How springing forward to daylight saving time could affect your health -- and how to prepare

WASHINGTON (AP) — Most of America “springs forward” Sunday for daylight saving time and losing that hour of sleep can do more than leave you tired and cranky the next day. It also could harm your health.

Darker mornings and more evening light together knock your body clock out of whack — which means daylight saving time can usher in sleep trouble for weeks or longer. Studies have even found an uptick in heart attacks and strokes right after the March time change.

There are ways to ease the adjustment, including getting more sunshine to help reset your circadian rhythm for healthful sleep.

“Not unlike when one travels across many time zones, how long it can take is very different for different people,” said Dr. Eduardo Sanchez of the American Heart Association. “Understand that your body is transitioning.”

When does daylight saving time start?

Daylight saving time begins Sunday at 2 a.m., an hour of sleep vanishing in most of the U.S. The ritual will reverse on Nov. 3 when clocks “fall back” as daylight saving time ends.

Hawaii and most of Arizona don’t make the spring switch, sticking to standard time year-round along with Puerto Rico, American Samoa, Guam and the U.S. Virgin Islands. Worldwide, dozens of countries also observe daylight saving time, starting and ending at different dates.

Some people try to prepare for daylight saving time’s sleep jolt by going to bed a little earlier two or three nights ahead. With a third of American adults already not getting the recommended seven hours of nightly shuteye, catching up can be difficult.

What happens to your brain when it's lighter later?

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re...