95% CI 0.91–1.06). Observing the first 3 days after each transition yielded similar results. Gender-specific results were comparable.
Conclusion
Based on data from a large, nationwide registry, there was no correlation between the transition to or from DST and a change in the incidence rate of PCI for acute MI.
... https://doi.org/10.1101/2020.10.20.20215756 doi: medRxiv preprint allowed us to avoid interfering and confounding effects at the baseline measurement due to the summertime beginning (for a review, 41 ). During the follow-up survey (Time 2), participants completed the same questionnaires of Time 1. ...
Study Objectives: During the COVID-19 lockdown, there was a worldwide increase in electronic devices' daily usage. The exposure to backlit screens before falling asleep leads to negative consequences on sleep health through its influence on the circadian system. We investigated the relationship between the changes in evening screen exposure and the time course of sleep disturbances during the home confinement period due to COVID-19. Methods: 2123 Italians were longitudinally tested during the third and the seventh week of lockdown. The web-based survey evaluated sleep quality and insomnia symptoms through the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. During the second assessment, respondents reported the changes in the backlit screen exposure in the two hours before falling asleep.
Results: Participants who increased electronic device usage showed decreased sleep quality, exacerbated insomnia symptoms, reduced sleep duration, higher sleep onset latency, and delayed bedtime and rising time. In this subgroup, the prevalence of poor sleepers and clinical insomniacs increased. Conversely, respondents reporting decreased screen exposure exhibited improved sleep quality and insomnia symptoms. In this subgroup, the prevalence of poor sleepers and clinical insomniacs decreased. Respondents preserving their screen time habits did not show any change in the sleep parameters. Conclusions: Our investigation demonstrated a strong relationship between the modifications of the evening electronic device usage and the time course of sleep disturbances during the lockdown period. Interventions to raise public awareness about the risks of excessive exposure to backlit screens are necessary to prevent sleep disturbances and foster well-being during the home confinement due to COVID-19.
... Moving clocks forward following the spring forward results in a reduction in the total sleep time. 9,10 Among healthcare workers, this reduced total sleep and associated partial sleep deprivation resulting from the spring forward time change could potentially result in an increase in medical errors. [6][7][8] Additionally, with the change in time, healthcare workers report to and commence work at a start time that is earlier than usual while likely still experiencing cognitive impairment secondary to sleep inertia. ...
Background“Spring forward,” the start of daylight savings time (DST), reduces sleep opportunity by an hour. Insufficient sleep in healthcare workers resulting from the spring forward time change could potentially result in an increase in medical errors.Objective
We examined the change in reported patient safety-related incidents (SRIs), in the week following the transition into and out of DST over a period of 8 years.DesignObservational studySettingA US-based large healthcare organization with sites across multiple statesMeasurementsVoluntarily reported SRIs that occurred 7 days prior to and following the spring and fall time changes for years 2010–2017 were ascertained. SRIs likely resulting from human error were identified separately. The changes in the number of SRIs (either all SRIs or SRIs restricted to those likely resulting from human error) from the week before and after the time change (either spring or fall) were modeled using a negative binomial mixed model with a random effect to correct for non-independent observations in consecutive weeks.ResultsOver the 8-year period, we observed 4.2% (95% CI: − 1.1 to 9.7%; p = 0.12) and 8.8% (95% CI: − 2.5 to 21.5%; p = 0.13) increases in overall SRIs in the 7 days following DST when compared with 7 days prior for spring and fall, respectively. By restricting to SRIs likely resulting from human errors, we observed 18.7% (95% CI: 5.6 to 33.6%; p = 0.004) and 4.9% (95% CI: − 1.3 to 11.5%; p = 0.12) increases for spring and fall, respectively.Conclusion
Policy makers and healthcare organizations should evaluate delayed start of shifts or other contingency measures to mitigate the increased risk of SRIs during transition to DST in spring.
... Chronotype, which refers to the individual preference regarding daily activity patterns and sleep wake cycles differ with regards to their sleeping behavior, personality, mental health, smoking and dietary habits, school achievements, and so on [23]. Individuals with late chronotype more frequently show increased vulnerability to psychological distress [24] and sleep-related issues, e.g., later bedtime and wake-up, decreased sleep quality and quantity, more pronounced metabolic risk, reduced physical activity, and unhealthy dietary patterns, including also smoking and drinking habits [25,26], Moreover, late chronotype seem to have more problems in adjusting to the spring shift of DST [27]. ...
From early on the European Union has kept the existence of Daylight Savings Time, but a recent public inquiry in the EU countries led the European Commission and Parliament to approve the ending of DST in 2021, despite the very statistically biased result. However, there are still a significant amount of uncertainty related to the actual impact of DST on health both in general public and in the clinical and scientific community. With this in mind, an international group of specialists joined together in August 2018 with the aims of: 1) to reflect, analyze and clarify on the literature regarding the numerous effects potentially attributed to DST-induced circadian misalignment; 2) to define whether adherence to DST should be considered a dangerous rather risky behavior in terms of health and wellbeing.
... reporting beneficial effects [12,13]. Studies observing a risk increase after DST transition generally concluded that circadian misalignment and sleep loss due to DST were responsible for their findings [5,6,[14][15][16][17]. In instances of decreased risk, the beneficial effects were attributed to allowing the afternoon rush hour to take place in better illumination [12,13], and thus better visibility. ...
There is evidence that the spring Daylight Saving Time (DST) transition acutely increases motor vehicle accident (MVA) risk ("DST effect"), which has been partly attributed to sleep deprivation and circadian misalignment [1-6]. Because spring DST also shifts clock time 1 h later, mornings are darker and evenings brighter, changing illumination conditions for peak traffic density. This daytime-dependent illumination change ("time of day effect") is hypothesized to result in DST-associated afternoon and evening accident risk reductions [2, 5, 7]. Furthermore, sunrise and local photoperiod timing depend on position in time zone. The sun rises at an earlier clock time in the eastern regions of a given time zone than in the western regions, which is thought to induce higher levels of circadian misalignment in the west than in the east ("time zone effect") [8, 9]. This study evaluated the acute consequences of the DST transition on MVAs in a chronobiological context, quantifying DST, time of day, and time zone effects. We used large US registry data, including 732,835 fatal MVAs recorded across all states (1996-2017), and observed that spring DST significantly increased fatal MVA risk by 6%, which was more pronounced in the morning and in locations further west within a time zone. DST-associated MVA risk increased even in the afternoon hours, despite longer daylight hours. The MVA risk increase waned in the week subsequent to DST, and there were no effects of the fall-back transition to Standard Time (ST) on MVA risk, further supporting the hypothesis that DST-transition-associated, preventable circadian misalignment and sleep deprivation might underlie MVA risk increases.
