Timer in PHP on registration - php

Question

I want to make little timer on my registration, per user. So basically I want to make it when someone makes the account, they are put on timer for lets say 5 minutes before registering again (same user).
I've tried the below, but it doesn't seem to be working:
$now = date('Y-m-d H:i:s');
if ($stmt->num_rows > 0) {
exit('user already exists');
} else {
$expire = date('Y-m-d H:i:s',+30);
if($now>$expire) {
create new acc
} else {
exit('You need to wait.');
}

Answer 1

Just add "+ 5 min to expire" docs: https://www.php.net/manual/de/function.strtotime.php
$now = date('Y-m-d H:i:s');
if ($stmt->num_rows > 0) {
exit('user already exists');
} else {
$expire = date('Y-m-d H:i:s', "+ 5 minutes");
if($now>$expire) {
create new acc
} else {
exit('You need to wait.');
}
You can basically use this code it will work

Answer 2

this code snippet will not work. Both variables, $now and $expire, are defined on the same flow.
On time of evaluation, the expression $now>$expire is never true.
You need store the state for the lock. One way to achieve this is a cookie that carries the date of last registration attempt.
PseudoCode
if isRegistered(user): exit("Already signed up")
else if notSet(cookie['lastAttemptAt']) : proceedWithSignUp()
else if cookie['lastAttemptAt'].plus(5, Minutes) < now() : proceedWithSignUp()
else : exit("You need to wait")
in this case the function proceedWithSignUp needs to take care as well to set the cookie value of lastAttemptAt
Be aware, that this can be easily by passed, by either not accepting cookies at all or clearing the cookies.