Is there a preferred method between using PHP functions like strtotime() or MySQL functions like date_add() for calculating dates in PHP applications?

When calculating dates in PHP applications, it is generally recommended to use PHP functions like strtotime() rather than MySQL functions like date_add(). PHP functions offer more flexibility and ease of use when working with dates in PHP applications. Additionally, using PHP functions allows for better portability of the code across different database systems.

// Example of calculating a future date using strtotime()
$today = date('Y-m-d');
$future_date = date('Y-m-d', strtotime('+1 week', strtotime($today)));
echo $future_date;