me21n get runtime posting date (BUDAT)

Hi,

I need to make a check when using transaction ME21N, and for this check, I need the Posting Date (BUDAT).

I'm using BAdI ME_PROCESS_PO_CUST and IF_EX_ME_PROCESS_PO_CUST~CHECK.

I was hoping finding this field in mepoheader but it's not the case.

How can I find the BUDAT on runtime.

Thanks