Neither the magnetic poles nor the rotational (geographic) poles move in a fashion that should be called a "shift" - implying a discrete event. The magnetic poles "drift", their intensity rises and falls, and sometimes when the field intensity declines to zero, the poles gradually re-emerge with reversed polarity. As Penny says, the rotational (geographic) poles precess, but again this is gradual. the geographic and magnetic poles cannot get too far apart since the magnetic field is produced by eddy currents (vortices) in the liquid outer core due to the slight differential rotation rates of the solid crust/mantle and the solid inner core (separated by the liquid outer core). These vortices are necessarily aligned sub-parallel to the rotational axis, so the mangetic field must also be sub-aprallel to the rotation.
No worries folks. Uniformitarianism prevails.