Date_Holidays_Filter_Whitelist | --Date_Holidays_Filter_Austria_Official
By Karin Seifert-Lorenz; based on Ireland/Official.php by Ken Guest.
Date_Holidays_Filter_Austria_Official Date_Holidays_Filter_Austria_Official( )
Only accepts official Austria public holidays as described on https://www.ris.bka.gv.at/Dokument.wxe?Abfrage=Bundesnormen&Dokumentnummer=NOR40060439
Date_Holidays_Filter_Austria_Official __construct( )