Right: Children, especially school-aged children, are particularly affected, at least in the short term, by DST changes twice each year, but medical research suggests that other mental and physical harm can result from upset circadian rythms.
 Found a word you're not familiar with? Double-click that word to bring up a dictionary reference to it. The dictionary page includes an audio sound file with which to actually hear the word said. |
Arguments against daylight saving in Australia
1. Daylight saving is not an effective power-saving strategy and does not reduce greenhouse gas emissions
The main reason daylight saving was first adopted was as a power-saving measure. With the urgent need to reduce greenhouse gas emissions to combat global warming, energy reduction has become an even greater consideration in Australia and around the world. However, daylight saving's critics note that in Australia, at least, it fails in this, and so maintain that one of the main supposed reasons for its retention is a fallacy. Daylight saving time does not mean lower electricity usage overall and is not helping Australia reduce emissions.
Western Australia has opted into and out of daylight saving on a couple of occasions. This has allowed researchers to compare power consumption in the state between periods when daylight saving was in place and periods when it was removed. Virginie Masson, an economist at the University of Adelaide analysed power usage over the course of the day during Western Australia's most recent experiment with daylight saving time, from 2006 to 2009. Compared to a (non-pandemic) period with year-round standard time, Masson and her team found daylight saving time resulted in no overall energy savings. During standard time, there would usually be a large spike in energy use that coincided with people returning from work in the late afternoon and early evening. During daylight saving time that spike was reduced but energy consumption was extended over a longer period across the day. The researchers also saw a slight increase in morning electricity use during daylight saving time. Dr Masson concluded, 'And so when you put the two effects together, the decrease in demand in the 4.30 to 8.30pm window is completely cancelled by the little increase in the mornings and later at night.'
A similar conclusion was reached by two American economists in 2007, who analysed power usage during another natural Australian experiment: the 2000 Sydney Olympics. That year, daylight saving time in the south-eastern states was moved to August 27. When the economists compared the extended daylight-saving period with previous years, they found daylight saving time reduced electricity demand in the evening but had the opposite effect in the morning.
Similar findings were made by Cahit Guven, an economist at Deakin University, as part of a team that analysed Australian electricity usage data and daily weather conditions from 1998 to 2015. They found any energy-saving benefits of daylight-saving time are dependent on weather and air conditioner ownership.
The use of air conditioners is why the energy saving aspect of daylight saving no longer seems to hold true in many warm parts of the world. When daylight saving time was first introduced, most household energy during summer was used for indoor lighting. Now the principal energy use is air conditioners, which more than offsets any lighting-related savings. Dr Guven has stated, 'We found we can explain all the previous literature - that electricity consumption [during daylight saving time] declines in a place where the temperatures are low and air conditioner usage is low. On the other hand, daylight saving time can be harmful in terms of cost savings, and it can increase electricity consumption, if in summertime there are higher temperatures and higher air conditioner ownership.'
However, Dr Guyen noted that if more Australian households used solar panels to generate their electricity, then the power-hungry nature of daylight saving in hot climates would no longer be a factor.
However, daylight saving critics have noted that general use of renewable energy would reduce greenhouse gas emissions, irrespective of the adoption of daylight saving.Similar findings to those of Dr Guyen had been made in the United States in 2008 when the National Bureau of Economic Research evaluated all eight months of daylight-saving time and the impact it had on electricity costs in Indiana. The researchers found it cost residents an additional $9 million a year in energy costs when the state started observing the time change in 2006. That was because while the use of lighting dropped, there was more demand for heating and cooling.
2. Daylight saving endangers people's mental health
One of the principal concerns of those opposed to daylight saving is the harm that it causes to people's mental health.
It is believed that people's mental wellbeing is related to their circadian rhythms. These are physical, mental, and behavioral changes that follow a 24-hour cycle within the body. They are regulated by 'biological clocks', which are natural timing devices found within all living things. These 'clocks' are composed of specific protein molecules that interact with the body's cells. A master clock, situated in the brain's anterior hypothalamus, coordinates all the biological clocks keeping them in sync.
