Hello.
I use WP-3.6-ru localization and last Polylang. Russian default language.
But the date and time (am/pm) I have in all languages are displayed in Russian. Equally at lokalhost and www
see here
Similar problems were considered.
Here, have established localization *. mo files in wp-content/languages /.
Here, ultimately offer a new archive polylang.
But it did not help me.
Konstantin.