Daylight saving time was originally proposed to shift daylight hours to times when people are actually awake. The theory: fewer lights burning in the evening means less electricity used. A century later, the evidence for that energy saving is surprisingly mixed.
The Origin
British builder William Willett published 'The Waste of Daylight' in 1907, proposing that clocks be advanced in summer to make better use of morning light. Germany and Austria-Hungary were first to implement the idea in 1916 during World War I, purely to conserve coal. Britain and most of Europe followed within weeks. The United States adopted it in 1918.
After World War I, most countries abandoned DST as an inconvenience. It returned during World War II for the same energy reasons. In the US, it remained a patchwork of state and local decisions until the Uniform Time Act of 1966 standardized it nationally.
Does It Actually Save Energy?
The evidence is weak. A 2008 study of Indiana (which adopted DST statewide in 2006) found that electricity use actually increased slightly — because air conditioners ran more in warm evenings, offsetting any lighting savings. Similar studies in Australia and California found negligible or no energy benefit.
Other costs are clearer. Studies consistently show a spike in heart attacks, car accidents, and reduced productivity in the days after the spring clock change. The circadian disruption of losing one hour is measurably worse than gaining one.
The Push to Abolish It
The European Union voted in 2019 to eliminate DST transitions, leaving each member state to choose a permanent time. Implementation has stalled over disagreement about whether to stay on standard or summer time permanently. In the US, the Sunshine Protection Act to make DST permanent passed the Senate unanimously in 2022 but stalled in the House. As of 2025, both regions still change their clocks twice a year.
