Validation of date in JSON using JSON schema

JSON-Date-Validate.js

{
    "$schema": "http://json-schema.org/draft-03/schema#",
    "type": "object",
    "properties": {

        "orderDate": {
            "type": "string",
            "format": "date"
        }
    }
}

{
  "orderDate": "2014-02-31"
}

Results :- 

[ {
  "level" : "error",
  "schema" : {
    "loadingURI" : "#",
    "pointer" : "/properties/orderDate"
  },
  "instance" : {
    "pointer" : "/orderDate"
  },
  "domain" : "validation",
  "keyword" : "format",
  "attribute" : "date",
  "message" : "string \"2014-02-31\" is invalid against requested date format(s) yyyy-MM-dd",
  "value" : "2014-02-31",
  "expected" : "yyyy-MM-dd"
} ]