Within the depth-psychology corpus, ‘Equinox’ functions less as an astronomical datum than as a symbolic hinge-point marking the intersection of opposing cosmic forces — light and darkness, ascent and descent, individual and collective time. The term appears most substantively in three registers. First, in Jung’s aeonological writings, particularly Aion and Memories, Dreams, Reflections, the spring equinox serves as the astronomical anchor for synchronistic interpretations of cultural history: the entrance of the vernal equinox into Pisces is read as objectively correspondent to the life of Christ, making the equinox a calendar of the collective psyche’s transformations. Second, in Rudhyar’s psychologically inflected astrology, the equinoctial cycle — subsumed under the larger ‘Great Polar Cycle’ of the precession of the equinoxes — becomes a metric of civilizational selfhood, distinguishing the individual’s axial-rotation unit from the collective’s orbital and precessional units. Third, in Campbell’s mythological surveys, the equinox functions iconographically, as the zodiacal crossing-point encoded in the chimeric guardian figures of ancient Near Eastern art. Eliade’s index references to the autumnal equinox situate it within New Year ceremonialism and the regeneration of cosmic time. Tension runs throughout between equinox as literal astronomical marker and equinox as depth-symbolic threshold of transformation.