Ok, for the 11 month window just take the month you want to go and then just add one month. Example, if you are planning a trip for June 2003 then you can call July 2002. For the 7 month window just count ahead 5 months. Same example, for June 2003 count ahead 5, you can book November 2002. It's easier for me to count forward than to count backwards.
Hope this helps!!