What best practices should be followed when dealing with time zone differences in server-side scripting for web development?

When dealing with time zone differences in server-side scripting for web development, it is best practice to set the default time zone for your script to ensure consistency in date and time calculations. This can be done using the `date_default_timezone_set()` function in PHP.

// Set the default time zone to UTC
date_default_timezone_set('UTC');