{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "id": "http://www.52north.org/schema/json/TimeInstant#",
    "oneOf": [
        {
            "_format": "date-time"
        },
        {
            "enum": [
                "template",
                "first",
                "latest"
            ]
        }
    ],
    "type": "string"
}