FIX: properly set tz for YearLocator

jklymak · jklymak · commit b17f5aecb011 · 2018-10-31T08:27:18.000-07:00
diff --git a/lib/matplotlib/dates.py b/lib/matplotlib/dates.py
@@ -1394,8 +1394,9 @@ def __init__(self, base=1, month=1, day=1, tz=None):
                          'minute': 0,
                          'second': 0,
                          }
-        # Note that tzinfo does not work with pytz timezones, so
-        # we need to set this here, and convert using astimezone
+        # Note that tzinfo does not work with pytz timezones, and
+        # astimezone doesn't work unless a datetime has timezone info (for
+        # py3.5).  So the user should provide time-zone aware dates.  
 
     def __call__(self):
         # if no data have been set, this will tank with a ValueError
diff --git a/lib/matplotlib/tests/test_dates.py b/lib/matplotlib/tests/test_dates.py
@@ -576,10 +576,10 @@ def _create_auto_date_locator(date1, date2, tz):
     d1 = tz.localize(datetime.datetime(1997, 1, 1))
     for t_delta, expected in results:
         with rc_context({'_internal.classic_mode': False}):
-
             d2 = d1 + t_delta
             locator = _create_auto_date_locator(d1, d2, tz)
-            assert list(map(str, mdates.num2date(locator(), tz=tz))) == expected
+            strings = list(map(str, mdates.num2date(locator(), tz=tz)))
+            assert  strings == expected
 
 
 @image_comparison(baseline_images=['date_inverted_limit'],
