Keep in mind also that the OP question was when credit reporting takes place. Without going into boring detail, reporting takes place almost every day. However, an account is not reported as "past due" until it passes one "Cycle" delinquent. That means that even if you don't pay on the due date the account will not be reported as delinquent unless you do not pay iot before the next payment due date. So, don't worry about the credit reporting side of this if you're a day or two late in paying the bill.

American Express is far more generous than most in allowing slightly late payments without imposing fees. However, duw to new regulations all credit cards will see far mor stringent rules applied for fee imposition than were normal until now. Bein g even one day late will get a late fee from many card companies now, not usually American Express, as I said.

So, no credit reporting problem for a day or two late, but be prepared for possible late fees.

lastly, the new regulations that are causing more stringent rules are in the US, Canada and the EU. The specific regulations differ quite a bit, but the net consumer impact is very similar.