Contao\Date::resolveCustomModifiers PHP Method

    protected static function resolveCustomModifiers($strDate)
    {
        if (strpos($strDate, '::') === false) {
            return $strDate;
        }
        if (!$GLOBALS['TL_LANG']['MSC']['dayShortLength']) {
            $GLOBALS['TL_LANG']['MSC']['dayShortLength'] = 3;
        }
        if (!$GLOBALS['TL_LANG']['MSC']['monthShortLength']) {
            $GLOBALS['TL_LANG']['MSC']['monthShortLength'] = 3;
        }
        $strReturn = '';
        $chunks = preg_split("/([0-9]{1,2}::[1-4])/", $strDate, -1, PREG_SPLIT_DELIM_CAPTURE);
        foreach ($chunks as $chunk) {
            list($index, $flag) = explode('::', $chunk);
            switch ($flag) {
                case 1:
                    $strReturn .= $GLOBALS['TL_LANG']['DAYS'][$index];
                    break;
                case 2:
                    $strReturn .= $GLOBALS['TL_LANG']['DAYS_SHORT'][$index];
                    break;
                case 3:
                    $strReturn .= $GLOBALS['TL_LANG']['MONTHS'][$index - 1];
                    break;
                case 4:
                    $strReturn .= $GLOBALS['TL_LANG']['MONTHS_SHORT'][$index - 1];
                    break;
                default:
                    $strReturn .= $chunk;
                    break;
            }
        }
        return $strReturn;
    }