Midnight, especially a deeply silent night, was considered to be overlapping tokoyo, so the time when something mysterious that did not exist in reality appeared was called 'ushimitsudoki' (the third quarter of the hour of the Ox (approximately 3:00 to 3:30 a.m.)), and people were afraid of the time.
深夜なども深い静寂な夜は、常世と重なることから、現実には存在しない怪異のものが現れる時刻を、「丑三つ時」と呼び恐れた。