The body has light receptors which allow it to register external light conditions. It is important that our internal clocks remain coordinated with the external changes in light through the day. Daylight saving is believed to disrupt this co-ordination. Increasing evidence points to the role of the biological clock in the development of depression. In seasonal depression and in bipolar disorders it seems likely that a disruption in the circadian system plays a significant part in causing the disorders. One 2017 study from Denmark analysed 185,419 hospital contacts for unipolar depression and showed that the transition from daylight-saving time to standard time was associated with an 11 percent increase in the incidence rate of these depressive episodes.
Daylight saving has also been connected to anxiety and lapses in emotional control. In 2015, research from Tel Aviv University found sleep disruption can stir anxiety and increase the likelihood of emotional outbursts. Also concerning is the impact that daylight saving may have on the incidence of suicide. A study conducted in 2007 examined Australian suicide data from 1971 to 2001. It was analysed to determine the impact on the number of suicides of a one-hour time shift due to daylight saving. The results demonstrated that male suicide rates increased in the weeks following the beginning 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 time-related biological rhythms are potentially destabilising in vulnerable individuals.
A United States study released in 2020 had similar findings. It concluded, 'The results demonstrated a statistically significant increase in suicides during daylight-saving time. Most suicides were committed during July-October, compared to March-June, and November-February. Despite disagreement in the literature, this study would suggest eliminating daylight-saving time altogether. These results support other evidence which suggest a detrimental effect of daylight-saving time, especially with respect to the psychological and behavioral aspects of public health.' Many sleep researchers and neurologists argue that while permanent daylight saving might remove problems associated with the human body adjusting between daylight-saving time and standard time, it would not remove the underlining problem. This underlying problem is that people's internal clocks are out of synch with their external exposure to light which disrupts circadian rhythms and disturbs mental health.
These specialists argue that the only permanent solution is a full-time return to standard time. On March 11, 2022, The Conversation published a comment by Beth Ann Malow, Professor of Neurology and Pediatrics at Vanderbilt University. Professor Marlow states, 'My colleagues and I believe that the health-related science for establishing permanent standard time is strong. Standard time most closely approximates natural light, with the sun directly overhead at or near noon. In contrast, during daylight saving time from March until November, the natural light is shifted unnaturally by one hour later. Based on abundant evidence that daylight saving time is unnatural and unhealthy, I believe we should abolish daylight saving time and adopt permanent standard time.' 3. Daylight saving endangers people's physical health
Another concern regarding the adoption of daylight saving is that it puts people's physical health at risk. While turning the clocks back appears to jeopardise individual's mental health, there are also studies that show that disruptions in sleep prompted by daylight saving result in an increase in road traffic and workplace accidents, a rise in cardiac events, and an increase in the rates of stroke. Additionally, one study has suggested that daylight saving might increase skin cancer risks.
There have been studies indicating that daylight saving results in increased accident risks in several settings. One of these is a significant short-term increase in vehicle accidents in the United States. The Fritz study conducted in 2019 and published in Current Biology in February 2020, found evidence that the spring daylight saving time transition acutely increases motor vehicle accident risk, which has been partly attributed to sleep deprivation and circadian misalignment.
The increased accident rate was put at 6 percent. For the study, the researchers analysed 732,835 accidents recorded through the U.S. Fatality Analysis Reporting System from 1996 to 2017. In all, over the 22 years of data analysed, about 627 people died in fatal car accidents associated with the spring shift to daylight saving time, the study estimated. Other research supports these findings. A University of British Columbia study, using data from the Canadian Ministry of Transport, found that when Canada went into daylight saving time, there was an 8 percent increased risk of accidents on the Monday after the changeover. Daylight saving has also been found to affect workplace accidents. A 2009 study examined over 500,000 mining injuries over a more than 20-year period and found a 5.7 percent increase in injuries on the Monday following the time change. The study also found these injuries to be more severe, resulting in a 68 percent increase in the number of days missed due to these accidents. Other studies have indicated that daylight saving, particular the spring transition to daylight saving, appears to increase the risk of cardiac events and strokes. A study from New York, presented at the American Heart Association's Scientific Sessions in 2018, reported that hospital admissions for atrial fibrillation, the most common type of irregular heartbeat, increase with over the daylight-saving time transition period. Researchers found that on the Monday to Thursday following the start of the time transition in the spring there were 3.13 atrial fibrillation hospital admissions a day compared to 2.56 daily admissions for the same days on average over the rest of year. Stroke rates also appear to increase with the change to daylight saving time. In a 2016 study from Finland, researchers found that the overall rate of ischemic stroke was 8 percent higher during the first two days after a daylight-saving time transition.
