Referenced document date format is missing

Error FX-SCH-A-001134 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 format attribute is missing from the qdt:DateTimeString element for the issue date of the referenced document.

What the rule means

The format attribute identifies the format used for the content of qdt:DateTimeString. Without it, the date representation cannot be interpreted by its format.

Please add the format for the referenced document date

The qdt:DateTimeString for the referenced document’s issue date has no format information. Add the missing attribute so that the date representation is specified.

What to do
  1. Locate qdt:DateTimeString under ram:FormattedIssueDateTime in ram:InvoiceReferencedDocument.
  2. Add the format attribute to qdt:DateTimeString with an allowed value.
  3. Generate the invoice again and check it.
Technical details

The test checks whether the format attribute is present on qdt:DateTimeString.

Where the rule applies

The rule applies to the qdt:DateTimeString date field for the issue date in ram:FormattedIssueDateTime of a referenced document within an invoice line.

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