the repayment date refers to the date when you must repay the loan before this, otherwise it will be a breach of contract, and three consecutive defaults or one default for more than 9 days will lead to bad credit reporting.
the 12th day of the billing date indicates that your credit card is a consumption cycle from the 13th day of each month to the 12th day of next month, and the billing ends on the 12th day of each month.
the 5th repayment date means that the consumption of your current bill needs to be repaid before the 5th next month.
Take the May bill as an example: the consumption from April 13th to May 12th is a billing cycle. Repayment shall be made before June 5th.