Many think that daylight saving time was conceived to give farmers an extra hour of sunlight to till their fields, but this is a common misconception. In fact, farmers have long been opposed to springing forward and falling back, since it throws off their usual harvesting schedule.

The real reasons for daylight saving are based on energy conservation and a desire to match daylight hours to the times when most people are awake. The idea dates back to 1895 when entomologist George Vernon Hudson unsuccessfully proposed an annual two-hour time shift to the Royal Society of New Zealand.

Ten years later, the British construction magnate William Willett picked up where Hudson left off when he argued that the United Kingdom should adjust their clocks by 80 minutes each spring and fall to give people more time to enjoy daytime recreation. Willett was a tireless advocate of what he called “Summer Time,” but his idea never made it through Parliament.

The first real experiments with daylight saving time began during World War I. On April 30, 1916, Germany and Austria implemented a one-hour clock shift to conserve electricity needed for the war effort. The United Kingdom and several other European nations adopted daylight saving shortly after that, and the United States followed suit in 1918. (While Germany and Austria were the first countries to implement daylight savings, the first towns to implement a seasonal time shift were Port Arthur and Fort William, Canada in 1908.)

Most Americans only saw the time adjustment as a wartime act, and it was later repealed in 1919. Standard time ruled until 1942, when President Franklin D. Roosevelt re-instituted daylight saving during World War II. This time, more states continued using daylight saving after the conflict ended, but for decades there was little consistency with regard to its schedule. Finally, in 1966, Congress passed the Uniform Time Act, which standardized daylight saving across the country and established its start and end times in April and October (later changed to March and November in 2007).

Today, daylight saving time is used in dozens of countries across the globe, but it remains a controversial practice. Most studies show that its energy savings are only negligible, and some have even found that costs are higher since people in hot climates are more apt to use air conditioners in the daytime. Meanwhile, Hawaii and Arizona have opted out of daylight saving all together and remain on standard time year-round.