select ?con ((?dt - xsd:dateTime("1970-01-01T00:00:00.000+00:00")) * 1000 as ?date) where { ?post snvoc:id %messageId% . { {?post snvoc:content ?con } union { ?post snvoc:imageFile ?con } union { ?post snvoc:gifFile ?con }} . ?post snvoc:creationDate ?dt . }