[Adam Harley (Kawauso)]

In post.php, change <?php printf( __('Posted %s ago'), bb_get_post_time() ); ?> to <?php printf( __('Posted %s'), bb_get_post_time(array('format'=>'datetime')) ); ?>. You need to change the option datetime_format to change how the date/time is formatted, not sure where that’s set, so the All Options plugin might help.