ZF-6931: Zend_Date::RFC_822 format does not accept four digit years.
When using RFC 822 format Zend_Date throws an exeption when the provided date has the year in four-digit format. RSS specifies that it uses RFC 822 and at the moment most RSS feeds are using four digits for the year e.g. the feeds on http://framework.zend.com. It should be changed to accept 2 or 4 digits.