ZF-7812: Zend_Validate_Date no longer has class constant NOT_YYYY_MM_DD
In r17874 (August 28) the NOT_YYYY_MM_DD class constant for Zend_Validate_Date was removed in trunk.
Not sure if it was intentional or not, but it triggers fatal errors across two of my applications in testing since I am hooking into it from Zend_Form. If intentional, I'll switch over. This does not affect the release-1.9 branch, only trunk.