'Late' is simply missing the due date. The fine print with probably say you can't just ignore the card for 60 days, they are just willing to play loose with the one due date. No, the report doesn't get hit. But, interest is accruing. So if you were planning to pay in full, but miss the date, no penalty, but the month's interest, say 1.5%, will be charged. 

Edit - ask the bank how many days grace there is before the late payment is reported to the credit bureau, we don't have consensus on that number here.