After clocks “sprang forward” in March for Daylight Saving Time, people will have to adjust their clocks again in November, and for those who enjoy sleeping in on the weekend, that’s good news.
Read more Large law enforcement response underway at Miami International Airport
When does the time change?
Daylight Saving Time will end the first Sunday of November, which this year will be on Nov. 1 at 2 a.m. When clocks “fall back” by one hour, it will be 1 a.m.
Which states do not follow daylight saving time?
Hawaii and Arizona (except the Navajo Indian Reservation) are the only two states that do not observe daylight saving time. The U.S. territories of Puerto Rico, Guam, American Samoa and the U.S. Virgin Islands also do not follow daylight saving time.
What’s the history of daylight saving time?
Before the U.S. adopted standardized time zones, cities set their clocks based on the sun, leading to widespread inconsistencies, especially for railroads, according to the Bureau of Transportation Statistics. To address this, U.S. and Canadian railroads implemented four time zones in 1883, creating the foundation of today’s system.
In 1918, Congress officially established time zones and introduced daylight saving time during World War I to conserve energy. Though DST was later repealed in 1919, inconsistent local observances of time created confusion. The Uniform Time Act of 1966 sought to fix this by standardizing DST nationwide while allowing states to opt-out.
The Department of Transportation has helped ensure uniformity in timekeeping since 1966. Time zone boundaries have continued to evolve, with adjustments as recently as 2010, when Mercer County, North Dakota, chose to switch from Mountain to Central Time.
How does the time change affect 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.
Read more Alleged introducer who was fatally shot in Miami ID’d, police say
Fatal car crashes temporarily jump the first few days after the spring time change, according to a study of U.S. traffic fatalities. The risk was highest in the morning, and researchers attributed it to sleep deprivation.
Then there’s the cardiac connection. The American Heart Association points to studies that suggest an uptick in heart attacks on the Monday after daylight saving time begins, and in strokes for two days afterward.
Doctors already know that heart attacks, especially severe ones, are a bit more common on Mondays generally — and in the morning, when blood is more clot-prone.
Researchers don’t know why the time change would add to that Monday connection but it’s possible the abrupt circadian disruption exacerbates factors such as high blood pressure in people already at risk.
Will the U.S. ever eliminate the time change?
Every year there’s talk about ending the time change. In April, President Donald Trump urged congress to eliminate the time changes. The Senate in 2022 unanimously approved a measure that would make daylight saving time permanent across the United States, but it did not advance.
There has been growing interest in states to standardize daylight saving time in recent years.
Read more Video shows dog zooming across Naples Airport tarmac—earning nickname, happy ending
But daylight saving time is still recognized in most parts of the country.