There are too many predictions about Poland's entry to the eurozone that it seems foolish to believe any of them. The government's initial plans were to introduce the euro in 2012 which as we now know is not going to happen, the date was moved by 3 years. 2015 seems favoured by the country's officials now but I've just read an
article (in PL) in which it was said that banking 'experts' believe 2019 to be the earliest date to adopt the common currency in Poland...