This is not possible, you cannot query sub-values of serialised/structured data in post meta values.
To fix this, you need to store the dates you want to query/filter by as separate post meta key/value pairs. Values need to be string/number/boolean whole values to be queried this way. They cannot be complex structures or sub-strings, such as JSON, arrays, objects
Also note that saving an array or object is a security risk. This is because you can’t save an array/object so WordPress uses PHP’s serialize
function, turning it into a string. This exposes you to object deserialisation attacks.