It looks like format `date-time` only supports 3 digits of time-secfrac: ``` "message" : "string \"2015-01-24T20:45:08.7960Z\" is invalid against requested date format(s) [yyyy-MM-dd'T'HH:mm:ssZ, yyyy-MM-dd'T'HH:mm:ss.SSSZ]" ``` [RFC 3339](http://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-7.3.1.2) defines time-secfrac as: ``` time-secfrac = "." 1*DIGIT ``` which I believe means one or more digits. We have systems that are creating secfracs with 4 or more digits. Not sure how easy it would be to make it general like that, but it would seem that more than 3 digits is common. Thanks