Got credit card debt? If so, good news: the card issuer can no longer hike your interest rate without warning or raise rates on an existing balance. They have to send your bill at least 21 days before it’s due (up from 14 days). And each bill has to show how long it will take to pay off the balance if you make the minimum payment–and how much you’ll pay in interest if you do that. Call it the credit card equivalent of the Surgeon General’s warning.