Shanghai Futures Exchange currently stipulates that the delivery date is five consecutive working days after the last trading day; The last trading day is 15 of the contract month (in case of national legal holidays, the exchange may adjust and notify the last trading day such as the Spring Festival month); Contracts for the last three consecutive months and bimonthly contracts within the last 13 months ("1-3-5-7-9-1"belongs to bimonthly rotation).