Hi,

Declare an array varible with a name days in the form bean class and change the name attribute in the page to days,or else you can use struts taglibraries and set the property attribute to days then the selected check boxes will be stored in that array, use it to store in the database.
If you are using plain JSP/Servlets then give the name attribute for the check boxes as days and in the servlet use request.getParameterValues() method to get the array of values [selected check boxes] as a String array.

Regards,
Rakesh