I did this journey last year
Googe map directions from Rzeszow Airport to Lviv
While its only 160 KMs, it still took nearly 5 hours due to customs/immigrationa nd the worst roads I've ever seen (on both sides of the border) on a privately hired Ukrainian bus. In fairness the journey back in daylight was only 4 hours or so, and they were doing roadworks on the main roads between the big cities. We paid €650 for a 15 seater that collected us at airport on Wednesday and dropped us back on the Friday.
It took other Pats fans 7 hours to drive from Kiev to Lviv (including two stops to bribe police).
More fans flew into Krakow and made their way using public transport. Their are no trains that cross the border as both countries use different types of tracks. train journeys advertised as Cross border involved getting off, walking a mile, going through customs and immigration on foot, then getting back on train. Pats fans missed last train, so got a bus from border to Lviv (cost about €10 a head)
I stayed in the Grand Hotel in Lviv, which is perfectly located in the city centre, and would recommend it to anyone
Oh and mypost is wrong above. Poland is +1 hour, Ukraine is +2 hours (so crossing the border jumps time too...)