3561434 - Can't edit Invoice Date when creating new invoice

I'm creating a new invoice from a Purchase Order and the Invoice Date field is non-editable in the invoice creation screen.

When I click in the information icon beside the field the following message is displayed: You cannot edit Invoice Date for this invoice. Invoice Date is automatically added when the buyer approves the service sheet and the invoice moves from Pending Approval to Sent status.

SAP Business Network

Invoice Approval, Pending Approval, On Hold, Invoice Date, SES , KBA , SBN-AN-TX-SS , Service Procurement/Service Sheet (O&G) , SBN-AN-TX-POA , Transaction (Purchase Orders, Ship Notices & Goods Receipts) , SBN-AN-TX-INV , Transaction (Invoicing) , How To