You are talking about the Peony Shutong Credit Card. ICBC also has Shutong chip card debit card. You first need to check what your accounting date is. Then the billing date is pushed forward seven days to the repayment date. For example, if you record your account on the 8th, you will repay on the 1st. The accounting date is fixed.

How to calculate it. For example, if you make a purchase on February 7th, it will be recorded on February 8th. Then the payment will be made on March 1st.

On the contrary, if you consume on February 9th, then it will be recorded on March 8th, and then the payment will be made before April 1st. This period becomes the number of interest-free repayment days.

Figure it out for yourself.