A period of one year; used to indicate something over the course of a year (e.g., annually, for a year).
この工場の年間生産量は100万台です。
This factory's annual production is one million units.
年間のイベントスケジュールを確認してください。
Please check the annual event schedule.
彼は年間を通して忙しい。
He is busy throughout the year.
Used as a suffix meaning 'during the era of ...' (e.g., in the Showa years).
昭和年間には多くの変化があった。
There were many changes during the Showa years.