dead of night; middle of the night
Refers to the deep, quiet hours of the night, often with a spooky or eerie connotation. In modern usage, it is a literary or traditional expression rather than a precise time.
They say that at the dead of night, strange sounds can be heard from the old mansion.
The silence of the middle of the night was frightening.
third quarter of the hour of the ox (approx. 2:00–2:30 AM)
Historical timekeeping term. In the traditional Japanese temporal system, the hour of the ox (丑の刻) was divided into four quarters; the third quarter was considered especially inauspicious and associated with supernatural events.
See also: 丑の刻
Ushimitsudoki corresponds to the third quarter of the hour of the ox.
In old tales, monsters are said to appear at the third quarter of the hour of the ox.