If the marketing department at Disney does their job right there isnt a 'slow' time. If you go and look at the DVC
point charts and look at the dates for the 'adventure' season, that is the 'cheapest' time for DVC rentals and will go along with the 'slow' dates that WDW has. Just use any of them, here is animal kingdoms
http://www.wdwinfo.com/disney-vacation-club/AK-Points.htm
It is funny to NOT see 4th of July in the premier season though.. Or thanksgiving, or the other 'big' summer holidays.. Granted they are almost in premier.
so the 'slowest' time SHOULD be
Jan 1-31
Sep 1-30
Dec 1-14
then
Oct 1-31
Nov 1-23
Nov 27-30
Dec 15-23
then
Feb 1-15
May 1-31
June 1-10
Aug 16-31
then
Feb 16-28
Mar 1- 27
Apr 11-30
June 11-30
July 1-31
Aug 1-15
Nov 24-26
then the PREMIERE season..
March 28-31
April 1-10
Dec 24-31