There were several patches to resampling, which probably had an impact on rightedge. Use this code as a template to achieve your desired effect. rd = cerebro.resampledata(data, timeframe=bt.TimeFrame.Minutes, compression=5) def _new_load(self): ret = self._old_load() if ret: dt = self.datetime.datetime(0) self.datetime[0] = bt.date2num(dt - datetime.timedelta(minutes=5)) return ret rd._old_load, rd._load = rd._load, _new_load.__get__(rd, rd.__class__)