4 dias de trabalho/4 dias de folga, a sua ideia esta correcta.

http://www.workingtime-solutions.com/expertise_shiftpatterns...
Regular 4-on4 off
This is a classic continuous working pattern based on 12 hour shifts. Participants work for four consecutive 12-hour days, followed by four consecutive days off, then four consecutive 12-hour nights, followed by four consecutive days off, then four more days and so on. The starting day for each set of day or night shifts moves ahead by one day per week. This leads to a long cycle time (16 weeks) before the pattern returns to the original starting place. In a 4-team application, the teams need to take up weeks 1, 5, 9 and 13 relative to each other for the system to deliver the required pattern of presence. One drawback is the consecutive number of weekends which are affected by the working pattern. 4-on-4-off patterns are also found as days only or nights only variants. The 4-teams average 42 hours per week during the 16 week cycle.