31 days or more, points are returned to your account with the same status they originally had at the time you made the original reservation: Regular pts, Banked pts, or Borrowed pts.
At 30 days to 1 day prior to check-in, points are returned to your account as Holding Points, regardless of the original status they had when you made the reservation.
On day of check-in, all points are considered used, so if you cancel that day, or check our early, none of the points are returned at all.
Hope this helps.