Ausfarm, do you by some miracle have a copy of the terms and conditions on this account? If so, check to see what they say. You can also try looking online for the T&C's, but I don't know if generally-published ones like that would be the same as what you have for your own account.
I've seen everything counted as 30-days: 1 day after the due date, 30 days after the statement date, 30 days after the due date, you name it. The rules are what they say they are...
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007