
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
{
    UUID tmp;
    if (!tryReadUUIDText(tmp, rb))
        return false;
    x = tmp.toUnderType();
    return true;
}
/** Throw exception with verbose message when string value is not parsed completely.
  */
[[noreturn]] inline void throwExceptionForIncompletelyParsedValue(ReadBuffer & read_buffer, const IDataType & result_type)
{
    WriteBufferFromOwnString message_buf;
    message_buf << "Cannot parse string " << quote << String(read_buffer.buffer().begin(), read_buffer.buffer().size())
                << " as " << result_type.getName()
                << ": syntax error";
    if (read_buffer.offset())
        message_buf << " at position " << read_buffer.offset()
                    << " (parsed just " << quote << String(read_buffer.buffer().begin(), read_buffer.offset()) << ")";
    else
        message_buf << " at begin of string";
    
    if (isNativeNumber(result_type) && !(result_type.getName() == "IPv4" || result_type.getName() == "IPv6"))
        message_buf << ". Note: there are to" << result_type.getName() << "OrZero and to" << result_type.getName() << "OrNull functions, which returns zero/NULL instead of throwing exception.";
    throw Exception(message_buf.str(), ErrorCodes::CANNOT_PARSE_TEXT);
}
enum class ConvertFromStringExceptionMode