The spoken use of "night" as an off-the-cuff, common Model of "very good night" (wishing just one a restful rest) is prevalent, but I am unsure what the right published equivalent is - if there is just one. I've constantly employed 'Night with the apostrophe, commonly capitalized: eight ᴀ�???12 ᴘᴍ?? https://lukashx864.livebloggs.com/44461021/helping-the-others-realize-the-advantages-of-night-gangnam-퍼펙트가라오케-karaoke-guide