一いっ昨さく晩ばん

noun, adverb

night before last

Refers to the night of the day before yesterday. Often used adverbially as 一昨晩に.

• 一いっ昨さく晩ばんはよく眠ねむれなかった。

  I couldn't sleep well the night before last.

• 一いっ昨さく晩ばんに届とどいたメールを今朝けさ確かく認にんした。

  I checked the email that arrived the night before last this morning.