Multiple Check Box A probable failed code but can be compiled successfully by perfection

.erb

  <div class="field">
      <%= label_tag 'days_monday', 'Monday' %>
      <%= check_box_tag 'business_pro[days][]','Monday',checked('pop'), id: 'days_monday' %>
      <%= label_tag 'days_tuesday', 'Tuesday' %>
      <%= check_box_tag 'business_pro[days][]','Tuesday',checked('pop'), id: 'days_tuesday' %>
      <%= label_tag 'days_wednesday', 'Wednesday' %>
      <%= check_box_tag 'business_pro[days][]','Wednesday',checked('pop'), id: 'days_wednesday' %>
  </div>

helper.rb

	def checked(area)
		@business_pro.days.nil? ? false : @business_pro.days.match(area)
	end

model.rb

before_save do
  		self.days.gsub!(/[\[\]\"]/,"") if attribute_present?("days")
  	end