Replace $minutesUntilProcessing calculation to use timestamps

The minute formatter only returned the minutes but not the hours, days,
etc

Model/Cron.php

@@ -352,9 +352,9 @@ class Cron
             // Remove OFFER_CLOSED notifications arrived in the last 10 minutes from the list to process to ensure it
             // won't close any order which has an AUTHORISED notification arrived a bit later than the OFFER_CLOSED one.
             $createdAt = \DateTime::createFromFormat('Y-m-d H:i:s', $notification['created_at']);
-            // Difference between $offerClosedMinDate and $createdAt in minutes is the time until processing the
-            // notification in minutes
-            $minutesUntilProcessing = $offerClosedMinDate->diff($createdAt)->i;
+            // To get the difference between $offerClosedMinDate and $createdAt, $offerClosedMinDate time in seconds is
+            // deducted from $createdAt time in seconds, divided by 60 and rounded down to integer
+            $minutesUntilProcessing = floor(($createdAt->getTimestamp() - $offerClosedMinDate->getTimestamp()) / 60);
             if ($notification['event_code'] == Notification::OFFER_CLOSED && $minutesUntilProcessing > 0) {
                 $this->_adyenLogger->addAdyenNotificationCronjob(
                     sprintf('OFFER_CLOSED notification %s skipped! Wait %s minute(s) before processing.',