Adjusting the system time zone from "Date & Time - Systems Settings Module" "Time Zone" leads to the Digital Clock Widget showing the wrong time in case of the clock being setup to show multiple timezones. The clock works correctly once plasmashell is restarted (i.e. logout, login). It seems that the clock widget does not recalculate the offsets of the displayed timezones to the system timezone, and naively applies the old offset to the changed system time, leading to a wrongly displayed time.
What distro are you using, do you have an /etc/timezone file? I have noticed the same behavior on Arch Linux. Restarting kplasmashell can also be done without logout/login, e.g. press Alt+F2 and run: kquitapp5 plasmashell && kstart5 plasmashell For me it turned out that I had a /etc/timezone file from 2012 which is no longer used. Patch: https://codereview.qt-project.org/209715
Thanks Peter. I'm on Gentoo. My /etc/timezone file contains a single line with the active time zone. Do you mean the /etc/timezone file is obsolete?
(In reply to Leonard Lausen from comment #2) > Thanks Peter. I'm on Gentoo. My /etc/timezone file contains a single line > with the active time zone. Do you mean the /etc/timezone file is obsolete? It seems obsolete and can be deleted, especially if you use systemd-timedated (timedatectl). Is your /etc/localtime a symlink?