On the second Sunday of March， at 2 a.m.， clocks in most of the United States and many other countries move forward one hour and stay there for nearly eight months in what is called Daylight Saving Time. On the first Sunday of November， at 2 a.m.， clocks fall back an hour to standard time.

每年3月第二个周日的凌晨两点，美国大部分地区和其他许多国家的时钟都会拨快一个小时，然后维持差不多8个月，实行所谓的夏令时（也叫日光节约时制）。到11月第一个周日的凌晨两点，时钟又会调回到标准时间。

The current March to November system that the US follows began in 2007， but the concept of “saving daylight” is much older. Daylight Saving Time has its roots in train schedules， but it was put into practice in Europe and the United States to save fuel and power during World War I， according to the US Department of Transportation’s Bureau of Transportation Statistics.

美国现行的3月至11月夏令时开始于2007年，但“节约日光”的概念却有更久远的历史。美国交通部交通统计局的资料显示，夏令时源自列车时刻表，但将其付诸实施的是第一次世界大战期间的欧洲和美国，目的是节约燃料和电力。

Reasons for Daylight Saving Time

实行夏令时的缘由

The US kept Daylight Saving Time permanent during most of World War II. The idea was put in place to conserve fuel and keep things standard. As the war came to a close in 1945， Gallup asked respondents how we should tell time. Only 17% wanted to keep what was then called “war time” all year.

第二次世界大战期间的大部分时间里，美国一直实行夏令时，旨在节省燃料，保持标准统一。1945年，大战接近尾声，美国民调公司盖洛普就时制问题展开调查，只有17%的受访者表示愿意全年保留当时所谓“战争时间”的制度。

During the energy crisis of the 1970s， we tried permanent Daylight Saving Time again in the winter of 1973–1974. The idea again was to conserve fuel. It was a popular move at the time when President Richard Nixon signed the law in January 1974. But by the end of the month， Florida’s governor had called for the law’s repeal after eight schoolchildren were hit by cars in the dark. Schools across the country delayed start times until the sun came up. By summer， public approval had plummeted1， and in early October Congress voted to switch back to standard time.

20世纪70年代能源危机期间，美国在1973年至1974年的那个冬天再次尝试长期实行夏令时，这次还是为了节省燃料。1974年1月，时任总统理查德·尼克松签署了夏令时法案，实行夏令时在当时是个很受欢迎的举措。然而，就在那个月底，有8名小学生在黑暗中遭遇车祸，佛罗里达州州长呼吁撤销该法案。接着，全美的学校把上学时间推迟到太阳升起后。到了夏季，民众对夏令时法案的支持率已直线下降，10月初国会投票决定改回标准时间。

In the US， states are not required by law to “fall back” or “spring forward.” Hawaii， most of Arizona and some territories in the Pacific and Caribbean do not observe Daylight Saving Time. The twice-yearly switcheroo2 is irritating enough to lawmakers of all political stripes that the US Senate passed legislation in March 2022 to make Daylight Saving Time permanent. The bill passed by unanimous consent. It would need to pass the House of Representatives and be signed by President Joe Biden to become law.

美国法律并不要求各州必须“向后”或“向前”调整时间。夏威夷州、亚利桑那州大部分地区以及太平洋和加勒比海的部分美国属地都不实行夏令时。每年两次大调时间对各个派别的立法者来说都是件很恼人的事，于是，2022年3月，美国国会参议院通过了将夏令时永久化的法案。……