SUMMARY On Slackware GNU/Linux 14.n,14-current (and probably anything equally Unix-like, or Unix like FreeBSD 12.n,13-CURRENT) the system tray's digital clock won't honour my system time setting. I'm at US/Pacific but the digital clock in system tray apparently doesn't use /etc/localtime (on Slackware, forgot what it is on Unix but possibly similar in that case of FreeBSD.) STEPS TO REPRODUCE 1. Select clock to show local time zone. 2. Select time zone. 3. Says 'Unable to authenticate/execute the action: 3, Tried to start invalid action.' (even as root!) (not that I run KDE as root except sometimes to add printers) OBSERVED RESULT Sometimes might honour or let one choose your time zone (PT: PST, PDT) to display but sometimes when resetting things (like setting night colour earlier at end of daylight saving time) it breaks then won't let you choose your time zone to display, and claims it's UTC while actually at same time showing the time for UTC-8/GMT-8/PT. EXPECTED RESULT Simply use /etc/localtime or whatever else has to be used. Don't assume a computer is a server in UTC. Don't assume people are running systemd garbage that probably is trying to control system time to make the Internet a time machine to takeover universe. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Slackware GNU/Linux 14.n,14-current/5.19.4 (available in About System) KDE Plasma Version: 5.19.4 KDE Frameworks Version: 5.72.0 Qt Version: 5.15.1 ADDITIONAL INFORMATION Would work on a fresh installation. After some changes even months/years later, breaks permanently.
FWIW you change the system timezone in System Settings > Regional Settings > Date & Time, not in the clock widget.
The two or more clock options that let you save time zone just take you to a version of that system setting, and they--even system settings->regional->date & time--all have the same error 'Unable to authenticate/execute the action: 3, Tried to start invalid action.' In clock it says I'm not allowed to save it, but even as root it says that!
OK so when it seems like the bug is in the System Settings Date & Time page. Any ideas, Adriaan? Is this known to be broken in FreeBSD?
*** Bug 428588 has been marked as a duplicate of this bug. ***
I'd suggest considering the OP's system -- Slackware -- and FreeBSD separately, although similar issues occur on FreeBSD as well. I may comment on the weekend, if I have time.
I had used KDE on both this year and had many of the same bugs. Usually I used different ~/.kde . I just found a workaround: run systemsettings5 as root, set the time zone, then it's set for other users. However, you shouldn't have to use systemsettings5 as root or even as a user, for this. KDE should simply read /etc/localtime on Unix (*BSD) and Unix-like (Slackware.)
After a few more tries as root, I finally was able (without error message pop-up this time) to set time zone. KDE night color works now, and I'd guess KOrganizer does also. Just I doubt if I did a fresh installation that the bug wouldn't necessarily happen again of it using my local time but claiming the time zone was different than in /etc/localtime .
This works on new installations and as root (installed Fresh FreeBSD 13.1 and Slackware 15.1-current) though there might be something users do that can still cause this (or maybe daylight saving time does it) but may no longer be a bug.