Add UTC flag to date strings

app/events/sqlalchemy.py

@@ -59,7 +59,7 @@ def ressource_after_update_handler(mapper, connection, ressource):
         # In order to be JSON serializable, DateTime attributes must be
         # converted to a string
         if isinstance(new_value, datetime):
-            new_value = new_value.isoformat()
+            new_value = new_value.isoformat() + 'Z'
         jsonpatch.append(
             {
                 'op': 'replace',