PHP4.4.0 での mktime
http://ml.php.gr.jp/pipermail/php-users/2005-August/026870.html
<?php define(SECOND_DAY,60 * 60 * 24); function smktime($hour = 0,$minute = 0,$second = 0,$month = 0,$day = 0,$year = 0,$dst = 0){ if ($year >= 1970 || mktime(0,0,0,1,1,1969) == -31568400){ $ret = mktime($hour,$minute,$second,$month,$day,$year,$dst); }else{ $base = 1972 + ($year % 4); $_y = $base - $year; $ret = mktime($hour,$minute,$second,$month,$day,$base); $ret = $ret - ($_y * SECOND_DAY * 365) - (ceil($_y / 4) * SECOND_DAY); } return $ret; }