As an XML file: 
http://unicode.org/repos/cldr/trunk/common/supplemental/windowsZones.xml  

As a C .h file:
https://github.com/mirror/newlib-cygwin/blob/master/winsup/utils/tzmap.h 

As a shell script to convert the first to the second
https://github.com/mirror/newlib-cygwin/blob/master/winsup/utils/tzmap-from-unicode.org 

We'll need this information later, probably.