そしてなんだこれは

require 'date'

if ARGV.empty?
	print "Friday 13 Finder / usage: [count]\n"
	exit 1
end

limit = ARGV.shift.to_i
count = 0
year = Date.today.year
month = Date.today.month


while count < limit
	date_of_13th = Date.new(year,month,13)
	
	if date_of_13th.wday == 5
		count += 1
		print date_of_13th.strftime("%B 13, %Y") + "\n"
	end
	# next month
	if month == 12
		month = 1
		year += 1
	else 
		month += 1
	end		
end

13日の金曜日を指定した数検索して表示するツール。誰得…