A national debate in the United States over Daylight saving time (DST) is a timely issue. In March 2022, the U.S. Senate passed the Sunshine Protection Act to make DST permanent in states that previously have chosen to make that change. The U.S. House has not passed this legislation. Daylight saving time (DST) refers to the practice of advancing clock time by one hour each spring, with a return (setting back) to standard time (ST) each fall. Numerous sleep and circadian societies have published statements in support of permanent ST, which also has received support from multiple medical societies and organizations. Recently, the Sleep Research Society (SRS) in the December 2022 issue of its journal Sleep advocates the adoption of permanent ST. In contrast, on the opposing side of the debate is that the business community, including the National Association of Convenience Stores and the Sporting Goods Manufacturing Association support permanent DST. One of the most prominent arguments in the debate over adopting permanent ST (rather than permanent DST) is how health, sleep, and circadian biology are affected.
DST shifts daylight into the early evening in exchange for less daylight in the early morning when more individuals are presumed to be asleep. This light exchange has both social and economic benefits, with more natural light for evening activities and less need for artificial light in the evening. Nonetheless, there are health consequences to DST for those whose school or jobs require them to awaken early. Evening light extended too close to bedtime also can disrupt sleep patterns. Compared to individuals living on the eastern edge of a time zone, residents living on the western edge of a time zone, who obtain light later in the morning, and later in the evening, self-report having less sleep based on time-use data. Sleep loss in adults has been associated with weight gain and obesity; diabetes; hypertension; heart disease; and stroke, depression, and increased risk of death, along with impaired immune function, increased pain, impaired performance, increased errors, and greater risk of accidents. Sleep loss in children has been associated with attention, behavior, and learning problems; along with increased risk of accidents, injuries, hypertension, obesity, diabetes, depression, self-harm, suicidal thoughts, and suicide attempts.