My Ubuntu 14.04 is in Polish and this translation is quite low quality. How to set up Ubuntu so that it is displayed in English, but keep calendar and date format Polish-like (i.e. week starting from Monday, not Sunday)?
If you have an Installed version: Go to System Settings -> Language Support and under Language tab choose English as the language for menus and windows. In the Regional Formats tab, choose your local preferences.
If you install a fresh copy: Choose English as the installation language, and then when asked for location and keyboard layout, choose your local preferences.