PHP complains if you do date time functions without setting the web servers local. To accomplish this, edit the PHP.ini file and set the "date.timezone" value.
=====
>cd /etc/
>ls -l | grep "php"
...
php.ini
...
>vi php.ini
set
date.timezone = America/Los_Angeles
Save changes and exit
Resources:
PHP Date Time Zones
php.net/manual/en/timezones.php