not exactly 20 hours roughly 24 ... Isb to Naran 6 to 7 Hours. Naran to chilas via babu sar, 6 to 7 hours. Chilas to skardu 6 to 8 hours. we leave isb at mid night so we make the most of our time with no traffic. and when its around 9 am the shady traffic parts r all over.