Sometimes it takes between 1.5 - 3 weeks for me to receive a package. However, going the other way it's taken a 4-6 for mine to get there. Maybe it depends on whether the PL postal worker want to work that day :)
Thanks! I'm a little weary sending a package to Poland. We sent a small package last year for Christmas, and it failed to arrive to its destination. I'm hoping the same thing is not going to happen to Polish packages sent to the USA.