I var:

$lastActivationDelay = time() + 8;
if($lastActivationDelay<$last_activation)

şu anda, düzgün çalışmıyor.

What i want to do is if you try to enter the page, and
if $last_activation is under the $lastactivationdelay time, then echo false, else true.

Yani if eight seconds from now is over $last_activation, then true, if its under, then false.