Show 'submitted by' date in a language different from English
Month names are not added automatically.

An elegant way to do this is described here:

https://drupal.org/comment/8251325#comment-8251325

function monthname_install() {
  $months = array(
    'January',
    'February',
    'March',
    'April',
    'May',
    'June',
    'July',
    'August',
    'September',
    'October',
    'November',
    'December',
  );

  $options['context'] = 'Long month name';

  foreach($months as $m) {
    t($m, array(), $options);
  }

  drupal_set_message(t('Month names have been made available for translation. The rest is up to the translation team :-)'));
}