DETROIT – People will be turning their clocks back an hour Sunday morning, and that one-hour change could have a big impact. People will push the clock back an hour and get an extra hour of sleep. Daylight Saving Time plan was first adopted in the United States in March 1918 -- a year after the country entered World War I. However, the policy went back into effect during World War II for the same reason -- to save energy. Daylight Saving Time is also a good time to check the batteries on your smoke detectors.