How to use 12-hour clock on Gnome Clocks outside of Gnome
Oct/05/2023
The solution is pretty simple, open dconf-editor and navigate to: /org/gnome/desktop/interface/clock-format and change the value to 12h from 24h.
That's pretty much it. Only posting it here because it's pretty hard to find this information, so maybe a search engine will pick it up =P