note 106916 modified in function.checkdate by danbrown

don't use strtotime() to format inputs to checkdate(). It would give false results. Eg, Below function would return true though it should have been false <?php $str = '2011-11-31'; //invalid date, november has 30 days only function isDateValid($str) { $stamp = strtotime($str); if (!is_numeric($stamp)) return FALSE; //checkdate(month, day, year) if ( checkdate(date('m', $stamp), date('d', $stamp), date('Y', $stamp)) ) { return TRUE; } return FALSE; } ?> The reason is that strtotime() coverts 2011-11-31 to 2011-12-01. check with date('Y-m-d', strtotime('2011-11-31')) --was-- don't use strtotime() to format inputs to checkdate(). It would give false results. Eg, Below function would return true though it should have been false $str = '2011-11-31'; //invalid date, november has 30 days only function isDateValid($str) { $stamp = strtotime($str); if (!is_numeric($stamp)) return FALSE; //checkdate(month, day, year) if ( checkdate(date('m', $stamp), date('d', $stamp), date('Y', $stamp)) ) { return TRUE; } return FALSE; } The reason is that strtotime() coverts 2011-11-31 to 2011-12-01. check with date('Y-m-d', strtotime('2011-11-31')) http://php.net/manual/en/function.checkdate.php