Sometime Saturday, people across most of the United States will be setting their clocks back at 2 a.m. Sunday to mark the end of daylight savings time and a return to standard time, continuing a practice going back to 1908.

The time change is also a good opportunity for people to check the batteries in their smoke alarms, local fire and emergency management officials said.

“It’s a good time to check your batteries,” Warren County Emergency Management Director John Elfer said. “That’s something we recommend.”

“We change times twice, so we tell people to check their batteries twice a year, when we change to daylight savings time and then change back,” Fire Chief Charles Atkins said. “You want to make sure the alarms are in good shape and the batteries are working.”

Daylight savings time was first implemented in Thunder Bay, Ontario, Canada, in 1908, but the first modern national use of daylight savings time was in 1916, when it was implemented in World War I by Germany as a way to reduce the use of fuel by reducing the need for lighting at night.

It was instituted in the U.S. in 1918 to help the war effort, and in 1942, President Franklin Roosevelt instituted year-round daylight savings time during World War II.

In 1966, Congress passed the Uniform Time Act of 1966 setting daylight savings time from last Sunday of April and end on the last Sunday of October, but states had the ability to be exempt by passing a state ordinance.

Daylight savings time was extended to 10 months during the Arab oil embargo, and was later amended several times until 2007, when the Energy Policy Act of 2005 set daylight savings time on its present formula to start on the second Sunday in March and ends on the first Sunday in November.