The House of Representatives has passed the Sunshine Protection Act, a bill that would establish Daylight Saving Time (DST) as permanent across the United States. If enacted, the legislation would eliminate the twice-yearly practice of altering clocks, a change proponents argue would benefit public health and safety.
The bipartisan bill will now proceed to the Senate for consideration. However, its path forward remains uncertain, with some senators expressing reservations. Senator Tom Cotton of Arkansas recalled the 1974 experiment with permanent DST, citing instances of children traveling to school in darkness and tragic accidents. He suggested that permanent DST could lead to millions of Americans commuting and attending school in the dark during winter months.
Despite these concerns, supporters of the bill, including former President Donald Trump, contend that permanent DST would reduce traffic accidents, enhance productivity, and potentially lower crime rates.
Experts, however, point to the disruptive effects of clock changes on the human body. Research indicates that the shift from standard time to DST is associated with a notable increase in traffic accidents. A 2020 study found a 6% rise in overall car crashes, with specific increases in freeway, non-intersection, and nighttime collisions following the spring time change.
Sleep experts note that altering clocks disrupts the body's natural circadian rhythm, which regulates sleep-wake cycles. This disruption can lead to acute adverse health consequences, including increased risks of heart attack and stroke, according to Johns Hopkins sleep expert Adam Spira. "The consequences of insufficient sleep include decreases in cardiovascular health, increases in diabetes and obesity, poorer mental health, lower cognitive performance, and an increase in the risk of motor vehicle accidents," Spira stated.
Dr. Donald Lloyd-Jones, president of the American Heart Association, highlighted the link between clock changes and disruptions to the body's internal clock, which may contribute to increases in heart disease and stroke.
Furthermore, the end of DST in the fall is associated with Seasonal Affective Disorder (SAD), a form of depression linked to reduced sunlight exposure. Up to 5% of the adult population is affected by SAD, with an additional 10-20% experiencing milder winter blues. Symptoms can include fatigue, low energy, loss of interest, and hopelessness. Experts believe a lack of sunlight during shorter winter days may affect brain chemistry, potentially leading to increased production of melatonin, a hormone associated with sleep.
Some research suggests that permanent standard time, rather than permanent DST, might be more beneficial for health. Morning sunlight is crucial for maintaining circadian rhythms, hormone regulation, and improving mood. Concerns exist that a later sunrise during winter under permanent DST could exacerbate sleep issues, alertness problems, and depression, potentially increasing the risk of obesity, type 2 diabetes, and cardiovascular disease.
Daylight Saving Time, the practice of advancing clocks during warmer months to extend daylight into the evening, has been observed in various parts of the world for over a century. Originally adopted to conserve energy by reducing the need for artificial lighting after dark, its effectiveness and health implications are now subjects of renewed debate as many countries have shifted to year-round standard time.