Open the card at any time. If you don't consume after activation, you won't generate interest and you can "casually". Of course, there is another detail. Think about it, that is, if you don't activate it, there will never be any problems such as annual fees and handling fees, but once you activate it and don't use it, there will still be annual fees, and you will be in arrears! So if you decide to use it, you will swipe your card more after activation. Generally, if you swipe your card more than once a year, you will be exempted from the annual fee.

Of course, it is best to spend on the 6th of every month, so the interest-free period is the longest. Because the bill was just delivered yesterday, the consumption on the 6th is the farthest from the next billing date and the farthest from the repayment date, haha.