Daylight-saving time begins the second Sunday of March.

Wagner and Barnes found daylight-saving time resulted in 40 minutes less sleep for workers. They also found workplace injuries increased about 6 percent after daylight-saving time.

Not only are there more injuries, but the researchers believe the injuries are more severe, Wagner said.

“The people who got injured on other days could come back (to work) years earlier,” he said, adding that daylight-saving time injuries have delayed workers’ return to work by an average of 2,000 days as compared to non-daylight-saving time injuries.

The data used was from two databases — one, the American Time Use Survey from the Bureau of Labor Statistics, was from a representative sample of the U.S. population and the other, from the Mine Safety and Health Administration, with data from coal miners, Wagner said.

Barnes said the most surprising aspect of the study was that it hadn’t been conducted before.

“One would think that this would have come to light sooner,” Barnes said in an e-mail. “People are getting hurt, sometimes seriously. But sleep is a topic that is usually ignored in workplace settings.”

Barnes studied sleep for the four-and-a-half years he has been a doctoral student at MSU, and for two years in the Air Force Research Laboratory prior to his arrival at MSU. After a discussion with Wagner after daylight-saving time in 2008, they decided to research it. At first they focused on the cognitive errors that could result from the loss of sleep after the time change.

“But as we discussed it further, we focused more on what might result from those cognitive errors, such as workplace injuries,” Barnes said in an e-mail.

The research began last April and the pair presented it at the Society for Industrial and Organizational Psychology’s annual conference in New Orleans in April of this year.

Industrial and organizational psychology is the application of psychological research to topics in the workplace, said Ann Marie Ryan, a psychology professor at MSU.

“It might be using psychology to predict behavior, some organizational psychologists try to predict who will be a good employee, some might be doing training,” she said.

“It’s anything in psychology put in the context of people in the workplace.”

Wagner and Barnes are planning to follow up their research by possibly looking into other negative effects the change to daylight-saving time has on employees, especially on their motivation. They also are considering another study that would investigate strategies for managing the negative effects of changing to daylight-savings time, Barnes said.