[Datetime-SIG] IANA TZ database statistics

[Alexander Belopolsky]

On Fri, Sep 25, 2015 at 10:50 PM, Alexander Belopolsky <
alexander.belopolsky at gmail.com> wrote:

> It fails on Europe/Tallinn which seems to have transitions separated by 22
> hours with the *same* utcoffset.
>
> I don't understand why zic would ever produce something like this.
>

Interestingly, system zdump misses the problem transition:

$ zdump -v Europe/Tallinn | grep 1999
Europe/Tallinn  Sun Mar 28 00:59:59 1999 UTC = Sun Mar 28 02:59:59 1999 EET
isdst=0
Europe/Tallinn  Sun Mar 28 01:00:00 1999 UTC = Sun Mar 28 04:00:00 1999
EEST isdst=1
Europe/Tallinn  Sun Oct 31 00:59:59 1999 UTC = Sun Oct 31 03:59:59 1999
EEST isdst=1
Europe/Tallinn  Sun Oct 31 01:00:00 1999 UTC = Sun Oct 31 03:00:00 1999 EET
isdst=0

You need to use my zdump.py tool [1] to see it:

$ ./python.exe Tools/tz/zdump.py Europe/Tallinn | grep 1999
1999-03-28 01:00:00 UTC = 1999-03-28 04:00:00 EEST  isdst=1 +1
1999-10-31 01:00:00 UTC = 1999-10-31 03:00:00 EET   isdst=0 -1
1999-10-31 22:00:00 UTC = 1999-11-01 00:00:00 EET   isdst=0 +0

[1] :
https://github.com/abalkin/cpython/blob/issue24773-s3/Tools/tz/zdump.py
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