Caption: An animation illustrating the axial precession of the Earth's axis.
The axial precession causes a westward or clockwise circular rotation of the north celestial pole (NCP) on the celestial sphere as seen from outside the celestial sphere looking down on the NCP.
Features:
The astronomical perturbations make it impossible to predict the rate beyond a few thousand years to the past or the future.
If the current rate is taken as constant, the period would be almost exactly 25,771.5 Julian years (Jyr) (see Wikipedia: Axial precession: Values). A Julian year is exactly 365.25 days.
Since the current rate is NOT constant and the variation NOT fully predictable, ∼ 26,000 years is about the most accurate one can be.
Also due to the astronomical perturbations, the period of axial precession will NEVER be exactly the same twice.
One wonders who will notice.