Why is delivery date is mandatory while creating an Order Confirmation (OC)?

Buyer has enable the rule "Require delivery dates for order confirmations and ship notices".

If you do not want to provide a delivery date while creating an order confirmation, reach out to your customer and ask them to disable the rule "Require delivery dates for order confirmations and ship notices".

SAP Help Portal > SAP Business Network for Procurement > SAP Business Network Buyer Administration Guide > SAP Business Network Configuration > Default Transaction Rules > Order Confirmation and Ship Notice Rules > Require delivery dates for order confirmations and ship notices

SAP Business Network for Procurement & Supply Chain > SAP Ariba Supply Chain Collaboration > Supply Chain Collaboration - Order Collaboration
SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Purchase Orders, Ship Notices & Goods Receipts)