Daylight Saving Time: Health Risks, Sleep Tips, and What to Expect

Every year, much of the United States “springs forward” in early March to begin daylight saving time (DST). Many other countries also follow this practice, although their start and end dates can differ. While gaining an extra hour of evening daylight may feel helpful, the sudden time change often leaves people tired, irritated, and even at risk for certain health problems.

When Does Daylight Saving Time Start?

In the U.S., daylight saving time begins on Sunday at 2:00 a.m., when clocks are moved one hour ahead. The schedule reverses on November 2, when clocks “fall back” and return to standard time.

Some places in the U.S. do not observe DST at all. Daylight saving time is not observed in Hawaii, most areas of Arizona, Puerto Rico, Guam, American Samoa, or the U.S. Virgin Islands. Virgin Islands stay on standard time throughout the year.

Why the Time Change Affects the Body

A big reason the time shift feels difficult is the body’s internal 24-hour clock called the circadian rhythm. This natural cycle is controlled mainly by light and darkness. It guides our body on when to get sleepy and when to become alert.

Exposure to morning sunlight resets this rhythm each day. In the evening, the hormone melatonin rises, preparing the body for sleep. But when DST adds an extra hour of evening light, the body delays melatonin release. This pushes the sleep cycle later, making it harder to fall asleep and harder to wake up early the next day.

Circadian rhythms don’t just control sleep. They influence blood pressure, heart rate, hormone levels, and overall body functioning. That’s why even a one-hour shift can affect health.

Health Problems Linked to Daylight Saving Time

A lack of sleep—even a small amount—can lead to serious issues. Researchers have reported that right after the spring time change:

• Deadly car crashes increase, especially in the morning

• Heart attacks rise on the Monday after the change

• Strokes are more common for the next two days

Doctors believe these spikes may happen because sleeplessness triggers stress in the body. People already at risk for high blood pressure or heart problems may be more sensitive to sudden changes in sleep schedules.

Why Many People Struggle With the Change

About one-third of American adults already fail to get the recommended seven hours of nightly sleep. Because of that, adjusting to a new schedule becomes even more difficult. Trying to “catch up” on lost sleep can take several days or even a full week.

How to Prepare for Daylight Saving Time

Experts share several simple strategies to make the transition smoother:

• Go to bed 15–20 minutes earlier for two or three nights before the time change

• Wake up a bit earlier the next morning to train your body

• Get morning sunlight during the first week of DST to reset your internal clock

• Shift daily habits—like meals, exercise, and screen time—a little earlier

• Avoid napping and reduce caffeine late in the day

• Limit evening screen time, since bright devices delay melatonin

These small adjustments help your circadian rhythm settle into the new schedule more quickly.

Should Daylight Saving Time End?

For years, Americans have debated whether DST should continue. Although many people find the longer daylight helpful in the evening, several major health organizations disagree. Groups such as the American Medical Association and the American Academy of Sleep Medicine support ending seasonal time changes completely. They argue that staying on standard time all year is healthier for the human body and supports more natural sleep patterns.

Final Thoughts

Daylight saving time brings more sunshine later in the day, but the one-hour shift can affect sleep, mood, and even heart health. Preparing ahead—by adjusting bedtime gradually and seeking morning light—can help your body adapt with less stress. As the debate over ending DST continues, one thing remains clear: protecting healthy sleep habits is essential for overall well-being.