@classmethod
    def string_to_date_with_xls_validation(cls, date_str):
        date_obj = datetime.strptime(date_str, '%Y-%m-%d').date()
        try:
            SharedDate().datetime_to_julian(date_obj)
        except __HOLE__:
            return date_str
        else:
            return date_obj
dataset/ETHPy150Open kobotoolbox/kobocat/onadata/libs/utils/export_tools.py/ExportBuilder.string_to_date_with_xls_validation