This paper examines the impact of daylight saving time (DST) on fatal road crashes in Australia. I exploit within year transitions to and from DST in a regression discontinuity in time framework. To examine the long run effect of the policy, I use trials of DST implemented in various states, and a DST extension due to the Sydney Olympics. Neither the transition to or out of DST, nor the long run effects of DST have an impact on fatalities on the road. However, there is evidence of reallocation of accidents over the day due to ambient light.
Social constraints posed by work schedules influence sleep duration and timing. Everyday light exposure can help (or hinder) sleep outcomes. This study investigated the differences in the relationship between light exposure and sleep outcomes on days with and without social constraints using ambulatory assessment for 4–6 weeks for 15 office employees. The effects of light on sleep were investigated for both clock time and wake time (related to individual sleep times). Participants were exposed to more light during the morning and afternoon on workdays, and sleep times were later on days without social constraints. The relationship between light exposure and sleep was more pronounced, or sometimes even only present, for days without social constraints. In addition, no differences were found between clock time and wake time, which underlines the complexity of the relationship between everyday light exposure and sleep. Despite increased light exposure during workdays, the effects of light on sleep were more pronounced on days without social constraints. It may signal that office workers need a more substantial circadian stimulus (i.e. higher light exposure) for light to influence sleep outcomes on days with social constraints.
The objective of this study was to examine the effect of transitions between daylight saving time (DST) and standard time (ST) on traffic crashes in Florida. The study was conducted using 37 years of crash data from Florida from 1983 to 2019. The analysis was based on crashes that occurred during the week before and the week following the time change. The paired Wilcoxon rank test implemented using a Bayesian approach was used to compare the difference in crash frequency following the clock shift to DST. The analysis showed that the time shift has a significant effect on traffic crashes. More specifically, the beginning of DST in the spring, when the clock moves forward by one hour, was associated with a higher frequency of fatal and nighttime crashes. The shift at the end of DST in the fall, when the clock moves back by one hour, resulted in a significant increase in all, no injury, morning peak hours, afternoon off-peak hours, two-vehicle, and multiple-vehicle crashes. Crashes during evening peak hours decreased in the week immediately following the time change. These findings were particularly significant on the Sunday when the shift occurred and the following Monday and Tuesday. It can be inferred from these findings that the impact of DST on safety may be attributed to the disruption of circadian rhythms as well as to the one-hour loss in the spring and one-hour gain in the fall. The study findings could assist researchers and practitioners in understanding the impacts of DST on roadway safety.
Daylight-Saving Time (DST) was introduced in Bulgaria on April 1st, 1979. Since 1997, DST begins at 3 a.m. on the last Sunday in March and lasts until 3 a.m. on the last Sunday in October. In 1999, daylight saving time began at 3 a.m. on the last Sunday in March and lasted until 4 a.m. on the last Sunday in October. The original idea of daylight-saving time was focused on saving electricity and using the light part of the day, but as a more serious argument at the moment is the impact of time change on the health of citizens, MEPs decided to stop this practice in 2021 [1]
The paper presents data from an Electronic Health Record system (EHR), developed for Central Emergency Help Services in Sofia Municipality, which stores each emergency call on the territory of the district, and for the purposes of the study data were studied and processed as follows: number of emergency calls 1 week before the time change, the week after the time change and one additional week for a two-year period of the system‘s operation. The results showed an increase of the number of emergency calls on all the days of the first week with a peak on the first and last working days and a decrease in the second week regardless of the season. The results support the decision to cancel the time change due to the fact that it affects the health status of people negatively.
Advancing clock times by 1 h in the spring to daylight savings time and setting clock times back 1 h in the autumn to standard time disrupts circadian timing, sleep and skilled motor behavior such as driving an automobile. It is unknown if endurance performance is impacted by daylight savings transition (DST). The natural experiment described here examined whether exposure to a DST in the 10 h prior to the start of a marathon race was associated with a different mean completion time compared to participants who ran the same course but were unexposed to a recent DST. The primary outcome was the average running time of finishers of United States marathons that were completed on either spring-DST or autumn-DST days in the years 2000-2018. Comparisons were made to results from the same marathon held in a different year that was not run on a DST day. Data were obtained from the public data base marathonguide.com/results. Analysis of the primary outcome used paired samples t-tests weighted by sample size. Spring and autumn data were analyzed separately. Eighteen spring and 29 autumn marathons met the inclusion criteria. Compared to control marathons, the weighted spring-DST performance was worse by 12.3 min (4.1%; P < .001) and equal to a moderate standardized effect size of 0.57 while autumn-DST was trivially worse by 1.4 min (0.5%), which was equivalent to an effect size of 0.13. Ambient temperatures for the DST and control races did not differ for either the spring (10.6 vs. 8.9℃; P = .212) or autumn marathons (7.6 vs. 9.3℃; P = .131). Within the limitations of a natural experiment research design, it is concluded that the findings support worse running performance in marathon races held in the spring on the day of transition to daylight savings time when there is a forced circadian change and sleep loss.
Background/Aim
Permanent daylight saving time has been implemented in Turkey since 2016. The present study determines the characteristics of road traffic collisions in the short term, trauma severity, and whether permanent daylight saving time has an impact on these parameters.
Materials and Methods
Drivers admitted due to road traffic collisions to a tertiary care university hospital emergency service two weeks before and after the transition to wintertime in 2014 and 2015 and summertime in 2015 and 2016 as well as those admitted two weeks before and after the same period with permanent daylight saving time in 2016 and 2017 wintertime and 2017 and 2018 summertime were included in the study. Trauma severity was measured using the Injury Severity Score.
