diff --git a/addons/resource/models/resource.py b/addons/resource/models/resource.py
index ebe4fd24066..ebb2ab7ba6f 100644
--- a/addons/resource/models/resource.py
+++ b/addons/resource/models/resource.py
@@ -422,7 +422,7 @@ class ResourceCalendar(models.Model):
 
         for day in rrule.rrule(rrule.DAILY,
                                dtstart=start_dt,
-                               until=end_dt,
+                               until=end_dt.replace(hour=23, minute=59, second=59, microsecond=999999),
                                byweekday=self._get_weekdays()):
             start_time = datetime.time.min
             if day.date() == start_dt.date():
@@ -451,7 +451,7 @@ class ResourceCalendar(models.Model):
 
         for day in rrule.rrule(rrule.DAILY,
                                dtstart=start_dt,
-                               until=end_dt,
+                               until=end_dt.replace(hour=23, minute=59, second=59, microsecond=999999),
                                byweekday=self._get_weekdays()):
             start_time = datetime.time.min
             if day.date() == start_dt.date():
diff --git a/addons/resource/tests/test_resource.py b/addons/resource/tests/test_resource.py
index 16d6c5a0ede..2e8df285e8f 100644
--- a/addons/resource/tests/test_resource.py
+++ b/addons/resource/tests/test_resource.py
@@ -233,6 +233,15 @@ class ResourceWorkingHours(TestResourceCommon):
             compute_leaves=False)
         self.assertEqual(res, 40.0)
 
+    def test_calendar_working_hours_count(self):
+        calendar = self.env.ref('resource.resource_calendar_std_35h')
+        res = calendar.get_work_hours_count(
+            Datetime.from_string('2017-05-03 14:03:00'),  # Wednesday (8:00-12:00, 13:00-16:00)
+            Datetime.from_string('2017-05-04 11:03:00'),  # Thursday (8:00-12:00, 13:00-16:00)
+            resource_id=None,
+            compute_leaves=False)
+        self.assertEqual(res, 5.0)
+
     def test_calendar_working_hours_leaves(self):
         # new API: resource and leaves
         # res: 2 weeks -> 40 hours - (3+4) leave hours