关于php 从 5.2 升级到 5.4 后 mantis 报错的问题

mantis 版本 1.1.8，升级 php 版本后页面报错：
SYSTEM WARNING: date(): 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 the timezone 'UTC' for now, but please set date.timezone to select your timezone.

解决方法也很简单，修改配置文件 php.ini 设置时区部分：
[Date]
; Defines the default timezone used by the date functions
date.timezone = Asia/Shanghai