I booted the Fedora Rawhide KDE live image Fedora-KDE-Desktop-Live-Rawhide-20250226.n.0.x86_64.iso on bare metal. Plasma 6.3.1 on Wayland started. The time was set to UTC. I right-clicked on the clock in the system tray and clicked on Adjust Date and Time. System Settings started. I selected the Time Zone tab in the Date & Time page. I selected the timezone with UTC-05:00 in the Area column and clicked Apply. An error message Unable to set timezone was shown. The journal showed the error systemsettings[4036]: Failed to set timezone "org.freedesktop.DBus.Error.InvalidArgs" "Invalid or not installed time zone 'UTC-05:00'"

I selected the America/Toronto (EST) timezone which is equivalent to UTC-05:00, and the time was updated properly.  I selected various other UTC- or UTC+ timezones, and they had the same errors Unable to set timezone. The problem seemed to be with the timezones starting UTC- and UTC+.

Reproducible: Always

Steps to Reproduce:
1. Download the Fedora Rawhide KDE live image Fedora-KDE-Desktop-Live-Rawhide-20250226.n.0.x86_64.iso from https://koji.fedoraproject.org/koji/buildinfo?buildID=2666595
2. Boot Fedora-KDE-Desktop-Live-Rawhide-20250226.n.0.x86_64.iso on bare metal or in a VM. 
3. right-click on the clock in the system tray 
4. click on Adjust Date and Time in the context menu. 
5. select the Time Zone tab in the Date & Time page in System Settings. 
6. select the timezone with UTC-05:00 in the Area column 
7. click Apply.

Actual Results:  
Unable to set timezone to UTC- or UTC+ timezones in System Settings

Expected Results:  
The timezone should've changed to UTC-05:00

I reported this problem at https://bugs.kde.org/show_bug.cgi?id=500763

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora Rawhide/43
KDE Plasma Version: 6.3.1
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2