Results
The study analyzed the data of 710 patients. There was no statistically significant difference was found between admissions in summertime and permanent daylight saving time periods in terms of gender, time of admission, week of admission, Injury Severity Score, and outcome (p > 0.05 for all values).
Conclusions
In this study, we examined the short-term effects of daylight saving time on road traffic collisions, and demonstrated that it had no impact on the number or time of admission, trauma severity, and patient outcomes. More comprehensive studies covering longer periods can be performed across the country.
The original rationale for the adoption of daylight saving time (DST) was to conserve energy; however, the effects of DST on energy consumption are questionable or negligible. Conversely, there is substantial evidence that DST transitions have the cumulative effect on sleep deprivation with its adverse health effects. In light of current evidence, the European Commission in 2018 decided that biannual clock change in Europe would be abolished. Current indirect evidence supports the adoption of perennial standard time, which aligns best with the human circadian system and has the potential to produce benefits for public health and safety.
Children increase time demands with important consequences for sleep. Here, we test whether parents’ paid and unpaid time demands and the presence of young children equally reduce mothers’ and fathers’ sleep, comparing the married/cohabiting to unmarried. Applying data from the American Time Use Survey (ATUS, 2003–2016), we find married/cohabiting mothers report less sleep when young children or multiple children are present; they are employed; their spouses are employed; and they spend more time in housework and childcare. By contrast, unmarried mothers report less sleep when children are present because of their larger domestic loads. For married/cohabiting fathers, the presence of multiple children is associated with less sleep but doing more housework results in more sleep. Finally, unmarried fathers’ employment time explains the association of children on their sleep. Parents report a sleep deficit relative to the childless but the reasons vary by gender and the co-presence of a partner.
Previous research on the effects of daylight saving time (DST) on electricity consumption has provided mixed results. We use daily state-level panel data on electricity consumption in Australia between 1998 and 2015, during which period there was considerable variation in the presence and timing of DST implementation, as well as in weather conditions and cooling usage within and between states. This provides us with a unique opportunity to study the interaction effects of DST with exogenous variation in daily weather conditions and cooling usage over two decades. Our results show that the effect of DST on electricity consumption depends strongly on weather conditions and cooling usage. Forward DST increases the electricity consumption when temperatures and air conditioner ownership are higher. We provide simulations for countries in the European Union that need to decide on DST adoption in the coming year. Our findings are policy-relevant given rising temperatures and worldwide increases in cooling usage during summer.
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In modern societies, human rest–activity rhythms and sleep result from the tensions and dynamics between the conflicting poles of external social time (e.g., work hours and leisure activities) and an individual’s internal biological time. A mismatch between the two has been suggested to induce ‘social jetlag’ [1] and ‘social sleep restriction’, that is, shifts in sleep timing and differences in sleep duration between work days and free days. Social jetlag [2,3] and sleep restrictions [4] have repeatedly been associated with negative consequences on health, mental wellbeing, and performance. In a large-scale quasi-experimental design, we investigated the effects of the phase with the most rigorous COVID-19 restrictions on the relationship between social and biological rhythms as well as sleep during a six-week period (mid-March until end of April 2020) in three European societies (Austria, Germany, Switzerland). We found that, on one hand, the restrictions reduced the mismatch between external (social) and internal (biological) sleep–wake timing, as indexed by significant reductions in social jetlag and social sleep restriction, with a concomitant increase in sleep duration. Sleep quality on the other hand was slightly reduced. The improved individual sleep–wake timing can presumably be attributed to an increased flexibility of social schedules, for instance due to more work being accomplished from home. However, this unprecedented situation also led to a significant increase in self-perceived burden, which was attendant to the decrease in sleep quality. These adverse effects may be alleviated by exposure to natural daylight as well as physical exercise.
Vetter et al. respond to Martín-Olalla's comment about their study linking motor vehicle fatalities to the transition to Daylight Saving Time.
Wildfires shape landscapes and ecosystems, affecting health and infrastructure. Understanding the complex interactions between social organization, human activity and the natural environment that drive wildfire occurrence is becoming increasingly important as changing global environmental conditions combined with the expanding human-wildland interface, are expected to increase wildfire frequency and severity. This paper examines the anthropogenic drivers of wildfire, and the relationship between the organization of human activity in time and wildfire occurrence focusing on the effects of transitions into and out of Daylight Saving Time (DST). DST transitions shift activity in relation to natural wildfire risk within a solar day, induce changes in the time allocated to wildfire-causing activities and disrupt sleep patterns. The paper estimates short and medium run effects of DST-induced changes in the temporal organization of human activity through a Regression Discontinuity Design with time as the running variable and Fixed Effects models, using data from over 1.88 million non-prescribed ignitions recorded in the contiguous US over 23 years. Estimates suggest that DST has a quantitatively and statistically significant immediate and medium-run effect on wildfire occurrence. Wildfire occurrence jumps by around 30% in the immediate aftermath of transitions into DST, adding about 98 human-caused wildfires across the contiguous US per year, while the transition's effect is detectable for 3 weeks. Transitions induce within-day temporal displacement of wildfires in a pattern compatible with the shifting of human activity mechanism, while the result cannot be attributed exclusively on disruptions in sleep patterns. Naturally arising lightning-strike wildfires do not respond to changes in civil time, while the results are robust to changes in assumptions. Results suggest that wildfire policy should account for the temporal organization of human activity.
Background
Twenty-five percent of the global population lives in one of the more than 70 countries that observe daylight saving time (DST). These people are exposed to 1 hour of time transition twice a year, influencing the circulatory system. We aimed to analyze the incidence of thrombolysis to treat acute ischemic stroke in relation to clock changes in Hungary over a 10-year period.
Methods
The number of thrombolytic treatments performed within the period between 2006 and 2015 was analyzed. Anonymized nationwide data on the dates and exact daily numbers of thrombolysis interventions were provided by the National Health Insurance Fund. We compared the mean number of thrombolytic treatments on the day before with that on the day after each transition, and also between the preceding and following one week and month.
