It means if you want you can call tomorrow at 9 (eastern) in the morning and extend it to Dec 31 and then call Tuesday morning and extend it to Jan 1, etc. In other words, you can add day by day to your original 7. I would HIGHLY recommend you do that particularly for the night of Dec 30 and Dec 31 because if you do not that standard view at BWV will likely be gone for those nights before you reserve. In fact, there is some likelihood that standard view for the night of Dec 31, the highest DVC demand night of the year, will be gone before 10:00 a.m. on Tuesday.