According to Equations (11.206) and (11.284), the mean ecliptic longitude of the lunar perigee evolves in time as

(11.337) 
where

(11.338) 
Equation (11.337) implies that
the perigee precesses (i.e., its longitude increases in time) at the mean rate
of
degrees per year. (Of course, a year corresponds to
.) Furthermore, it is clear that this precession is entirely due to the perturbing influence of the Sun, because it depends only on the parameter ,
which is a measure of this influence. Given that , we find that the perigee advances by
degrees per year. Hence, we predict that the perigee completes a full circuit about the Earth every
years.
In fact, the lunar perigee completes a full circuit every years. Our prediction is somewhat inaccurate because
our previous analysis neglected
, and smaller, contributions to the parameter [see Equation (11.284)],
and these turn out to be significant. (See Section 11.17.)