美国有线新闻 CNN 夏令时的起源及争议（在线收听）

It was in 1918 during the First World War, that the U.S. followed Germany and then Britain in observing daylight-saving time.

There's a bit of controversy surrounding who first proposed daylight-saving time. Some credit U.S. founding father Ben Franklin when he wrote about a schedule switch in an essay. A New Zealand entomologist named George Hudson purposed a time shift in 1895. And William Willet, the great-great grandfather of Coldplay's lead singer, also gets credit, as you're about to hear, for daylight-saving time. But regardless of who's to thank or to blame for it, it's been observed by several countries since the First World War, and getting rid of it, at least in the U.S. would take an act of Congress.

JIM BOLDEN, CNN CORRESPONDENT: This was a war where every hour counted. On the battlefield and on the home front. By 1916, an old idea had resurfaced, one that was born in Britain near the home of time, the Royal Observatory at Greenwich.

DR. LOUISE DEVOY: With the publication of a pamphlet called "The Wasted Daylight". And this was composed by a very entrepreneurial builder called William Willett. He lived in Chislehurst which is about 15 kilometers south of Greenwich. And Willet was a keen horse rider and he used to go for early morning rides in the local woods. And it was on one of his rides that he noticed that all the blinds in the local houses were all down. Eeveryone seemed to be in bed. And as a very industrious and productive man, he was appalled at this waste of time.

UNIDENTIFIED MALE: "Everyone appreciates the long light evenings. Everyone laments their shrinkage as the days grow shorter. And nearly everyone has given utterance to a regret that the clear bright light of early mornings during spring and summer months is so seldom seen or used. Now, if some of the hours of wasted sunlight could be withdrawn from the beginning and added to the end of the day, how many advantages would be gained by all?"

BOLDEN: Willet died before he saw his idea put into action, to save coal for the war effort. But it was adopted at first by the Germans, not the British. Post cards warn the population about the shift, and why they owed it to their country not to forget. The British followed a few weeks later and didn't miss a chance for a dig at the Germans. America came on board in 1918. As DST spread around the world, countries adopted it, dumped it or never tried it.

Still, the daylight debate rages every year. The arguments exist whether it helps or harms our health and the economy. While the war time wisdom of saving energy may no longer apply, for many of us, the long summer evenings still endure. The legacy of a war where so much was lost to give us these freedoms. Jim Bolden, CNN, London.