Annually, around 70 countries adjust their clocks one hour ahead in spring and revert an hour in the autumn/fall. This custom was first proposed by George Hudson in 1895 with the intention of allowing people to get more solar time in the summer. This was followed by similar proposals in different countries that wanted to help their populace to make optimal use of day light and save on energy costs. The goal of coming up with such measures in agrarian societies was to align work and personal routines with daylight hours. However, 100 years later, work routines have changed thus rendering this practice archaic. Further, time alterations during daylight saving time have been found to be disruptive to sleep patterns and have been linked to multiple health issues such as strokes and heart attacks. Therefore, from a health point of view, the practice is detrimental though there are some measures that people can use to cope with its effects.

Effects of daylight savings time on sleep

The human body relies on the natural 24-hour cycle to set up its circadian rhythm. Disruptions to this cycle causes the internal clock to become out of sync with the day-night cycle. In spring, when people are expected to set their clocks ahead by an hour, an hour of sleep is lost. Hence, most people experience the jet lag symptoms, just as someone traveling between time zones would feel. The following are some of the ways that daylight savings adjustments interrupt sleep:

1. Circadian rhythm disturbances

The circadian rhythm is a repetitive 24-hour cycle that regulates one’s physical, mental, and behavioral processes. It helps regulate things such as metabolism, stress, body temperature, and sleep. While an adjustment of an hour might not seem like much, the unexpected shift throws the rhythm out of sync.  In the 24-hour cycle, the internal clock will have fixed certain times to induce sleep and wakefulness. However, adjustments due to Daylight Savings Time transitions exert unanticipated external pressure to the rhythm. Notably, the new sleep and wake up times adopted during DST put undue stress on the body and offset the internal clock. Thus, the circadian rhythm becomes unable to correctly regulate sleep-related processes, which can lead to sleep deprivation.

2. Reduced sleep duration

When clocks spring forward to the Daylight Saving Time, an actual hour of sleep is lost. Further, researches show that people lose 40-50 hours of sleep for a period ranging from several days to weeks until the internal clock resets. The consequences of inadequate amounts of sleep might vary but in the long term, they can manifest as sleep disorders.

3. Longer sleep latency

When time is pushed forward in spring, it is expected that people will sleep earlier to compensate for the adjustment. However, sleep onset in the early days or weeks of daylight savings time could be delayed as the body is not accustomed to falling asleep at such times. This is because several internal body processes will not be tuned with immediacy to facilitate sleep onset at the new sleeping times. Therefore, daylight savings time causes increased sleep latency whereby people take more time to fall asleep once they go to bed. Long sleep latency reduces the amount and quality of sleep and can lead to sleep disorders such as excessive daytime sleepiness.
Sleep fragmentation

An immediate consequence of daylight savings is the desynchronization of the internal clock. The internal clock is a vital sleep regulator that ensures that one gets the recommended 7-8 hours of sleep per night. However, when it is out of sync, it is common for people to wake up several times during a sleepful episode. Sleep fragmentation leads to poor sleep quality which can cause fatigue, daytime sleepiness, and sleep deprivation.

Other consequences of daylight savings

1. Increased fatal car accidents

A 2014 study by Austin Smith found a relationship between increased fatal crashes and DST transition. The analyzed data showed that the first week after a spring time change recorded a 6.3% increase in fatal car accidents. The researcher argued that the upsurge of accidents was caused by interrupted sleeping patterns during DST that caused drivers to feel drowsy in the morning and late evenings. In a prior study conducted in 1999 by John Hopkins and Stanford University researchers, the Mondays after switching to DST recorded more fatal crashes than the average Monday. Therefore, researchers have uncovered that Daylight Saving Time transitions lead to severe accidents that would otherwise not occur.

2. Depression

Daylight savings time can to lead to depressive feelings, irritability, and anxiety. Sleep studies have shown that sleep deprivation has negative effects on one’s moods. People who experience sleep deprivation are, therefore, likely to become moody, sad, anxious, disinterested, and depressed.  A Danish research team confirmed that the number of depression cases reported in hospitals peaks after a daylight saving time transition. Depression has been linked to the disturbances of the circadian rhythm when adapting to DST. It can lead to more serious disorders such as insomnia and excessive daytime sleepiness.

3. Cardiovascular conditions

Daylight saving time has been reported to expose people to greater risks of heart attacks and stroke. In 2018, the American Heart Association published an article that indicated that the risk of heart attack rose by 24% on the Monday following the start of daylight saving time and reduced by 21% after the autumn/fall change to standard time. Thus, the change poses a significant risk to patients with high blood pressure as they are more likely to get heart attacks and stroke. Heart function involves several variables, such as heart rate, heart rate variability, and diastolic and systolic blood pressure. The variables are affected by the circadian rhythm. When a daylight saving time transition occurs, the circadian rhythm becomes unsynchronized, and this can cause cardiac arrhythmia where the heart beats too quickly, slowly, or irregularly. Abnormal heart function can lead to stroke and cardiac arrest.

