Sure, as long as you’ve kept it wrapped up. Puff pastry, as you know, consists of hundreds of alternating layers of dough and fat. In the oven, the water in the fat evaporates, blowing the layers of dough apart, causing the pastry to puff up dramatically as the layers separate. As long as you haven’t let the pastry toughen and dry out from exposure to air, it should puff grandly.
There is nothing in puff pastry particularly prone to spoiling. We have kept homemade puff pastry dough (made with butter) in the refrigerator for a week and still had it turn out fine. When it begins to get too old, you will notice it taking on a slightly gray color and perhaps smelling a little sour. The additives in frozen, store-bought puff pastry and the vegetable shortening used instead of butter will guarantee a longer refrigerator life than our humble, spectacularly delicious, mile-high, perfectly produced homemade pastry.
The main reason to keep it frozen and thaw only when you’re ready to use it, is that you have to be more gentle with it once it has thawed. Use it as a baseball bat while it’s frozen, but don’t crimp it or smash it when thawed, or you may get an uneven rise. But even that you can live with.
By the way, did we mention that homemade is better?