Specify the date format

Error FX-SCH-A-000670 Factur-X

Attribute '@format' is required in this context.

Mandatory rule: As long as it is violated, the invoice is invalid and will be rejected by validators.
What is wrong

The qdt:DateTimeString element is missing the format attribute. In this context, the attribute must be present.

What the rule means

The format attribute identifies the format of the date value for the issue date associated with the buyer order reference.

Please specify the format of the order date

The issue date for the buyer order reference is missing the format attribute on qdt:DateTimeString. Add the attribute to state the date format.

What to do
  1. Locate qdt:DateTimeString in ram:BuyerOrderReferencedDocument.
  2. Add the format attribute to qdt:DateTimeString.
  3. Generate the invoice again and validate it once more.
What it looks like
✗ Triggers the message 
<qdt:DateTimeString>20250131</qdt:DateTimeString>
✓ Correct 
<qdt:DateTimeString format="...">20250131</qdt:DateTimeString>
Technical details

The check only tests whether format is present on qdt:DateTimeString.

Where the rule applies

The rule applies to qdt:DateTimeString within the issue date of the buyer order reference ram:BuyerOrderReferencedDocument.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ ram:BuyerOrderReferencedDocument/ram:FormattedIssueDateTime/qdt:DateTimeString
Test expression (assert/@test)
@format