use tzdata for timezone funnies

Author: rerpha

pyproject.toml

@@ -7,7 +7,8 @@ name = "saluki"
 dynamic = ["version"]
 dependencies = [
     "ess-streaming-data-types",
-    "confluent-kafka"
+    "confluent-kafka",
+    "tzdata"
 ]
 readme = {file = "README.md", content-type = "text/markdown"}
 license-files = ["LICENSE"]

src/saluki/utils.py

@@ -1,6 +1,7 @@
 import datetime
 import logging
 from typing import List, Tuple
+from zoneinfo import ZoneInfo
 
 from confluent_kafka import Message
 from streaming_data_types import DESERIALISERS
@@ -66,8 +67,10 @@ def _parse_timestamp(msg: Message) -> str:
     """
     timestamp_type, timestamp_ms_from_epoch = msg.timestamp()
     if timestamp_type == 1:  # TIMESTAMP_CREATE_TIME
-        return datetime.datetime.fromtimestamp(timestamp_ms_from_epoch / 1000).strftime(
-            "%Y-%m-%d %H:%M:%S.%f"
+        return (
+            datetime.datetime.fromtimestamp(timestamp_ms_from_epoch / 1000)
+            .astimezone(ZoneInfo("UTC"))
+            .strftime("%Y-%m-%d %H:%M:%S.%f")
         )
     else:
         # TIMESTAMP_NOT_AVAILABLE or TIMESTAMP_LOG_APPEND_TIME

tests/test_utils.py

@@ -64,11 +64,11 @@ def test_deserialising_message_which_raises_does_not_stop_loop(mock_message):
         ok_message = Mock(spec=Message)
         ok_message.value.return_value = b""
         ok_message.error.return_value = False
-        ok_message.timestamp.return_value = 1, 1
+        ok_message.timestamp.return_value = 2, 1
 
         mock_message.value.side_effect = Exception
         mock_message.error.return_value = False
-        mock_message.timestamp.return_value = 1, 1
+        mock_message.timestamp.return_value = 2, 1
 
         _deserialise_and_print_messages([mock_message, ok_message], None)
         assert logger.info.call_count == 1
@@ -125,7 +125,7 @@ def test_message_that_has_valid_schema_and_valid_payload(mock_message):
 
 def test_parse_timestamp_with_valid_timestamp(mock_message):
     mock_message.timestamp.return_value = (1, 1753434939336)
-    assert _parse_timestamp(mock_message) == "2025-07-25 10:15:39.336000"
+    assert _parse_timestamp(mock_message) == "2025-07-25 09:15:39.336000"
 
 
 def test_parse_timestamp_with_timestamp_not_available(mock_message):