diff --git a/api/html/index.php b/api/html/index.php
index 3330c7b..300a3bd 100644
--- a/api/html/index.php
+++ b/api/html/index.php
@@ -6,6 +6,9 @@ $dotenv->load();
 
 use DI\Container;
 use Slim\Factory\AppFactory;
+use Slim\Routing\RouteCollectorProxy;
+use TorstenHettstedt\TimekeepingApi\Controller\WorkingHoursController;
+use TorstenHettstedt\TimekeepingApi\Middleware\JsonBodyParserMiddleware;
 
 $container = new Container();
 
@@ -16,6 +19,7 @@ $container->set('databases', function () {
 
 AppFactory::setContainer($container);
 $app = AppFactory::create();
+$app->add(new JsonBodyParserMiddleware());
 
 $app->get(
     '/',
@@ -37,6 +41,15 @@ $app->get(
     'TorstenHettstedt\TimekeepingApi\Controller\WorkingHoursViewController:browseYearly'
 );
 
+$app->group('/working-hours', function (RouteCollectorProxy $group) {
+    $group->get('', WorkingHoursController::class . ':browse');
+    $group->post('', WorkingHoursController::class . ':creat');
+    $group->group('/{id:\d\d\d\d-\d\d-\d\d}', function (RouteCollectorProxy $group) {
+        $group->get('', WorkingHoursController::class . ':read');
+        $group->put('', WorkingHoursController::class . ':update');
+    });
+});
+
 $app->addErrorMiddleware(true, true, true);
 
