Precession of the Equinoxes

4 Planetary Rounds = 1 Planetary Cycles = 1 Astrological Age = Aeon = 26,000 (26,566) years = precession of Earth’s axis of rotation with respect to inertial space.

At the end of every cycle, we become aligned to the galactic core; Stargate portals open (See Planetary Gates, and we are eligible to proceed with an Ascension timeline.

Also:
Refers to the precession of Earth's axis of rotation with respect to inertial space. A complete precession cycle (One Astrological Age) covers a period of approximately 25,765 years, the so called Great Platonic Year, during which time the equinox regresses over a full 360°. The precessional movement also is the determining factor in the length of an Astrological Age or Aeon. (Note that there are 12 Zodiac Archetypes that are each of the 12 Astrological Ages. We are moving from the Age of Pisces to the Age of Aquarius.) The precession of the equinoxes is caused by the differential between the gravitational forces of the Sun and Moon on the Earth.

Reference
Precession of the Equinoxes