The good news is that you will gain an additional hour of sleep, but the downside is that it will be dark outside by late afternoon for the next few months in the U.S.
Daylight saving time concludes at 2 a.m. local time on Sunday, November 3, so remember to set your clocks back an hour before going to bed. Standard time will remain in effect until March 9, when we will “spring forward” once more.
Adjusting to the spring time change can be more challenging for your body. The transition to darker mornings and lighter evenings may disturb your internal body clock, potentially making it difficult to fall asleep at the right time for weeks or longer. Research has noted an increase in heart attacks and strokes immediately following the March time change.
The transition to standard time in the fall is generally easier, although it may still take some time to adjust your sleep patterns. Moreover, the adjustment can bring challenges, such as leaving work in the dark or exercising while there is still daylight. Individuals with seasonal affective disorder, a form of depression associated with shorter days and reduced sunlight during the fall and winter months, may also find the transition difficult.
Various health organizations, including the American Medical Association and the American Academy of Sleep Medicine, advocate for the elimination of time changes. They argue that sticking with standard time aligns better with natural daylight and human biology.
Most countries do not observe daylight saving time, and among those that do, mainly in Europe and North America, the clock change dates vary. There are two states, Arizona and Hawaii, that do not participate in these changes and remain on standard time.
Here’s a breakdown of how the body responds to light exposure. The brain regulates a master clock that is influenced by sunlight and darkness, maintaining a circadian rhythm that follows a roughly 24-hour cycle that affects sleepiness and alertness. This cycle can change with age, explaining why young children tend to rise early while teenagers might struggle to wake up.
Morning light calibrates this rhythm, while evening levels of melatonin, a hormone that induces drowsiness, rise as darkness falls. Extended evening light, like that gained from daylight saving time, can disrupt this natural rhythm.
The impact of time changes on sleep is notable. Even a one-hour shift can disrupt sleep schedules, particularly because work and school hours remain unchanged. This issue is exacerbated by the fact that one in three U.S. adults do not get the recommended seven-plus hours of sleep, and over half of U.S. teenagers do not achieve the advised eight-plus hours during weekdays. Lack of sleep is linked to various health issues, including heart disease and obesity.
To prepare for the time change, some people gradually adjust their bedtimes in the days leading up to the switch. Several strategies can help facilitate this adjustment, such as increasing exposure to sunlight to realign your circadian rhythm and promote better sleep.
Legislators periodically propose legislation to eliminate time changes altogether. The most notable recent initiative is the stalled bipartisan Sunshine Protection Act, which aimed to make daylight saving time permanent. However, health experts contend that making standard time permanent would be a more beneficial approach.
The Associated Press Health and Science Department receives financial support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.