I already have language pack installed. Let me better explain my requierment. If I use "en_GB" as operator locale, then texts are in English and dates are of the format "01/04/2016". And if I use "nl_NL" as locale, then texts are translated to Dutch and dates are in format "01-04-2016".
What I'm trying to figure out, if there's a way to show text in Dutch and dates in format '01/04/2016'.
Also, PRThread offers different constants (LOCALE_FOR_DATES, LOCALE_FOR_MESSAGES) while invoking setLocale method. But if if use 'GB' for LOCALE_FOR_DATES and 'nl' for LOCALE_FOR_MESSAGES, that doesn't seem to work. My observation is LOCALE_FOR_MESSAGES is overriding LOCALE_FOR_DATES.
I agree that would work Santanu, but that is not a suitable solution for me. The situation is like this: a user logs in as English user. Then he does a 'switch language'. And it should change only his language, not the date or number format. So my code has to play with the setLocale method.