Mixed up environment after english installation (unexpected translations)

[hawran]

I had to install a new system on my pc so I've chosen Xubuntu 14.04 LTS.
For practical resons I've decided to use a full ENGLISH version, NO whatever language clone, so:

Installation (from DVD) -> Welcome window -> a language selected: English -> ... Keyboard: English -> ... -> Time Zone(!!!): Europe/Prague.
Reboot.
I've copied a conky's configuration from other PC of mine (english as well). Conky restarted.

To my great surprise, conky reads a date as follows:
Date: Po Ä en 02 (czech, wrong fonts, garbled, 'Pondělí Červen' probably ('Monday June' in czech) )

I felt a sense of betrayal si I opened an xterm and listed files:
... 57 čen 2 11:07 .Xauthority
... 1601 kvě 25 16:01 .Xdefaults
... 3519 kvě 27 12:45 .Xresources
... 7572 kvě 31 17:37 .xscreensaver
... 190 čen 2 11:07 .xsession-errors

čen = June
kvě = May

man - in english

Environment (menu items, icons, ...) - english
A current date/time within the clock widget: 08 čen, 18:30 - CZECH!!!

Locale:
LANG=en_US.UTF-8
LANGUAGE=en_US
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC=cs_CZ.UTF-8
LC_TIME=cs_CZ.UTF-8
LC_COLLATE="en_US.UTF-8"
LC_MONETARY=cs_CZ.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=cs_CZ.UTF-8
LC_NAME=cs_CZ.UTF-8
LC_ADDRESS=cs_CZ.UTF-8
LC_TELEPHONE=cs_CZ.UTF-8
LC_MEASUREMENT=cs_CZ.UTF-8
LC_IDENTIFICATION=cs_CZ.UTF-8
LC_ALL=

My problem:
When I've chosen the ENGLISH language I have really meant it seriously.
I have chosen the the ENGLISH intentionally and I've expected ALL stuff within my system to be ENGLISH.

What I've done wrong?

System Info:
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Codename: trusty

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1327815/+editstatus and add the package name in the text box next to the word Package.

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