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 plummeted', 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。此法案经参议员们一致同意，但还需经众议院通过，再由时任总统乔拜登签字才能成为法律。
House lawmakers failed to vote on the bill in 2022. However, on March 2,a dozen senators forming a bipartisan group reintroduced the legislation that would end clock switching in favor of permanent Daylight Saving Time. Companion legislation to the Sunshine Proiection Act was introduced by Rep. Vern Buchanan, a Republican from Florida,in the House.
众议院在2022年未就该法案进行投票。然而，2023年3月2日，由12位参议员组成的两党合作小组再次提出关于夏令时永久化的法案，以期省去每年两次大调时间的麻烦。来自佛罗里达州的共和党众议员维恩·布坎南还提出了《阳光保护法》的附属法案。
Why do we need Daylight Saving Time
我们为什么需要夏令时
Studies over the last 25 years have shown the one-hour change disrupts body rhythms tuned to Earth's rotation,adding fuel to the debate over whether having Daylight Saving Time in any form is a good idea.
过去25年开展的相关研究已表明，一个小时的时间调整会打乱与地球自转相适应的人体节律——这让各方就是否应该实行任何形式的夏令时的争论变得更为激烈。
The issue is that for every argument there is a counterargument. There are studies, for example, that show we have more car accidents when people lose an extra hour of sleep. There are also studies that show robberies decline when there is an extra hour of sunlight at the end of the day. We also know that people suffer more heart attacks at the start of Daylight Saving Time. But what about our mental health? People seem to be happier when there is an extra hour of daylight.
问题是，每个论点都有可反驳它的论证。比如，有研究显示，人们少睡一小时，就会发生更多车祸事故。另有研究显示，傍晚多一小时日照，抢劫案件会减少。我们还知道，夏令时开始的时候，心脏病发作率会提高。但我们的心理健康状态会怎样呢？多一小时的日照时间，人们似乎更开心。
Of course, there's the economy, which pays for all that outdoor fun in the sun. Although saving energy was often put out as a reason to have Daylight Saving Time, the energy saved isn't much if anything at all. Instead, the lobbying effort for Daylight Saving Time came mostly from different sectors of the economy. In the mid-20th century, lobby groups for the recreational sports industry (think driving ranges) wanted more customers to come out after a day at the office. It's easier to do so when there is more light at the end of the day.
当然了，还有经济因素，户外阳光下的所有快乐都由它买单。虽然节省能源常常被说成是实行夏令时的原因，但节省下来的能源就算有也并不多。事实上，努力游说实行夏令时的人大多来自各经济领域。20世纪中叶，休闲体育产业（比如高尔夫球练习场）的游说团体希望有更多的人在一天工作结束后出去消费，而如果傍晚有更充足的光线，这就比较容易实现。
But the movie industry didn't like Daylight Saving Time. You're less likely to go to a movie when it's bright outside.Despite the myth, farmers didn't like it either because it made it difficult to get their food to the market in the morning.
但是电影产业不喜欢夏令时，因为人们不太会在大白天去影院看电影。听起来让人不太理解，农民们也不喜欢夏令时，原因是夏令时不利于他们清晨把食物送到市场。
The bottom line: It's not clear whether having that extra hour of sunlight at the end of the day versus the beginning is helpful. It just depends on who you are and what you want. And it doesn't look like Daylight Saving Time in the US is going away anytime soon.
关键的是，傍晚多一小时日照是否比清晨多一小时日照更有益，这个问题尚无明确答案。这取决于你的身份和需求。不过就目前来看，美国在短期内不会取消夏令时。
