Help EventCalendar

I am developing an application for days and times for school and I'm
using the gem EventCalendar, but I have a problem in time to paint the
day of the week for a particular discipline, the discipline
mathematics does not happen every day only on days Mon / Wed / Fri.
When creating a discipline I submit this:

class CreateDisciplines <ActiveRecord :: Migration

       def change create_table: disciplines do | t |
             t.string: name
             t.integer: user_id
             t.boolean: monday
             t.boolean: thursday
             t.boolean: wednesday
             t.boolean: thursday
             t.boolean: friday
             t.time: hour_begin
             t.time: hour_end
       end
             t.timestamps
      end
end
end

class CreateEvents <ActiveRecord :: Migration

         def change create_table: events do | t |
                t.integer: discipline_id
                t.date: start_at
                t.date: end_at
                t.boolean: all_day
                t.timestamps
           end
       end
end

You can tell me how do I create a method to paint only the day of the
week a particular discipline registered?

Thank you for help.