需要有关基于以下条件返回日期列表的sql语句的帮助：
每月的第n天。
我有下面的语句，它返回一个基于循环模式的日期列表，循环模式包括开始日期和结束日期、循环（例如每x周）和星期天。

CREATE DEFINER=`root`@`%` PROCEDURE `GETEVERYOTHERDATE`(IN _START DATE, IN _END DATE, IN _REC INT(5), IN _DAY VARCHAR(10))
BEGIN

SET CHARACTER SET 'UTF8';

select * from 
(select adddate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) DATES from
 (select 0 t0 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
 (select 0 t1 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
 (select 0 t2 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
 (select 0 t3 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
 (select 0 t4 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where DATES between _START and _END
and dayname(DATES) = _DAY
AND WEEK(DATES) % _REC = WEEK(_START) % _REC;

END

如果条件是：

START = 2019-01-01
END = 2019-06-30
DAY = FIRST TUESDAY
RECURRENCE = every month

结果是：

2019-01-01
2019-02-05
2019-03-05
2019-04-02
2019-05-07
2019-06-04

所以我没能想出正确的where子句。也许我的方法完全错了。
感谢所有的帮助。