How long do fish need to stay in the bag before it get put into a aquarium?

The water is usually not too dirty and the bag is pumped with air, so the fish can survive for the better part of a day (though not comfortably) if the temperature is tolerable. While they can technically survive in bags for longer than that, they may not be able to survive the stress of transitioning into a new aquarium afterwards if kept in the bag too long. The intention is to have the water in the bag reach the approx temperature of the water in the tank. Should be there in an hour or so.