{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "This schema represents a full date (for example: 2014-11-20). See RFC 3339 5.6 for details.",
    "type": "string",
    "references": [
        {
            "description": "The SNOMED code represents Date (qualifier value).",
            "url": "http://purl.bioontology.org/ontology/SNOMEDCT/410672004"
        }
    ],
    "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}$"
}