avoid warnings in Apache.log during every pageview

The Apache log was full of "PHP 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."
PHP documentation says the warning started in PHP version 5.1

Test case:
$ php -v
PHP 5.5.3-1ubuntu2 (cli) (built: Oct  9 2013 14:49:12)
$ php -r 'require_once("lib/init-cmd.php"); require_once("lib/log.php"); $oDB =& getDB(); logStart($oDB,"search");'