甲こう夜や

noun

first watch of the night (approx. 7pm to 9pm)

Archaic timekeeping term from the traditional Chinese-influenced system dividing the night into five watches. Not used in modern everyday Japanese.

• 昔むかしの時じ刻こくでは、甲こう夜やは夜よるの最さい初しょの刻こく限げんにあたる。

  In the old time system, 甲夜 corresponds to the first period of the night.