Using UTC for times, that seems to look better.

messages.py

@@ -14,7 +14,8 @@ app = Flask(__name__, static_url_path=base_path + "/static")
 
 @app.template_filter("datefmt")
 def format_datetime(value):
-    dt = pendulum.from_timestamp(value, tz=pendulum.tz.local_timezone())
+    # dt = pendulum.from_timestamp(value, tz=pendulum.tz.local_timezone())
+    dt = pendulum.from_timestamp(value)
     return dt.to_datetime_string()