Create invoice in SAP FI

Hello Every one,

I want to create a invoice in SAP to test the entry date in my extractor program.

the client ask the entry date  =   entry date - 2 or - 3

In our system we do not have record of entry date for today or yesterday.

can some one help me to create the invoice to test the entry date.

Thank u for your help.

Best regard,

Ouail