diff --git a/airbyte-integrations/connectors/source-kobotoolbox/source_kobotoolbox/source.py b/airbyte-integrations/connectors/source-kobotoolbox/source_kobotoolbox/source.py
index bfaf4c5b6d31..a32d0b5746f8 100644
--- a/airbyte-integrations/connectors/source-kobotoolbox/source_kobotoolbox/source.py
+++ b/airbyte-integrations/connectors/source-kobotoolbox/source_kobotoolbox/source.py
@@ -102,6 +102,16 @@ def mk_query(self):
         else:
             start_sub_time = datetime.fromisoformat(self.state[self.cursor_field])
             start_sub_time -= timedelta(days=self.max_days_to_close)
+            from datetime import timezone
+
+            tzaware_start_time = datetime.fromisoformat(self.start_time)
+            if tzaware_start_time.tzinfo is None:
+                # interpret as utc
+                tzaware_start_time = tzaware_start_time.replace(tzinfo=timezone.utc)
+            else:
+                # convert to utc if necessary
+                tzaware_start_time = tzaware_start_time.astimezone(timezone.utc)
+            start_sub_time = max(start_sub_time, tzaware_start_time)
             return {"_submission_time": {"$gte": start_sub_time.isoformat()}, self.cursor_field: {"$gte": self.state[self.cursor_field]}}
 
     def request_params(
@@ -157,6 +167,12 @@ def parse_response(self, response: requests.Response, **kwargs) -> Iterable[Mapp
             retval = {"_id": record["_id"], "data": record}
             retval["_submission_time"] = record["_submission_time"]
             retval["endtime"] = record.get("endtime")
+            if retval["endtime"]:
+                from datetime import timezone
+
+                # endtime is in utc
+                endtime = datetime.fromisoformat(retval["endtime"]).astimezone(timezone.utc)
+                retval["endtime"] = endtime.isoformat()
             yield retval
 
     def read_records(self, *args, **kwargs) -> Iterable[Mapping[str, Any]]: