# File lib/whenever/outputs/cron.rb, line 51
      def parse_symbol
        shortcut = case @time
          when :reboot          then '@reboot'
          when :year, :yearly   then '@annually'
          when :day, :daily     then '@daily'
          when :midnight        then '@midnight'
          when :month, :monthly then '@monthly'
          when :week, :weekly   then '@weekly'
          when :hour, :hourly   then '@hourly'
        end
        
        if shortcut
          if @at.is_a?(Time) || (@at.is_a?(Numeric) && @at>0)
            raise ArgumentError, "You cannot specify an ':at' when using the shortcuts for times."
          else
            return shortcut
          end
        else
          parse_as_string
        end
      end