 $app->run();
\ No newline at end of file
diff --git a/api/src/Controller/HttpConflictRequestException.php b/api/src/Controller/HttpConflictRequestException.php
new file mode 100644
index 0000000..f37fa77
--- /dev/null
+++ b/api/src/Controller/HttpConflictRequestException.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace TorstenHettstedt\TimekeepingApi\Controller;
+
+use Slim\Exception\HttpSpecializedException;
+
+class HttpConflictRequestException extends HttpSpecializedException
+{
+    /**
+     * @var int
+     */
+    protected $code = 409;
+
+    /**
+     * @var string
+     */
+    protected $message = 'Conflict.';
+
+    protected $title = '409 Conflict';
+    protected $description = 'The 409 (Conflict) status code indicates that the request could not be completed due to a conflict with the current state of the target resource.';
+}
diff --git a/api/src/Controller/WorkingHoursController.php b/api/src/Controller/WorkingHoursController.php
new file mode 100644
index 0000000..dd3e5ca
--- /dev/null
+++ b/api/src/Controller/WorkingHoursController.php
@@ -0,0 +1,173 @@
+<?php
+
+namespace TorstenHettstedt\TimekeepingApi\Controller;
+
+
+use DateInterval;
+use DateTime;
+use Exception;
+use Fig\Http\Message\StatusCodeInterface;
+use PDO;
+use Psr\Container\ContainerInterface;
+use Slim\Exception\HttpBadRequestException;
+use Slim\Exception\HttpInternalServerErrorException;
+use Slim\Exception\HttpNotFoundException;
+use Slim\Psr7\Request;
+use Slim\Psr7\Response;
+use TorstenHettstedt\TimekeepingApi\Models\WorkingHours;
+use TorstenHettstedt\TimekeepingApi\Repositories\RepositoryModelAlreadyExists;
+use TorstenHettstedt\TimekeepingApi\Repositories\RepositoryRecordNotFoundException;
+use TorstenHettstedt\TimekeepingApi\Repositories\WorkingHoursRepository;
+
+class WorkingHoursController
+{
+
+    protected PDO                $databases;
+    protected ContainerInterface $container;
+
+    /**
+     * WorkingHoursController constructor.
+     *
+     * @param ContainerInterface $container
+     *
+     * @throws NotDatabasesException
+     */
+    public function __construct(ContainerInterface $container)
+    {
+        $this->container = $container;
+        if ($this->container->has('databases') === false) {
+            throw new NotDatabasesException('Datenbank ist nicht Vorhanden');
+        }
+        $this->databases = $this->container->get('databases');
+    }
+
+    /**
+     * @param Request  $request
+     * @param Response $response
+     * @param mixed[]  $args
+     *
+     * @return Response
+     *
+     * @throws HttpBadRequestException
+     * @throws HttpNotFoundException
+     */
+    public function update(Request $request, Response $response, array $args): Response
+    {
+        $body = $request->getParsedBody();
+        $repository = new WorkingHoursRepository($this->databases);
+        $model = $this->buildModel($request, $args['id'], $body['workingTime']);
+        try {
+            $repository->update($model);
+        } catch (RepositoryRecordNotFoundException $exception) {
+            throw new HttpNotFoundException($request, 'Der Eintrag ist nicht vorhanden.', $exception);
+        }
+        return $this->printResponse($response, $model, StatusCodeInterface::STATUS_OK);
+    }
+
+    /**
+     * @param Request  $request
+     * @param Response $response
+     * @param mixed[]  $args
+     *
+     * @return Response
+     *
+     * @throws Exception
+     * @noinspection PhpUnusedParameterInspection
+     */
+    public function browse(Request $request, Response $response, array $args): Response
+    {
+        $repository = new WorkingHoursRepository($this->databases);
+        return $this->printResponse($response, $repository->findAll(), StatusCodeInterface::STATUS_OK);
+    }
+
+    /**
+     * @param Request  $request
+     * @param Response $response
+     * @param mixed[]  $args
+     *
+     * @return Response
+     *
+     * @throws HttpNotFoundException
+     * @throws HttpInternalServerErrorException
+     */
+    public function read(Request $request, Response $response, array $args): Response
+    {
+        $repository = new WorkingHoursRepository($this->databases);
+        try {
+            return $this->printResponse($response, $repository->findByKey($args['id']), StatusCodeInterface::STATUS_OK);
+        } catch (RepositoryRecordNotFoundException $exception) {
+            throw new HttpNotFoundException($request, 'Der Eintrag ist nicht vorhanden.', $exception);
+        } catch (Exception $exception) {
+            throw new HttpInternalServerErrorException($request, 'Der Wert für das Datum oder die Zeit ist falsch in der Datenbank', $exception);
+        }
+    }
+
+    /**
+     * @param Request  $request
+     * @param Response $response
+     * @param mixed[]  $args
+     *
+     * @return Response
+     *
+     * @throws HttpBadRequestException
+     * @throws HttpConflictRequestException
+     * @throws HttpInternalServerErrorException
+     * @noinspection PhpUnusedParameterInspection
+     */
+    public function creat(Request $request, Response $response, array $args): Response
+    {
+        $body = $request->getParsedBody();
+        $repository = new WorkingHoursRepository($this->databases);
+        $model = $this->buildModel($request, $body['workingDay'], $body['workingTime']);
+        try {
+            $repository->insert($model);
+        } catch (RepositoryModelAlreadyExists $exception) {
+            throw new HttpConflictRequestException($request, 'Der Eintrag ist schon vorhanden.', $exception);
+        } catch (Exception $exception) {
+            throw new HttpInternalServerErrorException($request, 'Der Wert für das Datum oder die Zeit ist falsch in der Datenbank', $exception);
+        }
+        return $this->printResponse($response, $model, StatusCodeInterface::STATUS_CREATED);
+    }
+
+    /**
+     * @param Response $response
+     * @param mixed    $data
+     * @param int      $status_code
+     *
+     * @return Response
+     */
+    protected function printResponse(Response $response, mixed $data, int $status_code): Response
+    {
+        $payload = json_encode($data);
+
+        $response->getBody()->write($payload);
+
+        return $response
+            ->withHeader('Content-Type', 'application/json')
+            ->withStatus($status_code);
+    }
+
+    /**
+     * @param Request $request
+     * @param string  $date
+     * @param string  $time
+     *
+     * @return WorkingHours
+     * @throws HttpBadRequestException
+     */
+    protected function buildModel(Request $request, string $date, string $time): WorkingHours
+    {
+        try {
+            $workingDay = new DateTime($date);
+        } catch (Exception $exception) {
+            throw new HttpBadRequestException($request, 'Der Wert für das Datum ist falsch', $exception);
+        }
+        try {
+            $workingTime = new DateInterval('P0000-00-00T' . $time);
+        } catch (Exception $exception) {
+            throw new HttpBadRequestException($request, 'Der Wert für die Zeit ist falsch', $exception);
+        }
+        return (new WorkingHours())->setWorkingDay($workingDay)->setWorkingTime($workingTime);
+    }
+
+}
\ No newline at end of file
diff --git a/api/src/Middleware/JsonBodyParserMiddleware.php b/api/src/Middleware/JsonBodyParserMiddleware.php
new file mode 100644
index 0000000..1c020e6
--- /dev/null
+++ b/api/src/Middleware/JsonBodyParserMiddleware.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace TorstenHettstedt\TimekeepingApi\Middleware;
+
+use Psr\Http\Message\ResponseInterface as Response;
+use Psr\Http\Message\ServerRequestInterface as Request;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface as RequestHandler;
+
+class JsonBodyParserMiddleware implements MiddlewareInterface
+{
+    public function process(Request $request, RequestHandler $handler): Response
+    {
+        $contentType = $request->getHeaderLine('Content-Type');
+
+        if (strstr($contentType, 'application/json')) {
+            $contents = json_decode(file_get_contents('php://input'), true);
+            if (json_last_error() === JSON_ERROR_NONE) {
+                $request = $request->withParsedBody($contents);
+            }
+        }
+
+        return $handler->handle($request);
+    }
+}