What I had in mind is simply looking at how long are cachers willing to hunt for a cache by looking at how long they have already, So I suppose it is from the point of when one would start using the GPS, or barring that when you set foot upon the trail that will take you there, till you return to that point. (if you drive for 4 hours then pop out of the car for 1/2 hour to cache I consider it a 1/2 hour cache trip) Cache exclusive. And if you're spending several days on a cache/multi-cache I'd assume it would fall into the 3+ hr. catagory.