Recently during a conversation about the tzdb and a colleague of mine mentioned that it seems to be a strange outlier that Europe/Zaporozhye has its own zone, since Zaporozh'ye is not a particularly large city (it's quite close to Donetsk, which he deemed more likely to be the major city in the area). I looked at the source code and saw that it mentions: # Zaporozh'ye and eastern Lugansk oblasts observed DST 1990/1991. (https://github.com/eggert/tz/blob/master/europe#L3850) He seemed to think that this was an absurd notion and that more or less any city in Ukraine would either follow Moscow time or Crimea time, but none of them would have yet a third history. It does seem a bit strange (though perfectly consistent with the weird nonsense everyone else gets up to) that only Zaporozh'ye and eastern Lugansk would follow a different time zone than their immediate neighbors - these are not even contiguous regions. In the timezone-boundary-builder project (https://github.com/evansiroky/timezone-boundary-builder), it seems that only Zaporozhia Oblast is included in the shapefile. We did a cursory search for references (including in the archives of this mailing list and the git history) in English and Russian and couldn't find any reference to Zaporozhia and Lugansk having a different time zone that wasn't derived from this project. So, questions about this: 1. Can anyone point to a reference to the fact that these regions used a different time zone than their neighbors? 2. If no reference is handy, does anyone know on what basis this zone was included in the database in the first place? 3. Is there any clarification as to the geographic extent of the zone? Does it cover Donetsk as well? What part of Lugansk counts as "eastern Lugansk"? Best, Paul