Set date.timezone in php.ini

 When I installed zen cart  http://www.zen-cart.com/index.php
(Zen Cart® truly is the art of e-commerce; free, user-friendly, open source shopping cart software written in PHP).)There is an error message:

ERROR: date.timezone not set in php.ini. Please contact your hosting company to set the timezone in the server PHP configuration before continuing.

There are to ways to fix this:
1) in php.in add 
date.timezone = 'America/Vancouver' and restart webserver.
or
2) going to zc_install/includes/application_top.php and add following line on the top:

ini_set('date.timezone', 'America/Vancouver');