Guy Harris wrote:
What if [the pre-1970] data 1) has been determined to be correct based on sources we deem sufficiently reliable and 2) it applies to more than just the city and its environs, but it doesn't apply to, for example, the entire country? Should one or more new tzdb regions be created for those other locations?
I'm starting to feel like I'm dealing with Vroomfondel and Majikthise here, demanding rigidly-defined areas of doubt and uncertainty. :-) In all seriousness, I think we need to take some of the energy we're expending on the pre-1970 database correctness problem, and redirect it towards exhorting end users *not* to depend on pre-1970 data too much. In particular, if there are people out there who are taking pre-1970 local timestamps, using tzdb to compute proleptic Unix time_t values, and storing those timestamps in databases, such that changes to tzdb will later cause interestingly-wrong local timestamps to pop back out, we need to get the word out that this may not be the best way of doing things, after all!