Comment 31 for bug 1322968

Fixed in 16.04 LTS (Xenial).

You can select the

region (with defines the default)

and if you don't like default settings, you can set individually:

Numbers
Time
Currency
Measurement units
Collation and Sorting

Which results in settings like:

(0)ach@allee:~$ cat .config/plasma-localerc
[Formats]
LANG=en_US.UTF-8
LC_MEASUREMENT=de_DE.UTF-8
LC_MONETARY=de_DE.UTF-8
LC_TIME=en_GB.UTF-8
useDetailed=true

[Translations]
LANGUAGE=en_US
(0)ach@allee:~$ cat .config/plasma-localerc
[Formats]
LANG=en_US.UTF-8

[Translations]
LANGUAGE=en_US
(0)ach@allee:~$ cat .config/plasma-localerc
[Formats]
LANG=en_US.UTF-8

[Translations]
LANGUAGE=en_US