diff --git a/addons/website_event_exhibitor/models/event_sponsor.py b/addons/website_event_exhibitor/models/event_sponsor.py
index 293854d1646..9a08a723e09 100644
--- a/addons/website_event_exhibitor/models/event_sponsor.py
+++ b/addons/website_event_exhibitor/models/event_sponsor.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from datetime import datetime
+from datetime import datetime, timedelta
 from pytz import timezone, utc
 
 from odoo import api, fields, models, _
@@ -153,7 +153,7 @@ class Sponsor(models.Model):
         for sponsor in self:
             if not sponsor.event_id.is_ongoing:
                 sponsor.is_in_opening_hours = False
-            elif not sponsor.hour_from or not sponsor.hour_to:
+            elif sponsor.hour_from is False or sponsor.hour_to is False:
                 sponsor.is_in_opening_hours = True
             else:
                 event_tz = timezone(sponsor.event_id.date_tz)
@@ -166,6 +166,9 @@ class Sponsor(models.Model):
                 # compute opening hours
                 opening_from_tz = event_tz.localize(datetime.combine(now_tz.date(), float_to_time(sponsor.hour_from)))
                 opening_to_tz = event_tz.localize(datetime.combine(now_tz.date(), float_to_time(sponsor.hour_to)))
+                if sponsor.hour_to == 0:
+                    # when closing 'at midnight', we consider it's at midnight the next day
+                    opening_to_tz = opening_to_tz + timedelta(days=1)
 
                 opening_from = max([dt_begin, opening_from_tz])
                 opening_to = min([dt_end, opening_to_tz])
diff --git a/addons/website_event_exhibitor/tests/test_sponsor_internals.py b/addons/website_event_exhibitor/tests/test_sponsor_internals.py
index 8021c3c4e7c..ef923de9bb0 100644
--- a/addons/website_event_exhibitor/tests/test_sponsor_internals.py
+++ b/addons/website_event_exhibitor/tests/test_sponsor_internals.py
@@ -13,7 +13,7 @@ class TestSponsorData(TestEventExhibitorCommon):
     @users('user_eventmanager')
     def test_event_date_computation(self):
         """ Test date computation. Pay attention that mocks returns UTC values, meaning
-        we have to take into account Europe/Brussels offset """
+        we have to take into account Europe/Brussels offset (+2 in July) """
         with freeze_time(self.reference_now):
             event = self.env['event.event'].browse(self.event_0.id)
             sponsor = self.env['event.sponsor'].browse(self.sponsor_0.id)
@@ -62,3 +62,32 @@ class TestSponsorData(TestEventExhibitorCommon):
             sponsor.invalidate_model(['is_in_opening_hours'])
             self.assertFalse(sponsor.is_in_opening_hours)
             self.assertFalse(event.is_ongoing)
+
+        # Use "00:00" as opening hours for sponsor -> should still work
+        event.invalidate_model(fnames=['is_ongoing'])
+        sponsor.hour_from = 0.0  # 0 -> 18
+
+        # Inside opening hours (17 < 18)
+        with freeze_time(datetime(2020, 7, 6, 15, 0, 1)):
+            sponsor.invalidate_model(fnames=['is_in_opening_hours'])
+            self.assertTrue(sponsor.is_in_opening_hours)
+
+        # Outside opening hours (21 > 18)
+        with freeze_time(datetime(2020, 7, 6, 19, 0, 1)):
+            sponsor.invalidate_model(fnames=['is_in_opening_hours'])
+            self.assertFalse(sponsor.is_in_opening_hours)
+
+        # Use "00:00" as closing hours for sponsor -> should still work
+        # (considered 'at midnight the next day')
+        sponsor.hour_from = 10.0
+        sponsor.hour_to = 0.0
+
+        # Inside opening hours (11 > 10)
+        with freeze_time(datetime(2020, 7, 6, 9, 0, 1)):
+            sponsor.invalidate_model(fnames=['is_in_opening_hours'])
+            self.assertTrue(sponsor.is_in_opening_hours)
+
+        # Outside opening hours (7 < 10)
+        with freeze_time(datetime(2020, 7, 6, 5, 0, 1)):
+            sponsor.invalidate_model(fnames=['is_in_opening_hours'])
+            self.assertFalse(sponsor.is_in_opening_hours)