  In the limit of a large number of flavors, the ground state of the chiral
Gross-Neveu model at finite fermion density exhibits a spatially periodic mean
field in the form of the chiral spiral, thereby breaking translational
invariance. Here we show that the ground state of the same model at finite
fermion current density gives rise to a mean field which is periodic in time, a
temporal chiral spiral. Since the current density is the same as axial charge
density in two dimensions and axial charge is conserved, this may serve as an
example of a time crystal. More specifically, as mean field theory is invoked
in the large N limit, we are dealing with a semiclassical time crystal.
