diff --git a/api/tests/unit/Models/WorkingHoursTest.php b/api/tests/unit/Models/WorkingHoursTest.php
index 0f7fc5d..200f997 100644
--- a/api/tests/unit/Models/WorkingHoursTest.php
+++ b/api/tests/unit/Models/WorkingHoursTest.php
@@ -60,8 +60,14 @@ class WorkingHoursTest extends Unit
         $obj
             ->setWorkingDay($date)
             ->setWorkingTime($interval);
+
         $this->assertNotNull($obj->getWorkingDay());
+        $this->assertInstanceOf(DateTime::class, $obj->getWorkingDay());
+        $this->assertEquals($date, $obj->getWorkingDay());
+
         $this->assertNotNull($obj->getWorkingTime());
+        $this->assertInstanceOf(DateInterval::class, $obj->getWorkingTime());
+        $this->assertEquals($interval, $obj->getWorkingTime());
 
         $json = $obj->jsonSerialize();
         $this->assertIsArray($json);