Actually, I think the issue was with the version of zdump I was using. Apparently it didn't work properly with the latest tz data. This is a bit weird since Ubuntu released an update with the 2022g changes, but apparently the zdump binary is part of a different package, and it hasn't been updated since April, AFAICT.



On Mon, Dec 12, 2022 at 2:42 PM Paul Eggert <eggert@cs.ucla.edu> wrote:
On 12/12/22 09:47, Dave Rolsky via tz wrote:
> I'm a bit confused regarding the output from zdump for the new
> America/Ojinaga zone. Here's the output for 2022:

I see different output with TZDB 2022g:

$ zdump -V -c 2022,2023 America/Ojinaga
America/Ojinaga  Sun Mar 13 08:59:59 2022 UT = Sun Mar 13 01:59:59 2022
MST isdst=0 gmtoff=-25200
America/Ojinaga  Sun Mar 13 09:00:00 2022 UT = Sun Mar 13 03:00:00 2022
MDT isdst=1 gmtoff=-21600
America/Ojinaga  Sun Oct 30 07:59:59 2022 UT = Sun Oct 30 01:59:59 2022
MDT isdst=1 gmtoff=-21600
America/Ojinaga  Sun Oct 30 08:00:00 2022 UT = Sun Oct 30 02:00:00 2022
CST isdst=0 gmtoff=-21600


> based on the zone's definition
> I'd expect to see these events:
>
> Oct 30 - change to _CST_
> Nov 30 - No change, I guess, since the change to the US rules on Nov 30
> doesn't actually change the offset or isdst flag.

Yes, that's what I'd expect too, and it's what I observed above.

Maybe you have an old Ojinaga somehow?