  Possible effects of Chern-Simons (CS) gravity on a quantum interferometer
turn out to be dependent on the latitude and direction of the interferometer on
the Earth in orbital motion around the Sun. Daily and seasonal variations in
phase shifts are predicted with an estimate of the size of the effects,
wherefore neutron interferometry with $\sim 5$ meters arm length and $\sim
10^{-4}$ phase measurement accuracy would place a bound on a CS parameter
comparable to Gravity Probe B satellite.
