By saying wobble, I was referring to:

en.wikipedia.org/wiki/Axial_precession

For identical reasons, the apparent position of the Sun relative to the backdrop of the stars at some seasonally fixed time slowly regresses a full 360° through all twelve traditional constellations of the zodiac, at the rate of about 50.3 seconds of arc per year, or 1 degree every 71.6 years.

Re leap years: On second thought you might be correct about that one.