Warning: date_default_timezone_get() [function.date-default-timezone-get]: 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.

If you find a semicolon in front of it, remove it. This directive will hold your default timezone. You can choose a timezone from the official PHP website.
We will use America/Los_Angeles as example. Fill in the value of the timezone as this:

date.timezone = America/Mexico_City

Save your php.ini file and restart your server. From now on, your date/time functions will rely on this setting.
The second option to solve this warning is by using a already existing PHP build-in function “date_default_timezone_set()”. Somewhere before your date/time function type the following line as this:

<?php
// Set timezone
date_default_timezone_set('America/Mexico_City');
 
// Create string, date of tomorrow
echo date('Y m-d', strtotime('+1 day', time()));
?>

Add the following line to .htaccess:

SetEnv TZ America/Mexico_City

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