Hi,
if you ask for a date, your idea is the worst of all (in my opinion).
Why?
You have to validate both fields of the multiple numeric input, to avoid "1673" and "24" as month.
For a date you should either use a date question.
or you may use an array(numbers)
Here the dropdowns are restricted to your allowed values
or you may use a different datepicker (which I found, but won't recommend)
Here an example of all three options.
Joffm