PHP 시간대 설정

문제상황

test.php에서 phpinfo();를 실행시켰더니 다음과 같은 경고 메시지가 나온다.

Warning: phpinfo(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Seoul' for 'KST/9.0/no DST' instead in /opt/apache2/htdocs/test.php on line 1