What Is Daylight Saving Time?

02 November 2023

As November begins, many countries in North America and Europe are turning the clock back as daylight saving time ends.

Daylight saving time is the practice of moving clocks forward by one hour during summer months so daylight lasts longer into the evening.

In Europe, the practice is called European Summer Time. The clock usually moves forward in March and turns back at the end of October. Most European countries follow the practice. Georgia, Russia, Turkey, Iceland and a few others are among the exceptions.

FILE - Clocks are displayed at Electric Time Company on Nov. 1, 2022, in Medfield, Massachusetts. (AP Photo/Charles Krupa)
FILE - Clocks are displayed at Electric Time Company on Nov. 1, 2022, in Medfield, Massachusetts. (AP Photo/Charles Krupa)

Across the Atlantic Ocean, Canada, Mexico, Cuba and the United States start daylight saving time in March also. The clock will be set back an hour on November 5 this year.

Countries closer to the equator usually do not follow daylight saving time because the period of daylight changes little. Those that do not change the times include countries in Central America, Asia and Africa.

How did it start?

The idea of changing the clocks with the seasons started with George Hudson, a New Zealand scientist who studied insects. In 1895, Hudson proposed a time change to extend summer daylight hours. The extra time would have helped him with collecting insects after work.

The idea did not appeal to anyone until the time of World War I when European countries sought to save energy. Germany was the first country to adopt daylight saving time, in 1916, and the U.S. followed in 1918.

Some people believe that the U.S. established daylight saving time to help farmers. But farmers generally do not like the practice. The publication Modern Farmer said American farmers were against the practice but that Congress approved it anyway.

Opponents of daylight saving time have pointed to studies that found an increase in traffic accidents, health issues, and lack of sleep in the days after clocks are moved forward every March.

As for saving energy, the Congressional Research Service said studies have found little, if any, energy savings from the time change.

Arguments to end the practice

Daylight saving time has been a fluid issue from the start. Some countries have adopted and rejected it several times. In South America, Uruguay ended the practice in 2015. Chile replaced it with "wintertime" from May to August in 2016.

Egypt announced in March it would return to daylight saving time after seven years to save energy. Japan briefly considered adopting the practice for the 2020 Olympics but rejected it due to a lack of popular support.

In the U.S. there have been several efforts to make daylight saving time permanent. Last year, a bill called the "Sunshine Protection Act" passed the Senate but got stuck in the House of Representatives. Lawmakers could not agree on whether to keep standard time or permanent daylight saving time.

The bill was proposed again this year.

I'm Caty Weaver.

Hai Do wrote this story for Learning English with additional reporting from Reuters.