parse4sq.rb

square = File.new "foursquare.kml"
date_array = Array.new

square.readlines.each do |line|
  date = line.match(/<updated>\w*, \S* \w* \S* \S* \+0000<\/updated>/)
  date_array << date
end

puts date_array

File.open('dates.txt', 'w') {|f| f.write(date_array) }