I think at least 24hrs...but prob like 36-48 depending on what everyone said. When I worked at a lfs the shipments would be very late and most of it would make it.
I currently have 3 bushy noise plecos sitting on my inlaws counter. I bought them today arround 3pm and they wont get into my tank untill about 4 tomorrow. One fish per bag...no pure o2...i'll report back tomorrow...but im sure they will be fine.