What is the recommended method to increase a date by a specific number of days in PHP?

To increase a date by a specific number of days in PHP, you can use the `DateTime` class along with the `modify()` method. This method allows you to add or subtract a specified amount of time to a `DateTime` object.

$date = new DateTime('2022-01-01');
$days_to_add = 7;
$date->modify('+' . $days_to_add . ' days');
echo $date->format('Y-m-d');