Company I worked for did 10 days on , 5 days off. You would often work 10 days in a row, some schedules had days off. Also available were 20 on ,10 off. Here you would have at least 30-40 hours off in the middle to reset the clock. On the 4 week on , 2 week off you would have a day off every week. Never enough time to commute home, just enough to avoid collapse. This was based on JAA part Q first edition, I would not be surprised if the Chinese rules are much less restrictive. My guess: day off while on the road is a shift from late show to early show.