Ruby 1.87 vs 1.92 Date.parse

Question

In Ruby 1.87 I could do:

Date.parse (\"3/21/2011\")

Now in 1.9.2 I get:

ArgumentError: invalid date

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Answer 1

Per this bug report, the ability to parse mm/dd/yy dates was intentionally removed in 1.9. Ruby's creator, Yukihiro Matsumoto says:

"dd/dd/dd" format itself is very culture dependent and ambiguous. It is yy/mm/dd in Japan (and other countries), mm/dd/yy in USA, dd/mm/yy in European countries, right? In some cases, you can tell them by accident, but we should not rely on luck in general cases. I believe that is the reason parsing this format is disabled in 1.9.

As hansengel suggests, you can use Date.strptime instead.

Answer 2

I like the american_date gem for accomplishing this...

Answer 3

I have always had difficulty parsing dates with Date.parse. My solution is gratutious of the chronic gem. I also like the strptime function found in another answer.

Answer 4

  class << self
    def parse_with_us_format(date, *args)
      if date =~ %r{^\d+/\d+/(\d+)$}
        Date.strptime date, "%m/%d/#{$1.length == 4 || args.first == false ? '%Y' : '%y'}"
      else
        parse_without_us_format(date, *args)
      end
    end
    alias_method_chain :parse, :us_format
  end

Answer 5

Use strptime and give a specific time format.

ruby-1.9.2-p136 :022 > Date.strptime '03/21/2011', '%m/%d/%Y'
 => #<Date: 2011-03-21 (4911283/2,0,2299161)>

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See michaelmichael's response for the reason for this difference between Ruby versions.