Give an example to illustrate the billing date and repayment date. If the credit card interest-free period is 50 days at the longest and 20 days at the minimum, that means the repayment date is the 20th day after the statement date. If the bill date is the 3rd day of the month, the repayment date will be the 20th day after the bill date, which is around the 23rd of the month.

So: the card consumption from January 4th to February 3rd will be debited on February 3rd, and the payment can be made before February 23rd. Card purchases made from February 4th to March 3rd will be debited on March 3rd, and the payment can be made before March 23rd. And so on. Therefore, the interest-free period is the shortest at 20 days for card payments made on the bill date; the interest-free period for payments made after the bill date is the longest at 50 days.