To answer your question, you need to know the date of your credit card bill. The final repayment date of CCB's credit card is the 20th day after the bill date, and full repayment before the final repayment date does not bear interest. Suppose the billing date of the credit card is 26th (fixed), that is to say

Generate bill 4.27, record the transactions from March 28th to April 27th, and the final repayment date is the 20th day after April 27th, that is, 5. 17.

Generate a bill 5. 17, and record the transactions from April 28th to May 27th. The final repayment date is the 20th day after May 27th, that is, 6. 15.

And so on.

Obviously, the interest-free period of consumption on 4.27 on the billing date is the shortest, which is 20 days (4.27 brush, 5. 17 times), and the interest-free period of consumption on 4.28 on the first day after the billing date is the longest, which is 50 days (4.28 brush, 6. 15 times). It should be noted that credit card consumption has an interest-free period, and cash withdrawal has no interest-free period.