DROP FUNCTION date_test_timezone(date);



CREATE OR REPLACE FUNCTION date_test_timezone( in_last_date timestamptz DEFAULT (now())::date::timestamptz)
  RETURNS timestamptz AS
$BODY$	

	SELECT in_last_date::date::timestamptz;
	-- нотис отсюда послать надо бы
$BODY$
  LANGUAGE sql VOLATILE
  COST 100;
ALTER FUNCTION date_test_timezone( timestamptz) SET TimeZone='-23';

RESET TimeZone ; --='Europe/Moscow';

SELECT date_test_timezone()::date  , (now()  AT TIME ZONE  '-23') ::date 
,  (now()  AT TIME ZONE  '+23') ::date
, ((now()::date)  AT TIME ZONE  '-23') ::date ,  ((now()::date)  AT TIME ZONE  '+23') ::date;