[ibr-119]-A time MUST be formatted hh:mm:ss with optional fractional seconds .sss and time zone expression (ibt-168).
ibr-119
//*[namespace-uri()='urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2' and ends-with(local-name(), 'Time')]
(string(.) castable as xs:time)