diff --git a/core/lib/Drupal/Component/Datetime/DateTimePlus.php b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
index 11611686728ba198e1c82cd16e4ff6891ea37bd6..d045679434c6ae4eb637c7ebf62b20db453f8230 100644
--- a/core/lib/Drupal/Component/Datetime/DateTimePlus.php
+++ b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
@@ -715,4 +715,14 @@ public function setDefaultDateTime() {
     $this->dateTimeObject->setTime(12, 0, 0);
   }
 
+  /**
+   * Gets a clone of the proxied PHP \DateTime object wrapped by this class.
+   *
+   * @return \DateTime
+   *   A clone of the wrapped PHP \DateTime object.
+   */
+  public function getPhpDateTime() {
+    return clone $this->dateTimeObject;
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
index b89d351c755c9c3067eb64904fdd91dc16fb9e9d..08eb2068ff5a97c191f40ac2010130c2e177ab99 100644
--- a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
+++ b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
@@ -891,4 +891,29 @@ public function testChainableNonCallable() {
     $date->setTimezone(new \DateTimeZone('America/New_York'))->nonexistent();
   }
 
+  /**
+   * @covers ::getPhpDateTime
+   */
+  public function testGetPhpDateTime() {
+    $new_york = new \DateTimeZone('America/New_York');
+    $berlin = new \DateTimeZone('Europe/Berlin');
+
+    // Test retrieving a cloned copy of the wrapped \DateTime object, and that
+    // altering it does not change the DateTimePlus object.
+    $datetimeplus = DateTimePlus::createFromFormat('Y-m-d H:i:s', '2017-07-13 22:40:00', $new_york, ['langcode' => 'en']);
+    $this->assertEquals(1500000000, $datetimeplus->getTimestamp());
+    $this->assertEquals('America/New_York', $datetimeplus->getTimezone()->getName());
+
+    $datetime = $datetimeplus->getPhpDateTime();
+    $this->assertInstanceOf('DateTime', $datetime);
+    $this->assertEquals(1500000000, $datetime->getTimestamp());
+    $this->assertEquals('America/New_York', $datetime->getTimezone()->getName());
+
+    $datetime->setTimestamp(1400000000)->setTimezone($berlin);
+    $this->assertEquals(1400000000, $datetime->getTimestamp());
+    $this->assertEquals('Europe/Berlin', $datetime->getTimezone()->getName());
+    $this->assertEquals(1500000000, $datetimeplus->getTimestamp());
+    $this->assertEquals('America/New_York', $datetimeplus->getTimezone()->getName());
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php b/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
index 6c4777953545e7c74b6d223ecbbec90294413b61..4e915f772b8ccca4811f0d75c70c77137a1149fb 100644
--- a/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
+++ b/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
@@ -212,4 +212,29 @@ public function testChainableNonCallable() {
     $date->setTimezone(new \DateTimeZone('America/New_York'))->nonexistent();
   }
 
+  /**
+   * @covers ::getPhpDateTime
+   */
+  public function testGetPhpDateTime() {
+    $new_york = new \DateTimeZone('America/New_York');
+    $berlin = new \DateTimeZone('Europe/Berlin');
+
+    // Test retrieving a cloned copy of the wrapped \DateTime object, and that
+    // altering it does not change the DrupalDateTime object.
+    $drupaldatetime = DrupalDateTime::createFromFormat('Y-m-d H:i:s', '2017-07-13 22:40:00', $new_york, ['langcode' => 'en']);
+    $this->assertEquals(1500000000, $drupaldatetime->getTimestamp());
+    $this->assertEquals('America/New_York', $drupaldatetime->getTimezone()->getName());
+
+    $datetime = $drupaldatetime->getPhpDateTime();
+    $this->assertInstanceOf('DateTime', $datetime);
+    $this->assertEquals(1500000000, $datetime->getTimestamp());
+    $this->assertEquals('America/New_York', $datetime->getTimezone()->getName());
+
+    $datetime->setTimestamp(1400000000)->setTimezone($berlin);
+    $this->assertEquals(1400000000, $datetime->getTimestamp());
+    $this->assertEquals('Europe/Berlin', $datetime->getTimezone()->getName());
+    $this->assertEquals(1500000000, $drupaldatetime->getTimestamp());
+    $this->assertEquals('America/New_York', $drupaldatetime->getTimezone()->getName());
+  }
+
 }