Period start date format is missing

Error FX-SCH-A-000541 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 udt:DateTimeString element for the period start date.

What the rule means

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

Please add the format for the period start date

The udt:DateTimeString for the period start date has no format information. Add the missing attribute so that the date representation is specified.

What to do
  1. Locate udt:DateTimeString under ram:StartDateTime in ram:BillingSpecifiedPeriod.
  2. Add the format attribute to udt: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 udt:DateTimeString.

Where the rule applies

The rule applies to the udt:DateTimeString date field for the period start in ram:BillingSpecifiedPeriod of an invoice line.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ ram:SpecifiedLineTradeSettlement/ram:BillingSpecifiedPeriod/ram:StartDateTime/ udt:DateTimeString
Test expression (assert/@test)
@format