gistfile1.txt

controller:
format.json { 
        render json: @ticket, :include => {
          :courses_users => { 
            :include => {
              :user => {
                :only => [:first_name, :last_name]
              },
              :course => {
                :only => :title
              }
            }
            }
        }, :except => [:created_at, :updated_at]
      }

Model:
  def self.valid?
    self.validFrom < Time.now && self.validTo < Time.now
  end