Let queue handle DateInterval and DateTimeInterface.

src/Illuminate/Bus/Queueable.php

@@ -21,7 +21,7 @@ trait Queueable
     /**
      * The number of seconds before the job should be made available.
      *
-     * @var \DateTime|int|null
+     * @var \DateTimeInterface|\DateInterval|int|null
      */
     public $delay;
 
@@ -61,7 +61,7 @@ public function onQueue($queue)
     /**
      * Set the desired delay for the job.
      *
-     * @param  \DateTime|int|null  $delay
+     * @param  \DateTimeInterface|\Da|int|null  $delay
      * @return $this
      */
     public function delay($delay)

src/Illuminate/Contracts/Mail/MailQueue.php

@@ -16,7 +16,7 @@ public function queue($view, $queue = null);
     /**
      * Queue a new e-mail message for sending after (n) seconds.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string|array|MailableContract  $view
      * @param  string  $queue
      * @return mixed

src/Illuminate/Contracts/Queue/Queue.php

@@ -45,7 +45,7 @@ public function pushRaw($payload, $queue = null, array $options = []);
     /**
      * Push a new job onto the queue after a delay.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string  $job
      * @param  mixed   $data
      * @param  string  $queue
@@ -57,7 +57,7 @@ public function later($delay, $job, $data = '', $queue = null);
      * Push a new job onto the queue after a delay.
      *
      * @param  string  $queue
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string  $job
      * @param  mixed   $data
      * @return mixed

src/Illuminate/Mail/Mailable.php

@@ -145,7 +145,7 @@ public function queue(Queue $queue)
     /**
      * Deliver the queued message after the given delay.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  Queue  $queue
      * @return mixed
      */

src/Illuminate/Mail/Mailer.php

@@ -386,7 +386,7 @@ public function queueOn($queue, $view)
     /**
      * Queue a new e-mail message for sending after (n) seconds.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string|array|MailableContract  $view
      * @param  string|null  $queue
      * @return mixed
@@ -404,7 +404,7 @@ public function later($delay, $view, $queue = null)
      * Queue a new e-mail message for sending after (n) seconds on the given queue.
      *
      * @param  string  $queue
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string|array  $view
      * @return mixed
      */

src/Illuminate/Mail/PendingMail.php

@@ -130,7 +130,7 @@ public function queue(Mailable $mailable)
     /**
      * Deliver the queued message after the given delay.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  Mailable  $mailable
      * @return mixed
      */

src/Illuminate/Queue/InteractsWithTime.php

@@ -2,6 +2,8 @@
 
 namespace Illuminate\Queue;
 
+use DateTime;
+use DateInterval;
 use DateTimeInterface;
 use Illuminate\Support\Carbon;
 
@@ -10,11 +12,13 @@ trait InteractsWithTime
     /**
      * Get the number of seconds until the given DateTime.
      *
-     * @param  \DateTimeInterface  $delay
+     * @param  \DateTimeInterface|\DateInterval  $delay
      * @return int
      */
     protected function secondsUntil($delay)
     {
+        $delay = $this->handlesInterval($delay);
+
         return $delay instanceof DateTimeInterface
                             ? max(0, $delay->getTimestamp() - $this->currentTime())
                             : (int) $delay;
@@ -23,16 +27,33 @@ protected function secondsUntil($delay)
     /**
      * Get the "available at" UNIX timestamp.
      *
-     * @param  \DateTimeInterface|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @return int
      */
     protected function availableAt($delay = 0)
     {
+        $delay = $this->handlesInterval($delay);
+
         return $delay instanceof DateTimeInterface
                             ? $delay->getTimestamp()
                             : Carbon::now()->addSeconds($delay)->getTimestamp();
     }
 
+    /**
+     * Converts an interval to a DateTime instance.
+     *
+     * @param \DateTimeInterface|\DateInterval|int
+     * @return \DateTime
+     */
+    protected function handlesInterval($delay)
+    {
+        if ($delay instanceof DateInterval) {
+            $delay = (new DateTime)->add($delay);
+        }
+
+        return $delay;
+    }
+
     /**
      * Get the current system time as a UNIX timestamp.
      *

src/Illuminate/Queue/SqsQueue.php

@@ -93,7 +93,7 @@ public function pushRaw($payload, $queue = null, array $options = [])
     /**
      * Push a new job onto the queue after a delay.
      *
-     * @param  \DateTime|int  $delay
+     * @param  \DateTimeInterface|\DateInterval|int  $delay
      * @param  string  $job
      * @param  mixed   $data
      * @param  string  $queue