# File lib/rufus/scheduler/jobs.rb, line 370
      def determine_id

        [
          self.class.name.split(':').last.downcase[0..-4],
          @scheduled_at.to_f,
          @next_time.to_f,
          (self.object_id < 0 ? 'm' : '') + self.object_id.to_s
        ].map(&:to_s).join('_')
      end