25.04.2 apps docker timezone setting via TZ does not work

Apps and Virtualization
1

Hello!

Today I have have updated from 25.04.1 to 25.04.2. I have noticed an issue with my teamspeak server app which seems to be related to the time zone not being set correctly in the docker container. I think this has worked correctly in 25.04.1 since I have never experienced a similar issue on that version.

Facts:

  • BIOS time is set to UTC
  • TrueNAS system timezone is set to “Europe/Vienna”
  • Docker container TZ environment variable is set to “Europe/Vienna”
  • Command “date” in docker container still shows UTC time

Can anyone confirm the behavior? Is there a way to fix this?

Thank you!

2

Yes, I see a UTC timestamp in the logfiles of apps. I’m on Europe/Berlin.
I didn’t notice it before, it will probably have fit.

3

Hello,

I’m a newbie with TrueNas… and I installed the mariadb app. All was good until I noticed the timezone was UTC. When I tried to add the TZ variable in ‘Additional Environment Variable’ I got this error on updating : base_v2_1_48.error.RenderError: Environment variable [TZ] is already defined from the application developer.

This was very annoying, so I solved the problem by mounting the directory for the config files of mariadb (so persistent after restarts) on a host path.

I don’t know if you can configure the timezone in a config file for your app.

Rgds,
Digo

4

Hi,

I have the same problem. Did you solve it?

BR /Jorgen

5

If the container supports it, TZ does it’s job:

admin@truenas ~ % sudo docker run -ti --rm -e TZ="Europe/Berlin" alpine
/ # date
Thu Jan  8 21:24:41 UTC 2026
/ # apk add tzdata
(1/1) Installing tzdata (2025c-r0)
OK: 8658 KiB in 17 packages
/ # date
Thu Jan  8 22:24:54 CET 2026
/ #

Even though the TZ variable is set, the first date command ignored it because tzdata was not installed in the image. After installing the tzdata package, the date command used the setting from the TZ variable to render local date.

Not every image necessarily has the tzdata package installed.

Container logs are always written in UTC by the docker engine on the host.