In my program the hours get worse the higher you go. We interns only work 12 - 16 hour days (may be a little less, depending on the rotation). The PGY2s take 24 hour calls every 3 - 4 days. And it's not unusual for the 3rd and 4th years to work 12-13 days straight before they get 1 or 2 off day(s).