As far as I can see tzcode2011i/Theory is missing the fact that for each country at least one zone is created. I.e. maybe Luxembourg and France may have their own zones not due to different timestamp observance since 1970-01-01 00:00:00 UTC but simply due to the fact that they are different countries. CURRENT "the world is partitioned into regions whose clocks all agree about time stamps that occur after the somewhat-arbitrary cutoff point of the POSIX Epoch (1970-01-01 00:00:00 UTC). For each such region, the database records all known clock transitions, and labels the region with a notable location." PROPOSED "the world is partitioned into regions, named zones, whose clocks all agree about time stamps that occur after the somewhat-arbitrary cutoff point of the POSIX Epoch (1970-01-01 00:00:00 UTC). Additional for each country at least one zone is created. For each zone, the database records all known clock transitions, and labels the zone with a notable location. -- Tobias Conradi Rheinsberger Str. 18 10115 Berlin, Germany http://tobiasconradi.com