The Credit Card Act of 2008 requires the Payment Due Date to be the same every month now. The way I understand it (get clarification from the bank CC agent) is you maximize your "float" by charging your card on the first day of your billing opening date.

For example, this is my Chase Sapphire Preferred Statement:

Opening Date 02/18/2012
Closing Date 03/17/2012
Payment Due Date 04/14/2012

If you made a charge on 2/18/12, you could wait until 4/14/12 to pay in full.

Chase will give you open, close, and payment due date. My AmEx SPG, for example, only has closing date and payment due date. It is not always clear when your opening date is -- you sometimes have to call customer service as this opening date can fluctuate. The number of actual days you are given to pay your bill in full depends on the number of days in the month.

Two small points:

1) any bill with opening or closing date in Feb will be least favorable to you
2) a bill opening in Nov and closing in Dec will be most favorable since both months contain 31 days.

Ideally, if you want to maximize "float" term, you want multiple cards with staggered "payment due dates". For example, you could have four credit cards with due date of 7, 14, 21, and 28. This way, you can rotate in cards that just started their opening date.

I know its a lot to take in, but I've thought a lot about it myself as I do my best to manage cash flow without paying interest.

Just checked my knuckles ... #2 should be July and August . But good tip!

Edit: Just looked at the piano keys, don't forget December and January.

Sorry I meant dec and jan earlier... Or any two months with 31 days

I know that you can't apply for any new cards now, but you should add a good 2% cashback card (Fidelity AMEX, Priceline, SallieMae) to your collection.........

Good Luck,