XML / XSD ISODateTime What is the correct format?

Question

I am working with some old XML/XSD code that requires dates to be in 'ISODateTime' format. I have tried a number of different ISO date/time formats, i.e. with 'T' in the middle, but the validation continues to fail.

Am I missing something obvious? The XML and XSD snippets are below along with the error message.

XSD:

<xs:complexType name="MessageId">
    <xs:sequence>
        <xs:element name="Id" type="Max35Text"/>
        <xs:element name="Credit" type="ISODateTime"/>
    </xs:sequence>
</xs:complexType>

XML:

<ParentId>
    <Id>unique id</Id>
    <Credit>2019-09-27 04:00:00</Credit>
</ParentId>   <!-- Fixed by edit -->

Validation error:

ERROR: Element '{urn:iso:std:iso:20022:tech:xsd:tsmt.017.001.03}Credit': '2019-09-27 04:00:00' is not a valid value of the atomic type '{urn:iso:std:iso:20022:tech:xsd:tsmt.017.001.03}ISODateTime'.

Answer 1

I could make your XSD work by changing your date format to xs:dateTime from the namespace http://www.w3.org/2001/XMLSchema, in your example this is 2019-09-27T04:00:00.

I did not find a definition for ISODateTime, but at W3.org is a definition for date/time formats and the closest I found was xs:dateTime described here.

So change your XML to (by simply adding the "T" you mentioned)

<?xml version="1.0" encoding="UTF-8"?>
<ParentId>
    <Id>unique id</Id>
    <Credit>2019-09-27T04:00:00</Credit>
</ParentId>

and this sample XSD

<?xml version="1.0" encoding="utf-8"?>
<xs:schema elementFormDefault="qualified"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">

    <xs:complexType name="MessageId">
        <xs:sequence>
            <xs:element name="Id" type="xs:string"/>   <!-- Changed for simplicity -->
            <xs:element name="Credit" type="xs:dateTime"/>
        </xs:sequence>
    </xs:complexType>

    <xs:element name="ParentId" type="MessageId" />

</xs:schema>

will validate your XML.