My longest day in a CT was flying the CTLS float plane from Sebring, FL. to Tulsa. The plane flies at 100 kts all day. however with major headwinds and bad weather, I sat in the LS seat for 14.5 hours. In one day. Yes I stopped for fuel a couple of times. One time I stopped and sat in the plane for 1.5 hours waiting for the ceilings to raise up enough to keep flying.