When cloning an order with products, Salesforce enforces guidelines to ensure the cloned order's dates are valid relative to the contract it is associated with. Specifically, the cloned order's start date must be within the contract's start and end dates. This ensures that the cloned order remains aligned with the terms of the contract and is valid for fulfillment under the existing contract constraints. This rule maintains consistency and accuracy in order and contract management.
For more on order and contract management, review Salesforce's Order Guidelines.