How can PHP functions like date() and strtotime() be used to manipulate date and time values effectively?

PHP functions like date() and strtotime() can be used effectively to manipulate date and time values. The date() function allows you to format a timestamp into a human-readable date, while strtotime() can convert textual date/time descriptions into Unix timestamps. By combining these functions, you can easily manipulate date and time values in PHP to perform tasks like adding or subtracting days, months, or years from a given date.

// Example: Adding 1 week to the current date
$currentDate = date('Y-m-d');
$newDate = date('Y-m-d', strtotime($currentDate . ' +1 week'));
echo $newDate;