Results
Our data including the last days of each month suggested a significant increase in thrombolysis numbers both in spring and in autumn on the day and the week after the clock change. However, when the last days of each month were excluded from analysis (as this in itself was associated with a 7-fold increase in stroke incidence in our earlier study), no significant difference in the number of thrombolysis treatments between the days and weeks before and after the clock change was detectable. The long-term, monthly analysis also did not reveal a significant difference.
Conclusions
Our findings reflect that psychosocial factors, such as the approach of the last day of the month override the intrinsic effect of disturbances of the circadian rhythm on stroke incidence.
Background:
Daylight saving time (DST) imposes a twice-yearly hour shift. The transitions to and from DST are associated with decreases in sleep quality and environmental hazards. Detrimental health effects include increased incidence of acute myocardial infarction (MI) following the springtime transition and increased ischemic stroke following both DST transitions. Conditions effecting sleep are known to provoke atrial fibrillation (AF), however the effect of DST transitions on AF are unknown.
Methods:
Admitted patients aged 18-100 with primary ICD9 code of AF between 2009 and 2016 were included. The number of admissions was compiled and means were compared for the Monday to Thursday period and the entire seven day interval following each DST transition and the entire year for the entire cohort and separated by gender. Significance was determined with Wilcoxon nonparametric tests.
Results:
Admission data for 6089 patients were included, with mean age of 68 years and 53% female. A significant increase was found in mean AF admissions over the Monday to Thursday period (3.09 vs 2.47 admissions/day [adm/d], P = 0.017) and entire week (2.48 vs 2.09 adm/d, P = 0.025) following the DST spring transition compared to the yearly mean. When separated by gender, women exhibited an increase in AF admissions following the DST spring transition (1.78 vs 1.28 adm/d for Monday to Thursday period, P = 0.036 and 1.38 vs 1.11 adm/d for entire week, P = 0.050) while a non-significant increase was seen in men. No significant differences were found following the autumn transition for the entire cohort or when separated by gender.
Conclusion:
An increase in AF hospital admissions was found following the DST springtime transition. When separated by gender, this finding persisted only among women. This finding adds to evidence of negative health effects associated with DST transitions and factors that contribute to AF episodes.
Chronic sleep deprivation is a significant and understudied public health issue. Using BRFSS survey data from the United States and an administrative census of 160 million hospital admissions from Germany, we study the causal relationship between sleep and health. Our empirical approach exploits the end of Daylight Saving Time in a quasi-experimental setting on a daily basis. First, we show that setting clocks back by one hour in the middle of the night significantly extends people’s sleep duration. In addition, we find significant health benefits via sharp reductions in hospital admissions. For example, hospitalizations due to cardiovascular diseases decrease by ten per day, per one million population. Using an event study approach, we find that the effects persists for four days after the time shift. Admissions due to heart attacks and injuries also exhibit the same characteristic four-day decrease. We also provide a series of checks to rule out alternative, non-sleep related, mechanisms. Finally, we discuss the benefits of additional sleep for the sleep-deprived as well as policy implications for nudging people to sleep more. Our findings illustrate the importance of public policies that target sleep deprivation.
Generating a novel scion to several obliquely related literature streams, this study examined a particular high-profile cognitive outcome of a sometimes controversial government policy, daylight-saving time. Controlling for socioeconomic status by proxy, the principal finding was a surprisingly strong negative relationship between imposition of the time policy in a geographic area and SAT scores of local high school students. The cautious conclusion is that the daylight-saving time policy should possibly be even more controversial for, at minimum, its economic implications.
There is a rich array of evidence that suggests that changes in sleeping patterns affect an individual's decision-making processes. A nationwide sleeping-pattern change happens twice a year when the Daylight Saving Time (DST) change occurs. Kamstra, Kramer, and Levi argued in 2000 that a DST change lowers stock market returns. This study presents evidence that DST changes affect the relationship between stock market return and volatility. Empirical evidence suggests that the positive relationship between return and volatility becomes negative on the Mondays following DST changes.
The Internet is a powerful tool that has changed the way people work. However, the ubiquity of the Internet has led to a new workplace threat to productivity-cyberloafing. Building on the ego depletion model of self-regulation, we examine how lost and low-quality sleep influence employee cyberloafing behaviors and how individual differences in conscientiousness moderate these effects. We also demonstrate that the shift to Daylight Saving Time (DST) results in a dramatic increase in cyberloafing behavior at the national level. We first tested the DST-cyberloafing relation through a national quasi-experiment, then directly tested the relation between sleep and cyberloafing in a closely controlled laboratory setting. We discuss the implications of our findings for theory, practice, and future research. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Daylight saving time shifts can be looked upon as large-scale natural experiments to study the effects of acute minor sleep deprivation and circadian rhythm disturbances. Limited evidence suggests that these shifts have a short-term influence on the risk of acute myocardial infarction (AMI), but confirmation of this finding and its variation in magnitude between individuals is not clear.
To identify AMI incidence on specific dates, we used the Register of Information and Knowledge about Swedish Heart Intensive Care Admission, a national register of coronary care unit admissions in Sweden. We compared AMI incidence on the first seven days after the transition with mean incidence during control periods. To assess effect modification, we calculated the incidence ratios in strata defined by patient characteristics.
Overall, we found an elevated incidence ratio of 1.039 (95% confidence interval, 1.003-1.075) for the first week after the spring clock shift forward. The higher risk tended to be more pronounced among individuals taking cardiac medications and having low cholesterol and triglycerides. There was no statistically significant change in AMI incidence following the autumn shift. Patients with hyperlipidemia and those taking statins and calcium-channel blockers tended to have a lower incidence than expected. Smokers did not ever have a higher incidence.
Our data suggest that even modest sleep deprivation and disturbances in the sleep-wake cycle might increase the risk of AMI across the population. Confirmation of subgroups at higher risk may suggest preventative strategies to mitigate this risk.
