Translation guide
In Japanese, counting days uses specific counters that change depending on the number and context. The most common counter is 日 (にち/か), but the readings are irregular for many numbers. There are also alternative counters for formal or written contexts.
Expressing a number of days, such as 'for three days' or 'in two days'.
The standard counter for days. The reading changes irregularly for numbers 1–10, 14, 20, 24, and sometimes for others. For numbers 11 and above, it is usually read as にち, but there are exceptions.
The reading for 1日 as 'one day' (duration) is いちにち, but for the first day of the month it is ついたち. For 2–10 days, the readings are irregular: ふつか, みっか, よっか, いつか, むいか, なのか, ようか, ここのか, とおか. 14日 is じゅうよっか, 20日 is はつか, 24日 is にじゅうよっか.
三日間旅行します。
I will travel for three days.
あと二日で夏休みです。
Summer vacation starts in two more days.
十一日かかりました。
It took eleven days.
Adds 間 (かん) to explicitly indicate a duration of days. Often used when the number of days might be ambiguous or for emphasis. The reading of 日 follows the same irregular pattern as the standalone counter.
二日間待ちました。
I waited for two days.
五日間の休暇をもらいました。
I got a five-day vacation.
Using an alternative counter that is more regular and often preferred in formal writing, news, or technical contexts.
In formal or written Japanese, the reading にち is often used for all numbers, avoiding the irregular readings. This is common in news reports, official documents, and when clarity is important.
捜索は五日にち目に入りました。
The search entered its fifth day.
十にち間の調査が行われた。
A ten-day investigation was conducted.
Using the traditional Japanese counting system for days, which is now largely obsolete except in certain set phrases or literary contexts.
The native Japanese counter for days, used in some old expressions or poetic language. It is not productive in modern Japanese except for a few fixed words like 五日 (いつか) and 十日 (とおか).
This is not a standard way to count days in modern Japanese. The example shows a related usage in a compound word.
三か月
three months (literally 'three moons')
Both can indicate a number of days, but 日間 explicitly marks duration. In many cases, 日 alone is sufficient, especially with verbs like かかる (take time) or when the context is clear. 日間 is used for emphasis or to avoid ambiguity.
The readings for 1–10 days are highly irregular and must be memorized. Using the wrong reading can cause confusion or sound unnatural. For example, 一日 as 'one day' is いちにち, but as 'the first day of the month' it is ついたち. 二日 is always ふつか, never ににち.
The same counter 日 is used for days of the month, but the readings for 1–10, 14, 20, and 24 are the same as the duration readings. For other days, the reading is usually にち (e.g., 11日 じゅういちにち). Context distinguishes between duration and date.
京都に五日間滞在しました。
I stayed in Kyoto for five days.
その祭りは三日間続きます。
The festival lasts three days.
二日でできます。
It will be ready in two days.