Walking it out is not the same as leaving it there
Most new concrete firms up enough for light foot traffic somewhere between 24 and 48 hours after the pour. That window is early. The slab is nowhere close to full strength yet, it has simply set enough that a person or a chair carried across it will not leave a mark or scuff the finish. Carrying your patio set out and setting it in place falls into that same category as walking on the slab.
What is a different question is how long that furniture then sits in one spot without moving. Concrete at two days old and concrete at three weeks old handle a stationary chair leg very differently, and that difference is about staining, not strength.
Why concrete stains more easily while it is green
Fresh concrete keeps drinking in whatever touches it for as long as the surface stays open, and that window runs a few weeks past the pour. Anything left sitting there, or anything that drips onto it, has a real chance of working its way into the surface instead of wiping off it. None of that weakens the slab. It is purely a look, and a mark that has already worked its way into young concrete takes a lot more scrubbing to lift out than one that lands on a slab that already hardened.
The usual culprits on a patio are predictable: rust bleeding off a set of metal furniture feet, tannins from a damp planter or a pile of leaves left sitting in one spot, and any drink or grill drip nobody gets to right away.
The fork: use it lightly, or protect it while it cures
If you want to use the patio right away, the simplest move is to keep furniture light and moving rather than parked for the long haul in the first few weeks. Set chairs out for an evening, then move them, rather than leaving a full furniture arrangement locked in place from day two.
If the set is heavy, has metal feet, or you would rather not think about it at all, put something under each leg, a coaster, a paver, a scrap of plastic, and hold off on planters that can drip or seep. That takes the staining risk off the table without asking you to keep the patio empty.
What sealing changes
A sealer closes that absorbent surface up and cuts staining down a good deal, though not every patio calls for one right out of the gate, and applying it too soon can lock in dampness the slab still needs to shed on its own. Stamped and decorative work usually gets the most benefit from a sealer. A plain broom finished patio often holds up fine for years without one.
If sealing fits your patio and its finish, we will let you know once the timing is actually right for it. After that, furniture is far less likely to leave a mark, though the risk never fully goes to zero.