gistfile1.rb

# File: config/initializers/date.rb
# Parse date using Rails I18n or Ruby parse method if it failed.
# Reference https://gist.github.com/179712

module DateTimeI18nParser
  module ClassMethods
    def _parse_with_i18n(str, format = :default)
      format ||= :default
      date = self._strptime(str, I18n.translate("#{self.name.downcase}.formats.#{format}")) || _parse_without_i18n(str)
      date[:year] += increment_year(date[:year].to_i) if date[:year]
      date
    end

    def parse_with_i18n(str, format = :default)
      format ||= :default
      date = self.strptime(str, I18n.translate("#{self.name.downcase}.formats.#{format}"))
      self.new(date.year + increment_year(date.year), date.month, date.day)
    rescue ArgumentError
      parse_without_i18n(str)
    end

    def increment_year(year)
      if year < 100
        year < 30 ? 2000 : 1900
      else
        0
      end
    end
  end

  def self.included(receiver)
    receiver.extend ClassMethods
    class << receiver
      alias_method_chain :_parse, :i18n
      alias_method_chain :parse, :i18n
    end
  end
end

[Date, DateTime].each do |klass|
  klass.send :include, DateTimeI18nParser
end