There are very accurate alcohol tests that can tell if you were drinking heavily a couple of days ago. I don't know the exact lenght of time. But I've never been tested like that for a class 1. Why should they do that? It's not illegal to drink the night before a flight(it's still 12 hours military, what is it civilian, 10hrs I think?), so why would it be a problem for a physical? I wouldn't show up hungover though. That would be pretty poor SA.