Quarterly and monthly contracts are fixed, referring to contracts delivered in March, June and September, 65438+February, not +2 and +3 as you understand.

February is February, March, June and September.

March is March, April, June, September, February and April.

April is April, May, June, September and March, and it has gone, rising to 5.

May is May, June, September, 12, 4 is gone, 6 is already there, go to 12.

Do you understand?

This is the case with American futures and options. China copied American rules.