normal and leap years
Technical term used in calendar contexts to refer to common years and leap years collectively.
In calendar calculations, it is necessary to correctly distinguish between normal and leap years.
legitimate and illegitimate dynasties
Historical term used in discussions of imperial succession, particularly in the context of the Northern and Southern Courts period in Japan.
The debate over legitimate and illegitimate dynasties during the Nanboku-chō period is an important topic in historiography.