Why does daylight saving time exist?

The Senate has unanimously passed legislation that would end changing clocks. The bill will now head to the House and, if passed, will be sent to President Joe Biden’s desk. As lawmakers debate daylight saving time, many are wondering why we have it in the first place.

Germany was the first to adopt the practice during World War I as a way to conserve fuel. The rest of Europe followed soon after. The United States didn’t begin using daylight saving time until 1918. It was unpopular and abolished after World War I.

Daylight saving time didn’t become standard in the U.S. until the passage of the Uniform Time Act of 1966, which mandated standard time across the country within established time zones. It stated that clocks would advance one hour at 2 a.m. on the last Sunday in April and turn back one hour at 2 a.m. on the last Sunday in October.

Daylight saving time has continued to evolve. It now starts at 2 a.m. on the second Sunday of March and ends at 2 a.m. on the first Sunday of November. The change was advocated in part to allow children to go trick or treating in more daylight.

Only two states don’t observe daylight saving time: Arizona and Hawaii.