Hello, I need to do the following select: Number of days of month - weekends - holydays So this query will return the number of days that people can work Look that I have the holydays in one table, it's bellow: CREATE TABLE holidays ( id_holidays serial NOT NULL, dt_holiday date, holiday_description character varying(60), input_date timestamp without time zone NOT NULL, CONSTRAINT holidays_pkey PRIMARY KEY (id_holidays) ) I have no idea of how do it If someone could help, I would appreciate. Thanks