(じかん)

じかん
noun
time, hour
1. time
The general concept of time, or a period/amount of time. 時間(じかん)がない (no time), 時間(じかん)がかかる (takes time).
時間(じかん)ない
I don't have time.
時間(じかん)あります
Do you have time?
時間(じかん)かかる
It takes time.
Please value your time.
I'm busy and don't have time, but I think I can make some time on the weekend.
2. hour(s)
Used as a counter for hours. 三時間(さんじかん) (three hours).
I waited for one hour.
三時間(さんじかん)かかりました
It took three hours.
何時間(なんじかん)勉強(べんきょう)しました
How many hours did you study?
毎日(まいにち)八時間(はちじかん)()ています
I sleep eight hours every day.
It takes about two and a half hours from Tokyo to Osaka by bullet train.

時間(じかん) has two primary uses: as a general noun meaning "time" and as a counter for hours.

SENSE 1 - TIME (GENERAL):

  • 時間(じかん)がある/ない: to have/not have time
  • 時間(じかん)がかかる: to take time
  • 時間(じかん)無駄(むだ)にする: to waste time

SENSE 2 - COUNTER (HOURS):

  • 一時間(いちじかん): one hour
  • 二時間(にじかん): two hours
  • 何時間(なんじかん): how many hours?

KEY DISTINCTION:

  • 三時(さんじ): 3 o'clock (clock time)
  • 三時間(さんじかん): 3 hours (duration)

SPECIAL USAGE:
時間(じかん) can mean "class period" in school: 一時間目(いちじかんめ) (first period)

COMPARE:

  • 時間(じかん): time (general), hours (duration)
  • (とき): time, moment, when