If you are talking about a GV at OKW or SSR, they are a bit easier to get because there are quite a few more of them than at BWV. If you are traveling at a low points time, you would want to try to reserve at the 11 month window, but it is not crucial to call day by day unless you are looking for a GV at BWV or at a popular time of year. We have had a GV during the first week of January where we called 11 months from check out (not day by day) and had one two weeks ago where we did call day by day because of the F&W festival. These were both at OKW, where there are 27 GVs. I believe BWV only has 7, so they are more difficult to get.