Time Zone Area Polygons

I have read at several websites about there being time zone area polygon lists. For example a file called New_Yok.geo. I can't find the files anywhere though. In order to make use of your timezone database, such a database (area polygon) would be needed. Knowing that the New York area is EST isn't sufficient info, as it begs the question "what are the boundaries of this area?" So can you please direct me to where I can download the timezone area polygons. Thanks in advance. B"H John