if zone.localize(datetime(single_date.year, single_date.month, single_date.day)).dst() == tdelta_0:         logger.info('summertime')         start = single_date.strftime("%Y-%m-%d") + "T00:00:00-00:00"         end = single_date.strftime("%Y-%m-%d") + "T00:00:00-00:00"     elif zone.localize(datetime(single_date.year, single_date.month, single_date.day)