How to calculate the time difference between unix time stamps?

Question

I am creating time stamps in PHP using time();

I have the $current_time and $purchase_time. How do I make sure that purchase_time is less than 24 hours of current time?

Answer 1

If they are UNIX timestamps, then you can calculate this by yourself really easy, as they are seconds.

$seconds = $current_time - $purchase_time
$hours = floor($seconds/3600);
if ($hours < 24){
    //success
}

Answer 2

Since UNIX timestamps are just numbers of seconds, just use the difference:

$purchasedToday = $current_time - $purchase_time < 24 * 60 * 60;
if ($purchasedToday) {
  echo 'You just bought the item';
} else {
  echo 'You bought the item some time ago';
}