cakephp/cakephp — pull request #2436 by houseoftech (2013-12-05 18:02:33+00:00)
Title: 2.5 - Add format to date validation for 2 digit year

I know this breaks backward compatibility but mY looks like it should be for 4 digit year and my for 2 digit.

This would be useful for validating a credit card expiration date, for example `'rule' => array('date', array('my', 'mY'))`