{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "_format": "date-time",
    "references": [
        {
            "description": "This schema represents a point in time (ISO8601). If a timezone is not included, the timezone is assumed to be UTC. See RFC 3339 5.6 for details.",
            "url": "http://tools.ietf.org/html/rfc3339#section-5.6"
        },
        {
            "description": "The SNOMED codes represent Single point in time (qualifier value).",
            "url": "http://purl.bioontology.org/ontology/SNOMEDCT/123029007"
        }
    ],
    "type": "string"
}