diff --git a/kombu/utils/json.py b/kombu/utils/json.py
index f6429c3f..26583d61 100644
--- a/kombu/utils/json.py
+++ b/kombu/utils/json.py
@@ -41,9 +41,7 @@ class JSONEncoder(_encoder_cls):
                 if not isinstance(o, datetime):
                     o = datetime(o.year, o.month, o.day, 0, 0, 0, 0)
                 r = o.isoformat()
-                if r.endswith("+00:00"):
-                    r = r[:-6] + "Z"
-                return r
+                return {"datetime": r, "__datetime__": True}
             elif isinstance(o, times):
                 return o.isoformat()
             elif isinstance(o, textual):
@@ -71,6 +69,8 @@ def dumps(s, _dumps=json.dumps, cls=None, default_kwargs=None, **kwargs):
 
 def object_hook(dct):
     """Hook function to perform custom deserialization."""
+    if "__datetime__" in dct:
+        return datetime.datetime.fromisoformat(dct["datetime"])
     if "__bytes__" in dct:
         return dct["bytes"].encode("utf-8")
     if "__base64__" in dct:
diff --git a/requirements/test.txt b/requirements/test.txt
index 6674f34c..038d5e9d 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -3,3 +3,4 @@ pytest~=7.1.1
 pytest-sugar
 Pyro4
 hypothesis
+pytest-freezegun
diff --git a/t/unit/utils/test_json.py b/t/unit/utils/test_json.py
index c263b4f9..54d559e4 100644
--- a/t/unit/utils/test_json.py
+++ b/t/unit/utils/test_json.py
@@ -25,11 +25,10 @@ class Custom:
 
 
 class test_JSONEncoder:
-
+    @pytest.mark.freeze_time("2015-10-21")
     def test_datetime(self):
         now = datetime.utcnow()
         now_utc = now.replace(tzinfo=pytz.utc)
-        stripped = datetime(*now.timetuple()[:3])
         serialized = loads(dumps({
             'datetime': now,
             'tz': now_utc,
@@ -37,10 +36,10 @@ class test_JSONEncoder:
             'time': now.time()},
         ))
         assert serialized == {
-            'datetime': now.isoformat(),
-            'tz': '{}Z'.format(now_utc.isoformat().split('+', 1)[0]),
+            'datetime': now,
+            'tz': now_utc,
             'time': now.time().isoformat(),
-            'date': stripped.isoformat(),
+            'date':  datetime(now.year, now.month, now.day, 0, 0, 0, 0),
         }
 
     @given(message=st.binary())