How to switch to 12-hour clock for the system (not the panel)

[jrasmussen]

Hello,
I would like to change my system time to the 12-hour format.  I was able to change the panel clock without issue, but there does not seem to be an obvious way to change it system-wide under Time and Date.  When I open gnome-clocks or gnome-weather, they are showing the time in 24-hour format.  (I am on SparkyLinux (rolling) MATE).

Thanks!

[pavroo]

Check here, for example:
https://wiki.debian.org/DateTime