How soon until the interview? They often confirm date & then send you nothing anywhere from weeks to days before the actual interview.
If your schedule is very particular & you actually need to book flights like NOW, it's OK to email the PC that you just want to know if there is a dinner beforehand & approx time the interview day ends for booking a flight. But don't press for more detail than that they likely don't have any yet.
Sometimes an email is sent out and you didn't get it, but give it some time before jumping in the PC.