Apache 服务器的错误日志:

[Thu Aug 09 08:42:46 2012] [error] [client 10.10.10.10] PHP 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. ...

解决方案

为php设置正确的时区(php.ini 的“date.timezone”)并重新启动Apache