Encyclopedia Britannica | Britannica
The AI Debate
Spring Ahead
This weekend marks Daylight Saving Time (DST) in many countries, when clocks will jump ahead one hour. Here’s a quick look at why it began and how it has changed.
The practice was first suggested in an essay by Benjamin Franklin in 1784. In 1907 an Englishman, William Willett, campaigned for setting the clock ahead by 80 minutes in four moves of 20 minutes each during April and the reverse in September.
Several countries—including Australia, Great Britain, Germany, and the United States—adopted summer DST during World War I to conserve fuel by reducing the need for artificial light. During World War II clocks were kept continuously advanced by an hour in some countries.
In the U.S., DST once began on the last Sunday in April and ended in October. In 1986 the start of DST was moved to the first Sunday in April. In 2007 DST changed again, as the start date was moved to the second Sunday in March and the end date to the first Sunday in November. In most countries in western Europe, DST starts on the last Sunday in March and ends on the last Sunday in October.
© bortonia—DigitalVision Vectors/Getty Images; Animation Encyclopædia Britannica, Inc.
New on Britannica
The largest known arachnid by mass, this South American tarantula has an appetite that extends beyond insects and earthworms.
Here’s a look at the history of DEI programs, which aim to address historical and systemic disparities, in the United States.
Featured Games
Featured Videos
Madeleine Albright on immigrating to the United States
Encyclopædia Britannica, Inc.
Britannica Premium Subscription
Unlock Exclusive Content!
Britannica's content is among the most trusted in the world. Subscribe to Britannica Premium and unlock our entire database of trusted content today.
Subscribe Now!
Explore Britannica
More From Britannica
Award-winning ProCon promotes critical thinking, education, and informed citizenship by presenting the pro and con arguments to controversial issues in a straightforward, nonpartisan, freely accessible way.
Discover all you need to know about retirement, investing, and household finance, without the jargon or agenda. Get reliable guidance, insight, and easy-to-understand explanations, written, edited, and verified to Britannica’s exacting standards.
Presenting Advocacy for Animals, a blog focused primarily on animal rights, wildlife conservation, environmental health and safety, and the legal and cultural issues related to these topics. This blog is a source of information and a call to action. It is meant to be a provocation and a stimulus to thought regarding humanity’s relationship with nonhuman animals.
Alain has been writing a weekly interview column for the Italian newspaper La Stampa since 1989. His interviews celebrate some of the best known and successful personalities of the present day.