symfony
diff --git a/‎src/Symfony/Component/HttpFoundation/ParameterBag.php
Lines changed: 9 additions & 5 deletions b/‎src/Symfony/Component/HttpFoundation/ParameterBag.php
Lines changed: 9 additions & 5 deletions
diff --git a/‎src/Symfony/Component/HttpFoundation/Tests/ParameterBagTest.php
Lines changed: 2 additions & 0 deletions b/‎src/Symfony/Component/HttpFoundation/Tests/ParameterBagTest.php
Lines changed: 2 additions & 0 deletions
@@ -190,17 +190,21 @@ public function getBoolean($key, $default = false)
     /**
      * Returns the parameter value converted to a DateTime object.
      *
-     * @param string             $key      The parameter key
-     * @param string             $format   The expected date format
-     * @param string             $default  The default value to be converted to a DateTime object if the parameter key does not exist
-     * @param \DateTimeZone|null $timeZone A DateTimeZone object representing the desired time zone
+     * @param string                    $key      The parameter key
+     * @param string                    $format   The expected date format
+     * @param \DateTimeInterface|string $default  The default value to be converted to a DateTime object if the parameter key does not exist
      *
-     * @return \DateTime|null
+     * @return \DateTimeInterface|null
      */
     public function getDate($key, $format, $default = null, \DateTimeZone $timeZone = null)
     {
         $time = $this->get($key, $default);
 
+        if ($time instanceof \DateTimeInterface) {
+            return $default;
+        }
+
         // if the user has specified a timezone then pass that
         // otherwise do not even attempt to put a value but rather let the runtime decide
         // the default value by itself
 
@@ -138,12 +138,14 @@ public function testGetDate()
         $this->assertEquals(0, $diff->days, '->getDate() returns a date via the format specified');
         $this->assertNull($bag->getDate('d1', 'd/m/Y'), '->getDate() returns null if the format is not valid');
         $this->assertNull($bag->getDate('d2', 'd/m/Y'), '->getDate() returns null if the parameter is not found');
+        $this->assertEquals($date, $bag->getDate('d1', 'Y-m-d', new \DateTime('2016-12-01')), '->getDate() parses the value if the key is present');
 
         $date = $bag->getDate('iso', \DateTime::ISO8601);
         $this->assertEquals(new \DateTime($isoDate), $date);
         $this->assertEquals('UTC', $date->getTimezone()->getName());
 
         $this->assertEquals($date, $bag->getDate('nokey', \DateTime::ISO8601, $isoDate));
+        $this->assertInstanceOf(\DateTimeInterface::class, $bag->getDate('nokey', \DateTime::ISO8601, $date));
         $this->assertNull($bag->getDate('nokey', 'd/m/Y', $isoDate), '->getDate() returns null when the default value is not in the specified format');
 
         $tz = $bag->getDate('d1', 'Y-m-d', null, new \DateTimeZone('Europe/Tirane'))->getTimezone()->getName();