My table design:
How to get the records If dates '04-11-2016' OR '11-11-2016' available in
Note: The dates are not same, It's have one or more dates.
SELECT * FROM `sh_products` WHERE FIND_IN_SET('04-11-2016','11-11-2016',week_days);
Just OR together two calls to FIND_IN_SET:
WHERE FIND_IN_SET('04-11-2016', week_days) > 0 OR
FIND_IN_SET('11-11-2016', week_days) > 0