the interest-free period generally ranges from 2 to 6 days, and the interest-free period of each bank is different.
for example, the billing date is the 1st and the repayment date is the 25th. Then swipe your card on the 1st (provided that you swipe your card on the same day as the bank's billing date), then you can enjoy the longest interest-free period of about 55 days given by this bank. Why "about"? Because some months are 3 days, some are 31 days, and February is 28 days or 29 days.
If you swipe your card on May 1st, the corresponding repayment date is June 25th, and you enjoy the longest interest-free period. There are 31 days in May, and the repayment date on June 25th is 31+25=56 days.
You can log on to the online banking, mobile banking APP, official WeChat WeChat official account of the bank, or go to the outlets to check the billing date and repayment date of your credit card, and then see when it is more cost-effective to swipe your card according to your billing date and repayment date, so that you can enjoy a longer interest-free period.