diff --git a/demo/moulinrouge/tests.py b/demo/moulinrouge/tests.py
index 5a77701..aea539c 100644
--- a/demo/moulinrouge/tests.py
+++ b/demo/moulinrouge/tests.py
@@ -736,13 +736,16 @@ def get_test_routes(app):
     @app.route('/test/datetimeline')
     def test_datetimeline():
         line = DateTimeLine()
+        from datetime import timezone, timedelta
+        tz7 = timezone(timedelta(hours=7), 'GMT +7')
+        tzn4 = timezone(timedelta(hours=-4), 'GMT -4')
+
         line.add('dt', [
-            (datetime(2013, 1, 12, 8, 0), 300),
-            (datetime(2013, 1, 12, 12), 412),
-            (datetime(2013, 2, 22, 12), 823),
-            (datetime(2013, 2, 22, 20), 672)
+            (datetime(2013, 1, 12, 8, tzinfo=tz7), 300),
+            (datetime(2013, 1, 12, 8), 412),
+            (datetime(2013, 1, 12, 8, tzinfo=tzn4), 823)
         ])
-        line.x_value_formatter = lambda x: x.strftime("%Y-%m-%d")
+        line.x_value_formatter = lambda x: x.isoformat()  # strftime("%Y-%m-%d")
         line.x_label_rotation = 45
         return line.render_response()
 
diff --git a/docs/changelog.rst b/docs/changelog.rst
index bbc8b22..7726c29 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -27,6 +27,7 @@ Changelog
 * Add flake8 test to py.test in tox
 * Remove stroke style in style and set it as a global / serie configuration.
 * Fix None values in tables
+* Fix timezones in DateTimeLine
 
 1.7.0
 =====
diff --git a/docs/documentation/types/xy.rst b/docs/documentation/types/xy.rst
index 7ca171c..9d03de6 100644
--- a/docs/documentation/types/xy.rst
+++ b/docs/documentation/types/xy.rst
@@ -54,6 +54,11 @@ DateTime
       (datetime(2013, 2, 22, 9, 45), 672)
   ])
 
+.. caution::
+
+   datetime are taken in utc by default (ie: no tzinfo).
+   If you have dates with timezones ensure that all your dates
+   have timezone otherwise you will have incoherences.
 
 Date
 ++++
diff --git a/pygal/graph/time.py b/pygal/graph/time.py
index 57892c4..9c1ec7c 100644
--- a/pygal/graph/time.py
+++ b/pygal/graph/time.py
@@ -21,12 +21,14 @@ Various datetime line plot
 """
 from pygal.adapters import positive
 from pygal.graph.xy import XY
-from datetime import datetime, date, time, timedelta
+from datetime import datetime, date, time, timedelta, timezone
 from pygal._compat import timestamp, total_seconds
 
 
 def datetime_to_timestamp(x):
     if isinstance(x, datetime):
+        if x.tzinfo is None:
+            x = x.replace(tzinfo=timezone.utc)
         return timestamp(x)
     return x
 
@@ -82,7 +84,7 @@ class DateTimeLine(XY):
     def _x_format(self):
         """Return the value formatter for this graph"""
         def datetime_to_str(x):
-            dt = datetime.fromtimestamp(x)
+            dt = datetime.fromtimestamp(x, timezone.utc)
             if self.x_value_formatter:
                 return self.x_value_formatter(dt)
             return dt.isoformat()
diff --git a/pygal/test/test_date.py b/pygal/test/test_date.py
index 83db53d..5c5842f 100644
--- a/pygal/test/test_date.py
+++ b/pygal/test/test_date.py
@@ -77,10 +77,10 @@ def test_datetime():
     assert list(
         map(lambda t: t.split(' ')[0],
             q(".axis.x text").map(texts))) == [
-                '2013-01-12T15:13:20',
-                '2013-01-24T05:00:00',
-                '2013-02-04T18:46:40',
-                '2013-02-16T08:33:20']
+                '2013-01-12T14:13:20+00:00',
+                '2013-01-24T04:00:00+00:00',
+                '2013-02-04T17:46:40+00:00',
+                '2013-02-16T07:33:20+00:00']
 
 
 def test_timedelta():