CodeIgniter 在 PHP 5.3 时区报错

"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." 

ci根目录下的index.php文件中加如下代码即可
/*
|---------------------------------------------------------------
| DEFAULT TIMEZONE
|---------------------------------------------------------------
|
| Set the default timezone for date/time functions to use if
| none is set on the server.
|
*/

if( ! ini_get('date.timezone') )
{
   date_default_timezone_set('GMT');
}