夏令時，這是一個大部分中國人早已淡忘，或者不熟悉的製度，但它又是一個世界上半數以上國家都實行的製度。它又稱“夏時製”、“日光節約時製”和“夏令時間”，是一種為節約能源而人為規定地方時間的製度。一般在天亮早的夏季人為將時間提前一小時，可以使人早起早睡，減少人工照明，以充分利用自然光照資源，從而節約照明用電。
Host： It’s daylight saving time， and if you feel a bit 1)grumpy about losing an hour of sleep last night， you can blame one of the first people to 2)advocate having the government do something to get people out of bed early. That was Benjamin Franklin， not because he was in the habit of getting up early. As American Minister to France in 1784， Franklin wrote that he usually slept ’til noon， and was amazed after he forgot to close the 3)shutters one night and sunshine filled his room at six AM.
So did Franklin invent daylight saving time？
David Prerau (Researcher)： He probably didn’t do it himself.
Host： The person who actually invented it， I guess， was a British home-builder…
David： That’s right. His name was William Willett. He thought of it in about 1905， and he used to go each morning for an early morning horseback ride， and he was surprised to see that nobody was up and about while he was riding， because he thought it was the most beautiful time of the day. After thinking about this for a long time， he finally conceived of the idea of moving the clocks forward. Willett’s proposal was embodied in a bill that was put to Parliament， but Parliament rejected it for nine years， and eventually Willett died never having seen daylight saving time come to fruition.
Host： It was really World War I that put daylight saving time into use， wasn’t it？