Circadian rhythm disruptions may have harmful impacts on health. Circadian rhythm disruptions caused by jet lag compromise the quality and amount of sleep and may lead to a variety of symptoms such as fatigue, headache, and loss of attention and alertness. Even a minor change in time schedule may cause considerable stress for the body. Transitions into and out of daylight saving time alter the social and environmental timing twice a year. According to earlier studies, this change in time-schedule leads to sleep disruption and fragmentation of the circadian rhythm. Since sleep deprivation decreases motivation, attention, and alertness, transitions into and out of daylight saving time may increase the amount of accidents during the following days after the transition. We studied the amount of road traffic accidents one week before and one week after transitions into and out of daylight saving time during years from 1981 to 2006. Our results demonstrated that transitions into and out of daylight saving time did not increase the number of traffic road accidents.
The authors examine the differential influence of time changes associated with Daylight Saving Time on sleep quantity and associated workplace injuries. In Study 1, the authors used a National Institute for Occupational Safety and Health database of mining injuries for the years 1983-2006, and they found that in comparison with other days, on Mondays directly following the switch to Daylight Saving Time-in which 1 hr is lost-workers sustain more workplace injuries and injuries of greater severity. In Study 2, the authors used a Bureau of Labor Statistics database of time use for the years 2003-2006, and they found indirect evidence for the mediating role of sleep in the Daylight Saving Time-injuries relationship, showing that on Mondays directly following the switch to Daylight Saving Time, workers sleep on average 40 min less than on other days. On Mondays directly following the switch to Standard Time-in which 1 hr is gained-there are no significant differences in sleep, injury quantity, or injury severity.
A GREAT deal of attention has recently been paid to the circadian rhythms that have been found to exist in a number of human physiological and behavioural processes. There are several ways in which such rhythms can be disrupted, and extensive studies have been made of the effects of prolonged isolation1, abnormal working hours2, and flight across several time zones3. The adoption of Daylight Saving Time (DST) is another possible cause of disruption, but seems to have been generally ignored in spite of the large number of people potentially affected. We have found that significant disruptions of behaviour occur during adaptation to the time change.
An English language self-assessment Morningness-Eveningness questionnaire is presented and evaluated against individual differences in the circadian vatiation of oral temperature. 48 subjects falling into Morning, Evening and Intermediate type categories regularly took their temperature. Circadian peak time were identified from the smoothed temperature curves of each subject. Results showed that Morning types and a significantly earlier peak time than Evening types and tended to have a higher daytime temperature and lower post peak temperature. The Intermediate type had temperatures between those of the other groups. Although no significant differences in sleep lengths were found between the three types, Morning types retired and arose significantly earlier than Evening types. Whilst these time significatly correlated with peak time, the questionnaire showed a higher peak time correlation. Although sleep habits are an important déterminant of peak time there are other contibutory factors, and these appear to be partly covered by the questionnaire. Although the questionnaire appears to be valid, further evaluation using a wider subject population is required.
Fatal crashes were tabulated for 6-hour periods around sunrise and sunset, from 13 weeks before the fall change to standard time until 9 weeks after the spring change to daylight saving time. Fatal-crash occurrence was related to changes in daylight, whether these changes occurred abruptly with the fall and spring time changes or gradually with the changing seasons of the year. During daylight saving time, which shifts an hour of daylight to the busier evening traffic hours, there were fewer fatal crashes. An estimated 901 fewer fatal crashes (727 involving pedestrians, 174 involving vehicle occupants) might have occurred if daylight saving time had been retained year-round from 1987 through 1991.
To the Editor: It has become increasingly clear that insufficient sleep and disrupted circadian rhythms are a major public health problem. For instance, in 1988 the cost of sleep-related accidents exceeded $56 billion and included 24,318 deaths and 2,474,430 disabling injuries.1 Major disasters, including the nuclear accident at Chernobyl, the Exxon Valdez oil spill, and the destruction of the space shuttle Challenger, have been linked to insufficient sleep, disrupted circadian rhythms, or both on the part of involved supervisors and staff.2,3 It has been suggested that as a society we are chronically sleep-deprived4 and that small additional losses of . . .
Records of all accidental deaths in the USA for a 3-yr. period suggest that the minimal sleep loss associated with the spring shift to Daylight Savings Time produces a short-term increase of the likelihood of accidental death, while the fall shift has little effect.
Unlabelled:
Falling asleep while driving accounts for a considerable proportion of vehicle accidents under monotonous driving conditions. Many of these accidents are related to work--for example, drivers of lorries, goods vehicles, and company cars. Time of day (circadian) effects are profound, with sleepiness being particularly evident during night shift work, and driving home afterwards. Circadian factors are as important in determining driver sleepiness as is the duration of the drive, but only duration of the drive is built into legislation protecting professional drivers. Older drivers are also vulnerable to sleepiness in the mid-afternoon. Possible pathological causes of driver sleepiness are discussed, but there is little evidence that this factor contributes greatly to the accident statistics. Sleep does not occur spontaneously without warning. Drivers falling asleep are unlikely to recollect having done so, but will be aware of the precursory state of increasing sleepiness; probably reaching a state of fighting off sleep before an accident. Self awareness of sleepiness is a better method for alerting the driver than automatic sleepiness detectors in the vehicle. None of these have been proved to be reliable and most have shortcomings. Putative counter measures to sleepiness, adopted during continued driving (cold air, use of car radio) are only effective for a short time. The only safe counter measure to driver sleepiness, particularly when the driver reaches the stage of fighting sleep, is to stop driving, and--for example, take a 30 minute break encompassing a short (< 15 minute) nap or coffee (about 150 mg caffeine), which are very effective particularly if taken together. Exercise is of little use.
Conclusions:
More education of employers and employees is needed about planning journeys, the dangers of driving while sleepy, and driving at vulnerable times of the day.
