Repayment by billing cycle, not every billing cycle can enjoy the 50-day interest-free period. Suppose the bookkeeping date is 10 day and the repayment due date is 28th:

For example: generally speaking, customers spend money on August 9, bill on August 10, and need to repay on August 28, so the interest-free period is the shortest; If the customer spends money in August 10, the bill will not be issued until September 10, and the repayment on September 28 has a maximum interest-free period of 50 days. That is, customers can enjoy the longest interest-free period if they repay all the amount due before the due repayment date (inclusive).