The calculation formula for charging interest is (principal *0.05%* days from consumption date to current repayment date+unpaid principal *0.05%* days from current repayment date to next billing date). For example, the 5th is the billing date, the 23rd is the repayment date, the payable amount on the bill on March 5th is 1 1,000 yuan, and the minimum repayment date is 1 1,000 yuan, so the interest before the next repayment date is 1.7 yuan.