// Функция преобразует даты в "правильные", то есть в родительном падеже и ещё разные штучки делает.
function _calendar_list_conv_date($a, $format='front') {
  global $language;
  $date = strtotime($a);
  switch($format) {
    case 'front':
      $monthes = array (
        'en' => array('January','February','March','April','May','June','July','August','September','October','November','December'),
        'ru' => array('января','февраля','марта','апреля','мая','июня','июля','августа','сентября','октября','ноября','декабря'),
        'uk' => array('січня','лютого','березня','квітня','травня','червня','липня','серпня','вересня','жовтня','листопада','грудня'),
      );
      $weekday = array (
        'en' => array('Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'),
        'ru' => array('Понедельник','Вторник','Среда','Четверг','Пятница','Суббота','Воскресенье'),
        'uk' => array('Понеділок','Вівторок','Середа','Четвер','П’ятниця','Субота','Неділя'),
      );
      switch ($language->language) {
        case 'ru':
        case 'uk':
            $output = date("j",$date) .' '. $monthes[$language->language][date("n",$date)-1] .', '. $weekday[$language->language][date("N",$date)-1];
            break;
        case 'en':
        default:
            $output = $monthes[$language->language][date("n",$date)-1] .' '. date("j",$date) .', '. $weekday[$language->language][date("N",$date)-1];
            break;
      }

      break;
    case 'short':
      $output = date('d.m.Y', $date); //20.02.2010
      break;
    default:
      $output = date("j",$date).' '.$monthes[date("n",$date)-1].' '.date("Y",$date).' '.date("H",$date).':'.date("i",$date);
      break;
  }
  return $output;
}

/**
 * A function to translate ambiguous short date strings.
 *
 * Example: Pass in 'Monday', 'day_abbr' and get the translated
 * abbreviation for Monday.
 *
 * param string $string
 * param string $context
 * param int $langcode
 * return translated value of the string
 */
function date_t($string, $context, $langcode = NULL) {
  //static $replace = array();

  if (empty($replace[$langcode])) {
    // The function to create the date string arrays is kept separate
    // so those arrays can be directly accessed by other functions.
    date_t_strings($replace, $langcode);
  }
  switch ($context) {
    case 'day_name':
    case 'day_abbr':
    case 'day_abbr1':
    case 'day_abbr2':  
      $untranslated = array_flip(date_week_days_untranslated());
      break;
    case 'month_name':
    case 'month_genitive': //Добавляем в обработку новый контекст
    case 'month_abbr':
      $untranslated = array_flip(date_month_names_untranslated());
      break;  
    case 'ampm':
      $untranslated = array_flip(array('am', 'pm', 'AM', 'PM'));  
      break;
    case 'datetime':
      $untranslated = array_flip(array('Year', 'Month', 'Day', 'Week', 'Hour', 'Minute', 'Second', 'All Day', 'All day'));  
      break;
    case 'datetime_plural':
      $untranslated = array_flip(array('Years', 'Months', 'Days', 'Weeks', 'Hours', 'Minutes', 'Seconds'));  
      break;
    case 'date_order':
      $untranslated = array_flip(array('Every', 'First', 'Second', 'Third', 'Fourth', 'Fifth'));  
      break;
    case 'date_order_reverse':
      $untranslated = array_flip(array('', 'Last', 'Next to last', 'Third from last', 'Fourth from last', 'Fifth from last'));  
      break;
    case 'date_nav':
      $untranslated = array_flip(array('Prev', 'Next', 'Today'));  
      break;
  }
  $pos = $untranslated[$string];
  return $replace[$langcode][$context][$pos];
}

/**
 * Construct translation arrays from pipe-delimited strings.
 *
 * Combining these strings into a single t() gives them the context needed
 * for better translation.
 */
function date_t_strings(&$replace, $langcode) {
  $replace[$langcode]['day_name'] = explode('|', trim(t('!day-name Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday', array('!day-name' => ''), $langcode)));
  $replace[$langcode]['day_abbr'] = explode('|', trim(t('!day-abbreviation Sun|Mon|Tue|Wed|Thu|Fri|Sat', array('!day-abbreviation' => ''), $langcode)));
  $replace[$langcode]['day_abbr1'] = explode('|', trim(t('!day-abbreviation S|M|T|W|T|F|S', array('!day-abbreviation' => ''), $langcode)));
  $replace[$langcode]['day_abbr2'] = explode('|', trim(t('!day-abbreviation SU|MO|TU|WE|TH|FR|SA', array('!day-abbreviation' => ''), $langcode)));
  $replace[$langcode]['ampm'] = explode('|', trim(t('!ampm-abbreviation am|pm|AM|PM', array('!ampm-abbreviation' => ''), $langcode)));
  $replace[$langcode]['datetime'] = explode('|', trim(t('!datetime Year|Month|Day|Week|Hour|Minute|Second|All Day|All day', array('!datetime' => ''), $langcode)));
  $replace[$langcode]['datetime_plural'] = explode('|', trim(t('!datetime_plural Years|Months|Days|Weeks|Hours|Minutes|Seconds', array('!datetime_plural' => ''), $langcode)));
  $replace[$langcode]['date_order'] = explode('|', trim(t('!date_order Every|First|Second|Third|Fourth|Fifth', array('!date_order' => ''), $langcode)));
  $replace[$langcode]['date_order_reverse'] = explode('|', trim(t('!date_order |Last|Next to last|Third from last|Fourth from last|Fifth from last', array('!date_order' => ''), $langcode)));
  $replace[$langcode]['date_nav'] = explode('|', trim(t('!date_nav Prev|Next|Today', array('!date_nav' => ''), $langcode)));
 
