how can i make a countdown timer that goes past the 60minutes - php

Question

This is the flow of commands on my login page
User loads page
php checks if the ip address is in the db, if not it adds it
php checks in the ip address is blocked in the db, if not it proceeds
if it is blocked the script will proceed to get the time the ip was blocked at from the db and calculate the amount of time left until the user can try to login again. The blockout time is 15minutes.
However the problem is that if the user was blocked at 45-59 minutes past the hour then 45+15= 00(as 60 doesn't come up on the time) and any number between 45 and 60 excluding 45 and 60 will go past the hour so for example if i get blocked out at 11:48 i will be unblocked at 12:03.
The problem, if you haven't already figured out is how do i code the countdown timer so it goes past the hour and doesn't spazz out when it goes past 59minutes.
Also i want to do this in php as i have no need to actually present the time left in real-time.

Answer 1

The current minute is never an issue. You are concerned with the duration since last blocked, not with "what time was that":
block_user.php:
<?php
$now = new DateTime();
write_block_into_database($ip_address, $now->format('Y-m-d H:i:s'));
?>
check_block.php
<?php
$sql = 'SELECT 1 FROM sometable WHERE ip_address=? AND DATE_ADD(blocked_at, INTERVAL 1 HOURS) >= NOW()';
if(get_result($sql, $ip_address)) {
// this address is blocked
} else {
// no recent block found
}
Or, if you want to do the comparison in PHP:
check_locally.php:
<?php
$sql = "SELECT blocked_at FROM sometable WHERE ip_address=?";
$db_row = get_row($sql,$ip_address);
if ($db_row) {
$blocked = new DateTime($db_row->blocked_at);
$blocked->modify('+1 hour');
$now = new DateTime();
if ($blocked >= $now) {
// still blocked
} else {
// was blocked earlier, no more
}
} else {
// not blocked
}
In other words: "if I take the time the IP was blocked and add one hour, is now still before that point in time?"
Example:
blocked at 12:48
checking at 13:10: 12:48 + 1 hour = 13:48, 13:48 >= 13:10, fail
checking at 15:10: 12:48 + 1 hour = 13:48, 13:48 < 15:10, pass

Answer 2

This is what I managed to come up with
$date = new DateTime();
$currentTime = $date->getTimestamp();
$blockTime = "1453494620";//This value will be taken from the mysql db
$timeElapsed = $currentTime - $blockTime;
echo "Current Time: $currentTime";
echo "<br>Block Time: $blockTime <br>";
if ($timeElapsed < 900){
$leftTime = ((900 - $timeElapsed) / 60) + 1;
$DotPosition = (stripos($leftTime, ".")) + 1;
if($DotPosition == 3 || $DotPosition == 2){
$leftTime = substr($leftTime, 0, $DotPosition - 1);
}
if($leftTime == 1){
$minutesString = "minute";
} else $minutesString = "minutes";
echo "<br>You are blocked from trying to login for too many incorrect tries.
<br>Please try again in $leftTime $minutesString.";
} else {
/*for test purpose, here the user will get unblocked on the mysql by updating the
ips blockout field */
echo "<br>You have been unblocked.";
}
Current Time: 1453495488
Block Time: 1453494620
You are blocked from trying to login for too many incorrect tries.
Please try again in 1 minute.
Thank you guys for telling me about UNIX Timestamps. If I knew about them I wouldn't have asked. :)