It's important not to confuse use year with calendar year. Calendar year 2007 goes Jan 1, 2007 thru Dec 31, 2007. A 2007 April Use Year goes Apr 1, 2007 thru Mar 31, 2008.
It can help to make yourself a little Use Year Chart. An April chart would look like this:
Use Year.....Vacation Dates
2005....Apr 1, 2005 thru Mar 31, 2006
2006....Apr 1, 2006 thru Mar 31, 2007
2007....Apr 1, 2007 thru Mar 31, 2008
2008....Apr 1, 2008 thru Mar 31, 2009
2009....Apr 1, 2009 thru Mar 31, 2010
You may borrow points one Use Year ahead, so you could borrow 2008 points into the 2007 Use Year. But those points could only be used for vacation dates Apr 1, 2007 thru Mar 31, 2008.
In the chart above, just find what use year your vacation will fall in, and then remember you can only borrow from the next use year.
As mentioned, a January 2007 vacation falls within the 2006 Use Year. Thus this January 2007 vacation could use any of the following points in any combination: 1) Regular 2006 allocation points, 2) Banked points from Use Year 2005, or 3) Borrowed points from Use Year 2007.
Hope this helps