    def monthdays(date)

      pos = 1
      d = date.dup

      loop do
        d = d - WEEK_S
        break if d.month != date.month
        pos = pos + 1
      end

      neg = -1
      d = date.dup

      loop do
        d = d + WEEK_S
        break if d.month != date.month
        neg = neg - 1
      end

      [ "#{WEEKDAYS[date.wday]}##{pos}", "#{WEEKDAYS[date.wday]}##{neg}" ]
    end