Translation guide
In Japanese, expressing 'period of time' depends on whether you're talking about a duration, a specific span, or a defined era. The most common and versatile word is 期間 (kikan), but other terms like 時間 (jikan) for hours, 時期 (jiki) for a phase, and 時代 (jidai) for an era are used in specific contexts.
Referring to a length of time between two points, such as a vacation period, a contract term, or a waiting period.
The most common and neutral word for a defined period or duration. Used for anything from a few days to several years.
I will travel during the summer vacation period.
The period of this contract is three years.
Used as a suffix or standalone to mean 'during' or 'while'. Often follows a noun or verb phrase.
I was at the beach the whole period of summer.
I read a book during the waiting period.
Refers to a season, phase, or appropriate time for something. More about 'timing' than a strict duration.
Now is just the right period of time.
That period of time was busy.
Specifying a length of time measured in hours, minutes, or seconds.
Means 'time' or 'hours'. When used with a number, it indicates a period of hours. Can also mean 'time' in a general sense.
Suffix meaning 'for X minutes'. 間 (kan) is added to the counter for minutes to emphasize duration.
Let's take a break for a period of 30 minutes.
Referring to a long period in history, such as the Edo period or the Showa era.
Means 'era' or 'age'. Used for historical periods, or to describe a generation.
The Edo period lasted a long time.
I was born in the Showa period.
A period with a clear start and end, like a school term, a prison sentence, or a project phase.
A suffix meaning 'period' or 'term'. Often used in compounds like 学期 (school term) or 任期 (term of office).
Means 'deadline' or 'time limit'. Refers to the end point of a period rather than the period itself, but often used in contexts like 'period of validity'.
A brief, often unspecified period of time.
期間 (kikan) is for a defined span between two points (e.g., a vacation period). 時間 (jikan) is for hours or time in general. 時期 (jiki) is for a season or phase (e.g., cherry blossom season). Use 期間 when you can mark the start and end dates; use 時間 for clock time; use 時期 for the right timing.
The training period is three months.
The training time is from 9 to 5.
The training period (season) is spring.
The loanword ピリオド (piriodo) means a punctuation mark (full stop) or a menstrual period, not a general span of time. Avoid using it to mean 'period of time'.
Incorrect for 'summer period'
I lived in Japan for a period of three years.
This is a difficult period for our company.
The Heian period was a time of peace.
The validity period of this ticket is one week.
一時の感情で決めてはいけない。
Don't decide based on a momentary feeling.