How to fix this in my website?

[campomanes25]

Warning: date() [function.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 'America/Los_Angeles' for '-8.0/no DST' instead in C:\Program Files (x86)\Apache Software Foundation\Apache2.2\htdocs\htdocs\inc\info.panel. php on line 16

How to fix that error?

[Flyff_Service]

PHP Code:

// Disables the output of php errors
error_reporting(0);
// Default timezone
date_default_timezone_set("America/Los_Angeles");