Specify the date format

Error FX-SCH-A-000021 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 udt:DateTimeString.

What the rule means

The format attribute identifies the format used for the date value. Without it, the format is not specified in this XML context.

Please specify the invoice date format

The date in udt:DateTimeString is missing the format attribute. Add the attribute to specify the format of the date value.

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

The XPath test checks only whether the format attribute is present on the current udt:DateTimeString.

Where the rule applies

The rule applies to udt:DateTimeString as the invoice date in the document header.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:ExchangedDocument/ram:IssueDateTime/udt:DateTimeString
Test expression (assert/@test)
@format