I then asked her "Alexa - What date is Tuesday week?"
She replied "This might answer your question. Tuesday will occur on 6th of February 2018"
Credit to Alexa, for acknowledging that it might (or might not) be the right answer. Siri rarely admits to being uncertain. If she (mine is configured with female voice) misunderstands, she will usually just guess and give a commited answer, like starting navigation to Costco when I asked for (say) a weather forecast
In the case of “Next Tuesday” though, I sympathise. I know nothing at all about Artificial Intelligence. But I do wonder whether what we doing here is to compare AI with context-dependent common sense, and finding not much of an overlap.