Paul Eggert wrote in <f256f787-9a80-35bc-271b-5269ebf3836f@cs.ucla.edu>: |On 9/23/21 7:32 AM, Tom Lane via tz wrote: |> That's half of the issue. The other half is "if a zone does not contain |> relevant pre-1970 data, how would end users know that?" | |For most users the answer is simple: the pre-1970 data should not be |relied upon for anything other than an estimate. That data are intended |only for exact locations named, and most people in the world do not live |in those exact locations. | |For example, Europe/Berlin is wrong for most of Germany before 1970. I do not think so? MEZ (CET) was introduced in 1893-04-01, with clock adjustments all over Germany (-30 .. +30 minute range i read). This goes so far that GNU date(1) in conjunction with the IANA TZ displays "date: invalid date X" where X is 00:00:00..00:06:31" for TZ=Europe/Berlin! |Similarly for Europe/Rome and Italy, Asia/Shanghai and China, etc., etc. |etc. | |None of the pre-1970 data should be used for anything important, at |least not without understanding its severe limitations. | |Luckily for us, tzdb users invariably follow the advice I'm giving here, |whether consciously or not. --End of <f256f787-9a80-35bc-271b-5269ebf3836f@cs.ucla.edu> --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt)