The STR carries a different sentence: available on days considered business days for national financial system operations. A refused authorization cannot be re-offered for 30 dias corridos — calendar days, in the same rulebook that computes payment dates in business days. “Is the obligation counted in business days or calendar days?” Brazilian card receivables answer the first with calendar days and the second with business days on the same transaction. Normalising to calendar days doesn’t remove the rule, it just moves the error somewhere it won’t be caught until an audit.