Searching by date field doesn't work

I have a grid app that includes several fields set as date or dattime type with and appears in the grid with the form dd/mm/yyyyy (spanish format). These fields are included in the quick search as searchable, so that’s not the problem.
The problem comes when I try to search in the quick search input for instance with “1998”, that is a valid year that is included in the grid data. But the search never cmopares with the date or datetime fields.
Is this a scriptcase bug or a thing that must be configurated?