From the context I think it is 4-7 days. The first part of the recipe says to start the fermentation, and while you are waiting 10-14 days for it to finish to prepare the oak chips. If it took 47 days (an unusually precise number for a period that long), the recipe should have told you to prepare the oak chips long in advance of brewing the beer.
I used this technique to get some strong oak flavor into a stout last fall, and it worked great. My previous attempts had a lot of bourbon flavor but not much oak, and this gave me what I wanted.