ORACLE根据星期几查询日期个数

SELECT
	COUNT(*) 
	FROM
		(
			SELECT TO_CHAR(to_date("2020-03-23","yyyy-mm-dd") + rownum-2, "yyyy-mm-dd") date_, TO_CHAR(to_date("2020-03-23","yyyy-mm-dd") + rownum-2, "D") week
		FROM
			dual
		CONNECT BY
			rownum <=(to_date("2020-03-31","yyyy-mm-dd")-to_date("2020-03-23","yyyy-mm-dd"))+ 1) b
	WHERE
		INSTR("123", b.week)>0;