American Heart Association president, Donald M. Lloyd-Jones, stated, 'We don't really know the specific reason for increases in heart disease and stroke during the daylight-saving time change, but it likely has something to do with the disruption to the body's internal clock, or its circadian rhythm.' Finally, it has been suggested that daylight saving time, which results in increased late-afternoon sun exposure could increase the risk of skin cancer. In 2006, having decided not to introduce daylight saving to Queensland, the state's premier, Peter Beattie stated, 'We've got the highest incidence of skin cancer in the world. An extra hour of daylight is going to make that worse.'
This claim was subsequently disputed by Queensland Cancer Fund's director of epidemiology, associate professor Joanne Aitken, who claimed there was no research to support it. However, five years later, a review of a 2011 study conducted using mice tentatively suggested that afternoon sun exposure could be harmful to human beings. 4. Daylight saving does not boost the economy
Contrary to popular belief, studies in the United States and Australia have suggested that daylight saving does not boost the economy by contributing to consumer spending. It has also been found that the transition period during which workers adapt to daylight saving results in significantly reduced productivity in at least some sectors and causes increased workplace accidents.
A 2016 analysis of 380 million bank and credit card transactions by US bank JPMorgan Chase has challenged the assumption that daylight saving boosts consumer spending. The study compared data from Los Angeles, California, which changes its clocks in March and November, with data from Phoenix, Arizona, one of only two US states that does not adopt daylight savings. It found that while the extra hour of daylight in the spring slightly boosted card spending per person (by less than I percent) the negative impact of the shift back wiped out the benefit, with Los Angeles residents spending 3.5 per cent less after the November change. Shoppers made far fewer trips to the store during the week, with grocery, discount and other retailers showing the largest declines.
A study conducted in Western Australia in 2008 came to similar conclusions to the United States research, finding either that daylight saving had no effect on consumer spending or had a negative impact. The study examined the impacts of daylight savings among small businesses represented by a group of 41 operators including of small wineries, bed and breakfasts, food factories and other facilities open to the public located in and around Perth. While the largest group of respondents in this study did not perceive any major impacts of daylight savings on their businesses, just over a third of operators viewed daylight saving as detrimental to their businesses. Respondents also complained that daylight saving was negatively affecting business operators' lifestyle and working patterns.
There have also been numerous studies which suggest that the disruption to people's sleep rhythms caused by transitioning into daylight saving can have negative impacts on workers' productivity. One 2012 United States study published on APAPsycNet found that these transition periods resulted in a loss of focus and productivity for those working on computers. The researchers termed this cyberloafing. They concluded, '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.'
American research has also indicated that the loss of sleep caused when people move their clocks forward has a significant effect on workplace accidents and so negatively affects the economy. The National Sleep Foundation states that it will take most people a few days to adjust to the loss of sleep. According to a 2009 study published by the Journal of Applied Psychology, losing just an hour of sleep could pose dangerous consequences for those in hazardous work environments. Using U.S. Department of Labor and Mine Safety and Health Administration injury data from 1983-2006, the study found that compared with other days, more injuries happened on the Monday after daylight saving time went into effect and the injuries were more severe. The DST switch resulted in U.S. workers getting 40 minutes less sleep, a 5.7 percent increase in workplace injuries and nearly 68 percent more workdays lost to injuries.
