diff --git a/muk_models_groupby_hour/tests/__init__.py b/muk_models_groupby_hour/tests/__init__.py
new file mode 100644
index 0000000..38143f7
--- /dev/null
+++ b/muk_models_groupby_hour/tests/__init__.py
@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+
+###################################################################################
+# 
+#    MuK Document Management System
+#
+#    Copyright (C) 2018 MuK IT GmbH
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+###################################################################################
+
+from . import test_attachment
\ No newline at end of file
diff --git a/muk_models_groupby_hour/tests/test_groupby.py b/muk_models_groupby_hour/tests/test_groupby.py
new file mode 100644
index 0000000..1f3cefa
--- /dev/null
+++ b/muk_models_groupby_hour/tests/test_groupby.py
@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+
+###################################################################################
+# 
+#    MuK Document Management System
+#
+#    Copyright (C) 2018 MuK IT GmbH
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+###################################################################################
+
+import os
+import json
+import base64
+import logging
+import unittest
+import requests
+
+import odoo
+from odoo import _
+from odoo.tests import common
+
+_logger = logging.getLogger(__name__)
+
+class AttachmentTestCase(common.TransactionCase):
+    
+    at_install = False
+    post_install = True
+    
+    def setUp(self):
+        super(AttachmentTestCase, self).setUp()
+        self.attachment = self.env['ir.attachment'].sudo()
+        
+    def tearDown(self):
+        super(AttachmentTestCase, self).tearDown()
+    
+    def test_groupy(self):
+        result = self.attachment.read_group(
+            domain=[],
+            fields=['name'],
+            groupby='date:hour')
+        _logger.warning(result)
+        self.assertTrue(result)
+        
\ No newline at end of file