{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "schema:Duration",
  "title": "Duration",
  "description": "Quantity: Duration (use [ISO 8601 duration format](http://en.wikipedia.org/wiki/ISO_8601)).",
  "type": "object",
  "allOf": [
    {
      "description": "Quantities such as distance, time, mass, weight, etc. Particular instances of say Mass are entities like '3 kg' or '4 milligrams'.",
      "$ref": "schema:Quantity"
    }
  ]
}