The Pot-Life of a polyurethane mixture is influenced by various factors such as the exact chemical composition of the mixture (with particular reference to the hardener), the temperature and the percentage of humidity present in the environment.
In this case the paint is stored in a container isolated from the humidity present abroad and this considerably prolongs the Pot-Life, usually a few days is the norm.
Pay close attention to the fact that probably after a week or two the paint in the can will still be liquid and you can still spray it but the paint will no longer have its original resistance characteristics. Pot-Life will be outdated.
This can also happen with normal products in can, it can happen that you prepare the mixture in the late afternoon and the following morning you discover that the leftover material is still liquid, perhaps just a little thicker.
Also in this case the paint (if applied) will no longer have all the characteristics that distinguished it.
I hope I was helpful. Massimo