BR-KSA-F-01

A date MUST be formatted YYYY-MM-DD, in accordance to the "Calendar date complete representation" as specified by ISO 8601:2004, format YYYY-MM-DD.

error: the document is invalid

What the rule checks

As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.

Context
cbc:IssueDate | cbc:DueDate | cac:Delivery/cbc:ActualDeliveryDate | cac:BillingReference/cac:InvoiceDocumentReference/cbc:IssueDate | cac:InvoiceLine/cac:DocumentReference/cbc:IssueDates | cbc:TaxPointDate
Test
(string-length(.) = 10 and (string(.) castable as xs:date))

Checked with Saudi Arabia ZATCA Tax Invoice (UBL), Saudi Arabia ZATCA Simplified Tax Invoice (UBL)