Objectives. People working on a 5-2 days work-rest schedule have different sleep habits on weekdays and weekends, they extend and delay their sleep during weekends. The aim of this study was to assess adjustment of sleep to daylight saving time (DST), during weekdays and weekends. Methods. Subjects were 10 day shift workers, mean age=24.8y, SD=3.94, 5 males, 5 females. Subjects worked from Monday to Friday, five worked also on Saturdays. All kept a sleep-wake diary for two weeks before and two weeks after daylight saving time introduction, in which they recorded their bedtimes, wakeup times and sleep-onset latencies. Results. Bedtime during weekdays adjusted almost immediately to summer time (Friedman= l0.67, df=2, p<0.01, bedtime before DST=23:34, SD=47 min, first week after DST=22:48 , SD=66 min, second week after DST=22:43 , SD=42 min). Bedtime during weekends did not change during the first weekend after summer time introduction , this variable adjusted until the second weekend on summer time (Wilcoxon T=O, p < 0.01, bedtime before DST=24:22 , SD=58 min, second weekend after DST=22:49, SD=21 min) . As a secondary result, visual inspection of individual data showed that three persons did not adjust their bedtimes during the two weeks recording period on DST, this lack of adaptation refers both to weekdays and weekends. Conclusions. Sleep during weekends requires at least two weeks to adjust to DST. Individual analysis indicates that some workers require more than two weeks to adjust their weekdays and weekends bedtimes to DST.
The end of Daylight Saving Time provides a valuable opportunity to study the effects of a small, 1-h shift in local clock time in a naturalistic setting. Previous research suggests a delay in adjusting activity patterns by at least one week, possibly more. This study was designed to investigate the importance of prior sleep habits in predicting adaptation to the new schedule. One hundred and twenty participants completed the Pittsburgh Sleep Diary for six days before and six days after the October, UK transition (2010). A subsample (n = 35) also wore activity watches throughout the study. Adherence to the external clock by adjusting bed times and rise times was apparent on the first night, but difficulties in following this timing on subsequent nights, along with deterioration in sleep latency and efficiency, point to a delay in full adjustment, particularly for those who habitually sleep for less than 7.5 h/night.
Until 1883 local time was used in the US. In that yr most of the railroads began to operate on Standard Railway Time. The new system met with opposition in many parts of the country. Beginning in 1918, the Interstate Commerce Commission modified the boundaries of the 4 time zones. Daylight-saving time was used in both world wars. The benefits were expected to be a reduction in use of energy, more time in the evening for recreation, reduction in crime and car accidents. The Uniform Time Act of 1966 established a 6 month period for daylight time, from the last Sunday in April to the last Sunday in October. States, or parts of states could be exempted. This 6 month period has been used except in 1974 when yr round daylight time was used and 1975 when an 8 month period was used. -Forrest McElhoe Jr
Recent research has shown that the frequency of traffic accidents is influenced by changes in clocks from standard time to daylight savings time. A study was conducted to determine if a similar phenomenon existed with the occurrence of injuries in the construction industry. Data relating to injury claims of construction workers in the state of Washington for 1990-1996 were analyzed to determine if stress due to the change in time from standard to daylight savings in the spring and from daylight savings to standard time in the fall, respectively, resulted in an increase and decrease in construction accidents. For spring and fall, with respect to injury frequency, the injury frequency for the Monday following the change of time was compared with that of the Monday before the change, and the Monday 1 week later. No statistical differences were found to exist. In addition, injury statistics for the week before the change were compared with the week following the change. Again, no statistical differences between the two were found to exist.
Changes of schedules larger than 3 h, such as jet lag and shift work, require an adjustment period of several days to resynchronize the sleep-wake cycle and several weeks to resynchronize other circadian rhythms to the new schedule. Initial studies on adaptation to small changes of schedule (1-2 h) found that the sleep-wake cycle adapts to the new schedule in less than 48 h, and such modifications are generally not studied because they may be confounded by a potential masking effect. This article summarizes the few published studies on Daylight Saving Time (DST) and sleep during weekends, two examples of small changes in schedule. There are individual differences in adaptation to daylight saving time, while some persons adjust immediately; other persons require more than 2 weeks. During weekends, people tend to go to bed and wake up later, and to extend their sleep. Delay and extension of sleep depend on factors such as shift of work during weekdays and chronotype (morningness-eveningness). Both DST and sleep during weekends offer the opportunity to study adaptation of the sleep-wake cycle in recurrent, social conditions. Studying these phenomena is also relevant to some socioeconomic issues, like the reported increase of traffic accidents and complaints from the population during daylight saving time; or the possible decrease in productivity and absenteeism during the ‘Blue Monday’.
The deportment of 14 male and 12 female 3rd graders was rated by the teacher before and after the fall change from Daylight Saving Time (DST) as a test of the hypothesis that change to or from DST has a disruptive effect on behavior. Results show a significant interaction of sex of student × ratings. Subsequent to the change from DST, the deportment of the males improved significantly while deportment of the females was significantly disrupted. (3 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Large disruptions of chronobiological rhythms are documented as destabilizing individuals with bipolar disorder; however, the impact of small phase altering events is unclear. Australian suicide data from 1971 to 2001 were assessed to determine the impact on the number of suicides of a 1-h time shift due to daylight saving. The results confirm that male suicide rates rise in the weeks following the commencement of daylight saving, compared to the weeks following the return to eastern standard time and for the rest of the year. After adjusting for the season, prior to 1986 suicide rates in the weeks following the end of daylight saving remained significantly increased compared to the rest of autumn. This study suggests that small changes in chronobiological rhythms are potentially destabilizing in vulnerable individuals.
In the summer of 1980 for the first time clocks in the Federal Republic of Germany were advanced 1 h ahead of Central European Time (CET), which had been in use until then. In a sample of a total of 1070 accident patients, who had accidents on data pairs taken from the months of May 1979 (before the introduction of the so-called Central European Summer Time—CEST) and May 1980, comparable by day of the week, holiday, and weather conditions, and were seen at the University of Heidelberg Dept. of Surgery, a statistically significant increase in accident frequency between 7:30 p.m. and 5:30 a.m. was found when comparing the years 1979 and 1980 (P < 0.05). At the same time, the services of the outpatient department were claimed to a greater extent in the evening and night time in 1980 than prior to the introduction of CEST. Since the sample must be considered comparably as to age and sex distribution as well as calendar days and climatic influence, a change in routine due to the adaptation to daylight saving time is discussed as the most probable reason for the observed increase of accidents. The influence of CEST apparently exceeds a short adjustment phase. Further studies are recommended to investigate a possible correlation between daylight saving time and an increased risk of accidents.
