how add day to date in php code example

Example 1: Add days to date in PHP

$date = new DateTime('2020-11-24');
$date->add(new DateInterval("P9D"));

echo $date->format('Y-m-d');

Example 2: add 1 day php datetime

$date = new DateTime('2000-01-01');
$date->add(new DateInterval('P1D'));