Alternately I've introduced methods for the build_statement_for_date and build_statement_for_datetime_or_timestamp (fun names!) in AbstractModel - see https://github.com/awagener/rails_admin/blob/81cc739f952b3b37437648eb033ff65a3e34a484/lib/rails_admin/abstract_model.rb#L137 - this code could slot into this method.