4. Changes in appetite

Appetite is dependent on hormones such as ghrelin and leptin that affect one’s cravings and satiety. The production of these hormones is directly affected by sleep. During daylight time saving transitions, disturbances to the sleep-wake cycle cause the hormone levels to become unbalanced leading to increased cravings and a lack of satiety. Hence, people report feeling insatiable hunger the day after transitioning to DST. Further, the new time schedules that come with daylight savings time affect one’s meal times too. The mismatch between the body’s accustomed eating periods and the actual time that one eats during DST can, therefore, lead to increased cravings.

5. Workplace injuries

Daylight savings time is associated with increased workplace injuries more so in jobs that require high levels of alertness or physical labor. In a study of mining accidents, researchers found that there was an increased number and severity of injuries on the Monday following the transition to DST. In contrary, the recorded injuries plummeted in November after the switch back to standard time. The underlying reason was that daylight saving time shifts affected sleep quality and sleep duration. This highlights that employees are likely to feel drowsy during the daytime after switching to DST. In some occupations, drowsiness can lead to severe bodily harm or fatalities due to reduced cognitive abilities. focus and poor alertness levels.

Coping with sleep and health challenges of Daylight Saving Time

Daylight savings time transition can affect one’s overall well-being. The time alteration practice has pronounced health effects including cardiovascular conditions and fatal accidents. Hence, it is advisable to anticipate and prepare for the transition to minimize the chances of suffering the negative effects. The following are some of the ways that can help one handle the changes in time better:

1. Making gradual shifts

The circadian rhythm is not usually tolerant of sudden changes and once disturbed, it can take days or weeks to reset. Most of the complications that arise from DST transition are tied to disruptions to the circadian rhythm; hence, they can be avoided by making subtle changes during the transition. Therefore, 10 days before transitioning to DST, one can go to bed progressively 10 minutes earlier. The subtle changes avoid interruptions to the circadian rhythm and prevent an onset of the complications associated with the transition.

2. Maintaining a fixed schedule

A consistent routine can either avoid disrupting the body’s internal clock or aid it to recover from the effects of DST. Thus, following a set routine for meal times, exercise, and sleep duration prior to and after switching to DST is highly recommended.

3. Following a bed time routine

The dreaded effect of DST is sleep deprivation since it can aggravate most other negative consequences of the transition. Therefore, getting sufficient night time sleep can help prevent or mitigate the severe effects of DST transition. A bed time routine can help one to naturally prepare for sleep and get restorative sleep for the recommended number of hours (7-8). Before bed time, one should avoid meals, alcohol, and blue light emitters such as phone and computer screens. Further, one should dim lights to allow melatonin production to increase. These practices motivate the natural onset of sleep and allow one to get sufficient rest throughout the night.

4. Avoiding daytime naps

After switching to DST, day time naps become more tempting. However, they can significantly reduce sleep pressure and further affect one’s normal sleep-wake cycle. Sleep pressure is an unconscious biological response that increases the body’s need for sleep. The pressure increases with the amount of time that one is awake. Therefore, taking day time naps relieves the pressure and can make it hard to fall asleep at night. Consequently, after transitioning to DST, day time naps should be avoided. Instead, one should step into direct sunlight regularly for the production of the sleep hormone to be hindered during the day.

5. Melatonin supplements

When the body’s internal clock has been disturbed, the sleep-wake cycle becomes inconsistent. Nonetheless, getting enough night time sleep is vital for normal bodily function. Thus, before the internal clock adjusts to the new sleep schedules, one can use melatonin supplements, which are available over the counter.

Is Daylight Saving Time still beneficial?

Germany, which was among the first countries to adopt daylight savings time, anticipated that the change would allow people to save on energy. People would stay out longer during the day, hence minimizing the use of artificial light sources. The argument was plausible at the time since the commonly used tungsten bulbs alongside other light sources were expensive or uneconomical. However, a century later, the cost of energy is low and highly economical light sources are available. Hence, switching to daylight saving time to save on energy is no longer valid reasoning.

Further, another motivator for switching to daylight saving time was to increase the productivity of workers. At the time, most jobs were done during the day time. Thus, adjusting time would get people working in fields and factories for longer during the day time. Today, researchers have used time tracking software to monitor the productivity of employees after daylight saving time transitions and noted poor productivity in the days following the switch. It is estimated that $480 million is lost annually from decreased productivity arising from DST transition. Therefore, switching to DST to improve employee productivity is no longer viable.

However, it is apparent is that DST has considerable negative health effects. Researchers have discovered direct relationships between daylight savings time transition and many health complications. Most of these health problems are linked to the disruptions that DST transitions have to the body’s vital circadian rhythm.  From a health perspective and stand point there is no benefit to daylight savings time, it causes more harm than good in our modern world.


Daylight saving time (DST) is the practice of adjusting clocks one hour ahead during warmer months. The practice dates back to the late 19th Century and it was intended to allow people to make optimal use of daylight hours. The custom has been held for more than 100 years in at least 70 countries, even though it has outlasted its usefulness. Daylight saving time has a significant effect on sleep and, by extension, causes several other medical complications. DST has been found to cause circadian rhythm disturbances, reduced sleep duration, longer sleep latency, and sleep fragmentation. Further, the transition to DST has been found to have a direct relationship with increased fatal car crashes, depression, cardiovascular conditions, changes in appetite, and workplace injuries. One can cope with the challenges of DST transition by making gradual shifts, maintaining a fixed schedule, following a bedtime routine, avoiding daytime naps and taking melatonin supplements.