Ruby incorrectly parses 2 digit year

ruby, ruby-on-rails-3

Solution

The `strptime` method is parsing the text "63" to the year 2063, not 1963 as you want. This is because the method decides the century by using the POSIX standard.

The `chronic` gem has a similar issue because it decides the century, though differently.

A solution is to adjust the date:

d = Date.strptime("15/10/63","%d/%m/%y")
if d > Date.today
  d = Date.new(d.year - 100, d.month, d.mday)
end

In the comments of this post, Stefan suggests a good one liner:

d = d.prev_year(100) if d > Date.today

If you need speed, you can try optimizing like this:

d <= Date.today || d = d << 1200

Problem

Ruby correctly parses the first date but the second one is incorrect. Tested with ruby 1.9.3 and 2.1.2. Any idea how to get it to work consistently? (We are getting in birth dates as 2 digit years) ``` Date.strptime("10/11/89","%d/%m/%y") => Fri, 10 Nov 1989 Date.strptime("15/10/63","%d/%m/%y") => Mon, 15 Oct 2063 ```

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