"We think that there's no need to change the clocks," Kelly said to Deutsche Welle. "It came in during World War One, it was supposed to be for energy savings—the indications are that there are very few energy savings, if any—and there are an awful lot of disadvantages to both human beings and animals that make it outdated at this point."
The claim that setting clocks an hour ahead in spring doesn't save energy or make societies safer is often used by Daylight Saving opponents. In the past, when lighting a home was the primary driver of electricity consumption, adjusting clocks to take advantage of late-evening sunlight might have made a dent in that consumption. But in today's world, air conditioning and electronics are also significant portions of electricity demand, and optimizing business hours to coincide with daylight hours doesn't significantly impact that draw of electricity.
In fact, the US added three more weeks to Daylight Saving Time in 2005, in part in the hopes of capitalizing on potential energy savings. But by 2007 that dream hadn't panned out: people just consumed more electricity in the dark morning hours instead of in the dark evening hours.