From 1a05c43d0cb852d79d6e92a1fbf2944a20c15f24 Mon Sep 17 00:00:00 2001
From: Jon Mease <jon.mease@gmail.com>
Date: Mon, 27 May 2019 08:08:23 -0400
Subject: [PATCH 1/2] Added timezones future flag

---
 _plotly_future_/timezones.py | 5 +++++
 _plotly_future_/v4.py        | 1 +
 2 files changed, 6 insertions(+)
 create mode 100644 _plotly_future_/timezones.py

diff --git a/_plotly_future_/timezones.py b/_plotly_future_/timezones.py
new file mode 100644
index 00000000000..e6437b4a232
--- /dev/null
+++ b/_plotly_future_/timezones.py
@@ -0,0 +1,5 @@
+from __future__ import absolute_import
+from _plotly_future_ import _future_flags, _assert_plotly_not_imported
+
+_assert_plotly_not_imported()
+_future_flags.add('timezones')
diff --git a/_plotly_future_/v4.py b/_plotly_future_/v4.py
index a4acb8cf132..e6bdb567bff 100644
--- a/_plotly_future_/v4.py
+++ b/_plotly_future_/v4.py
@@ -6,5 +6,6 @@
     remove_deprecations,
     v4_subplots,
     orca_defaults,
+    timezones,
 )
 

From 7a4006b4cbeb9e99f24fbccb718a1641d1af6333 Mon Sep 17 00:00:00 2001
From: Jon Mease <jon.mease@gmail.com>
Date: Mon, 27 May 2019 08:23:29 -0400
Subject: [PATCH 2/2] Don't convert datetimes to UTC or strip timezone info
 during JSON encoding

---
 _plotly_utils/utils.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/_plotly_utils/utils.py b/_plotly_utils/utils.py
index 94d37a8b81b..10ae668946e 100644
--- a/_plotly_utils/utils.py
+++ b/_plotly_utils/utils.py
@@ -3,8 +3,8 @@
 import json as _json
 import sys
 import re
-
 import pytz
+from _plotly_future_ import _future_flags
 
 from _plotly_utils.optional_imports import get_module
 
@@ -104,7 +104,9 @@ def default(self, obj):
             self.encode_as_sage,
             self.encode_as_numpy,
             self.encode_as_pandas,
-            self.encode_as_datetime,
+            (self.encode_as_datetime_v4
+             if 'timezones' in _future_flags
+             else self.encode_as_datetime),
             self.encode_as_date,
             self.encode_as_list,  # because some values have `tolist` do last.
             self.encode_as_decimal
@@ -170,6 +172,14 @@ def encode_as_numpy(obj):
         else:
             raise NotEncodable
 
+    @staticmethod
+    def encode_as_datetime_v4(obj):
+        """Convert datetime objects to iso-format strings"""
+        try:
+            return obj.isoformat()
+        except AttributeError:
+            raise NotEncodable
+
     @staticmethod
     def encode_as_datetime(obj):
         """Attempt to convert to utc-iso time string using datetime methods."""