first thing: I'm using KDEneon as system, no particular mods.
I have a small problem is really small but is bothering me...
I set system-wide English language, but than something puzzling happen.
The 12h time format was bothering me pretty much, so I set on the system settings C as time format (Settings->Regional Settings->Formats) and the login screen was not changing the time format.
I found that I need to change the locale settings, so I opened and modified etc/default/locale and under LC_TIME=I put as well C. It worked for a while, but after a while it got broken.
Anyone can tell me what could have went wrong or if the SDDM login screen is related to a different config file for setting date and time format? Any help for troubleshooting?