For example, the bookkeeping date is 10 and the repayment date is 29. Customers who spend before 165438+ 10 (inclusive) need to repay before165438+10/29 (inclusive), with a minimum interest-free period of 20 days. Consumption after 165438+ 10/1needs to be repaid on February 29th, 65438, with the longest interest-free period of 50 days.