PO: Default Need-By Time

Hello,

Is there a way to get the system to not default a Need-By date on the purchase requisition lines in iProcurement? We want the user to manually populate. It does not default in core requisition form. only iProcurement requisition during checkout. I removed the site definition on the  PO: Default Need-By Time profile option. But now it defaults to the system date.

Thanks,

Anthony