The default setting for a new planbook is a Monday-Friday schedule.  If your school operates on a rotating schedule, such as A/B days, A/B weeks, 4 day, 8 day, etc., it is easy to customize your planbook to accommodate your schedule.

Click on "Planbooks" in your blue navigation bar, and then "Edit" by the planbook you are working on.  You will see a section marked "Rotation".  Select the kind of schedule you need and click Save.  If you create recurring plans or need to bump plans forwards or backwards, your schedule will be remembered and plans will be moved accordingly.