dedicate table for days closed or not?

[jimfog]

I have a table that stores the hours of the week a business(hair salon for example) is open monday 11:00 to 18:00 tuesday etx so on so on

CREATE TABLE `store_open` (
  `id` int NOT NULL AUTO_INCREMENT,
  `b_user_ID` mediumint unsigned DEFAULT NULL,
  `open_time` time DEFAULT NULL,
  `close_time` time DEFAULT NULL,
  `open_time_b` time DEFAULT NULL,
  `close_time_b` time DEFAULT NULL,
  `day` tinyint DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `b_user_ID` (`b_user_ID`),
  KEY `day_idx` (`day`),
  CONSTRAINT `day` FOREIGN KEY (`day`) REFERENCES `weekdays` (`dayID`)
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=utf8

the day foreign key refrences this table here..which holds the days of the week,

CREATE TABLE `weekdays` (
  `dayID` tinyint NOT NULL AUTO_INCREMENT,
  `days` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`dayID`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8

QUESTION...

I must also store the days where the business will be closed...do you think a separate table for that is needed?

Which I assume this table will have a foreing key referencing the weekdays table....

OR you think is better to add another column  to the store_open table(probably a boolean-closed or no closed)

In that last scenario the days that the business will be closed the values of open_time,close_time(see the store open table create statement) will be set to null.