As clocks move forward this Sunday across most of the United States, the seasonal ritual reveals a deeper story – from wartime energy policies to modern debates about sleep, health and global timekeeping.
LOS ANGELES — Early Sunday morning, millions of Americans will move their clocks forward by one hour as daylight saving time returns across most of the United States.
The change takes effect at 2 a.m. on Sunday, March 8, when clocks advance to 3 a.m., shortening the night but extending daylight later into the evening.
The adjustment, commonly remembered through the phrase “spring forward, fall back,” has become a familiar marker of the approach of spring. Smartphones and digital devices update automatically, but wall clocks, appliances and vehicle dashboards often require manual resetting.
Yet behind this annual routine lies a complex history – one shaped by war, energy policy, economic interests and ongoing public debate.
A system shaped by war and energy concerns
Modern daylight saving time first gained widespread adoption during World War I, when several countries shifted their clocks in an effort to conserve fuel by extending evening daylight.
The United States later adopted similar measures during World War II, when the country observed year-round daylight saving time — known as “War Time” — from 1942 to 1945.
The modern schedule was later standardized under the Uniform Time Act, which established national rules for when clocks should change.
Supporters argued that the system helped maximize daylight hours for commerce, recreation and energy efficiency.
A debate that continues today
More than half a century later, the twice-yearly clock change remains the subject of debate among lawmakers, health researchers and the public.
Some studies have linked the spring time shift to temporary disruptions in sleep and the body’s internal Circadian rhythm. Researchers have also examined possible short-term increases in fatigue, workplace accidents and traffic incidents in the days following the clock change.
These concerns have fueled legislative proposals such as the Sunshine Protection Act, which would eliminate the clock change and keep the United States on daylight saving time year-round. The proposal has been discussed in Congress but has not yet been enacted into law.
For now, the twice-yearly adjustment remains part of American life.
Where daylight saving time does not apply
Two states remain on standard time throughout the year:
• Hawaii
• Arizona, except for the Navajo Nation, which follows daylight saving time.
Several U.S. territories also remain on standard time year-round, including Puerto Rico, Guam, American Samoa, Northern Mariana Islands, and the U.S. Virgin Islands.
Why the Philippines does not change its clocks
Unlike the United States and many European countries, the Philippines does not observe daylight saving time and remains on Philippine Standard Time (UTC+8) year-round.
Because the country lies near the equator, sunrise and sunset times vary only slightly across seasons, making clock adjustments largely unnecessary.
The Philippines experimented with daylight saving time several times in the past — including during World War II and again in 1978 during the energy crisis under Ferdinand Marcos — but the policy was later discontinued.
For Filipino families with relatives in the United States, the clock shift means the time difference between the two countries changes during the year.
Philippines–U.S. time difference
When the United States observes daylight saving time, the Philippines becomes slightly closer in time.
During U.S. daylight saving time (March–November)
- Los Angeles – Manila is 15 hours ahead
- San Francisco – Manila is 15 hours ahead
- Chicago – Manila is 13 hours ahead
- New York City – Manila is 12 hours ahead
During U.S. standard time (November–March)
- Los Angeles / San Francisco – Manila is 16 hours ahead
- Chicago – Manila is 14 hours ahead
- New York City – Manila is 13 hours ahead
Myths and little-known facts about daylight saving time
Several myths and surprising facts surround daylight saving time.
Farmers were not the original supporters.
Agricultural work follows sunlight rather than the clock, and many farmers historically opposed shifting time schedules.
Benjamin Franklin’s link to the idea was partly humorous.
In 1784, Benjamin Franklin wrote a satirical essay suggesting Parisians could save candles by waking earlier to use sunlight.
The system spread during wartime.
Energy conservation during World War I helped popularize daylight saving time.
Many countries near the equator do not use it.
Countries such as the Philippines experience little seasonal variation in daylight hours.
The debate continues.
The Sunshine Protection Act reflects ongoing discussions about whether the clock change should remain.
