GrandCycle
From Cassiopedia
In the Cassiopaea material, this term refers to a period of approximately 309000 years. The Wave or realm border, which is a cosmic phenomenon facilitating passage between densities, usually accompanied by physical cataclysm, is said to pass by Earth at such intervals.
The period of 309000 years, or 309882 years as it also was given, is close to 12 full cycles of precession of the equinoxes. The equinox precesses about 1 degree every 72 years, amounting to roughly 2 millennia per zodiac sign. Whether the precession of the equinoxes has anything to do with the Grand Cycle is unclear.
According the the Cassiopaea material, the mythical fall from Eden took place at the previous passage of the Wave