今夜|こんやkon'ya[1]atamadaka (head-high)

1. noun, adverbthis evening; tonight
   今夜こんや、パーティーを開ひらきます。↗

   We're giving a party tonight.

• Synonym今晩こんばんNeutralAlso means this evening, but leans toward dusk-to-nightfall more than 「今夜」; very common in spoken greetings like 「今晩は」.
• Synonym今宵こよいWrittenWritten, poetic word for tonight, as in 「今宵は満月」; found mostly in literature and song lyrics, not everyday speech.
• Antonym昨夜ゆうべNeutralThe opposite of 「今夜」: last night, as in 「昨夜はよく眠れた」.
• Antonym今朝けさNeutralAlso the opposite of 「今夜」 but at the other end of the day: this morning, as in 「今朝起きた時」.

For 'tonight', 「今夜」 and 「今晩」 are both fine; use 「今晩」 in greetings like 「今晩は」. For a poetic, literary tone pick 「今宵」. 「昨夜」 means last night and 「今朝」 this morning.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 今日きょうの夜よる。