timestamp:
  type: string
  description: Date and time in ISO 8601 format.
  example: "2020-04-09T18:14:30Z"
  readOnly: true
  nullable: true

timestamps:
  type: object
  properties:
    created_at:
      $ref: "#/timestamp"
    deleted_at:
      $ref: "#/timestamp"
    updated_at:
      $ref: "#/timestamp"
