Control actual GI date using BAPI_OUTB_DELIVERY_CONFIRM_DEC

Hi Guys:

             I am using BAPI_OUTB_DELIVERY_CONFIRM_DEC to perform PGI against delivery order automaticlly.

             But I find this BAPI can't specify the actual GI date,and SAP just default current date as GI date.

             Is there any parameter can control this GI date for this BAPI?

            Or any other solution?

            Thanks.

Stephen