Correct, so let's maintain the tradition. After all we don't usually have precise enough topics, so we can deviate a little and use the opportunity.
Date type reminds about some network-specific types which used to be in older version of JSON Schema (like IPv4 address?). Today we can use a string with regexp for an approximation. Do we have a mechanism in JSON Schema to define, mmm, dialects?..
Deserialization of a number as an integer, not a double, could be a similar problem. We can agree that we (try to) deserialize to most abstract class (?) or to use external explicit indicators of the class.