numeral · An ancient Chinese compass point indicating the direction of 330° (north-northwest).

罗盘上的亥位对应着西北偏北方向。

The twelfth of the twelve Earthly Branches, associated with the year of the Boar, the tenth solar month, and the period from 9 p.m. to 11 p.m.

亥时是指晚上九点到十一点这段时间。