Warning
The locale information is maintained per process, not per thread. If you are running PHP on a multithreaded server API like IIS, HHVM or Apache on Windows, you may experience sudden changes in locale settings while a script is running, though the script itself never called setlocale(). This happens due to other scripts running in different threads of the same process at the same time, changing the process-wide locale using setlocale().
I have experienced month name mixing in front page new product module (not all host!)
Full month name, based on the locale
PHP Manual: (http://php.net/manual/en/function.setlocale.php)