I am using KDE Plasma 5.18.5 in Ubuntu 20.04. Plasma by default came with 12-hour time format and it is displayed everywhere-- from the digital clock widget to the lock screen. But I prefer to use the 24-hour format.
However, I cannot understand how to change the time format globally to 24-hour. I have looked into many places in the System Settings, but there was no sign of that setting. I have searched thoroughly under the Regional Settings page, but still haven't found any such thing.
How to change the time format globally to 24-hour?