Start Preparing Now to Reduce the Harmful Effect of Daylight Saving Time


This Sunday at 2 a.m., much of the United States will once again begin observing Daylight Saving Time (DST). Several studies over the last few years have highlighted the negative effect this has on people’s sleep patterns and the resulting bodily harm that can occur.

Daylight Saving Time was first advocated by Benjamin Franklin in 1784 when he noticed that people slept past dawn in the summer, wasting early morning sunlight. The official time change was introduced during World War I as a part of an effort in the United States and other countries to conserve fuel.

On average, people return to the daily grind of work or school on the Monday after DST sleeping 40 minutes fewer than usual. A 2007 German study found that on days off, most people tend to sleep on standard time and their waking hour followed the seasonal progression of dawn. The transition of daylight saving time can disturb sleeping patterns and make them more restless at night because the body is not in tune with its personal circadian rhythm.


Due to the sleep deprivation that most people the first days after moving the clocks ahead an hour, researchers have found that the number of traffic accidents in the U.S. increases dramatically on the Monday after Daylight Saving Time. Different studies have shown the increase to be anywhere from 8 to 11%. DST does have a positive driving benefit – a study found that because people drive more safely during daylight hours, approximately 195 deaths of motor vehicle occupants and 171 pedestrian fatalities could be avoided.

A 2008 study from the Karolinska Institute used a Swedish database to determine that the number of serious myocardial infarctions (heart attacks) increases 6 to 10% in the first three workdays after the start of Daylight Saving Time. The study found that the most plausible explanation was sleep disturbances. (The study also found that the heart attacks are more likely on Mondays for the same reason).

A study from the journal Sleep and Biological Rhythms found that men are more likely to commit suicide during the first few weeks after the beginning of daylight saving time than they are during the rest of the year.

The early days of DST, waking up while the sun is still down, may also have a negative impact on another mental health concern – seasonal affective disorder, sometimes called “winter depression”. Some research has shown that dark mornings are more of a trigger for SAD than short days.

Be ready for the time change this year to prevent accidents and health concerns. Beginning today, go to bed and wake up 10 or 15 minutes earlier to prepare for the change. Avoid sleep disturbance activities, such as drinking alcohol or caffeine. This weekend, use those 10-15 minutes to enjoy some early morning sunlight to help resent the body’s internal clock. A brisk walk in the early morning is particularly beneficial to stimulate serotonin release in the brain that will help the body adjust to the changes. Also, avoid taking a nap Sunday afternoon which can further throw the body clock off balance.