Oh, to revel in New Year’s Eve. Cheer with good friends! A glass of Champagne or two. And, this year, ringing in a new decade.

Oh, wait. Are we?

In recent years there has been debate about when a decade begins and ends. For some people, the next decade will begin on Jan. 1, 2020, and end on Dec. 31, 2029. For others, it won’t start until Jan. 1, 2021, concluding on Dec. 31, 2030. To the average person — well, many of us — it can be very confusing. But what is correct? Should we celebrate the beginning of a new decade now or wait until next year, when it seems a little passé?

We decided to break it down for readers. We talked to an expert at the United States Naval Observatory, which runs the nation’s master clock. We interviewed an editor at the Farmers’ Almanac. We even talked to a curator of astrophysics.

There is one thing almost everyone agreed on. “Talking about it is a great way to get into a bar fight,” said Geoff Chester, an astronomer and a public affairs officer at the observatory.
几乎所有人同意一件事。“讨论这事能打起来,”海军天文台的天文学家和公共事务官杰夫·切斯特(Geoff Chester)说。

Why is this a controversy?

First, a little history. In 1999, people got into a spat over when the new millennium began. At the center of the dispute was the Naval Observatory, whose calculations of time influence government satellites, your iPhone and more. The agency’s position was that the new millennium began on Jan. 1, 2001, Mr. Chester said. That’s because the observatory uses a modification of the Julian date to measure time. The modified system is used by astronomers and geodesists, who study the size of the Earth. (The original Julian date begins Jan. 1, 4713 B.C.)

So that settled it, right?

Not so fast. In 525, a monk named Dionysius Exiguus wanted to pinpoint the date for Easter. So he devised a calendar system called anno Domini, which was based on when he believed Jesus was born. A.D., which is Latin for “the year of our Lord,” is commonly used today. One glitch: Because it identified the date of Jesus’ birth as Year 1, not Year 0, there is a time gap, Mr. Chester said. There is a lot of debate about this online, but, which studies such things, has a good explanation.
且慢。525年,一位名叫狄奥尼修斯·伊希格斯(Dionysius Exiguus)的僧侣想明确复活节的日期。因此,他设计了一个日历系统,称为基督纪年(anno Domini),这是基于他认为耶稣出生的时间。A.D.,拉丁语中的“主的年份”,如今已普遍使用。但有一个小问题:因为它把耶稣的出生日期定为公元1年,而不是0年,这就有了一个时间间隔,切斯特说。网上对此有很多争论,但是研究此事的timeanddate.com有一个很好的解释。

Because of this, many people insisted the new millennium began on Jan. 1, 2000. It was widely debated and everyone had something to say. Mr. Chester, who was at the center of the kerfuffle back in 1999, sighed when asked to explain the different dates. “It’s one of those things where numbers don’t satisfy everybody,” he said.

Did the debate make it easier to understand when a new decade begins?

Yes and no. Unlike the definition of daylight saving time, the definition of a decade is not governed by legal guidelines. But the debate got people talking. Mordecai-Mark Mac Low, a curator in the department of astrophysics at the American Museum of Natural History, said, “There are two different ways to designate decades.”
是也不是。10年的定义不像夏令时那样受法律准则的约束。但是对此的争辩让人们议论纷纷。美国自然历史博物馆天体物理学部策展人莫迪凯-马克·麦克·劳(Mordecai-Mark Mac Low)说:“有两种不同的方法来对10年加以明确。”

First, there is the modified Julian date. But, he added, “people work with language more than numbers.” The second way is to designate decades by popular convention and usage. An example? Most people would say the 1950s went from 1950 to 1959.

“People want simple answers,” Dr. Mac Low said. “But the answer is not always simple.”

Mr. Chester agreed. “There is no absolute,” he said.

So what is the answer?

Using a modified Julian date, the 2020s will begin on Jan. 1, 2021, Dr. Mac Low said.

But that is out of sync with common usage. According to Emily Brewster, a senior editor at Merriam-Webster, a decade in popular culture is not defined by scientific convention. Because of this, the 2020s will begin on Jan. 1, 2020, and end on Dec. 31, 2029, Ms. Brewster said.
但这不同于常规用法。韦氏出版公司(Merriam-Webster)的高级编辑艾米莉·布鲁斯特(Emily Brewster)表示,流行文化中的10年并没有被科学常规所定义。因此,布鲁斯特说,2020年代将从2020年1月1日开始,到2029年12月31日结束。

“It is interesting that there is this arbitrariness,” she said. “It’s unconventional, like language.”

So I can still throw an end-of-the-decade party in December, right?

Most definitely. Indeed, people have already begun celebrating the end of the 2010s. “This could be a great controversy,” said Peter Geiger, editor of the Farmers’ Almanac. “Or maybe it’s really just a great diversion.”
当然。确实,人们已经开始庆祝2010年代的结束。“这可能会是一个极大的争议,”《农民年鉴》的主编彼得·盖格(Peter Geiger)说。“或许它其实只是一个很大的乐子。”

本文最初发表于2019年11月28日。Jack Begg对本文有研究贡献。

Laura M. Holson是一名来自纽约的获奖特写作者。她自1998年加入时报,曾报道好莱坞、华尔街、硅谷。欢迎在Twitter上关注她 @lauramholson。


Leave a Reply

Your e-mail address will not be published. Required fields are marked *