setlocale() Turkish date problem

[eluser]Unknown[/eluser]
Hi,

I am trying to use setlocale() for the dates.

Code:

setlocale(LC_ALL, 'tr_TR.UTF-8');
echo strftime("%e %B %Y %A", mktime(0, 0, 0,$month,$day,$year));

Other languages work fine but when I try to use Turkish (tr_TR.UTF-8 and tr_TR), it gives me this error.

Fatal error: Class 'CI_Base' not found in /domain/html/system/codeigniter/Base5.php on line 50

Does anybody have any idea?

Thanks.