noun, adverb
last night; the previous night
Refers to the night before a reference point, often in narrative or formal contexts. Can be used adverbially with に.
前夜、彼は遅くまで起きていた。
The previous night, he stayed up late.
出発の前夜に荷造りを済
I finished packing the night before departure.
noun, adverb
eve; night before (an event)
Used for the night before a special day, festival, or major event, such as Christmas Eve or New Year's Eve.
クリスマス前夜に教会へ行った。
I went to church on Christmas Eve.
祭りの前夜、町は静かだった。
The night before the festival, the town was quiet.