
select toDateTime64(-86400 ,9,'UTC') ==  1969-12-31 00:00:00.000000000

select toDateTime64(-86400.00 ,9,'UTC') ==  1970-01-01 00:00:00.000000000 


However, I expect both outputs to be same. 

Version affected : 22.8
auto make_custom_serialization_wrapper = [&, cast_ipv4_ipv6_default_on_conversion_error_value](const auto & types) -> bool
        {
            using Types = std::decay_t<decltype(types)>;
            using ToDataType = typename Types::RightType;
            using FromDataType = typename Types::LeftType;
            if constexpr (WhichDataType(FromDataType::type_id).isStringOrFixedString())
            {
                if (to_type->getCustomSerialization() && to_type->getCustomName())
                {
                    if (to_type->getCustomName()->getName() == "IPv4")
                    {
                        ret = [cast_ipv4_ipv6_default_on_conversion_error_value](
                                  ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, const ColumnNullable * column_nullable, size_t)
                            -> ColumnPtr
                        {
                            if (!WhichDataType(result_type).isUInt32())
                                throw Exception(ErrorCodes::TYPE_MISMATCH, "Wrong result type {}. Expected UInt32", result_type->getName());
                            const auto * null_map = column_nullable ? &column_nullable->getNullMapData() : nullptr;
                            if (cast_ipv4_ipv6_default_on_conversion_error_value)
                                return convertToIPv4<IPStringToNumExceptionMode::Default>(arguments[0].column, null_map);
                            else
                                return convertToIPv4<IPStringToNumExceptionMode::Throw>(arguments[0].column, null_map);
                        };
                        return true;
                    }
                    if (to_type->getCustomName()->getName() == "IPv6")
                    {
                        ret = [cast_ipv4_ipv6_default_on_conversion_error_value](
                                  ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, const ColumnNullable * column_nullable, size_t)
                            -> ColumnPtr