Custom query filter by ACF date custom field

Probably the date format should be different – like:

        $date_debut = date('Y-m-d',$date_debut);
        $date_fin = date('Y-m-d',$date_fin);

I haven’t tested this but the doc says:

The ‘type’ DATE works with the ‘compare’ value BETWEEN only if the
date is stored at the format YYYY-MM-DD and tested with this format.