In the campaign to do away with biannual resetting of clocks in America, health experts point to studies showing heart attacks, strokes, and car accidents are more prevalent shortly after a time change.
"Most of our physiology is governed by a circadian clock," Dr. Till Roenneberg told The Wall Street Journal. "This body clock synchronizes to the sun time."
Standard time is closer to sun time, which is the time Americans use in the winter months from early November to early March, according to Roenneberg, a professor at Ludwig-Maximilian University in Munich, Germany.
The U.S. turned the clock ahead one hour Sunday morning to switch back to daylight savings time, which is intended to give an extra hour of sunlight in the evening, ostensibly making sunrise an hour later and leaving some to commute to work in darkness.
"Daylight-saving time means that we virtually live in another time zone without changing the day-light cycle," Dr. Roenneberg, who conducted a study on the topic, told the Journal. "The problem is the misalignment. The circadian clock is trying to optimize our physiology. Now suddenly we have to do things which are not at the biologically appropriate time.
"It's a general stress of the physiology."
Other experts argue the difference of an hour is not as significant as the mere change itself.
"Going back and forth is ridiculous and disruptive, it makes no sense," Dr. Beth Ann Malow, professor of neurology at Vanderbilt University told the Journal.
Malow wrote an opinion on the topic for JAMA Neurology.
The American Academy of Sleep Medicine reported studies show sleep patterns are affected for 5-to-7 days after time changes and issues are more common for those losing sleep amid the change.
"A lot of people think it's like traveling from Chicago to New York, you get used to it within a day," Malow told the Journal. "It's very different than that. It's kind of like a permanent thing, where for the next eight months you're an hour off."