https://www.w3.org/TR/xmlschema-2/#built-in-primitive-datatypes https://www.w3.org/TR/xmlschema-2/#built-in-primitive-dataty... For comparison, time formats in

https://www.w3.org/TR/xmlschema-2/#built-in-primitive-datatypes https://www.w3.org/TR/xmlschema-2/#built-in-primitive-dataty... For comparison, time formats in JSON are all over the place.