
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
return [wrapper_cast_type, type_index, scale, to_type, requested_result_is_nullable]
            (ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, const ColumnNullable *column_nullable, size_t input_rows_count)
        {
            ColumnPtr result_column;
            auto res = callOnIndexAndDataType<ToDataType>(type_index, [&](const auto & types) -> bool
            {
                using Types = std::decay_t<decltype(types)>;
                using LeftDataType = typename Types::LeftType;
                using RightDataType = typename Types::RightType;
                if constexpr (IsDataTypeDecimalOrNumber<LeftDataType> && IsDataTypeDecimalOrNumber<RightDataType> && !std::is_same_v<DataTypeDateTime64, RightDataType>)
                {
                    if (wrapper_cast_type == CastType::accurate)
                    {
                        AccurateConvertStrategyAdditions additions;
                        additions.scale = scale;
                        result_column = ConvertImpl<LeftDataType, RightDataType, FunctionName>::execute(
                            arguments, result_type, input_rows_count, additions);
                        return true;
                    }
                    else if (wrapper_cast_type == CastType::accurateOrNull)
                    {
                        AccurateOrNullConvertStrategyAdditions additions;
                        additions.scale = scale;
                        result_column = ConvertImpl<LeftDataType, RightDataType, FunctionName>::execute(
                            arguments, result_type, input_rows_count, additions);
                        return true;
                    }
                }
                else if constexpr (std::is_same_v<LeftDataType, DataTypeString>)
                {