In the space of just under a month Date_Holidays_Croatia and Date_Holidays_Australia were released - many thanks to the guys who did the actual hard work to be fair as all I did was package them up and release them!

You can find more of these Date packages on the PEAR site that could help you and your application get things a bit more localized. He also reminds you that, if you'd like to help out and pick up support for some of the older, unmaintained packages, you can follow this guide and get started easily.