(Now historical) one twelfth of the natural day or night (varying in length according to the time of the year and the latitude of the observer), especially (in Astrology) such a period ruled by a particular planet.
Origin
Late 16th century. Compare French heure planétaire.
Definition of planetary hour in US English:
planetary hour
noun
(Now historical) one twelfth of the natural day or night (varying in length according to the time of the year and the latitude of the observer), especially (in Astrology) such a period ruled by a particular planet.
Origin
Late 16th century. Compare French heure planétaire.