You want to set a locale that all your PHP programs can use.

At the beginning of a file loaded by the auto_prepend_file configuration directive, call setlocale( ) to set your desired locale:

Even if you set up appropriate environment variables before you start your web server or PHP binary, PHP doesn't change its locale until you call setlocale( ). After setting environment variable LC_ALL to es_US, for example, PHP still runs in the default C locale.

Section 16.3 shows how to use a particular locale; documentation on setlocale( ) at http://www.php.net/setlocale and auto_prepend_file at http://www.php.net/manual/en/configuration.directives.php#ini.auto-prepend-file.