SELECT DATE_FORMAT(DATE_SUB(NOW(), INTERVAL ac DAY), '%Y-%m-%d') as date

FROM (

SELECT @ai:=@ai+1 as ac from

(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) ac1,

(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6) ac2,

(SELECT @ai:=0) xc0

) ad