echo date('Y-m-d H:i:s'); // Output: 2021-11-01 09:12:05
$date_str = '2021-11-01'; $date = date('Y-m-d', strtotime($date_str)); // Output: 2021-11-01
$date_str = '2021-11-01'; $days_to_add = 7; $new_date = date('Y-m-d', strtotime($date_str . ' + ' . $days_to_add . ' days')); // Output: 2021-11-08Package Library: PHP Date is a built-in library and does not require any external package or library.