diff --git a/api/html/index.php b/api/html/index.php
index cbd9aca..addc91c 100644
--- a/api/html/index.php
+++ b/api/html/index.php
@@ -17,7 +17,7 @@ use TorstenHettstedt\TimekeepingApi\Middleware\OriginAccessControlHandler;
 $container = new Container();
 
 $container->set('databases', function () {
-    $dsn = "pgsql:host=${_ENV['DATABASES_HOST']};port=5432;dbname=${_ENV['DATABASES_NAME']}";
+    $dsn = "pgsql:host={$_ENV['DATABASES_HOST']};port=5432;dbname={$_ENV['DATABASES_NAME']}";
     return new PDO($dsn, $_ENV['DATABASES_USER'], $_ENV['DATABASES_PASS']);
 });
 
diff --git a/api/tests/unit/Controller/WorkingHoursControllerTest.php b/api/tests/unit/Controller/WorkingHoursControllerTest.php
index a9a3167..17ff3b8 100644
--- a/api/tests/unit/Controller/WorkingHoursControllerTest.php
+++ b/api/tests/unit/Controller/WorkingHoursControllerTest.php
@@ -19,11 +19,11 @@ use TorstenHettstedt\TimekeepingApi\Controller\WorkingHoursController;
 class WorkingHoursControllerTest extends AbstractControllerTest
 {
 
-    protected const FICTIONAL_STATUS_CODE = 666;
-    public const    EXISTING_DATE         = '2020-01-28';
-    public const    EXISTING_INTERVAL     = '07:20:00';
-    public const    NEW_DATE              = '2020-04-01';
-    public const    NEW_INTERVAL          = '07:59:00';
+    protected const int    FICTIONAL_STATUS_CODE = 666;
+    public const    string EXISTING_DATE         = '2020-01-28';
+    public const    string EXISTING_INTERVAL     = '07:20:00';
+    public const    string NEW_DATE              = '2020-04-01';
+    public const    string NEW_INTERVAL          = '07:59:00';
 
     protected ContainerInterface  $container;
     protected Request             $request;
diff --git a/api/tests/unit/Repositories/WorkingHoursRepositoryTest.php b/api/tests/unit/Repositories/WorkingHoursRepositoryTest.php
index 0dbef52..326caff 100644
--- a/api/tests/unit/Repositories/WorkingHoursRepositoryTest.php
+++ b/api/tests/unit/Repositories/WorkingHoursRepositoryTest.php
@@ -18,11 +18,11 @@ use TorstenHettstedt\TimekeepingApi\Repositories\WorkingHoursRepository;
 
 class WorkingHoursRepositoryTest extends Unit
 {
-    public const EXISTING_DATE     = '2020-01-28';
-    public const EXISTING_INTERVAL = 'PT7H20M';
-    public const NEW_DATE          = '2020-04-01';
-    public const NEW_INTERVAL      = 'PT7H59M';
-    public const RECORDS_COUNT     = 61;
+    public const string EXISTING_DATE     = '2020-01-28';
+    public const string EXISTING_INTERVAL = 'PT7H20M';
+    public const string NEW_DATE          = '2020-04-01';
+    public const string NEW_INTERVAL      = 'PT7H59M';
+    public const int    RECORDS_COUNT     = 61;
 
     protected PDO $pdoObject;
 
diff --git a/api/tests/unit/Repositories/WorkingHoursViewRepositoryTest.php b/api/tests/unit/Repositories/WorkingHoursViewRepositoryTest.php
index 8211985..14ebb54 100644
--- a/api/tests/unit/Repositories/WorkingHoursViewRepositoryTest.php
+++ b/api/tests/unit/Repositories/WorkingHoursViewRepositoryTest.php
@@ -6,7 +6,6 @@ use Codeception\Attribute\DataProvider;
 use Codeception\Test\Unit;
 use DateTime;
 use DateTimeZone;
-use Exception;
 use PDO;use TorstenHettstedt\TimekeepingApi\Models\WorkingHoursView;
 use TorstenHettstedt\TimekeepingApi\Repositories\RepositoryRecordNotFoundException;
 use TorstenHettstedt\TimekeepingApi\Repositories\WorkingHoursWeeklyViewRepository;
@@ -38,14 +37,13 @@ class WorkingHoursViewRepositoryTest extends Unit
 
     /**
      * @return array<array{string, string, int, DateTime}>
-     * @throws Exception
      */
     public function existingObjectProvider(): array
     {
         return [
-            [WorkingHoursYearlyViewRepository::class,  '2020',          61, new DateTime('2020-01-01', new DateTimeZone('UCT'))],
-            [WorkingHoursMonthlyViewRepository::class, '2020 February', 20, new DateTime('2020-02-01', new DateTimeZone('UCT'))],
-            [WorkingHoursWeeklyViewRepository::class,  '2020#03',        5, new DateTime('2020-01-13', new DateTimeZone('UCT'))],
+            [WorkingHoursYearlyViewRepository::class,  '2020',          61, date_create('2020-01-01', new DateTimeZone('UCT'))],
+            [WorkingHoursMonthlyViewRepository::class, '2020 February', 20, date_create('2020-02-01', new DateTimeZone('UCT'))],
+            [WorkingHoursWeeklyViewRepository::class,  '2020#03',        5, date_create('2020-01-13', new DateTimeZone('UCT'))],
         ];
     }