t_start = None when unknown
@@ -90,7 +90,7 @@ class NwbRecordingExtractor(BaseRecording):
if hasattr(self._es, 'starting_time'):
t_start = self._es.starting_time
else:
- t_start = 0.
+ t_start = None
timestamps = None
if hasattr(self._es, 'timestamps'):
