What is the best practice for setting the default timezone in PHP?

When working with date and time functions in PHP, it is important to set the default timezone to avoid unexpected behavior or errors. The best practice for setting the default timezone in PHP is to use the `date_default_timezone_set()` function and specify the timezone you want to use. This function should be called at the beginning of your script to ensure that all date and time functions operate in the desired timezone.

// Set the default timezone to UTC
date_default_timezone_set('UTC');