A 'date' type could be as simple as syntax indicating that a particular ISO8601 string IS a date. Right now, there's no reasonable way to infer that unless you'

A 'date' type could be as simple as syntax indicating that a particular ISO8601 string IS a date. Right now, there's no reasonable way to infer that unless you're already aware of the schema of the JSON object you're receiving. You could make the same argument with numbers - there's no reason you couldn't just pass strings containing the number - but there's advantages to being able to distinguish between a string and a number when the schema is unknown.