The key to correctly using credit card consumption to obtain the longest 50-day interest-free period is to master the billing cycle. Generally speaking, if you make purchases on the billing date, the interest-free period you enjoy will be relatively short. For example, if your China Merchants Bank credit card bill date is the 18th of each month and the repayment date is the 8th of each month, then the consumption on July 18 will be included in the July bill and should be repaid before August 8, interest-free. The period only covers this short period of one month. In contrast, if you consume one day after the bill date, such as July 19, then the consumption will be included in the August bill. At this time, the interest-free period will be extended to September 8, and you can enjoy a longer period. Interest-free period. Therefore, planning your consumption time reasonably and ensuring consumption as soon as possible after the bill date is an effective strategy to extend the interest-free period of your credit card.