The next day; the day following a referenced day (also used adverbially).
約束の翌日、彼女から連絡が来た。
The day after the appointment, I heard from her.
試験の翌日はゆっくり休んだほうがいい。
It's better to rest the day after the exam.
会議は三月一日に行われ、翌日には報告書が配られた。
The meeting was held on March 1, and the report was distributed the next day.