The first repayment of the credit card bill should be made before the first repayment date after the bill date.

For example, if your bill date is the 5th of each month, and you apply for the monthly installment bill, then your installment bill will come out on the 5th of next month, and the repayment date is generally about 20 days away from the bill date, so you can repay it between the 5th and 25th.