Automatically configure 24h clock
You don't need to hardcode the list of countries to get the 12h/24h, you can check if the current locale is using 12h by default by checking if Posix.nl_langinfo (Posix.NLItem.T_FMT) contains %r or %l or %I.
From https://github.com/elementary/initial-setup/pull/84#issuecomment-694749527