Sleep duration has figured into claims of two trends promoted recently as dysfunctional in the mass media. One is the observation
that the population at large is sleeping less than before. The second is that the annual change from Standard Time to Daylight
Savings (or summer) Time causes adverse effects, largely through the loss of an hour’s sleep. This paper relies on recent
Canadian and U.S. time-use data to empirically test both of these value-laden allegations. Analysis of Statistics Canada’s
general social surveys containing time-use information in 1986, 1992, 1998, and 2005 shows that the mean duration of sleep
was unchanged between 1986 and 1998 and actually declined by about 15min a night in 2005, reflecting an earlier bedtime and
unchanged arising time. Sleep duration is not constant in the population, though, and the media view might reflect the habits
of population sectors such as the intelligence with great access to the media. The American Time Use Study sample of 20,720
respondents in 2003 enabled the analysis of time-use before, on, and after the dates of semi-annual time changes that year.
These data showed that any sleep time “lost” in the spring-forward time change was insignificant and short-lived due to the
fact that it occurred on the night between Saturday and Sunday, when people typically sleep much longer than on weekdays.
While there are other time trade-offs observed after time changes, their explanation lies in other directions.
KeywordsSleep–Duration–Change–Erosion–Compression–Time-use–Daylight savings time
The principal reason for introducing (and extending) daylight saving time (DST) was, and still is, projected energy savings, particularly for electric lighting. This paper presents a literature review concerning the effects of DST on energy use. Simple estimates suggest a reduction in national electricity use of around 0.5%, as a result of residential lighting reduction. Several studies have demonstrated effects of this size based on more complex simulations or on measured data. However, there are just as many studies that suggest no effect, and some studies suggest overall energy penalties, particularly if gasoline consumption is accounted for. There is general consensus that DST does contribute to an evening reduction in peak demand for electricity, though this may be offset by an increase in the morning. Nevertheless, the basic patterns of energy use, and the energy efficiency of buildings and equipment have changed since many of these studies were conducted. Therefore, we recommend that future energy policy decisions regarding changes to DST be preceded by high-quality research based on detailed analysis of prevailing energy use, and behaviours and systems that affect energy use. This would be timely, given the extension to DST underway in North America in 2007.
The focus of this work is an investigation of the effect of prevailing time regime on energy consumption. In particular we perform analysis demonstrating potential energy savings which could be obtained were Great Britain to maintain daylight savings time (DST) over winter, instead of reverting to Greenwich mean time (GMT). We review the literature on the effect of DST on energy consumption and show that this indicates a justification for considering the issue. Our headline result is in agreement with many related studies in that advancing the clock by an hour in winter would lead to energy savings of at least 0.3% of daily demand in Great Britain. In deriving this result we have adopted methodologies currently used in load prediction, in particular Support Vector Regression, to estimate energy demand on a half-hourly basis.Corresponding cost savings are found to be higher (due to the nonlinear increase of costs) and we find them to be on the order of 0.6% over the months considered. In terms of environmental impact we find the saving to be approximately equivalent to 450,000 ton of CO2. In deriving these results we adopt a conservative approach such that we consider them lower bounds on any true savings.
Daylight saving time (DST), implemented as an energy saving policy, impacts many other aspects of life; one is road safety. Based on vehicle crash data in Minnesota from 2001 to 2007, this paper evaluates long- and short-term effects of DST on daily vehicle crashes.
To provide evidence to explain the causes of more/fewer crashes in DST, we examine the impact of DST on crashes in four periods of a day: 3 a.m.-9 a.m., 9 a.m.-3 p.m., 3 p.m.-9 p.m., 9 p.m.-midnight. The effects of risk and exposure to traffic are also separated. Our statistical models not only include weather conditions and dummy variables for days in DST as independent variables, but also consider traffic volumes on major roads in different periods of a day. Our major finding is that the short-term effect of DST on crashes on the morning of the first DST is not statistically significant. Moreover, it is interesting to notice that while DST per se is associated with fewer crashes during dusk, this is in part offset because it is also associated with more traffic on roads (and hence more crashes). Our path analysis shows that overall DST reduces crashes.
Daylight saving time can lead to fewer crashes on roads by providing better visibility for drivers.
Recent research has indicated that transitions into and out of daylight saving time (DST) unbalance the physiological circadian rhythm and may lead to sleep disturbance. Sleep deprivation may have negative effects on motivation, attention and alertness and thus it is possible that transitions into and out of DST may increase accident rates.
To explore the impact of DST transitions on the number of occupational accidents in Finland.
For the study, we analysed all occupational accidents that happened in Finland 1 week before and 1 week after DST transitions during the years 2002-06.
Transitions into and out of DST did not significantly increase the number of occupational accidents.
It seems that sleep deprivation after DST transition is not harmful enough to impact on occupational accident rates.
To measure the impact of the introduction of daylight saving in Western Australia in December 2006 on when during the day adults engaged in physical activity.
In early December 2006, 1,300 Western Australian adults were telephoned and asked about how the introduction of daylight saving would influence when during the day they typically engaged in physical activity. At the end of the daylight saving period in March 2007, 1,083 of the baseline cohort agreed to answer questions relating to how daylight saving had affected when during the day they were physically active.
Almost half the cohort (45.5%) reported that daylight saving had affected when during the day they were physically active. During daylight saving fewer people exercised in the morning and more people exercised in the evening. When analysed at the individual level, 23% of the cohort ceased to exercise in the morning during daylight saving and 22% exercised in the evening only during daylight saving. In addition, to changes in when during the day people exercised, there was also an overall reduction in the average number of daily exercise sessions, with 8% not exercising at all during daylight saving.
The results suggest that the introduction of daylight saving, a relatively modest compulsory change to increase daylight by one hour had an impact on patterns of when during the day people were physically active.
The study results reinforce the value of focusing on policy as an effective means of supporting population behaviour change.
To examine whether switching to and from Daylight Saving Time (DST)-1 h shift forward in the spring and 1 h shift back in the autumn-is associated with an increase in work injuries.
