Watch for the "Actual" Closing Date
My account normally has a closing date of the 15th, 16th or 17th. A few months ago my online account said it was going to be the 15th for that month. I made a purchase on the 16th and then the account really closed on the 17th. You guessed it, the charge was on my previous month's statement. Don't know why that happened, but it did.