  We revisit various results, which have been obtained by the BABAR and Belle
Collaborations over the last twelve years, concerning symmetry properties of
the Hamiltonian, which governs the time evolution and the decay of neutral B
mesons.We find that those measurements, which established CP violation in B
meson decay, 12 years ago, had as well established T (time-reversal) symmetry
violation. They also confirmed CPT symmetry in the decay (T_CPT = 0) and
symmetry with respect to time-reversal (epsilon? = 0) and to CPT (delta? = 0)
in the B0 ?B0bar oscillation.
