The good news is that you will enjoy an extra hour of sleep, but the downside is that the evenings will be dark early for the next few months in the United States. Daylight saving time will conclude at 2 a.m. local time on Sunday, November 3, so it’s advisable to set your clocks back one hour before bed. The return to standard time will last until March 9, when we will revert to daylight saving time.
The transition to springtime can be challenging for many, as the shift in light can disrupt the body’s internal clock, potentially leading to difficulties in falling asleep. Research has indicated an increase in heart attacks and strokes shortly after the time change in March.
In contrast, adjusting to the fall time change is often easier, but it can still take time for sleep patterns to normalize. Additionally, the shift means leaving work in the dark and exercising with limited daylight, which may pose challenges. Individuals suffering from seasonal affective disorder, a type of depression triggered by reduced daylight in fall and winter, may find this period particularly difficult.
Various health organizations, including the American Medical Association and the American Academy of Sleep Medicine, advocate for eliminating the time changes, arguing that maintaining standard time is more in line with natural sunlight patterns and human biology.
Most countries do not observe daylight saving time. Among those that do, primarily in Europe and North America, the dates for changing clocks differ. Notably, two states, Arizona and Hawaii, remain on standard time.
The human brain has a master clock governed by light exposure, which regulates the circadian rhythm—a roughly 24-hour cycle that affects alertness and sleepiness. This rhythm changes with age, which explains why children tend to wake early while teenagers often struggle to get up.
Morning light helps reset this internal clock, while melatonin levels rise in the evening to induce drowsiness. An additional hour of evening light from daylight saving time can delay this melatonin surge, disrupting the natural cycle.
Even minor adjustments to clocks can disturb sleep schedules since work and school start times remain constant. This is concerning, given that approximately one-third of U.S. adults do not get the recommended seven hours of sleep per night, and over half of teenagers fall short of the recommended eight hours.
Sleep deprivation is linked to various health issues, including heart disease and cognitive decline. To prepare for the time change, some individuals gradually adjust their bedtimes prior to the switch and seek more sunlight to help realign their circadian rhythms.
Occasional proposals have been made to eliminate the time change altogether. A notable recent effort, the Sunshine Protection Act, aimed to make daylight saving time permanent, yet health experts argue that standard time should be the one that is made permanent instead.