# FX-SCH-A-000460

Source: https://xmlvalid.com/rules/FX-SCH-A-000460

> Attribute '@format' is required in this context.

- Level: error
- Rule sets: Factur-X BASIC WL rules 1.09, Factur-X EN 16931 rules 1.09.2, Factur-X EXTENDED rules 1.09.2
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:BillingSpecifiedPeriod/ram:EndDateTime/udt:DateTimeString`
- Test: `@format`

Validate a document against these rules: https://xmlvalid.com/validate