Fixed weeks
With Fixed Week programs, an owner is given the ability to vacation during the same week and the same unit every year. In theory, a resort could sell a single unit to 52 different owners, given that there are 52 weeks in a year.
Commonly, the resort assigns every week a number, beginning with Week One in January. Every few years, a Week 53 will appear on a timeshare calendar. When this happens, Week 52 owners are able to add this time to their ownership, given that they pay the maintenance fees for it. For this extra time, Week 52 is a highly popular week to own.