manager.rb

      def months_til_renewal
        months = 0
        date_to_check = Date.current
        while(date_to_check < current_period_ends_at.to_date) do
          date_to_check = date_to_check.next_month
          months += 1
        end
        months
      end

def months_til_renewal
  (current_period_ends_at.year * 12 + current_period_ends_at.month) - (Date.current.year * 12 + Date.current.month)
end

def months_til_renewal
   ((current_period_ends_at - Time.now) / 1.month).ceil
end