PHP Holidays Library for Germany, Austria and Switzerland: Get the holiday dates of specific countries

This class provides some information for federal states of
 - germany
 - austria
 - switzerland ('federal states' -> 'cantons')
and the public holidays applicable to the individual federal states. For
moving public holidays (not on a fixed date, e.g. Easter), a calculation 
of the date for any calendar year is included.
 
Since there are sometimes several number ranges per state, the main issue 
of this class is the relationship between the postcode and the state to 
which the respective place belongs.
 
This information is often required to determine state-specific regulations 
(e.g. public holidays, school holidays, laws ...)
 
The class provides a list of all federal states and the corresponding 
abbreviation.
 
Conversely, a corresponding SQL WHERE condition can be created in order 
to find all addresses in a database in a particular state. (usually the 
address data do not contain the correct state information)
 
Since this information normally do not change, an XML file was chosen for 
data storage, which allows easily access with XPath.


1.Notes to the reverse search of federal state from postcode
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Since the backward search is based on areas from-to, it does not  necessarily
mean that the postcode that is being searched for actually exists - the 
validation of a postcode should be carried out via a database or an 
appropriate (web) service.

Due to the fact that some postcodes in Austria and Switzerland include a 
cross-federal state area, it is possible that in this case a comma-separated 
list of the affected federal states (or abbreviations) will be returned as a 
result. 

2. Notes about public holidays
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2.a  Germany
     In Germany there are a few public holidays that are only partially 
	 valid within a federal state - here you should then query directly 
	 via the postcode.
	 
2.b  Austria / Switzerland
	In the case, that a given postcode belongs to multiple states
	it does not make sense to query the valid public holidays using the 
	postcode, since no clear state can be assigned.