  // These start with a pipe so the January value will be in position 1 instead of position 0.
  $replace[$langcode]['month_name'] = explode('|', trim(t('!month-name |January|February|March|April|May|June|July|August|September|October|November|December', array('!month-name' => ''), $langcode)));
  //Строка с названиями месяцев, которую ещё нужно будет перевести на нужные языки:
  $replace[$langcode]['month_genitive'] = explode('|', trim(t('!month-genitive |January|February|March|April|May|June|July|August|September|October|November|December', array('!month-name' => ''), $langcode)));
  $replace[$langcode]['month_abbr'] = explode('|', trim(t('!month-abbreviation |Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec', array('!month-abbreviation' => ''), $langcode)));

}

/**
 * Reworked from Drupal's format_date function to handle pre-1970 and
 * post-2038 dates and accept a date object instead of a timestamp as input.
 *
 * Translates formatted date results, unlike PHP function date_format().
 *
 * param $oject
 *   A date object, could be created by date_make_date().
 * param $type
 *   The format to use. Can be "small", "medium" or "large" for the preconfigured
 *   date formats. If "custom" is specified, then $format is required as well.
 * param $format
 *   A PHP date format string as required by date(). A backslash should be used
 *   before a character to avoid interpreting the character as part of a date
 *   format.
 * return
 *   A translated date string in the requested format.
 */
function date_format_date($date, $type = 'medium', $format = '', $langcode = NULL) {
  if (empty($date)) {
    return '';
  }
  switch ($type) {
    case 'small':
    case 'short':
      $format = variable_get('date_format_short', 'm/d/Y - H:i');
      break;
    case 'large':
    case 'long':
      $format = variable_get('date_format_long', 'l, F j, Y - H:i');
      break;
    case 'custom':
      $format = $format;
      break;
    case 'medium':
    default:
      $format = variable_get('date_format_medium', 'D, m/d/Y - H:i');
  }
  $max = strlen($format);
  $datestring = '';
  for ($i = 0; $i < $max; $i++) {
    $c = $format[$i];
    switch ($c) {
      // Use date_t() for ambiguous short strings that need translation.
      // We send long day and month names to date_t(), along with context.
      case 'l':
        $datestring .= date_t(date_format($date, 'l'), 'day_name', $langcode);
        break;
      case 'D':
        $datestring .= date_t(date_format($date, 'l'), 'day_abbr', $langcode);
        break;
      case 'F':
        //Собственно логика вывода названия месяца в зависимости от ситуации:
        if ((strpos($format, 'd') === FALSE) && (strpos($format, 'j') === FALSE)) {
          $datestring .= date_t(date_format($date, 'F'), 'month_name', $langcode);
        }
        else {
          $datestring .= date_t(date_format($date, 'F'), 'month_genitive', $langcode);
        }
        break;
      case 'M':
        $datestring .= date_t(date_format($date, 'F'), 'month_abbr', $langcode);
        break;  
      case 'A':
      case 'a':
        $datestring .= date_t(date_format($date, $c), 'ampm', $langcode);
        break;  
      // The timezone name translations can use t().  
      case 'e':
      case 'T':
        $datestring .= t(date_format($date, $c));
        break;
      // Remaining date parts need no translation.
      case 'O':
        $datestring .= sprintf('%s%02d%02d', (date_offset_get($date) < 0 ? '-' : '+'), abs(date_offset_get($date) / 3600), abs(date_offset_get($date) % 3600) / 60);
        break;
      case 'P':
        $datestring .= sprintf('%s%02d:%02d', (date_offset_get($date) < 0 ? '-' : '+'), abs(date_offset_get($date) / 3600), abs(date_offset_get($date) % 3600) / 60);
        break;
      case 'Z':
        $datestring .= date_offset_get($date);
        break;              
      case '\\':
        $datestring .= $format[++$i];
        break;
      default:
        if (strpos('BdcgGhHiIjLmnsStTUwWYyz', $c) !== FALSE) {
          $datestring .= date_format($date, $c);
        }
        else if ($c == 'r') {
          $datestring .= format_date($date, 'custom', 'D, d M Y H:i:s O', $langcode);
        }
        else {
          $datestring .= $c;
        }
    }
  }
  return $datestring;
}