Created attachment 9110
Patch to display an error on invalid timezones
I mistakenly entered "BST" in the "Timezone" field in the Clock plugin's properties. This isn't valid (it needs to be Europe/London) but nothing told me this - it just fell back to UTC. (This would have showed up if I'd had timezone included in the display, but I didn't.)
This looks like it's ultimately a problem with g_time_zone_new not providing any error response (https://gitlab.gnome.org/GNOME/glib/issues/553).
However, the panel plugin could work around this by checking for itself whether the timezone exists, and I've got a patch that does so (attached).
Simon Steinbeiss referenced this bugreport in commit 285ee742f98707516c79a4d22f08285f448d28cd
clock: Validate timezone entry (Bug #16036)
Thanks, nice improvement (and goes along nicely with the format validator)!
Ooops, I forgot to amend the commit before pushing with you as the patch author. I apologize.
(I had to correct some small things, so I couldn't simply git am the commit)