>>12018265both
CPT is conserved in any quantum field theory
CP symmetry is violated by the weak force and CP symmetry is equivalent to T-symmetry violation according to the CPT symmetry
of course, if CPT symmetry is violated then this isn't necessarily the case that T is violated, but if it is then QFT is wrong
Here's a thought experiment: take a copy of our universe and take its CPT reflection. That universe should obey identical physical laws to our own, except charge, parity and time have all been reversed. So time would run in reverse, and entropy would decrease, but no one would ever notice it because CPT-reflected human brains would also be running on reverse time, so to them entropy would appear to be increasing.
