One day per month is the billing date, and 20 days after the billing date is the repayment date. If the billing date is July 2nd and you spend money on July 3rd, then August 2nd of next month will be the billing date and August 22nd will be the repayment date, enjoying the longest interest-free period. If it is consumed before the bill date, such as July 1, it should be repaid on July 22nd, with the shortest interest-free period. Therefore, it is recommended to spend on the second day after the bill date and enjoy a longer interest-free period. If you spend the same day and charge the next day, you can enjoy an interest-free period of up to 50 days.