hour of the Boar (around 10 p.m.)
Obsolete temporal unit in the traditional Chinese time system, corresponding roughly to 9–11 p.m. or 10 p.m. to midnight. Used in historical contexts.
See also: 亥の刻
In the Edo period, the gates closed at the hour of the Boar.
north-northwest
Obsolete directional term from the traditional Chinese zodiac compass points. Rarely used outside historical or divinatory contexts.
On old maps, the direction of the Boar indicates north-northwest.
tenth month of the lunar calendar
Obsolete month name in the traditional lunar calendar. Now only encountered in historical or literary texts.
The Boar month of the old lunar calendar corresponds roughly to October now.
year of the Boar; year of the Pig
day of the Boar in the month of the Boar
miswriting a word; using the wrong kanji
Standard kanji for the zodiac sign and related traditional uses.
The kanji 亥 is a Chinese zodiac character adopted into Japanese for calendrical and directional systems. The reading い is the Sino-Japanese on'yomi.