use local definition of UTC

1 files changed, 17 insertions, 1 deletions

diff --git a/dexcom_reader/dexcom_dumper.py b/dexcom_reader/dexcom_dumper.py
index 18724ac..6cfc720 100755
--- a/dexcom_reader/dexcom_dumper.py
+++ b/dexcom_reader/dexcom_dumper.py
@@ -286,11 +286,27 @@ def test0():
         for t in parseable_record_types():
                 remote_update(t)
 
+from datetime import tzinfo, timedelta, datetime
+
+ZERO = timedelta(0)
+
+class UTCtzinfo(tzinfo):
+    def utcoffset(self, dt):
+        return ZERO
+
+    def tzname(self, dt):
+        return "UTC"
+
+    def dst(self, dt):
+        return ZERO
+
+UTC = UTCtzinfo()
+
 class JSON_Time(json.JSONEncoder):
         def default(self, o):
                 if isinstance(o, datetime):
                         if o.tzinfo is None:
-                                from pytz import UTC
+
                                 return o.replace(tzinfo=UTC).isoformat()
                         else:
                                 return o.isoformat()