To make it easier, make yourself a Use Year chart like the one below. For an October UY, your chart looks like this.
<b>Use Year.......Vacation Dates</b>
2003.....Oct 1, 2003 through Sep 30, 2004
2004.....Oct 1, 2004 through Sep 30, 2005
2005.....Oct 1, 2005 through Sep 30, 2006
2006.....Oct 1, 2006 through Sep 30, 2007
2007.....Oct 1, 2007 through Sep 30, 2008
You can get points into a use year three different ways: (1) The regular allocation of points for that year. (2) Bank points from one year into the following year. (3) Borrow points from one year into the prior year.
A June 2004 trip requires 2003 year points. So for June 2004 you could use (1) Regular 2003 year points, (2) Banked 2002 year points, or (3) Borrowed 2004 year points.
A November, 2004 trip requires 2004 year points. For November's vacation you could use (1) Regular 2004 year points, (2) Banked 2003 year points, or (3) Borrowed 2005 year points.
Once points are banked or borrowed from one year into another year, they cannot go back and must be used within the use year into which they were banked/borrowed.
It looks like you did the following:
1. You have a 150 point contract at BCV
2. You made a reservation for June 2004 using whatever 2003 points you had remaining and borrowed 50 of your 2004 UY points, leaving only 100 points left in your October 2004 use year.
3. You want to make a November 2004 reservation. This will use all your 100 remaining 2004 UY points and you will need to borrow some of your 2005 UY points.
4. If possible, you want to change to OKW (at 7-months), which will use 30 fewer points.
The points you borrow from 2005 into 2004 to make the Nov 2004 reservation cannot be returned to their original use year of 2005. So when you make the OKW reservation, you make sure they use all of the borrowed 2005 points, and 70 of the 100 regular 2004 UY points. You can then bank the remaining 30 UY 2004 points into 2005.
However, you are incorrect in that you would have 180 points for UY 2005. You would have something fewer as follows:
Regular 150 point allocation minus whatever number of points you borrowed into your UY2004, plus the 30 regular UY2004 points that you banked into 2005.
Example: Suppose Nov 2004 requires 185 points. You only have 100 UY2004 points available so you borrow 85 points form UY2005, and make the 185 point vacation.
At 7-months you change to OKW which only requires 155 points. For the new reservation you have MS use the 85 borrowed UY2005 points, and 70 of the 100 regular UY2004 points to make the 155 point reservation. You then bank the remaining 30 UY2004 points into UY2005.
Your UY2005 then would then have 95 points available, not 180 points.
UY2005 = 150 points allocation, minus 85 points borrowed into 2004, plus 30 points banked from 2004, or Points = 150 - 85 + 30.
Hope this helps.