Hard to say since MAR doesn't keep track of stays. All that matters are nights. I presume you are asking this because of the current extravagant promo that will deliver an amazing 2025 pts per STAY! But it's only valid for 3 stays or a whopping 6075 MAR pts (2025 SPG pts in the old days). Give it a try if you wish, but there's no guarantee. I've had it both ways when I book my award nights individually. Usually what happens is I only get credit for 1 night on 2 back to back reservations, but that's easily fixed by contacting CS through the missing stay link.