Translation guide
The English word "day" can refer to a 24-hour period, daylight hours, a specific date, or an era. Japanese uses different words depending on the meaning.
良い一日を。
Have a nice day!
A common phrase, though slightly formal. In casual speech, you might just say じゃあね (see you).
Referring to a full day as a unit of time, from midnight to midnight.
The most common word for 'day' as a 24-hour period. Used in counting days and in everyday expressions.
一日は二十四時間です。
A day is 24 hours.
三日間休みます。
I will take three days off.
Specifically means 'one day' as a duration. Often used when emphasizing the length of a day.
Referring to the period of daylight, from sunrise to sunset.
Means 'daytime' or 'noon'. Used to contrast with night.
Referring to a particular calendar day, such as a date or a named day.
Referring to a particular period in history or someone's life, often used in a literary or figurative sense.
Means 'era' or 'period'. Used for historical periods or a phase in life.
Expressing a number of days using Japanese counter words.
English often uses 'day' in phrases where Japanese uses a different structure. For example, 'these days' is 最近 (さいきん) or この頃 (このごろ), not これらの日々. 'One day' as in 'someday' is いつか, not ある日 (which means 'one day' in a narrative past sense).
日 (ひ) is the general word for 'day' and is used in compounds and counting. 一日 (いちにち) specifically means 'one day' as a duration. For example, 一日中 (いちにちじゅう) means 'all day long'.
次の日、彼は来なかった。
The next day, he didn't come.
数日後に会いましょう。
I'll see you in a few days.
私の若い頃は、違いました。
Back in my day, things were different.
Literally 'When I was young, it was different.' Japanese often uses 若い頃 (わかいころ) instead of a direct translation of 'my day'.
一日中働きました。
I worked all day.
It's warm during the day, but cold at night.
Refers to the daytime hours, often in more formal or written contexts.
日中は仕事をしています。
I work during the day.
What day is it today?
月曜日は忙しいです。
Monday is a busy day.
Means 'anniversary' or 'memorial day'. Used for special days.
今日は結婚記念日です。
Today is our wedding anniversary.
学生時代は楽しかった。
My school days were fun.
Means 'days' in the sense of everyday life or a continuous period. Often used in literary contexts.
平和な日々を過ごしています。
I'm spending peaceful days.
Emphasizes the duration of days. Added after the number+日.
五日間雨が降りました。
It rained for five days.
I'll finish it in one day.