David Patte ₯ <dpatte@relativedata.com> writes:
I actually don't use the LMT value in tz, so I am not personally concerned if it is lost, but I do use the date and time that the city moved from LMT, which would be a shame to lose.
The time of switch to standardized time was already identical between Europe/Vaduz and Europe/Zurich. However, now that I've looked at this more closely, there is another (earlier) transition that may possibly be of issue for data completionists, which is a new consideration that people have only recently asked the database take into account. Let me help for the people who don't have a copy of the current data readily available. Current (well, 2013d) Europe/Vaduz: Zone Europe/Vaduz 0:38:04 - LMT 1894 Jun 1:00 - CET 1981 1:00 EU CE%sT Europe/Zurich: Zone Europe/Zurich 0:34:08 - LMT 1848 Sep 12 0:29:44 - BMT 1894 Jun # Bern Mean Time 1:00 Swiss CE%sT 1981 1:00 EU CE%sT So the result of this change for Europe/Vaduz is that the DST corrections for Europe/Zurich from 1941 to 1942 would be adopted (which as Paul notes is more likely to be correct than the previous state), the historic LMT offset would change by an irrelevant four seconds, and the times between 1848 and 1894 would track Berne instead of Vaduz/Zurich LMT. All of these changes are either more likely to be accurate than what we had or are trivial to the point of irrelevance except for the last, which does mean a change in abbreviation (LMT -> BMT) between 1848 and 1894, if I'm reading the rules correctly, and a time difference of a somewhat more significant 8 minutes and 20 seconds. In terms of the current scope of the project, there is no reason not to make this a link. In terms of the desire to expand the scope project to keep every piece of historical data as accurate as possible, I think there's some question about the LMT to BMT change. The question is whether Liechtenstein would have done something other than all of Switzerland during that time period (with the exception, noted in comments but not in rules due to being out of scope historically for the database, of Cantone Geneve, which kept LMT rather than Berne Mean Time from 1848 to 1894). I am about as far from an expert in European history as one can possibly get, so I don't know the answer to that question. Wikipedia seems to imply that Liechtenstein was closely aligned with Austria-Hungary up until World War I, whereas Switzerland was an independent state, which makes me a bit dubious that Liechtenstein would have standardized on Berne Mean Time. -- Russ Allbery (rra@stanford.edu) <http://www.eyrie.org/~eagle/>