Though I am a Ukrainian, I am also a software engineer and prefer English language for my interfaces, the computer world "original" and "default" with strictly unified tech terms.
However, as a European, I would never get used to imperial units and similar strangeness guys live with in the US.
This is my attempt to slip away from wierdness of en_US locale (which I used previously) and not to fall into embrace of new (possible) wierdness of other European nations.
The repo contains glibc custom non-standard configuration for English locale for Ukraine, which is based on en_IE (English locale for Ireland) and heavily influenced by uk_UA (Ukrainian locale for Ukraine).
Currency, address, numeric, telephone values are changed to fit Ukrainian formats and values.
Time values are unchanged, except for couple slight edits (mentioned in comments).
Tested on Arch Linux.
sudo cp en_UA /usr/share/i18n/locales/Add line en_UA.UTF-8 UTF-8 to /etc/locale.gen. (Would be nice to fit it right before en_US.)
Then run:
sudo locale-genSet it as a default locale (I just do it through GNOME GUI settings, but you can edit /etc/locale.conf).
Log out and log it.
You are done, enjoy metric system and native formats!