. The authors suggested employers consider rescheduling hazardous work for later in the week once workers have had a chance to adjust. Work schedules could also be modified, with workers starting 45 minutes later Monday and Tuesday, before gradually returning to their original schedules by the end of the week. Extra safety precautions could also be implemented during the week. All these adjustments, though likely to reduce the accident rate were also likely to impose a financial cost on businesses. . 5. Daylight saving harms children and adolescents
Opponents of daylight saving argue that although its supposed advantages for children are one of the main reasons given for introducing daylight saving, these benefits are outweighed by the harms caused to young people.
There are large amounts of anecdotal evidence from popular publications in both Australia and overseas claiming that daylight saving disrupts family routines and is unsettling for young children. On March 12, 2022, the New York Post published a segment quoting numerous United Sates parents' expressing their irritation with daylight saving and the negative effective it has on children's sleeping habits. One 'exasperated mother' is cited complaining, 'Please stop this nonsense... As soon as my kids settle into their bedtime routine, daylight savings starts again and messes everything up.'
An Australian KidSpot segment published in July 2017 similarly expressed new parents' frustration with daylight saving, 'You've just managed to get little Max/Annabelle/Tyrone into a regular routine. You're getting something closer to the 7 hours of sleep per night that you desperately crave. But BAM. Here's daylight saving to ensure that you're now being woken at 5am instead of 6am. It's back to the drawing board for you.' Medical authorities have also noted that daylight saving has negative impacts on the behaviour and functioning of children. Dr. Judith Owens, a professor of neurology at Harvard Medical School and co-director of the Pediatric Sleep Program at Boston Children's Hospital, has observed the adverse consequences of reduced sleep prompted by daylight saving on young children's learning capabilities and their behaviour. Owen's states, 'Sleep has been shown to improve cognitive functions like learning, problem-solving skills, decision-making and creativity. Insufficient sleep causes inattention, poor focusing and inability to monitor behavior...
Individuals who don't get enough sleep are more likely to take risks because they perceive less consequence. For example, a child in elementary school darts out into the road because they are more impulsive and less vigilant.'
It has further been argued that the disruptive impacts of daylight saving are especially acute for adolescents. Dr. Bhanu Kolla, associate professor of psychiatry and a consultant for the center for sleep medicine at the Mayo Clinic, has noted that adolescents may be most impacted by daylight saving time because their internal clock runs later than other age groups.
During puberty, hormonal responses to light exposure change, mean teenagers want to stay up later and sleep in longer. This can result in what is referred to as delayed sleep phase, also known as delayed sleep-wake phase sleep disorder, an internal sleep clock (circadian rhythm) sleep disorder. It occurs when your sleep pattern is delayed two hours or more from a conventional sleep pattern, causing you to go to sleep later and wake up later. Early school starts, and late nights spent studying exacerbate disruption to adolescents' sleep rhythms. The effects of daylight saving on adolescents have been claimed to be harmful. It has noted that the sleep-schedule realignment required by daylight saving is disruptive for adolescents. Dr Owens has stated, 'If you have misalignment in your own internal clock and the environment, that's going to have all kinds of physical repercussions in the short term. We very commonly see hyperactivity, impulsivity, inattention, acting out behaviors, oppositional behaviors, tied in with poor quality sleep. We see more irritability, lower frustration tolerance. We see more depression symptoms.' Dr Owens is also concerned that the increased incidents of accidents found among adults in the period of transitioning to daylight saving is also found among young people. Referring to their increased likelihood of vehicle accidents, she states, 'They may be cognitively impaired. They're not as vigilant, they're not as attentive, and that leads to things like accidents.' Dr Owens has further claimed that permanent daylight-saving time would work only if school start times shifted accordingly 'so that kids are not risking their lives by driving to school in the dark with their circadian rhythms telling them they should be asleep.'
It has additionally been noted that daylight saving has negative impacts on adolescents' academic performance. A study published in the Journal of Neuroscience, Psychology, and Economics looked at standardized testing scores at about 350 Indiana public high schools from 1997 to 2006. Researchers compared schools in counties that switched to daylight saving time to those in counties still on standard time. After controlling for socioeconomic status, race and ethnicity, they found SAT scores were negatively impacted by about 16 points in schools that transitioned to daylight saving time in the spring.