Is there a free source of U.S. time zone borders?

A shapefile of the TZ timezones of the United States

Last data update: September 30, 2012

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The tz_us shapefile captures the boundaries of the TZ timezones of the United States, as of TZ 2012c.

The geometries are entirely derived from the countyp020p and timeznp020 shapefiles provided by the National Atlas.

All the TZ timezones of United States listed in TZ’s zone.tab are represented, except for America/Shiprock which is included in America/Denver.

http://efele.net/maps/tz/us/

Shapefile Zipped (Direct Link) http://efele.net/maps/tz/us/tz_us.zip

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