core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php b/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
index 75f892a..70045df 100644
--- a/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
+++ b/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
@@ -81,18 +81,21 @@ public function testDateTime() {
     $this->assertTrue($entity->field_datetime[0] instanceof FieldItemInterface, 'Field item implements interface.');
     $this->assertEqual($entity->field_datetime->value, $value);
     $this->assertEqual($entity->field_datetime[0]->value, $value);
+    $this->assertEqual(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime[0]->getProperties()['value']->getDateTime()->getTimeZone()->getName());
     $this->assertEquals(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime->date->getTimeZone()->getName());
 
     // Verify changing the date value.
     $new_value = '2016-11-04T00:21:00';
     $entity->field_datetime->value = $new_value;
     $this->assertEqual($entity->field_datetime->value, $new_value);
+    $this->assertEqual(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime[0]->getProperties()['value']->getDateTime()->getTimeZone()->getName());
     $this->assertEquals(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime->date->getTimeZone()->getName());
 
     // Read changed entity and assert changed values.
     $this->entityValidateAndSave($entity);
     $entity = EntityTest::load($id);
     $this->assertEqual($entity->field_datetime->value, $new_value);
+    $this->assertEqual(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime[0]->getProperties()['value']->getDateTime()->getTimeZone()->getName());
     $this->assertEquals(DateTimeItemInterface::STORAGE_TIMEZONE, $entity->field_datetime->date->getTimeZone()->getName());
 
     // Test the generateSampleValue() method.