So… you are working on the next killer web app, with an international touch. Giving your LAMP based applications a locality is quite important when considering the scope of your users. Since most modern apps will be accessed globally, give your users a valid timezone for a starting point. It isn’t a great practice to rely upon your server’s default configuration… especially when using shared hosting.
Lets change it! In your php.ini config, locate and uncomment your date.timezone line. On Debian based servers, you can check in (/etc/php5/apache2). Change your config to read something like:ndate.timezone=America/Chicago
Here is a full listing of all the available PHP timezones