The hour of sleep we lost in the spring will be returned early Sunday morning as Daylight Saving Time (DST) ends. The annual “fall back” happens at 2 a.m., so it is recommended that everyone reset their clocks Saturday night before they go to bed.
The idea of adjusting the clocks dates back to 1895 when New Zealand entomologist George Hudson proposed a two-hour shift to gain extra daylight for his evening insect studies. It was British builder William Willett, however, who, in 1907, first earnestly advocated for the time shift to encourage more daytime activity and reduce energy use. The concept reached the U.S. in 1918 when it was adopted during World War I as a measure to save fuel. After the war, DST was abandoned, only to be revived during World War II and eventually standardized in 1966 with the Uniform Time Act.
This act established a uniform system of DST throughout the U.S., setting clocks forward one hour in the spring and back in the fall. Since then, DST has undergone tweaks, including a 2007 extension under the Energy Policy Act, which set DST from the second Sunday in March to the first Sunday in November.
Why We “Fall Back”
Initially, DST was meant to conserve energy by reducing the need for artificial light in the evening. Studies suggest that DST still leads to some reduction in electricity use for lighting, though it’s less pronounced in the modern era. However, health and safety considerations are also at play. The extra hour of sunlight during the evening in spring and summer is thought to encourage more outdoor activity, potentially benefiting physical health. Studies also suggest DST may reduce traffic accidents by providing more light during busy commuting hours in the spring.
Despite these perceived benefits, there’s ongoing debate about whether DST’s energy-saving impacts are still significant. Some researchers argue that DST disrupts sleep and natural rhythms, leading to health issues. This has fueled debates over whether to continue or abandon the practice altogether.
Exceptions in the U.S.
While most states observe DST, a few parts of the U.S. do not. Hawaii and most of Arizona (except the Navajo Nation) remain on standard time year-round. Hawaii’s proximity to the equator means it experiences relatively consistent sunrise and sunset times throughout the year, making the time shift unnecessary. Arizona, where the intense summer heat makes evening sunlight less desirable, opted out in 1968. Several U.S. territories, including Puerto Rico, Guam, and the U.S. Virgin Islands, also forgo DST.
How Other Countries Handle DST
The U.S. is far from alone in this biannual clock adjustment. Over 70 countries worldwide observe DST, although the dates of change vary. In Europe, the clocks “fall back” on the last Sunday in October and “spring forward” on the last Sunday in March. However, there has been a strong push within the European Union to eliminate the time changes entirely, with many in favor of sticking to either permanent standard time or permanent DST.
In contrast, most countries near the equator, where daylight hours are more consistent throughout the year, do not observe DST. For example, Russia, China, and Japan do not adjust their clocks.
A Growing Push for Change
As more research highlights potential downsides of DST, some U.S. states are pushing to change the tradition. In recent years, several states, including California, Florida, and Washington, have proposed staying on DST year-round, but federal approval is needed. In March 2022, the U.S. Senate even passed the Sunshine Protection Act, which would make DST permanent, though it has yet to pass in the House of Representatives.
Whether DST continues or ends in the U.S. remains uncertain. But for now, Americans can look forward to an extra hour of sleep this weekend—a small gift of time as winter approaches.