一いち日にち一いち夜や

noun

all day and night; a whole day and night

Refers to the entire period of one day and one night, often used in contexts emphasizing continuous duration or a complete 24-hour cycle.

• 一いち日にち一いち夜やかけて目もく的てき地ちに着ついた。

  We arrived at our destination after traveling all day and night.