当运行一些程序时，在httpd日志中会有如下警告日志：
PHP Warning: strftime(): 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/Chongqing' for 'CST/8.0/no DST'。。。。。。。。。。。PHP Warning: str
