April 24, 2006

[japan]英語で午後12時はランチタイム:12am is noon in Japan

In Japan, 12 am is a lunch time. In other nations, it's midnight. I realized this difference when my alarm set for a lunch meeting started to ring at night.

The same question was raised by Kuribo of Blogger Tips. He found that there's no zero o'clock in Blogger.com pulldown menu. "Watch out. On Blogger.com, 12pm is not a midnight," he warned.

'A.M. (ante meridiem)' means 'before noon' and 'P.M. (post meridiem)' means 'after noon' in Latin. It's same in Japanese; Gozen (午前) means before (前) noon (午), Gogo (午後) means after (後) noon (午), and '午 (horse)' represents noon in the Chinese zodiac system.

But somehow, most Japanese (not all) feel awkward if we switch the am/pm suffix in the middle of serial numbers. To avoid it, we use zero o'clock. In Japan, 12 midnight is generally called 12pm or 0am, while 12 noon is referred to as 12am or 0pm. The beauty of zero o'clock is that you don't need this fuss for converting 12-hr to 24-hr. All you need is to add 12 hours to PM part.

According to Japan Standard Time Project's FAQ "12am? or 0pm?," noon was first defined as 12am under an 1872 Japanese Law when Japan introduced Western calender. Japanese insurance companies follow this rule to this day.

However, digital clocks on video recorders, cellphones, and Windows, for example, show 12 pm at noon, which has changed this a lot (hot debate goes on and on). Back in 1972, a K-12 student got confused and asked the teacher which is right. The inquiry was forwarded to the principal, superintendents, all the way up to the Ministry of Education that eventually contacted Japan Clock & Watch Association(JCWA) for an official comment.

JCWA along with The Horological Institute of Japan (HIJ) conducted an extensive research and concluded that "24 hour notation is the ideal solution. For AM/PM, using zero o'clock is more logical than using 12 o'clock, though it's too early to call for an universal standard."

The 12 o'clock confuses even English-speaking folks (Google Groups: comp.lang.c).  Wikipedia tells us why it's less practical.

The interesting thing I found on Wiki is that, Romans numbered the morning hours originally in reverse: for example, "3 a.m.", or 3 hours ante meridiem meant "three hours before noon", compared to the modern meaning of "three hours after midnight."  --That's why 12 midnight is still called 12 hours before noon, which is 12 am... ! (Don't ask me why 12 pm lost its midnight front.)

Well, if you wanna do business with Japan, use 24-hour clock. We already use it for TV and train schedule. Because if you tell them to hand in the report by 12:30pm, some might guess that you'd work past midnight waiting for the report. Sounds crazy? In Tokyo, it doesn't.

updates: Which is correct: 12 Midnight A.M. or 12 Midnight P.M.? "NEITHER" by 我的天空: Some Chinese also think 12am is noon.




Blogger.comのトラバ設置、カテゴリ検索など便利な使い方のコツとツールを提供するクリボウさんも、先日ブロガー編集画面でこの問題に気付いた。→クリボウの Blogger Tips: 0 時台はありません

午後12時半の謎はmohno氏も採り上げており、そのリンク先・情報通信研究機構のQ&A「午前12時? 午後0時?」を読めば日本の状況は分かる。


家庭用デジタル時計の表示は、国の内外を問わずすべて12時間方式を採用 し、“11”時の次に来る数字は、例外なく“12”時を採用している。しか し、午前・午後の表示を伴うデジタル時計については、明らかに“12”時は不 適当であり“0”時を用いるのが妥当である。また、デジタル時計の究極の形 としては24時間表示が至当であろう。しかし、この問題は従来からの慣習と 深く関連するので早急に表示方式の規正統一をはかることは時期尚早である。


ただデジタルの影響は侮れず、日本でも12pm=正午という人がかなり増えた。12時に関してはアメリカ人同士でもたまに混乱するし(Google Groups: comp.lang.c)、問題点については"12-hour time : Wikipedia"がよくまとまっている。

英語で真夜中を12amと呼ぶのは何故か? ラテン語で「A.M. (ante meridiem)」は「午前(before noon)」、「P.M. (post meridiem)」は「午後(after noon)」。ここまでは日本も一緒だが、AMをAnte(イタリア語はanti)の語義通りに使おうと思ったら初期の古代ローマ人のように実は正午から逆算していかなきゃならない。つまり3AMは「正午3時間前」で今の午前9時、12AMは正午12時間前で真夜中になる。(追:何故12PMが昼に回されたのかは不明)


日本人の間でも大激論→日本の標準 正午の表記
イギリスの邦人も大混乱→[ 午前と午後] by 熊も踊る
goo!は法的根拠で12am=正午説→[教えて!goo] 午前12時って?

我的天空: 中国の方も「12am=正午」という感覚のようだ。

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Anonymous said...

Noon is AM
not PM )

satomi said...

funny domain...Seems like a Russian joke blog:)

Anonymous said...

The 29th edition of the U.S. Government Printing Office Style Manual (2000) section 12.9 recommended the use of "12 p.m." for midnight and "12 a.m." (formerly "12 m.") for noon.

HOWEVER, the 30th edition of the U.S. Government Style Manual (2008) sections 9.54 and 12.9b recommends the use of "12 a.m." for midnight and "12 p.m." for noon.

Anonymous said...

I noticed in Japan that some places state "open from 11:00 until 28:00". I think that is useful since it indicates 4 a.m., but avoids confusion that if one states 11:00 to 4:00, which may make you think it's 4 p.m.

Anonymous said...

I like the concept of 0:00 AM being midnight because we all know that 0:01 is 1 minute PAST midnight. and After Midnight is AM and also an
Eric Clapton song.

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