diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulChanged.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulChanged.php
index 3db5906..5e50b96 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulChanged.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulChanged.php
@@ -83,9 +83,13 @@ public function save() {
    * Simulates passage of one second.
    */
   protected function waitASecond() {
-    /** @var \Drupal\entity_test\TimeTest $timeService */
-    $timeService = \Drupal::time();
-    $timeService->increment('requestTime');
+    /** @var \Drupal\Tests\TimeTestHelper $time_service */
+    $time_service = \Drupal::time();
+
+    $request_time = $time_service->getRequestTime();
+    $request_time += 1;
+
+    $time_service->setRequestTime($request_time);
   }
 
 }
diff --git a/core/modules/system/tests/modules/entity_test/src/EntityTestServiceProvider.php b/core/modules/system/tests/modules/entity_test/src/EntityTestServiceProvider.php
index 8f5d8f6..661c36f 100644
--- a/core/modules/system/tests/modules/entity_test/src/EntityTestServiceProvider.php
+++ b/core/modules/system/tests/modules/entity_test/src/EntityTestServiceProvider.php
@@ -12,7 +12,7 @@ class EntityTestServiceProvider extends ServiceProviderBase  {
    */
   public function alter(ContainerBuilder $container) {
     $timeService = $container->getDefinition('datetime.time');
-    $timeService->setClass('Drupal\entity_test\TimeShifter');
+    $timeService->setClass('Drupal\Tests\TimeTestHelper');
   }
 
 }
diff --git a/core/modules/system/tests/modules/entity_test/src/TimeShifter.php b/core/tests/Drupal/Tests/TimeTestHelper.php
similarity index 50%
rename from core/modules/system/tests/modules/entity_test/src/TimeShifter.php
rename to core/tests/Drupal/Tests/TimeTestHelper.php
index 0f22068..0b50651 100644
--- a/core/modules/system/tests/modules/entity_test/src/TimeShifter.php
+++ b/core/tests/Drupal/Tests/TimeTestHelper.php
@@ -1,10 +1,10 @@
 <?php
 
-namespace Drupal\entity_test;
+namespace Drupal\Tests;
 
 use Drupal\Component\Datetime\Time;
 
-class TimeShifter extends Time {
+class TimeTestHelper extends Time {
 
   /**
    * @var int
@@ -27,31 +27,13 @@ class TimeShifter extends Time {
   protected $currentMicroTime = NULL;
 
   /**
-   * Increments given property.
-   *
-   * @param string $property
-   *   Property to increment, e.g. requestTime.
-   *
-   * @param int $amount
-   *   Amount to add. Defaults to 1.
-   */
-  public function increment($property, $amount = 1) {
-    if ($this->$property === NULL) {
-      // Initialize local counter when incrementing for the first time.
-      $getter = 'get' . ucfirst($property);
-      $this->$property = $this->$getter();
-    }
-
-    $this->$property += $amount;
-  }
-
-  /**
    * {@inheritdoc}
    */
   public function getRequestTime() {
     if ($this->requestTime === NULL) {
       return parent::getRequestTime();
-    } else {
+    }
+    else {
       return $this->requestTime;
     }
   }
@@ -60,10 +42,11 @@ public function getRequestTime() {
    * {@inheritdoc}
    */
   public function getRequestMicroTime() {
-    if ($this->currentMicroTime === NULL) {
+    if ($this->requestMicroTime === NULL) {
       return parent::getRequestMicroTime();
-    } else {
-      $this->currentMicroTime;
+    }
+    else {
+      return $this->requestMicroTime;
     }
   }
 
@@ -73,7 +56,8 @@ public function getRequestMicroTime() {
   public function getCurrentTime() {
     if ($this->currentTime === NULL) {
       return parent::getCurrentTime();
-    } else {
+    }
+    else {
       return $this->currentTime;
     }
   }
@@ -84,9 +68,46 @@ public function getCurrentTime() {
   public function getCurrentMicroTime() {
     if ($this->currentMicroTime === NULL) {
       return parent::getCurrentMicroTime();
-    } else {
-      $this->currentMicroTime;
     }
+    else {
+      return $this->currentMicroTime;
+    }
+  }
+
+  /**
+   * Sets the request time.
+   *
+   * @param int $request_time
+   */
+  public function setRequestTime($request_time) {
+    $this->requestTime = $request_time;
+  }
+
+  /**
+   * Sets the request time, with microseconds.
+   *
+   * @param float $request_micro_time
+   */
+  public function setRequestMicroTime($request_micro_time) {
+    $this->requestMicroTime = $request_micro_time;
+  }
+
+  /**
+   * Sets the current time.
+   *
+   * @param int $current_time
+   */
+  public function setCurrentTime($current_time) {
+    $this->currentTime = $current_time;
+  }
+
+  /**
+   * Sets the current time, with microseconds.
+   *
+   * @param int $current_micro_time
+   */
+  public function setCurrentMicroTime($current_micro_time) {
+    $this->currentMicroTime = $current_micro_time;
   }
 
 }