There are some resorts that participate in RCI Points and you can trade into those starting at 10 or 11 months (don't remember which) and those are for daily stays (so 5 daily stays and you have a week).
It is possible to trade for only 5 days (or others) but in almost all instances where it's less than 7 days, there is a hefty housekeeping fee. Also, many resort don't release inventory for less than 7 days even if they could. In general it's as good or better to get a full week and only use 5 days or to look at none DVC options for such a stay. For example, one might rent from an owner of that resort or system often MUCH cheaper.