Extending Date parsing in Ruby 1.9.3

gistfile1.rb

require 'date'

class Date

  class << self
   
    def convert_date_string(input)
      # mm-dd-yyyy
      if input =~ /^(\d{1,2})[^\d\w\s](\d{1,2})[^\d\w\s](\d{4})([T|\W].*)?/
        "%0.4d/%0.2d/%0.2d#{$4}" % [$3, $1, $2].map(&:to_i)
      # mm-dd-yy
      elsif input =~ /^(\d{1,2})[^\d\w\s](\d{1,2})[^\d\w\s](\d{1,2})([T|\W].*)?/
         "%0.4d/%0.2d/%0.2d#{$4}" % ["#{today.century}#{$3}", $1, $2].map(&:to_i)
      # mm-dd
      elsif input =~ /^(\d{1,2})[^\d\w\s](\d{1,2})([T\W].*)?/i
         "%0.4d/%0.2d/%0.2d#{$3}" % [today.year, $1, $2].map(&:to_i)
      # 28/Jan
      elsif input =~ /^(\d+)[^\w\d]((jan)|(feb)|(mar)|(apr)|(may)|(jun)|(jul)|(aug)|(sep)|(oct)|(nov)|(dec))(\s.*)?/i
         "#{$1}/#{$2}#{$3}"
      else
         input
      end
    end 

    alias _original_parse _parse

    def _parse(input, comp=true)
      _original_parse(convert_date_string(input), comp)
    end

    alias original_parse parse

    def parse(input, comp=true)
      original_parse(convert_date_string(input), comp)
    end
  end
end