Data on work-related injuries were obtained from compensation claim records from the Ontario Workplace Safety & Insurance Board for the period 1993-2007. A Poisson regression model was run separately comparing the number of no lost time claims and lost time claims during the week of DST change with the week following DST change, and the week preceding DST change. We also examined if differences in the relationship between DST and work injury claims were present across industry, age, gender and job tenure groups.
The results of our regression model did not show an increase in the incidence of work injury claims in the days immediately following the spring shift to DST. There was a significant decrease in the number of claims on Thursday, Friday and Saturday following the spring transition to DST. However, this decline was solely due to the years when Good Friday occurred during DST week (1993, 1998 and 2004) when fewer people are at work. For the autumn transition from DST, no evidence was found that the gain of 1 h sleep results in a decrease or increase in work injury claims.
Our findings show that the shift to and from DST had no detrimental effects on the incidence of claims for work injuries in Ontario, Canada.
Sleepiness and fatigue are important risk factors for traffic accidents. However, the relation between the accident type and lack of sleep as well as spells of driving has not been examined sufficiently. This study aimed to clarify that short sleep duration and long spells of driving are more associated with rear-end collisions and single-car accidents as compared with accidents of other types in cases of people who cause accidents. After removing drunken driving as a cause of accidents, 1772 parties involved in accidents were questioned. The quantities of rear-end collisions and single-car accidents were, respectively, 240 and 293. Logistic regression analysis showed that short nocturnal sleep (<6 h) and 10-min increments of spells of driving were significantly associated not only with rear-end collisions but also with single-car accidents as compared with accidents of other types. Furthermore, younger age (<or=25 years old) and nighttime (21:00-06:00 h) driving were significantly associated with single-car accidents as compared with accidents of other types. To prevent such accidents, countermeasures must be considered in light of the characteristics of drivers involved in each type of accident described above.
Individuals differ in their biological rhythms and preferences for time of day. Here, we looked at the transition into daylight saving time (DST) in adolescents. As adolescents tend to be evening types, one may expect that they suffer from a transition into DST.
To assess these changes, we measured daytime sleepiness and morningness-eveningness preference (CSM score) in adolescents.
Daytime sleepiness correlated with age and CSM score. Older pupils and evening types showed a higher sleepiness. Daytime sleepiness was higher after the transition until the third week after. Older pupils and pupils scoring higher on eveningness reported higher daytime sleepiness after the transition, suggesting that these pupils suffer most from the change. Using cut-off scores for larks and owls, we found that owls showed higher sleepiness than larks.
As one consequence, class and school performance tests should not take place in the first week(s) after the transition into DST.
Motivated by the recent flurry of activity in sleep research, this paper explores the connection between sleep disruptions following Spring and Fall clock shifts associated with daylight-savings time, and equity returns. It is shown that the "weekend effect" in the form of the lower-than-expected Friday-to Monday returns is particularly pronounced for the two weekends involving daylight-savings clock changes.
Kamstra et al. [Kamstra, M.J., Kramer, L.A., Levi, M.D., 2000. Losing sleep at the market: the daylight saving anomaly. The American Economic Review 90, 1005-1011] argue that the mean weekend return following the changes in daylight saving time is less than the mean weekend return throughout the rest of the year. Opposing studies, such as Pinegar [Pinegar, J.M., 2002. Losing sleep at the market: comment. The American Economic Review 92, 1251-1256), reason that the observed results depend upon methodology. We extend the ongoing discussions by providing further evidence for equity markets and bond markets in Germany and across Europe. We further demonstrate that the daylight saving effect does not serve as a potential rationale for the weekend effect.
Collectively the daily, seasonal, lunar and tidal geophysical cycles regulate much of the temporal biology of life on Earth. The increasing isolation of human societies from these geophysical cycles, as a result of improved living conditions, high-quality nutrition and 24/7 working practices, have led many to believe that human biology functions independently of them. Yet recent studies have highlighted the dominant role that our circadian clock plays in the organisation of 24 hour patterns of behaviour and physiology. Preferred wake and sleep times are to a large extent driven by an endogenous temporal program that uses sunlight as an entraining cue. The alarm clock can drive human activity rhythms but has little direct effect on our endogenous 24 hour physiology. In many situations, our biology and our society appear to be in serious opposition, and the damaging consequences to our health under these circumstances are increasingly recognised. The seasons dominate the lives of non-equatorial species, and until recently, they also had a marked influence on much of human biology. Despite human isolation from seasonal changes in temperature, food and photoperiod in the industrialised nations, the seasons still appear to have a small, but significant, impact upon when individuals are born and many aspects of health. The seasonal changes that modulate our biology, and how these factors might interact with the social and metabolic status of the individual to drive seasonal effects, are still poorly understood. Lunar cycles had, and continue to have, an influence upon human culture, though despite a persistent belief that our mental health and other behaviours are modulated by the phase of the moon, there is no solid evidence that human biology is in any way regulated by the lunar cycle.
It has been reported that the change in photoperiod induced by the occurrence of daylight saving time has an effect on psychiatric presentation. We therefore investigated the impact of daylight saving time in three conditions: (1) parasuicide presentations; (2) psychiatric outpatient contacts, and inpatient admissions; (3) registered suicides. Results indicate that neither the change in photoperiod nor the effect of a small change in circadian rhythm associated with daylight saving time has an effect on 'cases' in any of the three conditions.
Circadian rhythms, cyclic fluctuations in many physiological and psychological functions, are thought to influence adjustment to shiftwork. A widely acknowledged individual difference in circadian rhythms, commonly called morningness, indicates preferences associated with morning or evening activities. Various self-report instruments have been developed to measure morningness, although little measurement data have been published for these scales. Because morningness scales are being used to select workers for night shiftwork, psychometric evaluations of these scales are needed. Psychometric assessments of undergraduate responses (N = 501) on three widely used scales indicate internal (interitem) measurement deficiencies in all three. Therefore, a 13-item scale was developed that distills the best items from two of these scales. Relationships between the new composite scale and external criteria are comparable with or stronger than similar relationships between the published scales and external criteria.