Overnight

(-nīt'), n. The time when evening is past and night is begun: more usually, the night following yesterday, or the previous evening.

If I had given you this at overnight, She might have been o'ertaken. Shak.

adv. During the night; more usually, during the night previous, or the night following yesterday; yesterday night; last night.

I had been telling her all that happened overnight. Dickens.