hour of the Rooster; hour of the Cock
Archaic term for the time period around 6pm in the traditional Japanese temporal system, corresponding to the twelfth of the twelve earthly branches.
江戸時代には、酉の刻は日没の頃とされていた。
In the Edo period, the hour of the Rooster was considered to be around sunset.
From 酉 (とり, 'Rooster', the tenth earthly branch) + の (possessive particle) + 刻 (こく, 'time period'). The term follows the traditional Chinese zodiac-based timekeeping adopted in Japan.