If you mean something to tell you when you can call to make a reservation at 11 or 7 months- you can call 11 (or 7) months from your checkout date. Even if you wish to call daily the checkout date is the key- to reserve October 10, 2004 (checkout on October 11) you may call tomorrow on November 11, 2003.
If a date falls on a Saturday or Sunday- you'll need to wait until Monday to call.
Good Luck!