Daylight Saving Time 2024: When and Why Clocks 'Fall Back'

In just a few weeks, most Americans will experience the end of daylight saving time for 2024. On Sunday, November 3, 2024, at precisely 2 a.m., clocks will be turned back one hour, marking the annual transition to standard time. This change signals the start of shorter daylight hours, with the sun rising earlier and setting before 7 p.m. The adjustment, while granting us an extra hour of sleep, ushers in the darker, colder months of the year. Despite its long history, daylight saving time remains a topic of debate, especially as measures to make it permanent continue to stall in Congress. However, until those laws change, the U.S. will continue to "fall back" each November and "spring forward" in March.

The concept of daylight saving time is over a century old. It first gained prominence during World War I when Germany introduced the practice to conserve energy by extending daylight hours. The United States adopted daylight saving time in 1918, with the passage of the Standard Time Act. This wartime measure was originally intended to conserve fuel, allowing for more natural daylight during working hours. The U.S. implemented daylight saving time again during World War II for similar reasons. However, the practice was not standardized until 1966, when Congress passed the Uniform Time Act to provide a consistent schedule across the nation. Before this law, states had varying start and end dates for daylight saving time, leading to confusion.

Under the current system, established in 2005, daylight saving time begins on the second Sunday in March and ends on the first Sunday in November. This extension was signed into law by President George W. Bush, adding several weeks to the period in which daylight saving time is observed. When daylight saving time ends each fall, most Americans set their clocks back an hour, effectively moving an hour of daylight from the evening to the morning. This shift is intended to take advantage of the earlier daylight during the colder months, reducing the need for artificial lighting and energy use. However, not all states observe daylight saving time. Arizona and Hawaii are the notable exceptions. Both states have opted to remain on standard time year-round. Under federal law, states have the option to forgo daylight saving time, though they cannot remain on daylight time permanently without approval from Congress.

There has been an ongoing push in recent years to make daylight saving time permanent. Lawmakers have introduced multiple bills to eliminate the twice-yearly time change, citing potential benefits such as improved public health, increased economic productivity, and reduced confusion. One of the arguments for permanent daylight saving time is that it could lead to better overall sleep schedules. The biannual shift can disrupt circadian rhythms, contributing to sleep disorders and related health issues. Additionally, proponents believe that longer daylight hours in the evening could boost economic activity by encouraging people to spend more time outdoors and engage in leisure activities. However, these efforts have largely stalled in Congress, leaving Americans to continue adjusting their clocks twice a year for the foreseeable future.

As mentioned earlier, Arizona and Hawaii are the only U.S. states that do not observe daylight saving time. In Arizona, the extreme summer heat makes longer daylight hours less desirable, as residents prefer cooler evenings. Hawaii, on the other hand, is closer to the equator, where daylight hours remain relatively consistent throughout the year, making daylight saving time unnecessary. Other U.S. territories, such as Puerto Rico, the Virgin Islands, and Guam, also do not observe daylight saving time. These areas, like Hawaii, experience minimal variation in daylight hours across the seasons, negating the need for the time shift.