_getDigitFromName example

break;

            case self::RFC_2822:
                 $result = preg_match('/^\w{3},\s(\d{1,2})\s(\w{3})\s(\d{4})\s'
                                    . '(\d{2}):(\d{2}):{0,1}(\d{0,2})\s([+-]'
                                    . '{1}\d{4}|\w{1,20})$/', $date, $match);

                if (!$result) {
                    throw new Zend_Date_Exception("no RFC 2822 format ($date)", 0, null, $date);
                }

                $months  = $this->_getDigitFromName($match[2]);

                if (($calc == 'set') || ($calc == 'cmp')) {
                    --$months;
                    --$month;
                    --$match[1];
                    --$day;
                    $match[3] -= 1970;
                    $year     -= 1970;
                }
                return $this->_assign($calc, $this->mktime($match[4], $match[5], $match[6], 1 + $months, 1 + $match[1], 1970 + $match[3], false),
                                             $this->mktime($hour,     $minute,   $second,   1 + $month,  1 + $day,      1970 + $year,     false), false);