What is precession of the equinoxes?
The precession of equinoxes is attributed to the revolution of Earth's polar axis, with period 258 centuries, nearly, about a mean position that is perpendicular to Earth's orbital plane ( ecliptic).
In this precession with Great Year period of 258 centuries, the poles describe a circle of angular diameter
Corresponding to this axial precession, the location for the right-above-head noon, at the equinox instant, shifts the equinoxes (common points of the ecliptic and the Earth's equator) towards north by #360^o, in 258 centuries.
Corresponding time-rate is approximately (24 X 3600)/(25800)"/year = 3.35 sec/year.
Importantly, the tilt angle