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.
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.
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'.
The next day, he didn't come.
I'll see you in a few days.
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.
I work during the day.
What day is it today?
Monday is a busy day.
Means 'anniversary' or 'memorial day'. Used for special days.
Today is our wedding anniversary.
My school days were fun.
Means 'days' in the sense of everyday life or a continuous period. Often used in literary contexts.
I'm spending peaceful days.
The trip is for three days.
Emphasizes the duration of days. Added after the number+日.
It rained for five days.
I'll finish it in one day.
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'.