diff --git a/smartmeter_datacollector/smartmeter/cosem.py b/smartmeter_datacollector/smartmeter/cosem.py
index 4500963..28d0ac1 100644
--- a/smartmeter_datacollector/smartmeter/cosem.py
+++ b/smartmeter_datacollector/smartmeter/cosem.py
@@ -146,7 +146,8 @@ def retrieve_time_from_dlms_registers(self, dlms_objects: Dict[OBISCode, Any]) -
         if clock_obj and isinstance(clock_obj, GXDLMSClock):
             timestamp = self._extract_datetime(clock_obj)
             if timestamp:
-                return timestamp
+                # assume local time if tzinfo is None
+                return timestamp.astimezone(timestamp.tzinfo)
         return None
 
     def get_register(self, obis: OBISCode) -> Optional[RegisterCosem]:
diff --git a/smartmeter_datacollector/smartmeter/hdlc_dlms_parser.py b/smartmeter_datacollector/smartmeter/hdlc_dlms_parser.py
index cd8d22e..a2db3e3 100644
--- a/smartmeter_datacollector/smartmeter/hdlc_dlms_parser.py
+++ b/smartmeter_datacollector/smartmeter/hdlc_dlms_parser.py
@@ -86,8 +86,10 @@ def extract_data_from_hdlc_frames(self) -> bool:
     def extract_message_time(self) -> Optional[datetime]:
         if not isinstance(self._dlms_data.time, GXDateTime):
             return None
-        if isinstance(self._dlms_data.time.value, datetime):
-            return self._dlms_data.time.value
+        dt = self._dlms_data.time.value
+        if isinstance(dt, datetime):
+            # assume local time if tzinfo is None
+            return dt.astimezone(dt.tzinfo)
         return None
 
     def parse_to_dlms_objects(self) -> List[GXDLMSObject]:
@@ -133,9 +135,8 @@ def convert_dlms_bundle_to_reader_data(self, dlms_objects: List[GXDLMSObject],
             self._use_system_time = True
             timestamp = datetime.now(timezone.utc)
 
-        if not timestamp.tzinfo:
-            # if timezone info not set, assume UTC
-            timestamp = timestamp.replace(tzinfo=timezone.utc)
+        # convert to UTC format
+        timestamp = timestamp.astimezone(timezone.utc)
 
         # Extract register data
         data_points: List[MeterDataPoint] = []
diff --git a/tests/test_hdlc_dlms_parser.py b/tests/test_hdlc_dlms_parser.py
index f4908e7..76f843a 100644
--- a/tests/test_hdlc_dlms_parser.py
+++ b/tests/test_hdlc_dlms_parser.py
@@ -62,7 +62,8 @@ def test_parse_dlms_to_meter_data(self, unencrypted_valid_data_lg: List[bytes],
         assert any(data.type == MeterDataPointTypes.ACTIVE_POWER_N.value for data in meter_data)
         assert all(isinstance(data.value, float) for data in meter_data)
         assert all(data.source == "LGZ1030655933512" for data in meter_data)
-        assert all(data.timestamp.strftime(r"%m/%d/%y %H:%M:%S") == "07/06/21 14:58:18" for data in meter_data)
+        assert all(data.timestamp.astimezone().strftime(r"%m/%d/%y %H:%M:%S")
+                   == "07/06/21 14:58:18" for data in meter_data)
 
     def test_parse_dlms_to_meter_data2(self, unencrypted_valid_data_lg2: List[bytes], cosem_config_lg: Cosem):
         parser = prepare_parser(unencrypted_valid_data_lg2, cosem_config_lg)
diff --git a/tests/test_iskraam550.py b/tests/test_iskraam550.py
index f58f1d1..54a8335 100644
--- a/tests/test_iskraam550.py
+++ b/tests/test_iskraam550.py
@@ -65,4 +65,5 @@ def data_received():
     assert any(data.type == MeterDataPointTypes.REACTIVE_ENERGY_Q4.value for data in values)
     assert any(data.type == MeterDataPointTypes.POWER_FACTOR.value for data in values)
     assert all(data.source == "ISK1030775213859" for data in values)
-    assert all(data.timestamp.strftime(r"%m/%d/%y %H:%M:%S") == "08/15/20 06:19:45" for data in values)
+    # message time comes with timezone info (+02:00)
+    assert all(data.timestamp.strftime(r"%m/%d/%y %H:%M:%S") == "08/15/20 04:19:45" for data in values)
diff --git a/tests/test_lge450.py b/tests/test_lge450.py
index 469ee50..48d6ba4 100644
--- a/tests/test_lge450.py
+++ b/tests/test_lge450.py
@@ -65,7 +65,7 @@ def data_received():
     assert any(data.type == MeterDataPointTypes.REACTIVE_ENERGY_Q4.value for data in values)
     assert any(data.type == MeterDataPointTypes.POWER_FACTOR.value for data in values)
     assert all(data.source == "LGZ1030655933512" for data in values)
-    assert all(data.timestamp.strftime(r"%m/%d/%y %H:%M:%S") == "07/06/21 14:58:18" for data in values)
+    assert all(data.timestamp.astimezone().strftime(r"%m/%d/%y %H:%M:%S") == "07/06/21 14:58:18" for data in values)
 
 
 @pytest.mark.asyncio
diff --git a/tests/test_lge570.py b/tests/test_lge570.py
index a80ab44..c6a52f7 100644
--- a/tests/test_lge570.py
+++ b/tests/test_lge570.py
@@ -17,7 +17,6 @@
 from .utils import *
 
 
-@pytest.mark.skipif(sys.version_info < (3, 8), reason="Python3.7 does not support AsyncMock.")
 @pytest.mark.asyncio
 async def test_lge570_parse_and_provide_encrypted_data(mocker: MockerFixture,
                                                        encrypted_valid_data_lge570: List[bytes]):