UI should display time from timezone set in Linux

[deomaki]

I would like to be able to..

...see the UI display the time according to timezone set in Linux.

In the following case the time being displayed on UI is 22:40, expected time would be 00:40 (according to TZ)

Local time: Fr 2025-10-10 00:40:16 CEST
Universal time: Do 2025-10-09 22:40:16 UTC
RTC time: Do 2025-10-09 22:40:15
Time zone: Europe/Berlin (CEST, +0200)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

System used

• HP t620 Thin Client with 8GB RAM, 128GB SSD
• Linux version: Ubuntu 24.04.3 LTS
• Plan version: 5.6 Build 2965
• PaperMC version: 1.21.8

Is your feature request related to a problem? Please describe.

Running the exact same version of Plan with the exact same version of PaperMC on a Debian GNU/Linux 11 (bullseye) based RasPi 4 (with 8GB RAM, 128 GB SSD) shows the correct time on the UI which leads me to the conclusion that with an RTC being present, RTC time will be shown. Only if there is no RTC installed local time will be displayed.

[AuroraLS3]

Plan takes the timezone Java gets from the system unless overridden by user in the Timezone setting in Plan config.

I can not implement features Java does not support

If I misunderstood and you want local time of the browser then this is a duplicate of #1628

[deomaki]

Plan seems to behave differently on Debian and Ubuntu.
As already said I am running a RasPi 4 with Debian and a t620 with Ubuntu.

1. Timezone set on both systems is exactly the same: Europe/Berlin.
2. The time on both systems is exactly the same, down to the minute.
3. config.yml for Plan is exactly the same on both systems: TimeZone: 'server'

The frontend for the server running Debian (RasPi) shows the exact time as expected: 23:35
cli timedatectl reports:
Local time: Fr 2025-10-10 23:35:13 CEST
Universal time: Fr 2025-10-10 21:35:13 UTC
RTC time: n/a
Time zone: Europe/Berlin (CEST, +0200)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

The frontend for the server running Ubuntu is two hours behind the RasPi, though configuration is the same: 21:35
cli timedatectl reports:
Local time: Fr 2025-10-10 23:35:16 CEST
Universal time: Fr 2025-10-10 21:35:16 UTC
RTC time: Fr 2025-10-10 21:35:17
Time zone: Europe/Berlin (CEST, +0200)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no

The only difference is the RasPi not having an RTC...

[AuroraLS3]

When you set Timezone setting to 'server', Plan will use the default Timezone set for Java. If Java can't get the timezone from the system Java will default to UTC as seen here.

I can not implement something Java doesn't support