Why is the code behaving so strangely?

Question

PHP

This code does not write cookies:

$time = $time; // int количество дней
setcookie("username", 'admin', time() + $time * 86400, '/admin/');

If you remove the time variable and explicitly replace it with an integer, then cookies will be written. What is the problem? Why does it work this way?
PHP 5.6

setcookie("username", 'admin', time() + 20 * 86400, '/admin/');

Answer 1

before calling setcookie() we write
and see what is really in it