Tried many Google searches but failed to find the information I was looking for.
Question came up on magic item creation on the 4h/day rule. If a player goes out at 8am, clears a dungeon and is back by 4pm. Can he then craft for 4 hours that day, repeat the same the next day and gain the full 4 hours bonus or does this count as travelling/adventuring and you gain only 2 hours worth.
He should be able to craft the entire 4 hours. The crafting while adventuring from the way I read it is when he might be part of some caravan traveling across a desert. It won't be as suitable as when you are sitting in one place so you don't as much out of it.
PS: It does not have to be a caravan. That was just an example of not being in a comfortable location to do it in, but still allowing the crafter to get something done that day.
If time is dedicated to creation, it must be spent in uninterrupted 4-hour blocks. This work is generally done in a controlled environment, where distractions are at a minimum, such as a laboratory or shrine. Work that is performed in a distracting or dangerous environment nets only half the amount of progress (just as with the adventuring caster).
If he can get back to a controlled environment he should be able to get the benefit of the full 4 hours.
Another example of a bad place to craft items might be in a dungeon with enemies. I had not thought of that until I saw dragonhunterq's example.