I've never had one sit more than a day or so... Just to make sure, your talking about shipping in/out of the states right? Not carrying over as luggage?
Never had anything at any time of year sit more than a day, two at the absolute outside, when they have even bothered to look inside, from Europe or Australia.
Do you have something sitting in Customs now and if so how long?
Just a quick horror story. When I worked for Predator we had a cue that was shipped in from Asia. The cue arrived in a package that said it was inspected by customs. The but had 8-9 holes drilled in it, I have to assume that they suspected it had some type of contraband in it. But out of the 5 years I was there that was the only one that I saw that had any issues other than packages that had been repacked after inspection and things were missing.