[tz] zoneinfo generating issues
Brian.Inglis at SystematicSw.ab.ca
Wed Mar 3 16:45:04 UTC 2021
On 2021-03-03 04:20, 汪蒙蒙（木之） via tz wrote:
> Recently, I wanted to write a program to watch the change of timezone database.
> I got newest version from this address:
> <https://data.iana.org/time-zones/releases/tzdata2021a.tar.gz>. I used zic
> (version: zic (tzcode) 2020c, system: CentOS Linux release 7.6.1810 (Core))
> to generate the zoneinfo. I pick up some zones with local time to calculate
> utc time to verify the changes using both the new and currently used version
> tzdata, here is diff: >
> zone local time by 2021a utc time by 2020d utc time
> America/Adak 2022-11-01 00:00:00 2022-11-01 09:00:00 2022-11-01 10:00:00
> America/Anchorage 2022-11-01 00:00:00 2022-11-01 08:00:00 2022-11-01 09:00:00
> America/Asuncion 2022-10-01 00:00:00 2022-10-01 04:00:00 2022-10-01 03:00:00
> America/Atka 2022-11-01 00:00:00 2022-11-01 09:00:00 2022-11-01 10:00:00
> Those zones are not changed from version 2020d to 2021a. I am very confused and
> not sure if I generated the zoneinfo in the right way. Here was what do:
> # mkdir zoneinfo
> # cd tzdata2021a
> # zic -d ../zoneinfo -L ./leapseconds africa antarctica asia australasia europe
> northamerica southamerica etcetera backward factory
> I was wondering if you could provide me some help. I really appreciate your reply.
We have no clue whether what you are using accesses the data files you
generated, and what code it is using to display what times.
Please show logs of how you generated the tzdata files, then accessed them to
generate the times, and any custom scripts or source code you used.
The best way to display times is using the tzcode zdump utility on the zoneinfo
data files for the zones you are using.
In general, it is best to assume the problem is in what you are doing or how you
are doing it, and generate copious detailed debug output so you can see what
your code is actually doing, as opposed to what you may think it does.
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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