on the brink of; imminent
Literary expression for a critical moment or impending event. Often used in fixed phrases like 旦夕に迫る.
危機が旦夕に迫っている。
A crisis is imminent.
morning and evening; day and night
Classical literary term for 'always' or 'constantly', emphasizing the passage of time from morning to night. Rare in modern Japanese.
彼は旦夕努力を怠らなかった。
He never neglected his efforts, day and night.
Compound of 旦 (dawn, morning) and 夕 (evening, dusk). The meaning 'on the brink of' likely developed from the idea of a critical juncture between day and night.