public static ZonedDateTime createTimestamp(String spec) {
        return ZonedDateTime.parse(spec).truncatedTo(ChronoUnit.MILLIS);
    }
Create a timestamp by parsing the given string representation which must be in an extended ISO 8601 Format
with Nanoseconds since this is the format used by Docker for logging (e.g. "2014-11-24T22:34:00.761764812Z")

@param spec date specification to parse
src/main/java/io/fabric8/maven/docker/util/TimestampFactory.java