diff --git a/CHANGELOG.md b/CHANGELOG.md
index dbc23df..891af11 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### Features
 1. [#237](https://github.com/influxdata/influxdb-client-python/pull/237): Use kwargs to pass query parameters into API list call - useful for the ability to use pagination.
 1. [#241](https://github.com/influxdata/influxdb-client-python/pull/241): Add detail error message for not supported type of `Point.field`
+1. [#238](https://github.com/influxdata/influxdb-client-python/pull/238): Add possibility to specify default `timezone` for datetimes without `tzinfo`
 
 ## 1.17.0 [2021-04-30]
 
diff --git a/influxdb_client/client/util/date_utils.py b/influxdb_client/client/util/date_utils.py
index f7557b1..f1f6f39 100644
--- a/influxdb_client/client/util/date_utils.py
+++ b/influxdb_client/client/util/date_utils.py
@@ -10,6 +10,15 @@ date_helper = None
 class DateHelper:
     """DateHelper to groups different implementations of date operations."""
 
+    def __init__(self, timezone: datetime.tzinfo = UTC) -> None:
+        """
+        Initialize defaults.
+
+        :param timezone: Default timezone used for serialization "datetime" without "tzinfo".
+                         Default value is "UTC".
+        """
+        self.timezone = timezone
+
     def parse_date(self, date_string: str):
         """
         Parse string into Date or Timestamp.
@@ -40,7 +49,7 @@ class DateHelper:
         :return: datetime in UTC
         """
         if not value.tzinfo:
-            return UTC.localize(value)
+            return self.to_utc(value.replace(tzinfo=self.timezone))
         else:
             return value.astimezone(UTC)
 

diff --git a/tests/test_DateHelper.py b/tests/test_DateHelper.py
new file mode 100644
index 0000000..abff4e5
--- /dev/null
+++ b/tests/test_DateHelper.py
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+
+import unittest
+from datetime import datetime, timezone
+
+from pytz import UTC, timezone
+
+from influxdb_client.client.util.date_utils import DateHelper
+
+
+class DateHelperTest(unittest.TestCase):
+
+    def test_to_utc(self):
+        date = DateHelper().to_utc(datetime(2021, 4, 29, 20, 30, 10, 0))
+        self.assertEqual(datetime(2021, 4, 29, 20, 30, 10, 0, UTC), date)
+
+    def test_to_utc_different_timezone(self):
+        date = DateHelper(timezone=timezone('ETC/GMT+2')).to_utc(datetime(2021, 4, 29, 20, 30, 10, 0))
+        self.assertEqual(datetime(2021, 4, 29, 22, 30, 10, 0, UTC), date)
+
+
+if __name__ == '__main__':
+    unittest.main()

_convert_timestamp assumes passed datetime to be UTC
This function here https://github.com/influxdata/influxdb-client-python/blob/62f93503044dbbd86443555ccfac5cfd8359f91a/influxdb_client/client/write/point.py#L130 assumes a passed datetime object to be in UTC format if no timezone is specified. I find this to be highly misleading. From the moment on I set the local timezone when I install an OS I want my system to accept local timezone data from me if I don't specify otherwise.
tests/test_DateHelper.py::DateHelperTest::test_to_utc_different_timezone
tests/test_DateHelper.py::DateHelperTest::test_to_utc