noun
fourth division of the night (approx. 1am to 3am)
Archaic term from the traditional Chinese timekeeping system, dividing the night into five watches. 丁夜 corresponds to the fourth watch, roughly 1am to 3am. Not used in modern Japanese.
昔の時刻制度では、丁夜は丑の刻にあたる。
In the old time system, 丁夜 corresponds to the hour of the Ox (around 1am to 3am).