CREATE OR REPLACE FUNCTION schemefood.fc_close_day(IN x integer)
  RETURNS TABLE(id_class integer, class_name CHAR(75), id_uch integer, dates date, id integer) AS
  $BODY$
  WITH d(dt) AS (
     VALUES((SELECT MIN(date) FROM schemefood.close_day WHERE id_uch = x)),((SELECT MAX(date) FROM schemefood.close_day WHERE id_uch = x)),(CURRENT_DATE)
  )
SELECT * FROM (SELECT rdc.*, close_day.id 
FROM (SELECT class.id as id_class, CAST(class.name AS CHAR(75)) as class_name, class.id_uch, dates
  FROM (SELECT (SELECT min(dt) FROM d) + i as dates
        FROM generate_series(0, (SELECT max(dt)-min(dt) FROM d))i) as rdate,
  schemefood.class WHERE id_uch = x) as rdc LEFT OUTER JOIN schemefood.close_day
  ON rdc.id_class = close_day.id_class AND rdc.dates = close_day.date
) as fff;
$BODY$
  LANGUAGE sql

SELECT id_class, CAST(class_name AS CHAR(75)), id_uch, dates, id from schemefood.fc_close_day(15);