Daylight Saving Time – the biannual ritual of adjusting clocks forwards and backwards – has long been debated. Advocates argue it saves energy and promotes outdoor activities, while critics highlight its disruptive effects on health, productivity, and social routines. This column examines the health impacts, societal costs, and the outdated rationale behind the implementation of Daylight Saving Time, and argues that there is good reason to abolish it. This would imply trade-offs, however. While adopting Standard Time permanently would be better from a health perspective, ‘summer time’ is preferred in many countries.
The merits and drawbacks of Daylight Saving Time (DST) – the biannual practice of adjusting clocks forwards and backwards – have long been debated. In this column, I explore compelling reasons to abolish DST, focusing on the health impacts, societal costs, and the outdated rationale behind its implementation.
A burden on wellbeing?
A large share of the population is sleep deprived (Costa-Font et al. 2024a), and changes in exposure to sunlight early in the day and in sleep can alter circadian rhythms and affect mental health. One of the primary concerns surrounding DST is its profound impact on our social and body clock alignment, affecting our habits and routines that are, for the most part, automatic decisions that, even when we anticipate clock changes, still impact our wellbeing. DST imposes biannual time shifts that create short-term disorientation and fatigue, affecting workplace productivity and increasing the risk of accidents (Smith 2016), as evidenced by spikes in medical errors and traffic accidents following DST transitions (Laliotis et al. 2023). This is amplified in older age and among family members who are more sensitive to daily routines.
Several studies by health economists have linked DST transitions to significant disruptions in circadian rhythms, leading to increased rates of heart attack, stroke, and other health crises. In a paper with Sarah Fleche and Ricardo Pagan (Costa-Font et al. 2024b), my co-authors and I examine how the transition into and out of DST impacts individual wellbeing. Utilising a regression discontinuity combined with a difference-in-differences design, we document that that the spring transition into DST leads to a significant decline in life satisfaction, primarily driven by sleep disruption and other health effects, which altogether amounts to €750 a year per person. This decrease is attributed to deteriorated sleep quality and increased time stress, which adversely affect both physical and emotional health. Conversely, the autumn transition out of DST is associated with a significant increase in life satisfaction. The study suggests that eliminating DST could have a positive effect on overall welfare.
The abrupt time shift disrupts sleep patterns, contributing to widespread sleep deprivation. Surveys indicate that if given an extra hour, most individuals would use it for sleep, highlighting the chronic sleep deficit prevalent in societies adhering to DST (Costa-Font 2022). Among miners working in the US, for example, the one-hour time change induced by DST has been associated with a decrease in sleep of around 40 minutes (Barnes and Wagner 2009). This sleep deprivation is not merely inconvenient but has cascading effects on mental health, contributing to higher rates of anxiety, depression, and even suicide.
Even though digital technologies now make the time adjustment for us, the disjointed nature of the time changes creates confusion and inefficiencies across global markets and in international communication, impacting economic stability and performance. In a study examining the effect on productivity using data from GitHub, a popular cloud-based platform used by collaborative programmers, Dickinson and Waddell (2024) show that the two weeks following the transition to DST see declines in worker activity during early working hours that are not compensated later on.
A ‘one size does not fit all’ practice
The implementation of DST varies across geographical regions and climates. Only around one-third of countries worldwide observe it, with most of these located in Europe. In the US, some states and regions do not observe DST (e.g. Hawaii, most of Arizona, Indiana, Puerto Rico). Similarly, Australia, Brazil, and Canada have regions that opt out (e.g. Queensland, the Northern Territory, Western Australia, Christmas Island, and the Cocos (Keeling) Islands in Australia). Even within Europe, Armenia, Azerbaijan, Belarus, Georgia, Iceland, Russia, and Turkey do not follow the practice. Moreover, some countries only shift half an hour (e.g. Afghanistan, India, Iran, Myanmar, Sri Lanka), while Nepal shifts 45 minutes. Countries that have abandoned DST cite negligible benefits in terms of energy conservation and productivity, further questioning its continued relevance in a modern, interconnected world.
The political manoeuvring behind DST adjustments reflects a historical legacy rather than a practical solution to contemporary challenges. For example, in 2016 President Nicolás Maduro of Venezuela decided to reverse his predecessor’s time zone change, while Franco switched Spain to Central European Time despite most of the country being West of the Greenwich Meridian. Morocco has effectively adopted a permanent DST, shifting its standard time zone and only temporarily adjusting its clocks during Ramadan rather than making seasonal changes for summer and winter.
Debunking the energy-saving myth
Contrary to its initial purpose of conserving energy, the effects of DST on energy consumption are ambiguous at best and negative at worst. The modern era’s reliance on air conditioning and artificial lighting has mitigated any marginal gains from daylight extension during the evening. Instead, the biannual time shifts contribute to increased energy use during transitions and disrupt natural energy consumption patterns, thereby exacerbating environmental costs rather than mitigating them (Kotchen and Grant 2011).
One reason why DST is still in place is that it serves some interests such expanding consumption (even though it does not increase productivity) and the sale of antidepressants, as it is responsible for a rise in anxiety and depression around the transitions. However, a literature finds that it is responsible for both stock exchange and exchange rate fluctuations, in addition to the evidence suggesting it is responsible for medical errors, car accidents, as well as suicides.
The consensus, or lack thereof
Public opinion on DST varies across Europe and the US. In the US, 62% would prefer to end DST and 50% would prefer to be on DST permanently, which is not the healthiest option (source: YouGov). In Europe, 84% support ending biannual clock changes overall according to Eurobarometer data. However, while 75% of Germans wish to abolish the time change, in the UK, Spain, and Italy a majority prefer to stick with the current system of time changes. If DST were to be abolished, the majority in Sweden would prefer to stay on Standard Time, while the majority in most of the rest of Europe would prefer to remain on ‘summer time’ throughout the year (source: YouGov). Hence, it seems that despite attempts by the European Parliament and the US Senate, the lack of agreement pushes back any reform.
Options for change
The main reason for not ending DST is the limited agreement over which time to choose as the permanent one. While Standard Time would prioritise health outcomes by exposing individuals to sunlight earlier in the day, ‘summer time’, which is slightly preferred in many countries, increases opportunity for shopping and leisure activities. Whatever the choice of time, it will be a second best, and the challenge for social choice experts is to devise compensation mechanisms that would allow the status quo to be overcome.
One suggestion is for a smoother transition, but this would be hard to design in practice. Another option is to fix a time but allow for different opening times for nurseries, schools, and businesses as well as different working times. As with any policy change, there would be winners and also losers to compensate.
Source : VOXeu
