format must be present

Error FX-SCH-A-001022 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 qdt:DateTimeString. As a result, the format of the date and time value in that element is not identified.

What the rule means

format identifies the representation of the date and time value.

Please add the date format to DateTimeString

The format indicator is missing from the date and time value of the referenced document. Add the attribute to the affected qdt:DateTimeString.

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

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

Where the rule applies

The rule applies to qdt:DateTimeString within ram:FormattedIssueDateTime of a referenced document on the agreement level of an invoice line.

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