But there is no law of physics, psychology, economics, or philosophy that says that the future must resemble the past

Of course not. Though I'm pretty sure induction occurs in humans without them willing it. This is just Hume's view, certain perceptions become habitual to the point where we are surprised if we do not experience them, We have no choice but to do induction. But none of this matters. Induction is just what we're doing when we do science. If we can't trust it we can't trust science

With respect, the reason you believe that Thanksgiving will keep coming has everything to do with your a-priori theory about culture and nothing to do with inductivism. You and I probably have rich theories that cultures can be slow to change, that brains may be hard-wired and difficult to change, that memes reinforce each other, etc.

I'm sorry, my "a priori" theory? In what sense could I possibly know about Thanksgiving a priori? It certainly isn't an analytic truth and it isn't anything like math or something Kant would have considered a priori. Where exactly are these theories coming from if not from induction? And how come inductivists aren't allowed to have theories? I have lots of theories- probably close to the same theories you do. The only difference between our positions is that I'm explaining how those theories got here in the first place.

I'm afraid I don't know what to make of your calendar and number examples. Just because I think science is about induction doesn't mean I don't think that social conventions can be learned. Someone explaining math, that after 1999 comes 2000 counts as pretty good Bayesian evidence that that is how the rest of the world counts. Of course most children aren't great Bayesians and just accept what they are told as true. But the fact that people aren't actually naturally perfect scientists isn't relevant.

I think you can see that your rationality,( not a principle of induction, not that everything stays the same) is actually what caused you to have rational expectations to begin with.

Rationality is just the process of doing induction right. You have to explain what you mean if you mean something else by it :-) (And obviously induction does not mean everything stays the same but that there are enough regularities to say general things about the world and make predictions. This is crucial. If there were no regularities the notion of a "theory" wouldn't even make sense. There would be nothing for the theory to describe. Theories explain large class of phenomena over many times. They can't do that absent regularities.)