The Newton and the Schrödinger equations in the absence of the macroscopic magnetic fields and in the inertial frame of reference are T-invariant: if X(t) is a solution then X(-t) is also a solution (here X is the vector of all dynamic variables, including all the coordinates of particles for the Newton equations and the wave function in the configuration space for the Schrödinger equation).
There are two sources of the violation of this rule:
* First, if dynamics depend on a pseudovector like the magnetic field or the rotation angular speed in the rotating frame then the T-symmetry does not hold.
* Second, in microphysics of weak interaction the T-symmetry may be violated and only the combined CPT symmetry holds.