The word is charge-parity. All physical systems (at least I'm quantum physics, I cant speak for other fields) are symmetric (nothing changes) if you change C(harge), P(arity) and T(ime reversal) at the same time. This is called CPT symmetry, see https://en.m.wikipedia.org/wiki/CPT_symmetry

As antimatter can be described as normal matter going back in time (see the other comment), it means antimatter can also be described as normal matter transformed under the C and P operators. If T(particle) = antiparticle and CPT(particle) = particle then CP(particle) = antiparticle also.

And the reason you can reverse time is because most of the equations are quadratic: they have a positive and negative solution, one describes particles moving forward in time, the other solution describes antiparticles going backward in time.

NB: in quantum field theory it gets slightly more complicated, lets leave that as homework ;)