It refers to month that begins when your allocation of points are valid, but just keep in mind that you can always make a reservation at your Home Resort as early as 11 months before check-in date you would like ( during owner's priority booking window ) - - you don't need to wait until UY month rolls around.
Most will advise picking a UY where you will not travel during the last 4 months of your Use Year because at that point you are beyond the banking deadline and you wouldn't have much time left in the UY to reutilize points for another trip before the UY ends.
February, March, April, June, August, September, October & December are UYs.
ie you have a February UY :
right now you are in 2009 UY which runs 2/1/2009 - 1/31/2010 so you may book a trip during this time with your 2009 UY points (Current UY points) or
you may bank this allotment of 2009 UY points by Sept 30 2009 into
2010 UY which would make these points valid to use for a reservation from
2/1/2010 - 1/31/2011 along with 2010 UY points & MS can also borrow in points from 2011 UY too if needed.
Again, UY has nothing to do with WHEN you can make a reservation - - you can book as early as 11 months before at your HR and you may use banked points that are vaild during UY when ressie would occur and the Current UY points ( points from allocation of UY when trip would take place and borrowed points from next immediate upcoming UY). MS can 'see' what points you will have available for use in the reservation.
