You could potentially hole up in your house and live the same day forever, I guess, but a lot of people are going to want to use services. In order to have them and to pay for them, then, you have to provide services of some kind as well, and you get an economy.

Note that giving away the use of something you own for a particular day may be a really common one. Like, maybe I want to eat something that’s not in my fridge so I pick up leftovers from a neighbor for a fee. You could call that a good, but since there’s no manufacturing and probably little shipping I wouldn’t.

You wouldn’t get paid in paper for obvious reasons. At first it would be just barter, but we’ll get past that pretty quickly with all our accumulated knowledge. Like the other guy said, it might turn into bankers remembering your balance (or something like that) by heart.