
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 ret;
        if (callOnIndexAndDataType<void>(to_type->getTypeId(), make_default_wrapper))
            return ret;
        switch (to_type->getTypeId())
        {
            case TypeIndex::String:
                return createStringWrapper(from_type);
            case TypeIndex::FixedString:
                return createFixedStringWrapper(from_type, checkAndGetDataType<DataTypeFixedString>(to_type.get())->getN());
            case TypeIndex::Array:
                return createArrayWrapper(from_type, static_cast<const DataTypeArray &>(*to_type));
            case TypeIndex::Tuple:
                return createTupleWrapper(from_type, checkAndGetDataType<DataTypeTuple>(to_type.get()));
            case TypeIndex::Map:
                return createMapWrapper(from_type, checkAndGetDataType<DataTypeMap>(to_type.get()));
            case TypeIndex::Object:
                return createObjectWrapper(from_type, checkAndGetDataType<DataTypeObject>(to_type.get()));
            case TypeIndex::AggregateFunction:
                return createAggregateFunctionWrapper(from_type, checkAndGetDataType<DataTypeAggregateFunction>(to_type.get()));
            default:
                break;
        }
        if (cast_type == CastType::accurateOrNull)
            return createToNullableColumnWrapper();
        else
            throw Exception{"Conversion from " + from_type->getName() + " to " + to_type->getName() + " is not supported",
                ErrorCodes::CANNOT_CONVERT_TYPE};
    }
};
class MonotonicityHelper