No, time-based symmetry is the T-symmetry. It’s violated all the time because some events only run one way, never to the other; for example, if you burn sugar into carbon dioxide and water, you can’t simply “unburn” it by gathering the carbon dioxide and water together.
Then there’s the CPT-symmetry, that says that those violations of the T-symmetry should have a correspondent CP-symmetry violation, cancelling each other out exactly.
No, time-based symmetry is the T-symmetry. It’s violated all the time because some events only run one way, never to the other; for example, if you burn sugar into carbon dioxide and water, you can’t simply “unburn” it by gathering the carbon dioxide and water together.
Then there’s the CPT-symmetry, that says that those violations of the T-symmetry should have a correspondent CP-symmetry violation, cancelling each other out exactly.